Merge pull request #318 from alexlarsson/boost-176-support

Support boost 1.76

28 files changed, 13966 insertions, 2 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 65148a5..645825c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -164,8 +164,10 @@ else()
 endif()
 
 message( STATUS "Using boost version: ${VSOMEIP_BOOST_VERSION}" )
-if (${VSOMEIP_BOOST_VERSION} GREATER 107400)
-message( ERROR "boost version ${VSOMEIP_BOOST_VERSION} is not (yet) supported. Latest supported version is 1.74.0" )
+if (${VSOMEIP_BOOST_VERSION} GREATER 107600)
+message( ERROR "boost version ${VSOMEIP_BOOST_VERSION} is not (yet) supported. Latest supported version is 1.76.0" )
+elseif(${VSOMEIP_BOOST_VERSION} GREATER 107500)
+set(VSOMEIP_BOOST_HELPER implementation/helper/1.76)
 elseif(${VSOMEIP_BOOST_VERSION} GREATER 107300)
 set(VSOMEIP_BOOST_HELPER implementation/helper/1.74)
 elseif(${VSOMEIP_BOOST_VERSION} GREATER 106999)
diff --git a/implementation/helper/1.76/boost/asio/basic_datagram_socket_ext.hpp b/implementation/helper/1.76/boost/asio/basic_datagram_socket_ext.hpp
new file mode 100644
index 0000000..49a4950
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/basic_datagram_socket_ext.hpp
@@ -0,0 +1,1118 @@
+//
+// basic_datagram_socket_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (C) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_BASIC_DATAGRAM_SOCKET_EXT_HPP
+#define BOOST_ASIO_BASIC_DATAGRAM_SOCKET_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <cstddef>
+#include <boost/asio/basic_socket_ext.hpp>
+#include <boost/asio/detail/handler_type_requirements_ext.hpp>
+#include <boost/asio/detail/non_const_lvalue.hpp>
+#include <boost/asio/detail/throw_error.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/error.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+#if !defined(BOOST_ASIO_BASIC_DATAGRAM_SOCKET_EXT_FWD_DECL)
+#define BOOST_ASIO_BASIC_DATAGRAM_SOCKET_EXT_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Protocol, typename Executor = executor>
+class basic_datagram_socket_ext;
+
+#endif // !defined(BOOST_ASIO_BASIC_DATAGRAM_SOCKET_EXT_FWD_DECL)
+
+/// Provides datagram-oriented socket functionality.
+/**
+ * The basic_datagram_socket class template provides asynchronous and blocking
+ * datagram-oriented socket functionality.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ */
+template <typename Protocol, typename Executor>
+class basic_datagram_socket_ext
+  : public basic_socket_ext<Protocol, Executor>
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the socket type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The socket type when rebound to the specified executor.
+    typedef basic_datagram_socket_ext<Protocol, Executor1> other;
+  };
+
+  /// The native representation of a socket.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#else
+  typedef typename basic_socket_ext<Protocol,
+    Executor>::native_handle_type native_handle_type;
+#endif
+
+  /// The protocol type.
+  typedef Protocol protocol_type;
+
+  /// The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+  /// Construct a basic_datagram_socket without opening it.
+  /**
+   * This constructor creates a datagram socket without opening it. The open()
+   * function must be called before data can be sent or received on the socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   */
+  explicit basic_datagram_socket_ext(const executor_type& ex)
+    : basic_socket_ext<Protocol, Executor>(ex)
+  {
+  }
+
+  /// Construct a basic_datagram_socket without opening it.
+  /**
+   * This constructor creates a datagram socket without opening it. The open()
+   * function must be called before data can be sent or received on the socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   */
+  template <typename ExecutionContext>
+  explicit basic_datagram_socket_ext(ExecutionContext& context,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : basic_socket_ext<Protocol, Executor>(context)
+  {
+  }
+
+  /// Construct and open a basic_datagram_socket.
+  /**
+   * This constructor creates and opens a datagram socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_datagram_socket_ext(const executor_type& ex, const protocol_type& protocol)
+    : basic_socket_ext<Protocol, Executor>(ex, protocol)
+  {
+  }
+
+  /// Construct and open a basic_datagram_socket.
+  /**
+   * This constructor creates and opens a datagram socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_datagram_socket_ext(ExecutionContext& context,
+      const protocol_type& protocol,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : basic_socket_ext<Protocol, Executor>(context, protocol)
+  {
+  }
+
+  /// Construct a basic_datagram_socket, opening it and binding it to the given
+  /// local endpoint.
+  /**
+   * This constructor creates a datagram socket and automatically opens it bound
+   * to the specified endpoint on the local machine. The protocol used is the
+   * protocol associated with the given endpoint.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the datagram
+   * socket will be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_datagram_socket_ext(const executor_type& ex, const endpoint_type& endpoint)
+    : basic_socket_ext<Protocol, Executor>(ex, endpoint)
+  {
+  }
+
+  /// Construct a basic_datagram_socket, opening it and binding it to the given
+  /// local endpoint.
+  /**
+   * This constructor creates a datagram socket and automatically opens it bound
+   * to the specified endpoint on the local machine. The protocol used is the
+   * protocol associated with the given endpoint.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the datagram
+   * socket will be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_datagram_socket_ext(ExecutionContext& context,
+      const endpoint_type& endpoint,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : basic_socket_ext<Protocol, Executor>(context, endpoint)
+  {
+  }
+
+  /// Construct a basic_datagram_socket on an existing native socket.
+  /**
+   * This constructor creates a datagram socket object to hold an existing
+   * native socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket The new underlying socket implementation.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_datagram_socket_ext(const executor_type& ex,
+      const protocol_type& protocol, const native_handle_type& native_socket)
+    : basic_socket_ext<Protocol, Executor>(ex, protocol, native_socket)
+  {
+  }
+
+  /// Construct a basic_datagram_socket on an existing native socket.
+  /**
+   * This constructor creates a datagram socket object to hold an existing
+   * native socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket The new underlying socket implementation.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_datagram_socket_ext(ExecutionContext& context,
+      const protocol_type& protocol, const native_handle_type& native_socket,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : basic_socket_ext<Protocol, Executor>(context, protocol, native_socket)
+  {
+  }
+
+#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_datagram_socket from another.
+  /**
+   * This constructor moves a datagram socket from one object to another.
+   *
+   * @param other The other basic_datagram_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_datagram_socket(const executor_type&)
+   * constructor.
+   */
+  basic_datagram_socket_ext(basic_datagram_socket_ext&& other)
+    : basic_socket_ext<Protocol, Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_datagram_socket from another.
+  /**
+   * This assignment operator moves a datagram socket from one object to
+   * another.
+   *
+   * @param other The other basic_datagram_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_datagram_socket(const executor_type&)
+   * constructor.
+   */
+  basic_datagram_socket_ext& operator=(basic_datagram_socket_ext&& other)
+  {
+    basic_socket_ext<Protocol, Executor>::operator=(std::move(other));
+    return *this;
+  }
+
+  /// Move-construct a basic_datagram_socket from a socket of another protocol
+  /// type.
+  /**
+   * This constructor moves a datagram socket from one object to another.
+   *
+   * @param other The other basic_datagram_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_datagram_socket(const executor_type&)
+   * constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  basic_datagram_socket_ext(basic_datagram_socket_ext<Protocol1, Executor1>&& other,
+      typename enable_if<
+        is_convertible<Protocol1, Protocol>::value
+          && is_convertible<Executor1, Executor>::value
+      >::type* = 0)
+    : basic_socket_ext<Protocol, Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_datagram_socket from a socket of another protocol
+  /// type.
+  /**
+   * This assignment operator moves a datagram socket from one object to
+   * another.
+   *
+   * @param other The other basic_datagram_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_datagram_socket(const executor_type&)
+   * constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  typename enable_if<
+    is_convertible<Protocol1, Protocol>::value
+      && is_convertible<Executor1, Executor>::value,
+    basic_datagram_socket_ext&
+  >::type operator=(basic_datagram_socket_ext<Protocol1, Executor1>&& other)
+  {
+    basic_socket_ext<Protocol, Executor>::operator=(std::move(other));
+    return *this;
+  }
+#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the socket.
+  /**
+   * This function destroys the socket, cancelling any outstanding asynchronous
+   * operations associated with the socket as if by calling @c cancel.
+   */
+  ~basic_datagram_socket_ext()
+  {
+  }
+
+  /// Send some data on a connected socket.
+  /**
+   * This function is used to send data on the datagram socket. The function
+   * call will block until the data has been sent successfully or an error
+   * occurs.
+   *
+   * @param buffers One ore more data buffers to be sent on the socket.
+   *
+   * @returns The number of bytes sent.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The send operation can only be used with a connected socket. Use
+   * the send_to function to send data on an unconnected datagram socket.
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code socket.send(boost::asio::buffer(data, size)); @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send(const ConstBufferSequence& buffers)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, 0, ec);
+    boost::asio::detail::throw_error(ec, "send");
+    return s;
+  }
+
+  /// Send some data on a connected socket.
+  /**
+   * This function is used to send data on the datagram socket. The function
+   * call will block until the data has been sent successfully or an error
+   * occurs.
+   *
+   * @param buffers One ore more data buffers to be sent on the socket.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @returns The number of bytes sent.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The send operation can only be used with a connected socket. Use
+   * the send_to function to send data on an unconnected datagram socket.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, flags, ec);
+    boost::asio::detail::throw_error(ec, "send");
+    return s;
+  }
+
+  /// Send some data on a connected socket.
+  /**
+   * This function is used to send data on the datagram socket. The function
+   * call will block until the data has been sent successfully or an error
+   * occurs.
+   *
+   * @param buffers One or more data buffers to be sent on the socket.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes sent.
+   *
+   * @note The send operation can only be used with a connected socket. Use
+   * the send_to function to send data on an unconnected datagram socket.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags, boost::system::error_code& ec)
+  {
+    return this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, flags, ec);
+  }
+
+  /// Start an asynchronous send on a connected socket.
+  /**
+   * This function is used to asynchronously send data on the datagram socket.
+   * The function call always returns immediately.
+   *
+   * @param buffers One or more data buffers to be sent on the socket. Although
+   * the buffers object may be copied as necessary, ownership of the underlying
+   * memory blocks is retained by the caller, which must guarantee that they
+   * remain valid until the handler is called.
+   *
+   * @param handler The handler to be called when the send operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes sent.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The async_send operation can only be used with a connected socket.
+   * Use the async_send_to function to send data on an unconnected datagram
+   * socket.
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.async_send(boost::asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence, typename WriteHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
+      void (boost::system::error_code, std::size_t))
+  async_send(const ConstBufferSequence& buffers,
+      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
+  {
+    return async_initiate<WriteHandler,
+      void (boost::system::error_code, std::size_t)>(
+        initiate_async_send(), handler, this,
+        buffers, socket_base::message_flags(0));
+  }
+
+  /// Start an asynchronous send on a connected socket.
+  /**
+   * This function is used to asynchronously send data on the datagram socket.
+   * The function call always returns immediately.
+   *
+   * @param buffers One or more data buffers to be sent on the socket. Although
+   * the buffers object may be copied as necessary, ownership of the underlying
+   * memory blocks is retained by the caller, which must guarantee that they
+   * remain valid until the handler is called.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @param handler The handler to be called when the send operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes sent.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The async_send operation can only be used with a connected socket.
+   * Use the async_send_to function to send data on an unconnected datagram
+   * socket.
+   */
+  template <typename ConstBufferSequence, typename WriteHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
+      void (boost::system::error_code, std::size_t))
+  async_send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags,
+      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
+  {
+    return async_initiate<WriteHandler,
+      void (boost::system::error_code, std::size_t)>(
+        initiate_async_send(), handler, this, buffers, flags);
+  }
+
+  /// Send a datagram to the specified endpoint.
+  /**
+   * This function is used to send a datagram to the specified remote endpoint.
+   * The function call will block until the data has been sent successfully or
+   * an error occurs.
+   *
+   * @param buffers One or more data buffers to be sent to the remote endpoint.
+   *
+   * @param destination The remote endpoint to which the data will be sent.
+   *
+   * @returns The number of bytes sent.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * boost::asio::ip::udp::endpoint destination(
+   *     boost::asio::ip::address::from_string("1.2.3.4"), 12345);
+   * socket.send_to(boost::asio::buffer(data, size), destination);
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send_to(const ConstBufferSequence& buffers,
+      const endpoint_type& destination)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().send_to(
+        this->impl_.get_implementation(), buffers, destination, 0, ec);
+    boost::asio::detail::throw_error(ec, "send_to");
+    return s;
+  }
+
+  /// Send a datagram to the specified endpoint.
+  /**
+   * This function is used to send a datagram to the specified remote endpoint.
+   * The function call will block until the data has been sent successfully or
+   * an error occurs.
+   *
+   * @param buffers One or more data buffers to be sent to the remote endpoint.
+   *
+   * @param destination The remote endpoint to which the data will be sent.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @returns The number of bytes sent.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send_to(const ConstBufferSequence& buffers,
+      const endpoint_type& destination, socket_base::message_flags flags)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().send_to(
+        this->impl_.get_implementation(), buffers, destination, flags, ec);
+    boost::asio::detail::throw_error(ec, "send_to");
+    return s;
+  }
+
+  /// Send a datagram to the specified endpoint.
+  /**
+   * This function is used to send a datagram to the specified remote endpoint.
+   * The function call will block until the data has been sent successfully or
+   * an error occurs.
+   *
+   * @param buffers One or more data buffers to be sent to the remote endpoint.
+   *
+   * @param destination The remote endpoint to which the data will be sent.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes sent.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send_to(const ConstBufferSequence& buffers,
+      const endpoint_type& destination, socket_base::message_flags flags,
+      boost::system::error_code& ec)
+  {
+    return this->impl_.get_service().send_to(this->impl_.get_implementation(),
+        buffers, destination, flags, ec);
+  }
+
+  /// Start an asynchronous send.
+  /**
+   * This function is used to asynchronously send a datagram to the specified
+   * remote endpoint. The function call always returns immediately.
+   *
+   * @param buffers One or more data buffers to be sent to the remote endpoint.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param destination The remote endpoint to which the data will be sent.
+   * Copies will be made of the endpoint as required.
+   *
+   * @param handler The handler to be called when the send operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes sent.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * boost::asio::ip::udp::endpoint destination(
+   *     boost::asio::ip::address::from_string("1.2.3.4"), 12345);
+   * socket.async_send_to(
+   *     boost::asio::buffer(data, size), destination, handler);
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence, typename WriteHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
+      void (boost::system::error_code, std::size_t))
+  async_send_to(const ConstBufferSequence& buffers,
+      const endpoint_type& destination,
+      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
+  {
+    return async_initiate<WriteHandler,
+      void (boost::system::error_code, std::size_t)>(
+        initiate_async_send_to(), handler, this, buffers,
+        destination, socket_base::message_flags(0));
+  }
+
+  /// Start an asynchronous send.
+  /**
+   * This function is used to asynchronously send a datagram to the specified
+   * remote endpoint. The function call always returns immediately.
+   *
+   * @param buffers One or more data buffers to be sent to the remote endpoint.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @param destination The remote endpoint to which the data will be sent.
+   * Copies will be made of the endpoint as required.
+   *
+   * @param handler The handler to be called when the send operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes sent.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   */
+  template <typename ConstBufferSequence, typename WriteHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
+      void (boost::system::error_code, std::size_t))
+  async_send_to(const ConstBufferSequence& buffers,
+      const endpoint_type& destination, socket_base::message_flags flags,
+      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
+  {
+    return async_initiate<WriteHandler,
+      void (boost::system::error_code, std::size_t)>(
+        initiate_async_send_to(), handler, this, buffers, destination, flags);
+  }
+
+  /// Receive some data on a connected socket.
+  /**
+   * This function is used to receive data on the datagram socket. The function
+   * call will block until data has been received successfully or an error
+   * occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @returns The number of bytes received.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The receive operation can only be used with a connected socket. Use
+   * the receive_from function to receive data on an unconnected datagram
+   * socket.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code socket.receive(boost::asio::buffer(data, size)); @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().receive(
+        this->impl_.get_implementation(), buffers, 0, ec);
+    boost::asio::detail::throw_error(ec, "receive");
+    return s;
+  }
+
+  /// Receive some data on a connected socket.
+  /**
+   * This function is used to receive data on the datagram socket. The function
+   * call will block until data has been received successfully or an error
+   * occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @returns The number of bytes received.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The receive operation can only be used with a connected socket. Use
+   * the receive_from function to receive data on an unconnected datagram
+   * socket.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags flags)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().receive(
+        this->impl_.get_implementation(), buffers, flags, ec);
+    boost::asio::detail::throw_error(ec, "receive");
+    return s;
+  }
+
+  /// Receive some data on a connected socket.
+  /**
+   * This function is used to receive data on the datagram socket. The function
+   * call will block until data has been received successfully or an error
+   * occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes received.
+   *
+   * @note The receive operation can only be used with a connected socket. Use
+   * the receive_from function to receive data on an unconnected datagram
+   * socket.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags flags, boost::system::error_code& ec)
+  {
+    return this->impl_.get_service().receive(
+        this->impl_.get_implementation(), buffers, flags, ec);
+  }
+
+  /// Start an asynchronous receive on a connected socket.
+  /**
+   * This function is used to asynchronously receive data from the datagram
+   * socket. The function call always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param handler The handler to be called when the receive operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes received.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The async_receive operation can only be used with a connected socket.
+   * Use the async_receive_from function to receive data on an unconnected
+   * datagram socket.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.async_receive(boost::asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence, typename ReadHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+      void (boost::system::error_code, std::size_t, boost::asio::ip::address))
+  async_receive(const MutableBufferSequence& buffers,
+      BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
+  {
+    return async_initiate<ReadHandler,
+      void (boost::system::error_code, std::size_t, boost::asio::ip::address)>(
+        initiate_async_receive(), handler, this,
+        buffers, socket_base::message_flags(0));
+  }
+
+  /// Start an asynchronous receive on a connected socket.
+  /**
+   * This function is used to asynchronously receive data from the datagram
+   * socket. The function call always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @param handler The handler to be called when the receive operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes received.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The async_receive operation can only be used with a connected socket.
+   * Use the async_receive_from function to receive data on an unconnected
+   * datagram socket.
+   */
+  template <typename MutableBufferSequence, typename ReadHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+      void (boost::system::error_code, std::size_t, boost::asio::ip::address))
+  async_receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags flags,
+      BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
+  {
+    return async_initiate<ReadHandler,
+      void (boost::system::error_code, std::size_t, boost::asio::ip::address)>(
+        initiate_async_receive(), handler, this, buffers, flags);
+  }
+
+  /// Receive a datagram with the endpoint of the sender.
+  /**
+   * This function is used to receive a datagram. The function call will block
+   * until data has been received successfully or an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param sender_endpoint An endpoint object that receives the endpoint of
+   * the remote sender of the datagram.
+   *
+   * @returns The number of bytes received.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * boost::asio::ip::udp::endpoint sender_endpoint;
+   * socket.receive_from(
+   *     boost::asio::buffer(data, size), sender_endpoint);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive_from(const MutableBufferSequence& buffers,
+      endpoint_type& sender_endpoint)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().receive_from(
+        this->impl_.get_implementation(), buffers, sender_endpoint, 0, ec);
+    boost::asio::detail::throw_error(ec, "receive_from");
+    return s;
+  }
+  
+  /// Receive a datagram with the endpoint of the sender.
+  /**
+   * This function is used to receive a datagram. The function call will block
+   * until data has been received successfully or an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param sender_endpoint An endpoint object that receives the endpoint of
+   * the remote sender of the datagram.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @returns The number of bytes received.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive_from(const MutableBufferSequence& buffers,
+      endpoint_type& sender_endpoint, socket_base::message_flags flags)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().receive_from(
+        this->impl_.get_implementation(), buffers, sender_endpoint, flags, ec);
+    boost::asio::detail::throw_error(ec, "receive_from");
+    return s;
+  }
+  
+  /// Receive a datagram with the endpoint of the sender.
+  /**
+   * This function is used to receive a datagram. The function call will block
+   * until data has been received successfully or an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param sender_endpoint An endpoint object that receives the endpoint of
+   * the remote sender of the datagram.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes received.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive_from(const MutableBufferSequence& buffers,
+      endpoint_type& sender_endpoint, socket_base::message_flags flags,
+      boost::system::error_code& ec)
+  {
+    return this->impl_.get_service().receive_from(
+        this->impl_.get_implementation(), buffers, sender_endpoint, flags, ec);
+  }
+
+  /// Start an asynchronous receive.
+  /**
+   * This function is used to asynchronously receive a datagram. The function
+   * call always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param sender_endpoint An endpoint object that receives the endpoint of
+   * the remote sender of the datagram. Ownership of the sender_endpoint object
+   * is retained by the caller, which must guarantee that it is valid until the
+   * handler is called.
+   *
+   * @param handler The handler to be called when the receive operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes received.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code socket.async_receive_from(
+   *     boost::asio::buffer(data, size), sender_endpoint, handler); @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence, typename ReadHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+      void (boost::system::error_code, std::size_t, boost::asio::ip::address))
+  async_receive_from(const MutableBufferSequence& buffers,
+      endpoint_type& sender_endpoint,
+      BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
+  {
+    return async_initiate<ReadHandler,
+      void (boost::system::error_code, std::size_t, boost::asio::ip::address)>(
+        initiate_async_receive_from(), handler, this, buffers,
+        &sender_endpoint, socket_base::message_flags(0));
+  }
+
+  /// Start an asynchronous receive.
+  /**
+   * This function is used to asynchronously receive a datagram. The function
+   * call always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param sender_endpoint An endpoint object that receives the endpoint of
+   * the remote sender of the datagram. Ownership of the sender_endpoint object
+   * is retained by the caller, which must guarantee that it is valid until the
+   * handler is called.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @param handler The handler to be called when the receive operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes received.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   */
+  template <typename MutableBufferSequence, typename ReadHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+      void (boost::system::error_code, std::size_t, boost::asio::ip::address))
+  async_receive_from(const MutableBufferSequence& buffers,
+      endpoint_type& sender_endpoint, socket_base::message_flags flags,
+      BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
+  {
+    return async_initiate<ReadHandler,
+      void (boost::system::error_code, std::size_t, boost::asio::ip::address)>(
+        initiate_async_receive_from(), handler,
+        this, buffers, &sender_endpoint, flags);
+  }
+
+private:
+  struct initiate_async_send
+  {
+    template <typename WriteHandler, typename ConstBufferSequence>
+    void operator()(BOOST_ASIO_MOVE_ARG(WriteHandler) handler,
+        basic_datagram_socket_ext* self, const ConstBufferSequence& buffers,
+        socket_base::message_flags flags) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WriteHandler.
+      BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
+
+      detail::non_const_lvalue<WriteHandler> handler2(handler);
+      self->impl_.get_service().async_send(
+          self->impl_.get_implementation(), buffers, flags,
+          handler2.value, self->impl_.get_executor());
+    }
+  };
+
+  struct initiate_async_send_to
+  {
+    template <typename WriteHandler, typename ConstBufferSequence>
+    void operator()(BOOST_ASIO_MOVE_ARG(WriteHandler) handler,
+        basic_datagram_socket_ext* self, const ConstBufferSequence& buffers,
+        const endpoint_type& destination,
+        socket_base::message_flags flags) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WriteHandler.
+      BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
+
+      detail::non_const_lvalue<WriteHandler> handler2(handler);
+      self->impl_.get_service().async_send_to(
+          self->impl_.get_implementation(), buffers, destination, flags,
+          handler2.value, self->impl_.get_executor());
+    }
+  };
+
+  struct initiate_async_receive
+  {
+    template <typename ReadHandler, typename MutableBufferSequence>
+    void operator()(BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
+        basic_datagram_socket_ext* self, const MutableBufferSequence& buffers,
+        socket_base::message_flags flags) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ReadHandler.
+      BOOST_ASIO_READ_HANDLER_CHECK_EXT(ReadHandler, handler) type_check;
+
+      detail::non_const_lvalue<ReadHandler> handler2(handler);
+      self->impl_.get_service().async_receive(
+          self->impl_.get_implementation(), buffers, flags,
+          handler2.value, self->impl_.get_executor());
+    }
+  };
+
+  struct initiate_async_receive_from
+  {
+    template <typename ReadHandler, typename MutableBufferSequence>
+    void operator()(BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
+        basic_datagram_socket_ext* self, const MutableBufferSequence& buffers,
+        endpoint_type* sender_endpoint, socket_base::message_flags flags) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ReadHandler.
+      BOOST_ASIO_READ_HANDLER_CHECK_EXT(ReadHandler, handler) type_check;
+
+      detail::non_const_lvalue<ReadHandler> handler2(handler);
+      self->impl_.get_service().async_receive_from(
+          self->impl_.get_implementation(), buffers, *sender_endpoint, flags,
+          handler2.value, self->impl_.get_executor());
+    }
+  };
+};
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_BASIC_DATAGRAM_SOCKET_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/basic_socket_acceptor_ext.hpp b/implementation/helper/1.76/boost/asio/basic_socket_acceptor_ext.hpp
new file mode 100644
index 0000000..0a86539
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/basic_socket_acceptor_ext.hpp
@@ -0,0 +1,2381 @@
+//
+// basic_socket_acceptor_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_BASIC_SOCKET_ACCEPTOR_EXT_HPP
+#define BOOST_ASIO_BASIC_SOCKET_ACCEPTOR_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/basic_socket_ext_local.hpp>
+#include <boost/asio/detail/handler_type_requirements_ext.hpp>
+#include <boost/asio/detail/io_object_impl.hpp>
+#include <boost/asio/detail/non_const_lvalue.hpp>
+#include <boost/asio/detail/throw_error.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/error.hpp>
+#include <boost/asio/execution_context.hpp>
+#include <boost/asio/executor.hpp>
+#include <boost/asio/socket_base.hpp>
+
+#if defined(BOOST_ASIO_WINDOWS_RUNTIME)
+# include <boost/asio/detail/null_socket_service.hpp>
+#elif defined(BOOST_ASIO_HAS_IOCP)
+# include <boost/asio/detail/win_iocp_socket_service.hpp>
+#else
+# include <boost/asio/detail/reactive_socket_service_ext_local.hpp>
+#endif
+
+#if defined(BOOST_ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(BOOST_ASIO_HAS_MOVE)
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+#if !defined(BOOST_ASIO_BASIC_SOCKET_ACCEPTOR_EXT_FWD_DECL)
+#define BOOST_ASIO_BASIC_SOCKET_ACCEPTOR_EXT_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Protocol, typename Executor = executor>
+class basic_socket_acceptor_ext;
+
+#endif // !defined(BOOST_ASIO_BASIC_SOCKET_ACCEPTOR_EXT_FWD_DECL)
+
+/// Provides the ability to accept new connections.
+/**
+ * The basic_socket_acceptor_ext class template is used for accepting new socket
+ * connections.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Example
+ * Opening a socket acceptor with the SO_REUSEADDR option enabled:
+ * @code
+ * boost::asio::ip::tcp::acceptor acceptor(my_context);
+ * boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::tcp::v4(), port);
+ * acceptor.open(endpoint.protocol());
+ * acceptor.set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
+ * acceptor.bind(endpoint);
+ * acceptor.listen();
+ * @endcode
+ */
+template <typename Protocol, typename Executor>
+class basic_socket_acceptor_ext
+  : public socket_base
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// The native representation of an acceptor.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#elif defined(BOOST_ASIO_WINDOWS_RUNTIME)
+  typedef typename detail::null_socket_service<
+    Protocol>::native_handle_type native_handle_type;
+#elif defined(BOOST_ASIO_HAS_IOCP)
+  typedef typename detail::win_iocp_socket_service<
+    Protocol>::native_handle_type native_handle_type;
+#else
+  typedef typename detail::reactive_socket_service_ext_local<
+    Protocol>::native_handle_type native_handle_type;
+#endif
+
+  /// The protocol type.
+  typedef Protocol protocol_type;
+
+  /// The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+  /// Construct an acceptor without opening it.
+  /**
+   * This constructor creates an acceptor without opening it to listen for new
+   * connections. The open() function must be called before the acceptor can
+   * accept new socket connections.
+   *
+   * @param ex The I/O executor that the acceptor will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * acceptor.
+   */
+  explicit basic_socket_acceptor_ext(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Construct an acceptor without opening it.
+  /**
+   * This constructor creates an acceptor without opening it to listen for new
+   * connections. The open() function must be called before the acceptor can
+   * accept new socket connections.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the acceptor will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the acceptor.
+   */
+  template <typename ExecutionContext>
+  explicit basic_socket_acceptor_ext(ExecutionContext& context,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Construct an open acceptor.
+  /**
+   * This constructor creates an acceptor and automatically opens it.
+   *
+   * @param ex The I/O executor that the acceptor will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * acceptor.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_socket_acceptor_ext(const executor_type& ex, const protocol_type& protocol)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct an open acceptor.
+  /**
+   * This constructor creates an acceptor and automatically opens it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the acceptor will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the acceptor.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_socket_acceptor_ext(ExecutionContext& context,
+      const protocol_type& protocol,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct an acceptor opened on the given endpoint.
+  /**
+   * This constructor creates an acceptor and automatically opens it to listen
+   * for new connections on the specified endpoint.
+   *
+   * @param ex The I/O executor that the acceptor will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * acceptor.
+   *
+   * @param endpoint An endpoint on the local machine on which the acceptor
+   * will listen for new connections.
+   *
+   * @param reuse_addr Whether the constructor should set the socket option
+   * socket_base::reuse_address.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note This constructor is equivalent to the following code:
+   * @code
+   * basic_socket_acceptor<Protocol> acceptor(my_context);
+   * acceptor.open(endpoint.protocol());
+   * if (reuse_addr)
+   *   acceptor.set_option(socket_base::reuse_address(true));
+   * acceptor.bind(endpoint);
+   * acceptor.listen();
+   * @endcode
+   */
+  basic_socket_acceptor_ext(const executor_type& ex,
+      const endpoint_type& endpoint, bool reuse_addr = true)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    const protocol_type protocol = endpoint.protocol();
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+    if (reuse_addr)
+    {
+      impl_.get_service().set_option(impl_.get_implementation(),
+          socket_base::reuse_address(true), ec);
+      boost::asio::detail::throw_error(ec, "set_option");
+    }
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+    impl_.get_service().listen(impl_.get_implementation(),
+        socket_base::max_listen_connections, ec);
+    boost::asio::detail::throw_error(ec, "listen");
+  }
+
+  /// Construct an acceptor opened on the given endpoint.
+  /**
+   * This constructor creates an acceptor and automatically opens it to listen
+   * for new connections on the specified endpoint.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the acceptor will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the acceptor.
+   *
+   * @param endpoint An endpoint on the local machine on which the acceptor
+   * will listen for new connections.
+   *
+   * @param reuse_addr Whether the constructor should set the socket option
+   * socket_base::reuse_address.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note This constructor is equivalent to the following code:
+   * @code
+   * basic_socket_acceptor<Protocol> acceptor(my_context);
+   * acceptor.open(endpoint.protocol());
+   * if (reuse_addr)
+   *   acceptor.set_option(socket_base::reuse_address(true));
+   * acceptor.bind(endpoint);
+   * acceptor.listen();
+   * @endcode
+   */
+  template <typename ExecutionContext>
+  basic_socket_acceptor_ext(ExecutionContext& context,
+      const endpoint_type& endpoint, bool reuse_addr = true,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    const protocol_type protocol = endpoint.protocol();
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+    if (reuse_addr)
+    {
+      impl_.get_service().set_option(impl_.get_implementation(),
+          socket_base::reuse_address(true), ec);
+      boost::asio::detail::throw_error(ec, "set_option");
+    }
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+    impl_.get_service().listen(impl_.get_implementation(),
+        socket_base::max_listen_connections, ec);
+    boost::asio::detail::throw_error(ec, "listen");
+  }
+
+  /// Construct a basic_socket_acceptor on an existing native acceptor.
+  /**
+   * This constructor creates an acceptor object to hold an existing native
+   * acceptor.
+   *
+   * @param ex The I/O executor that the acceptor will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * acceptor.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_acceptor A native acceptor.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_socket_acceptor_ext(const executor_type& ex,
+      const protocol_type& protocol, const native_handle_type& native_acceptor)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_acceptor, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Construct a basic_socket_acceptor on an existing native acceptor.
+  /**
+   * This constructor creates an acceptor object to hold an existing native
+   * acceptor.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the acceptor will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the acceptor.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_acceptor A native acceptor.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_socket_acceptor_ext(ExecutionContext& context,
+      const protocol_type& protocol, const native_handle_type& native_acceptor,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_acceptor, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_socket_acceptor from another.
+  /**
+   * This constructor moves an acceptor from one object to another.
+   *
+   * @param other The other basic_socket_acceptor object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket_acceptor(const executor_type&)
+   * constructor.
+   */
+  basic_socket_acceptor_ext(basic_socket_acceptor_ext&& other)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_socket_acceptor from another.
+  /**
+   * This assignment operator moves an acceptor from one object to another.
+   *
+   * @param other The other basic_socket_acceptor object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket_acceptor(const executor_type&)
+   * constructor.
+   */
+  basic_socket_acceptor_ext& operator=(basic_socket_acceptor_ext&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+
+  // All socket acceptors have access to each other's implementations.
+  template <typename Protocol1, typename Executor1>
+  friend class basic_socket_acceptor_ext;
+
+  /// Move-construct a basic_socket_acceptor from an acceptor of another
+  /// protocol type.
+  /**
+   * This constructor moves an acceptor from one object to another.
+   *
+   * @param other The other basic_socket_acceptor object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket_acceptor(const executor_type&)
+   * constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  basic_socket_acceptor_ext(basic_socket_acceptor_ext<Protocol1, Executor1>&& other,
+      typename enable_if<
+        is_convertible<Protocol1, Protocol>::value
+          && is_convertible<Executor1, Executor>::value
+      >::type* = 0)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_socket_acceptor from an acceptor of another protocol
+  /// type.
+  /**
+   * This assignment operator moves an acceptor from one object to another.
+   *
+   * @param other The other basic_socket_acceptor object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket_acceptor(const executor_type&)
+   * constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  typename enable_if<
+    is_convertible<Protocol1, Protocol>::value
+      && is_convertible<Executor1, Executor>::value,
+    basic_socket_acceptor_ext&
+  >::type operator=(basic_socket_acceptor_ext<Protocol1, Executor1>&& other)
+  {
+    basic_socket_acceptor_ext tmp(std::move(other));
+    impl_ = std::move(tmp.impl_);
+    return *this;
+  }
+#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the acceptor.
+  /**
+   * This function destroys the acceptor, cancelling any outstanding
+   * asynchronous operations associated with the acceptor as if by calling
+   * @c cancel.
+   */
+  ~basic_socket_acceptor_ext()
+  {
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() BOOST_ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+  /// Open the acceptor using the specified protocol.
+  /**
+   * This function opens the socket acceptor so that it will use the specified
+   * protocol.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * acceptor.open(boost::asio::ip::tcp::v4());
+   * @endcode
+   */
+  void open(const protocol_type& protocol = protocol_type())
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Open the acceptor using the specified protocol.
+  /**
+   * This function opens the socket acceptor so that it will use the specified
+   * protocol.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * boost::system::error_code ec;
+   * acceptor.open(boost::asio::ip::tcp::v4(), ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID open(const protocol_type& protocol,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Assigns an existing native acceptor to the acceptor.
+  /*
+   * This function opens the acceptor to hold an existing native acceptor.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param native_acceptor A native acceptor.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  void assign(const protocol_type& protocol,
+      const native_handle_type& native_acceptor)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_acceptor, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Assigns an existing native acceptor to the acceptor.
+  /*
+   * This function opens the acceptor to hold an existing native acceptor.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param native_acceptor A native acceptor.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  BOOST_ASIO_SYNC_OP_VOID assign(const protocol_type& protocol,
+      const native_handle_type& native_acceptor, boost::system::error_code& ec)
+  {
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_acceptor, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the acceptor is open.
+  bool is_open() const
+  {
+    return impl_.get_service().is_open(impl_.get_implementation());
+  }
+
+  /// Bind the acceptor to the given local endpoint.
+  /**
+   * This function binds the socket acceptor to the specified endpoint on the
+   * local machine.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket
+   * acceptor will be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::tcp::v4(), 12345);
+   * acceptor.open(endpoint.protocol());
+   * acceptor.bind(endpoint);
+   * @endcode
+   */
+  void bind(const endpoint_type& endpoint)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+  }
+
+  /// Bind the acceptor to the given local endpoint.
+  /**
+   * This function binds the socket acceptor to the specified endpoint on the
+   * local machine.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket
+   * acceptor will be bound.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::tcp::v4(), 12345);
+   * acceptor.open(endpoint.protocol());
+   * boost::system::error_code ec;
+   * acceptor.bind(endpoint, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID bind(const endpoint_type& endpoint,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Place the acceptor into the state where it will listen for new
+  /// connections.
+  /**
+   * This function puts the socket acceptor into the state where it may accept
+   * new connections.
+   *
+   * @param backlog The maximum length of the queue of pending connections.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  void listen(int backlog = socket_base::max_listen_connections)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().listen(impl_.get_implementation(), backlog, ec);
+    boost::asio::detail::throw_error(ec, "listen");
+  }
+
+  /// Place the acceptor into the state where it will listen for new
+  /// connections.
+  /**
+   * This function puts the socket acceptor into the state where it may accept
+   * new connections.
+   *
+   * @param backlog The maximum length of the queue of pending connections.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * acceptor.listen(boost::asio::socket_base::max_listen_connections, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID listen(int backlog, boost::system::error_code& ec)
+  {
+    impl_.get_service().listen(impl_.get_implementation(), backlog, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Close the acceptor.
+  /**
+   * This function is used to close the acceptor. Any asynchronous accept
+   * operations will be cancelled immediately.
+   *
+   * A subsequent call to open() is required before the acceptor can again be
+   * used to again perform socket accept operations.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  void close()
+  {
+    boost::system::error_code ec;
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "close");
+  }
+
+  /// Close the acceptor.
+  /**
+   * This function is used to close the acceptor. Any asynchronous accept
+   * operations will be cancelled immediately.
+   *
+   * A subsequent call to open() is required before the acceptor can again be
+   * used to again perform socket accept operations.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * acceptor.close(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID close(boost::system::error_code& ec)
+  {
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Release ownership of the underlying native acceptor.
+  /**
+   * This function causes all outstanding asynchronous accept operations to
+   * finish immediately, and the handlers for cancelled operations will be
+   * passed the boost::asio::error::operation_aborted error. Ownership of the
+   * native acceptor is then transferred to the caller.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note This function is unsupported on Windows versions prior to Windows
+   * 8.1, and will fail with boost::asio::error::operation_not_supported on
+   * these platforms.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0603)
+  __declspec(deprecated("This function always fails with "
+        "operation_not_supported when used on Windows versions "
+        "prior to Windows 8.1."))
+#endif
+  native_handle_type release()
+  {
+    boost::system::error_code ec;
+    native_handle_type s = impl_.get_service().release(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "release");
+    return s;
+  }
+
+  /// Release ownership of the underlying native acceptor.
+  /**
+   * This function causes all outstanding asynchronous accept operations to
+   * finish immediately, and the handlers for cancelled operations will be
+   * passed the boost::asio::error::operation_aborted error. Ownership of the
+   * native acceptor is then transferred to the caller.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note This function is unsupported on Windows versions prior to Windows
+   * 8.1, and will fail with boost::asio::error::operation_not_supported on
+   * these platforms.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0603)
+  __declspec(deprecated("This function always fails with "
+        "operation_not_supported when used on Windows versions "
+        "prior to Windows 8.1."))
+#endif
+  native_handle_type release(boost::system::error_code& ec)
+  {
+    return impl_.get_service().release(impl_.get_implementation(), ec);
+  }
+
+  /// Get the native acceptor representation.
+  /**
+   * This function may be used to obtain the underlying representation of the
+   * acceptor. This is intended to allow access to native acceptor functionality
+   * that is not otherwise provided.
+   */
+  native_handle_type native_handle()
+  {
+    return impl_.get_service().native_handle(impl_.get_implementation());
+  }
+
+  /// Cancel all asynchronous operations associated with the acceptor.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  void cancel()
+  {
+    boost::system::error_code ec;
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "cancel");
+  }
+
+  /// Cancel all asynchronous operations associated with the acceptor.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  BOOST_ASIO_SYNC_OP_VOID cancel(boost::system::error_code& ec)
+  {
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Set an option on the acceptor.
+  /**
+   * This function is used to set an option on the acceptor.
+   *
+   * @param option The new option value to be set on the acceptor.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa SettableSocketOption @n
+   * boost::asio::socket_base::reuse_address
+   * boost::asio::socket_base::enable_connection_aborted
+   *
+   * @par Example
+   * Setting the SOL_SOCKET/SO_REUSEADDR option:
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::acceptor::reuse_address option(true);
+   * acceptor.set_option(option);
+   * @endcode
+   */
+  template <typename SettableSocketOption>
+  void set_option(const SettableSocketOption& option)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().set_option(impl_.get_implementation(), option, ec);
+    boost::asio::detail::throw_error(ec, "set_option");
+  }
+
+  /// Set an option on the acceptor.
+  /**
+   * This function is used to set an option on the acceptor.
+   *
+   * @param option The new option value to be set on the acceptor.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa SettableSocketOption @n
+   * boost::asio::socket_base::reuse_address
+   * boost::asio::socket_base::enable_connection_aborted
+   *
+   * @par Example
+   * Setting the SOL_SOCKET/SO_REUSEADDR option:
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::acceptor::reuse_address option(true);
+   * boost::system::error_code ec;
+   * acceptor.set_option(option, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename SettableSocketOption>
+  BOOST_ASIO_SYNC_OP_VOID set_option(const SettableSocketOption& option,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().set_option(impl_.get_implementation(), option, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get an option from the acceptor.
+  /**
+   * This function is used to get the current value of an option on the
+   * acceptor.
+   *
+   * @param option The option value to be obtained from the acceptor.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa GettableSocketOption @n
+   * boost::asio::socket_base::reuse_address
+   *
+   * @par Example
+   * Getting the value of the SOL_SOCKET/SO_REUSEADDR option:
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::acceptor::reuse_address option;
+   * acceptor.get_option(option);
+   * bool is_set = option.get();
+   * @endcode
+   */
+  template <typename GettableSocketOption>
+  void get_option(GettableSocketOption& option) const
+  {
+    boost::system::error_code ec;
+    impl_.get_service().get_option(impl_.get_implementation(), option, ec);
+    boost::asio::detail::throw_error(ec, "get_option");
+  }
+
+  /// Get an option from the acceptor.
+  /**
+   * This function is used to get the current value of an option on the
+   * acceptor.
+   *
+   * @param option The option value to be obtained from the acceptor.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa GettableSocketOption @n
+   * boost::asio::socket_base::reuse_address
+   *
+   * @par Example
+   * Getting the value of the SOL_SOCKET/SO_REUSEADDR option:
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::acceptor::reuse_address option;
+   * boost::system::error_code ec;
+   * acceptor.get_option(option, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * bool is_set = option.get();
+   * @endcode
+   */
+  template <typename GettableSocketOption>
+  BOOST_ASIO_SYNC_OP_VOID get_option(GettableSocketOption& option,
+      boost::system::error_code& ec) const
+  {
+    impl_.get_service().get_option(impl_.get_implementation(), option, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Perform an IO control command on the acceptor.
+  /**
+   * This function is used to execute an IO control command on the acceptor.
+   *
+   * @param command The IO control command to be performed on the acceptor.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa IoControlCommand @n
+   * boost::asio::socket_base::non_blocking_io
+   *
+   * @par Example
+   * Getting the number of bytes ready to read:
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::acceptor::non_blocking_io command(true);
+   * socket.io_control(command);
+   * @endcode
+   */
+  template <typename IoControlCommand>
+  void io_control(IoControlCommand& command)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().io_control(impl_.get_implementation(), command, ec);
+    boost::asio::detail::throw_error(ec, "io_control");
+  }
+
+  /// Perform an IO control command on the acceptor.
+  /**
+   * This function is used to execute an IO control command on the acceptor.
+   *
+   * @param command The IO control command to be performed on the acceptor.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa IoControlCommand @n
+   * boost::asio::socket_base::non_blocking_io
+   *
+   * @par Example
+   * Getting the number of bytes ready to read:
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::acceptor::non_blocking_io command(true);
+   * boost::system::error_code ec;
+   * socket.io_control(command, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename IoControlCommand>
+  BOOST_ASIO_SYNC_OP_VOID io_control(IoControlCommand& command,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().io_control(impl_.get_implementation(), command, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Gets the non-blocking mode of the acceptor.
+  /**
+   * @returns @c true if the acceptor's synchronous operations will fail with
+   * boost::asio::error::would_block if they are unable to perform the requested
+   * operation immediately. If @c false, synchronous operations will block
+   * until complete.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  bool non_blocking() const
+  {
+    return impl_.get_service().non_blocking(impl_.get_implementation());
+  }
+
+  /// Sets the non-blocking mode of the acceptor.
+  /**
+   * @param mode If @c true, the acceptor's synchronous operations will fail
+   * with boost::asio::error::would_block if they are unable to perform the
+   * requested operation immediately. If @c false, synchronous operations will
+   * block until complete.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  void non_blocking(bool mode)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().non_blocking(impl_.get_implementation(), mode, ec);
+    boost::asio::detail::throw_error(ec, "non_blocking");
+  }
+
+  /// Sets the non-blocking mode of the acceptor.
+  /**
+   * @param mode If @c true, the acceptor's synchronous operations will fail
+   * with boost::asio::error::would_block if they are unable to perform the
+   * requested operation immediately. If @c false, synchronous operations will
+   * block until complete.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  BOOST_ASIO_SYNC_OP_VOID non_blocking(
+      bool mode, boost::system::error_code& ec)
+  {
+    impl_.get_service().non_blocking(impl_.get_implementation(), mode, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Gets the non-blocking mode of the native acceptor implementation.
+  /**
+   * This function is used to retrieve the non-blocking mode of the underlying
+   * native acceptor. This mode has no effect on the behaviour of the acceptor
+   * object's synchronous operations.
+   *
+   * @returns @c true if the underlying acceptor is in non-blocking mode and
+   * direct system calls may fail with boost::asio::error::would_block (or the
+   * equivalent system error).
+   *
+   * @note The current non-blocking mode is cached by the acceptor object.
+   * Consequently, the return value may be incorrect if the non-blocking mode
+   * was set directly on the native acceptor.
+   */
+  bool native_non_blocking() const
+  {
+    return impl_.get_service().native_non_blocking(impl_.get_implementation());
+  }
+
+  /// Sets the non-blocking mode of the native acceptor implementation.
+  /**
+   * This function is used to modify the non-blocking mode of the underlying
+   * native acceptor. It has no effect on the behaviour of the acceptor object's
+   * synchronous operations.
+   *
+   * @param mode If @c true, the underlying acceptor is put into non-blocking
+   * mode and direct system calls may fail with boost::asio::error::would_block
+   * (or the equivalent system error).
+   *
+   * @throws boost::system::system_error Thrown on failure. If the @c mode is
+   * @c false, but the current value of @c non_blocking() is @c true, this
+   * function fails with boost::asio::error::invalid_argument, as the
+   * combination does not make sense.
+   */
+  void native_non_blocking(bool mode)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().native_non_blocking(
+        impl_.get_implementation(), mode, ec);
+    boost::asio::detail::throw_error(ec, "native_non_blocking");
+  }
+
+  /// Sets the non-blocking mode of the native acceptor implementation.
+  /**
+   * This function is used to modify the non-blocking mode of the underlying
+   * native acceptor. It has no effect on the behaviour of the acceptor object's
+   * synchronous operations.
+   *
+   * @param mode If @c true, the underlying acceptor is put into non-blocking
+   * mode and direct system calls may fail with boost::asio::error::would_block
+   * (or the equivalent system error).
+   *
+   * @param ec Set to indicate what error occurred, if any. If the @c mode is
+   * @c false, but the current value of @c non_blocking() is @c true, this
+   * function fails with boost::asio::error::invalid_argument, as the
+   * combination does not make sense.
+   */
+  BOOST_ASIO_SYNC_OP_VOID native_non_blocking(
+      bool mode, boost::system::error_code& ec)
+  {
+    impl_.get_service().native_non_blocking(
+        impl_.get_implementation(), mode, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get the local endpoint of the acceptor.
+  /**
+   * This function is used to obtain the locally bound endpoint of the acceptor.
+   *
+   * @returns An object that represents the local endpoint of the acceptor.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint = acceptor.local_endpoint();
+   * @endcode
+   */
+  endpoint_type local_endpoint() const
+  {
+    boost::system::error_code ec;
+    endpoint_type ep = impl_.get_service().local_endpoint(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "local_endpoint");
+    return ep;
+  }
+
+  /// Get the local endpoint of the acceptor.
+  /**
+   * This function is used to obtain the locally bound endpoint of the acceptor.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns An object that represents the local endpoint of the acceptor.
+   * Returns a default-constructed endpoint object if an error occurred and the
+   * error handler did not throw an exception.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * boost::asio::ip::tcp::endpoint endpoint = acceptor.local_endpoint(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  endpoint_type local_endpoint(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().local_endpoint(impl_.get_implementation(), ec);
+  }
+
+  /// Wait for the acceptor to become ready to read, ready to write, or to have
+  /// pending error conditions.
+  /**
+   * This function is used to perform a blocking wait for an acceptor to enter
+   * a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired acceptor state.
+   *
+   * @par Example
+   * Waiting for an acceptor to become readable.
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * acceptor.wait(boost::asio::ip::tcp::acceptor::wait_read);
+   * @endcode
+   */
+  void wait(wait_type w)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().wait(impl_.get_implementation(), w, ec);
+    boost::asio::detail::throw_error(ec, "wait");
+  }
+
+  /// Wait for the acceptor to become ready to read, ready to write, or to have
+  /// pending error conditions.
+  /**
+   * This function is used to perform a blocking wait for an acceptor to enter
+   * a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired acceptor state.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * Waiting for an acceptor to become readable.
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * acceptor.wait(boost::asio::ip::tcp::acceptor::wait_read, ec);
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID wait(wait_type w, boost::system::error_code& ec)
+  {
+    impl_.get_service().wait(impl_.get_implementation(), w, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Asynchronously wait for the acceptor to become ready to read, ready to
+  /// write, or to have pending error conditions.
+  /**
+   * This function is used to perform an asynchronous wait for an acceptor to
+   * enter a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired acceptor state.
+   *
+   * @param handler The handler to be called when the wait operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error // Result of operation
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void wait_handler(const boost::system::error_code& error)
+   * {
+   *   if (!error)
+   *   {
+   *     // Wait succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * acceptor.async_wait(
+   *     boost::asio::ip::tcp::acceptor::wait_read,
+   *     wait_handler);
+   * @endcode
+   */
+  template <typename WaitHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WaitHandler,
+      void (boost::system::error_code))
+  async_wait(wait_type w, BOOST_ASIO_MOVE_ARG(WaitHandler) handler)
+  {
+    return async_initiate<WaitHandler, void (boost::system::error_code)>(
+        initiate_async_wait(), handler, this, w);
+  }
+
+#if !defined(BOOST_ASIO_NO_EXTENSIONS)
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer into the
+   * given socket. The function call will block until a new connection has been
+   * accepted successfully or an error occurs.
+   *
+   * @param peer The socket into which the new connection will be accepted.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * acceptor.accept(socket);
+   * @endcode
+   */
+  template <typename Protocol1, typename Executor1>
+  void accept(basic_socket_ext_local<Protocol1, Executor1>& peer,
+      typename enable_if<
+        is_convertible<Protocol, Protocol1>::value
+      >::type* = 0)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, static_cast<endpoint_type*>(0), ec);
+    boost::asio::detail::throw_error(ec, "accept");
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer into the
+   * given socket. The function call will block until a new connection has been
+   * accepted successfully or an error occurs.
+   *
+   * @param peer The socket into which the new connection will be accepted.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::system::error_code ec;
+   * acceptor.accept(socket, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename Protocol1, typename Executor1>
+  BOOST_ASIO_SYNC_OP_VOID accept(
+      basic_socket_ext_local<Protocol1, Executor1>& peer, boost::system::error_code& ec,
+      typename enable_if<
+        is_convertible<Protocol, Protocol1>::value
+      >::type* = 0)
+  {
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, static_cast<endpoint_type*>(0), ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Start an asynchronous accept.
+  /**
+   * This function is used to asynchronously accept a new connection into a
+   * socket. The function call always returns immediately.
+   *
+   * @param peer The socket into which the new connection will be accepted.
+   * Ownership of the peer object is retained by the caller, which must
+   * guarantee that it is valid until the handler is called.
+   *
+   * @param handler The handler to be called when the accept operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error // Result of operation.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void accept_handler(const boost::system::error_code& error)
+   * {
+   *   if (!error)
+   *   {
+   *     // Accept succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * acceptor.async_accept(socket, accept_handler);
+   * @endcode
+   */
+  template <typename Protocol1, typename Executor1, typename AcceptHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(AcceptHandler,
+      void (boost::system::error_code))
+  async_accept(basic_socket_ext_local<Protocol1, Executor1>& peer,
+      BOOST_ASIO_MOVE_ARG(AcceptHandler) handler,
+      typename enable_if<
+        is_convertible<Protocol, Protocol1>::value
+      >::type* = 0)
+  {
+    return async_initiate<AcceptHandler, void (boost::system::error_code)>(
+        initiate_async_accept(), handler, this,
+        &peer, static_cast<endpoint_type*>(0));
+  }
+
+  /// Accept a new connection and obtain the endpoint of the peer
+  /**
+   * This function is used to accept a new connection from a peer into the
+   * given socket, and additionally provide the endpoint of the remote peer.
+   * The function call will block until a new connection has been accepted
+   * successfully or an error occurs.
+   *
+   * @param peer The socket into which the new connection will be accepted.
+   *
+   * @param peer_endpoint An endpoint object which will receive the endpoint of
+   * the remote peer.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * acceptor.accept(socket, endpoint);
+   * @endcode
+   */
+  template <typename Executor1>
+  void accept(basic_socket_ext_local<protocol_type, Executor1>& peer,
+      endpoint_type& peer_endpoint)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, &peer_endpoint, ec);
+    boost::asio::detail::throw_error(ec, "accept");
+  }
+
+  /// Accept a new connection and obtain the endpoint of the peer
+  /**
+   * This function is used to accept a new connection from a peer into the
+   * given socket, and additionally provide the endpoint of the remote peer.
+   * The function call will block until a new connection has been accepted
+   * successfully or an error occurs.
+   *
+   * @param peer The socket into which the new connection will be accepted.
+   *
+   * @param peer_endpoint An endpoint object which will receive the endpoint of
+   * the remote peer.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * boost::system::error_code ec;
+   * acceptor.accept(socket, endpoint, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename Executor1>
+  BOOST_ASIO_SYNC_OP_VOID accept(basic_socket_ext_local<protocol_type, Executor1>& peer,
+      endpoint_type& peer_endpoint, boost::system::error_code& ec)
+  {
+    impl_.get_service().accept(
+        impl_.get_implementation(), peer, &peer_endpoint, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Start an asynchronous accept.
+  /**
+   * This function is used to asynchronously accept a new connection into a
+   * socket, and additionally obtain the endpoint of the remote peer. The
+   * function call always returns immediately.
+   *
+   * @param peer The socket into which the new connection will be accepted.
+   * Ownership of the peer object is retained by the caller, which must
+   * guarantee that it is valid until the handler is called.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written. Ownership of the peer_endpoint object is
+   * retained by the caller, which must guarantee that it is valid until the
+   * handler is called.
+   *
+   * @param handler The handler to be called when the accept operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error // Result of operation.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   */
+  template <typename Executor1, typename AcceptHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(AcceptHandler,
+      void (boost::system::error_code))
+  async_accept(basic_socket_ext_local<protocol_type, Executor1>& peer,
+      endpoint_type& peer_endpoint, BOOST_ASIO_MOVE_ARG(AcceptHandler) handler)
+  {
+    return async_initiate<AcceptHandler, void (boost::system::error_code)>(
+        initiate_async_accept(), handler, this, &peer, &peer_endpoint);
+  }
+#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
+
+#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @returns A socket object representing the newly accepted connection.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(acceptor.accept());
+   * @endcode
+   */
+  typename Protocol::socket accept()
+  {
+    boost::system::error_code ec;
+    typename Protocol::socket peer(impl_.get_executor());
+    impl_.get_service().accept(impl_.get_implementation(), peer, 0, ec);
+    boost::asio::detail::throw_error(ec, "accept");
+    return peer;
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns On success, a socket object representing the newly accepted
+   * connection. On error, a socket object where is_open() is false.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(acceptor.accept(ec));
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  typename Protocol::socket accept(boost::system::error_code& ec)
+  {
+    typename Protocol::socket peer(impl_.get_executor());
+    impl_.get_service().accept(impl_.get_implementation(), peer, 0, ec);
+    return peer;
+  }
+
+  /// Start an asynchronous accept.
+  /**
+   * This function is used to asynchronously accept a new connection. The
+   * function call always returns immediately.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param handler The handler to be called when the accept operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   typename Protocol::socket peer // On success, the newly accepted socket.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void accept_handler(const boost::system::error_code& error,
+   *     boost::asio::ip::tcp::socket peer)
+   * {
+   *   if (!error)
+   *   {
+   *     // Accept succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * acceptor.async_accept(accept_handler);
+   * @endcode
+   */
+  template <typename MoveAcceptHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(MoveAcceptHandler,
+      void (boost::system::error_code, typename Protocol::socket))
+  async_accept(BOOST_ASIO_MOVE_ARG(MoveAcceptHandler) handler)
+  {
+    return async_initiate<MoveAcceptHandler,
+      void (boost::system::error_code, typename Protocol::socket)>(
+        initiate_async_move_accept(), handler, this,
+        impl_.get_executor(), static_cast<endpoint_type*>(0),
+        static_cast<typename Protocol::socket*>(0));
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param ex The I/O executor object to be used for the newly
+   * accepted socket.
+   *
+   * @returns A socket object representing the newly accepted connection.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(acceptor.accept());
+   * @endcode
+   */
+  template <typename Executor1>
+  typename Protocol::socket::template rebind_executor<Executor1>::other
+  accept(const Executor1& ex,
+      typename enable_if<
+        is_executor<Executor1>::value
+      >::type* = 0)
+  {
+    boost::system::error_code ec;
+    typename Protocol::socket::template
+      rebind_executor<Executor1>::other peer(ex);
+    impl_.get_service().accept(impl_.get_implementation(), peer, 0, ec);
+    boost::asio::detail::throw_error(ec, "accept");
+    return peer;
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param context The I/O execution context object to be used for the newly
+   * accepted socket.
+   *
+   * @returns A socket object representing the newly accepted connection.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(acceptor.accept());
+   * @endcode
+   */
+  template <typename ExecutionContext>
+  typename Protocol::socket::template rebind_executor<
+      typename ExecutionContext::executor_type>::other
+  accept(ExecutionContext& context,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+  {
+    boost::system::error_code ec;
+    typename Protocol::socket::template rebind_executor<
+        typename ExecutionContext::executor_type>::other peer(context);
+    impl_.get_service().accept(impl_.get_implementation(), peer, 0, ec);
+    boost::asio::detail::throw_error(ec, "accept");
+    return peer;
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param ex The I/O executor object to be used for the newly accepted
+   * socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns On success, a socket object representing the newly accepted
+   * connection. On error, a socket object where is_open() is false.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(acceptor.accept(my_context2, ec));
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename Executor1>
+  typename Protocol::socket::template rebind_executor<Executor1>::other
+  accept(const Executor1& ex, boost::system::error_code& ec,
+      typename enable_if<
+        is_executor<Executor1>::value
+      >::type* = 0)
+  {
+    typename Protocol::socket::template
+      rebind_executor<Executor1>::other peer(ex);
+    impl_.get_service().accept(impl_.get_implementation(), peer, 0, ec);
+    return peer;
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param context The I/O execution context object to be used for the newly
+   * accepted socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns On success, a socket object representing the newly accepted
+   * connection. On error, a socket object where is_open() is false.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket socket(acceptor.accept(my_context2, ec));
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename ExecutionContext>
+  typename Protocol::socket::template rebind_executor<
+      typename ExecutionContext::executor_type>::other
+  accept(ExecutionContext& context, boost::system::error_code& ec,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+  {
+    typename Protocol::socket::template rebind_executor<
+        typename ExecutionContext::executor_type>::other peer(context);
+    impl_.get_service().accept(impl_.get_implementation(), peer, 0, ec);
+    return peer;
+  }
+
+  /// Start an asynchronous accept.
+  /**
+   * This function is used to asynchronously accept a new connection. The
+   * function call always returns immediately.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param ex The I/O executor object to be used for the newly accepted
+   * socket.
+   *
+   * @param handler The handler to be called when the accept operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   typename Protocol::socket::template rebind_executor<
+   *     Executor1>::other peer // On success, the newly accepted socket.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void accept_handler(const boost::system::error_code& error,
+   *     boost::asio::ip::tcp::socket peer)
+   * {
+   *   if (!error)
+   *   {
+   *     // Accept succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * acceptor.async_accept(my_context2, accept_handler);
+   * @endcode
+   */
+  template <typename Executor1, typename MoveAcceptHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(MoveAcceptHandler,
+      void (boost::system::error_code,
+        typename Protocol::socket::template rebind_executor<
+          Executor1>::other))
+  async_accept(const Executor1& ex,
+      BOOST_ASIO_MOVE_ARG(MoveAcceptHandler) handler,
+      typename enable_if<
+        is_executor<Executor1>::value
+      >::type* = 0)
+  {
+    typedef typename Protocol::socket::template rebind_executor<
+      Executor1>::other other_socket_type;
+
+    return async_initiate<MoveAcceptHandler,
+      void (boost::system::error_code, other_socket_type)>(
+        initiate_async_move_accept(), handler, this,
+        ex, static_cast<endpoint_type*>(0),
+        static_cast<other_socket_type*>(0));
+  }
+
+  /// Start an asynchronous accept.
+  /**
+   * This function is used to asynchronously accept a new connection. The
+   * function call always returns immediately.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param context The I/O execution context object to be used for the newly
+   * accepted socket.
+   *
+   * @param handler The handler to be called when the accept operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   typename Protocol::socket::template rebind_executor<
+   *     typename ExecutionContext::executor_type>::other peer
+   *       // On success, the newly accepted socket.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void accept_handler(const boost::system::error_code& error,
+   *     boost::asio::ip::tcp::socket peer)
+   * {
+   *   if (!error)
+   *   {
+   *     // Accept succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * acceptor.async_accept(my_context2, accept_handler);
+   * @endcode
+   */
+  template <typename ExecutionContext, typename MoveAcceptHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(MoveAcceptHandler,
+      void (boost::system::error_code,
+        typename Protocol::socket::template rebind_executor<
+          typename ExecutionContext::executor_type>::other))
+  async_accept(ExecutionContext& context,
+      BOOST_ASIO_MOVE_ARG(MoveAcceptHandler) handler,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+  {
+    typedef typename Protocol::socket::template rebind_executor<
+      typename ExecutionContext::executor_type>::other other_socket_type;
+
+    return async_initiate<MoveAcceptHandler,
+      void (boost::system::error_code, other_socket_type)>(
+        initiate_async_move_accept(), handler, this,
+        context.get_executor(), static_cast<endpoint_type*>(0),
+        static_cast<other_socket_type*>(0));
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written.
+   *
+   * @returns A socket object representing the newly accepted connection.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * boost::asio::ip::tcp::socket socket(acceptor.accept(endpoint));
+   * @endcode
+   */
+  typename Protocol::socket accept(endpoint_type& peer_endpoint)
+  {
+    boost::system::error_code ec;
+    typename Protocol::socket peer(impl_.get_executor());
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, &peer_endpoint, ec);
+    boost::asio::detail::throw_error(ec, "accept");
+    return peer;
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns On success, a socket object representing the newly accepted
+   * connection. On error, a socket object where is_open() is false.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * boost::asio::ip::tcp::socket socket(acceptor.accept(endpoint, ec));
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  typename Protocol::socket accept(
+      endpoint_type& peer_endpoint, boost::system::error_code& ec)
+  {
+    typename Protocol::socket peer(impl_.get_executor());
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, &peer_endpoint, ec);
+    return peer;
+  }
+
+  /// Start an asynchronous accept.
+  /**
+   * This function is used to asynchronously accept a new connection. The
+   * function call always returns immediately.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written. Ownership of the peer_endpoint object is
+   * retained by the caller, which must guarantee that it is valid until the
+   * handler is called.
+   *
+   * @param handler The handler to be called when the accept operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   typename Protocol::socket peer // On success, the newly accepted socket.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void accept_handler(const boost::system::error_code& error,
+   *     boost::asio::ip::tcp::socket peer)
+   * {
+   *   if (!error)
+   *   {
+   *     // Accept succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * acceptor.async_accept(endpoint, accept_handler);
+   * @endcode
+   */
+  template <typename MoveAcceptHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(MoveAcceptHandler,
+      void (boost::system::error_code, typename Protocol::socket))
+  async_accept(endpoint_type& peer_endpoint,
+      BOOST_ASIO_MOVE_ARG(MoveAcceptHandler) handler)
+  {
+    return async_initiate<MoveAcceptHandler,
+      void (boost::system::error_code, typename Protocol::socket)>(
+        initiate_async_move_accept(), handler, this,
+        impl_.get_executor(), &peer_endpoint,
+        static_cast<typename Protocol::socket*>(0));
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param ex The I/O executor object to be used for the newly accepted
+   * socket.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written.
+   *
+   * @returns A socket object representing the newly accepted connection.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * boost::asio::ip::tcp::socket socket(
+   *     acceptor.accept(my_context2, endpoint));
+   * @endcode
+   */
+  template <typename Executor1>
+  typename Protocol::socket::template rebind_executor<Executor1>::other
+  accept(const Executor1& ex, endpoint_type& peer_endpoint,
+      typename enable_if<
+        is_executor<Executor1>::value
+      >::type* = 0)
+  {
+    boost::system::error_code ec;
+    typename Protocol::socket::template
+        rebind_executor<Executor1>::other peer(ex);
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, &peer_endpoint, ec);
+    boost::asio::detail::throw_error(ec, "accept");
+    return peer;
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param context The I/O execution context object to be used for the newly
+   * accepted socket.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written.
+   *
+   * @returns A socket object representing the newly accepted connection.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * boost::asio::ip::tcp::socket socket(
+   *     acceptor.accept(my_context2, endpoint));
+   * @endcode
+   */
+  template <typename ExecutionContext>
+  typename Protocol::socket::template rebind_executor<
+      typename ExecutionContext::executor_type>::other
+  accept(ExecutionContext& context, endpoint_type& peer_endpoint,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+  {
+    boost::system::error_code ec;
+    typename Protocol::socket::template rebind_executor<
+        typename ExecutionContext::executor_type>::other peer(context);
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, &peer_endpoint, ec);
+    boost::asio::detail::throw_error(ec, "accept");
+    return peer;
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param ex The I/O executor object to be used for the newly accepted
+   * socket.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns On success, a socket object representing the newly accepted
+   * connection. On error, a socket object where is_open() is false.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * boost::asio::ip::tcp::socket socket(
+   *     acceptor.accept(my_context2, endpoint, ec));
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename Executor1>
+  typename Protocol::socket::template rebind_executor<Executor1>::other
+  accept(const executor_type& ex,
+      endpoint_type& peer_endpoint, boost::system::error_code& ec,
+      typename enable_if<
+        is_executor<Executor1>::value
+      >::type* = 0)
+  {
+    typename Protocol::socket::template
+      rebind_executor<Executor1>::other peer(ex);
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, &peer_endpoint, ec);
+    return peer;
+  }
+
+  /// Accept a new connection.
+  /**
+   * This function is used to accept a new connection from a peer. The function
+   * call will block until a new connection has been accepted successfully or
+   * an error occurs.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param context The I/O execution context object to be used for the newly
+   * accepted socket.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns On success, a socket object representing the newly accepted
+   * connection. On error, a socket object where is_open() is false.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * boost::asio::ip::tcp::socket socket(
+   *     acceptor.accept(my_context2, endpoint, ec));
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename ExecutionContext>
+  typename Protocol::socket::template rebind_executor<
+      typename ExecutionContext::executor_type>::other
+  accept(ExecutionContext& context,
+      endpoint_type& peer_endpoint, boost::system::error_code& ec,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+  {
+    typename Protocol::socket::template rebind_executor<
+        typename ExecutionContext::executor_type>::other peer(context);
+    impl_.get_service().accept(impl_.get_implementation(),
+        peer, &peer_endpoint, ec);
+    return peer;
+  }
+
+  /// Start an asynchronous accept.
+  /**
+   * This function is used to asynchronously accept a new connection. The
+   * function call always returns immediately.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param ex The I/O executor object to be used for the newly accepted
+   * socket.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written. Ownership of the peer_endpoint object is
+   * retained by the caller, which must guarantee that it is valid until the
+   * handler is called.
+   *
+   * @param handler The handler to be called when the accept operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   typename Protocol::socket::template rebind_executor<
+   *     Executor1>::other peer // On success, the newly accepted socket.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void accept_handler(const boost::system::error_code& error,
+   *     boost::asio::ip::tcp::socket peer)
+   * {
+   *   if (!error)
+   *   {
+   *     // Accept succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * acceptor.async_accept(my_context2, endpoint, accept_handler);
+   * @endcode
+   */
+  template <typename Executor1, typename MoveAcceptHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(MoveAcceptHandler,
+      void (boost::system::error_code,
+        typename Protocol::socket::template rebind_executor<
+          Executor1>::other))
+  async_accept(const Executor1& ex, endpoint_type& peer_endpoint,
+      BOOST_ASIO_MOVE_ARG(MoveAcceptHandler) handler,
+      typename enable_if<
+        is_executor<Executor1>::value
+      >::type* = 0)
+  {
+    typedef typename Protocol::socket::template rebind_executor<
+      Executor1>::other other_socket_type;
+
+    return async_initiate<MoveAcceptHandler,
+      void (boost::system::error_code, other_socket_type)>(
+        initiate_async_move_accept(), handler, this,
+        ex, &peer_endpoint,
+        static_cast<other_socket_type*>(0));
+  }
+
+  /// Start an asynchronous accept.
+  /**
+   * This function is used to asynchronously accept a new connection. The
+   * function call always returns immediately.
+   *
+   * This overload requires that the Protocol template parameter satisfy the
+   * AcceptableProtocol type requirements.
+   *
+   * @param context The I/O execution context object to be used for the newly
+   * accepted socket.
+   *
+   * @param peer_endpoint An endpoint object into which the endpoint of the
+   * remote peer will be written. Ownership of the peer_endpoint object is
+   * retained by the caller, which must guarantee that it is valid until the
+   * handler is called.
+   *
+   * @param handler The handler to be called when the accept operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   typename Protocol::socket::template rebind_executor<
+   *     typename ExecutionContext::executor_type>::other peer
+   *       // On success, the newly accepted socket.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void accept_handler(const boost::system::error_code& error,
+   *     boost::asio::ip::tcp::socket peer)
+   * {
+   *   if (!error)
+   *   {
+   *     // Accept succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::acceptor acceptor(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint;
+   * acceptor.async_accept(my_context2, endpoint, accept_handler);
+   * @endcode
+   */
+  template <typename ExecutionContext, typename MoveAcceptHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(MoveAcceptHandler,
+      void (boost::system::error_code,
+        typename Protocol::socket::template rebind_executor<
+          typename ExecutionContext::executor_type>::other))
+  async_accept(ExecutionContext& context,
+      endpoint_type& peer_endpoint,
+      BOOST_ASIO_MOVE_ARG(MoveAcceptHandler) handler,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+  {
+    typedef typename Protocol::socket::template rebind_executor<
+      typename ExecutionContext::executor_type>::other other_socket_type;
+
+    return async_initiate<MoveAcceptHandler,
+      void (boost::system::error_code, other_socket_type)>(
+        initiate_async_move_accept(), handler, this,
+        context.get_executor(), &peer_endpoint,
+        static_cast<other_socket_type*>(0));
+  }
+#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+private:
+  // Disallow copying and assignment.
+  basic_socket_acceptor_ext(const basic_socket_acceptor_ext&) BOOST_ASIO_DELETED;
+  basic_socket_acceptor_ext& operator=(
+      const basic_socket_acceptor_ext&) BOOST_ASIO_DELETED;
+
+  struct initiate_async_wait
+  {
+    template <typename WaitHandler>
+    void operator()(BOOST_ASIO_MOVE_ARG(WaitHandler) handler,
+        basic_socket_acceptor_ext* self, wait_type w) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WaitHandler.
+      BOOST_ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;
+
+      detail::non_const_lvalue<WaitHandler> handler2(handler);
+      self->impl_.get_service().async_wait(
+          self->impl_.get_implementation(), w, handler2.value,
+          self->impl_.get_implementation_executor());
+    }
+  };
+
+  struct initiate_async_accept
+  {
+    template <typename AcceptHandler, typename Protocol1, typename Executor1>
+    void operator()(BOOST_ASIO_MOVE_ARG(AcceptHandler) handler,
+        basic_socket_acceptor_ext* self, basic_socket_ext_local<Protocol1, Executor1>* peer,
+        endpoint_type* peer_endpoint) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a AcceptHandler.
+      BOOST_ASIO_ACCEPT_HANDLER_CHECK(AcceptHandler, handler) type_check;
+
+      detail::non_const_lvalue<AcceptHandler> handler2(handler);
+      self->impl_.get_service().async_accept(
+          self->impl_.get_implementation(), *peer, peer_endpoint,
+          handler2.value, self->impl_.get_executor());
+    }
+  };
+
+  struct initiate_async_move_accept
+  {
+    template <typename MoveAcceptHandler, typename Executor1, typename Socket>
+    void operator()(BOOST_ASIO_MOVE_ARG(MoveAcceptHandler) handler,
+        basic_socket_acceptor_ext* self, const Executor1& peer_ex,
+        endpoint_type* peer_endpoint, Socket*) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a MoveAcceptHandler.
+      BOOST_ASIO_MOVE_ACCEPT_HANDLER_CHECK(
+          MoveAcceptHandler, handler, Socket) type_check;
+
+      detail::non_const_lvalue<MoveAcceptHandler> handler2(handler);
+      self->impl_.get_service().async_move_accept(
+          self->impl_.get_implementation(), peer_ex, peer_endpoint,
+          handler2.value, self->impl_.get_implementation_executor());
+    }
+  };
+
+#if defined(BOOST_ASIO_WINDOWS_RUNTIME)
+  detail::io_object_impl<
+    detail::null_socket_service<Protocol>, Executor> impl_;
+#elif defined(BOOST_ASIO_HAS_IOCP)
+  detail::io_object_impl<
+    detail::win_iocp_socket_service<Protocol>, Executor> impl_;
+#else
+  detail::io_object_impl<
+    detail::reactive_socket_service_ext_local<Protocol>, Executor> impl_;
+#endif
+};
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_BASIC_SOCKET_ACCEPTOR_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/basic_socket_ext.hpp b/implementation/helper/1.76/boost/asio/basic_socket_ext.hpp
new file mode 100644
index 0000000..777a0bf
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/basic_socket_ext.hpp
@@ -0,0 +1,1859 @@
+//
+// basic_socket_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2018,2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_BASIC_SOCKET_EXT_HPP
+#define BOOST_ASIO_BASIC_SOCKET_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/handler_type_requirements.hpp>
+#include <boost/asio/detail/io_object_impl.hpp>
+#include <boost/asio/detail/non_const_lvalue.hpp>
+#include <boost/asio/detail/throw_error.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/error.hpp>
+#include <boost/asio/execution_context.hpp>
+#include <boost/asio/executor.hpp>
+#include <boost/asio/post.hpp>
+#include <boost/asio/socket_base.hpp>
+
+#if defined(BOOST_ASIO_WINDOWS_RUNTIME)
+# include <boost/asio/detail/null_socket_service.hpp>
+#elif defined(BOOST_ASIO_HAS_IOCP)
+# include <boost/asio/detail/win_iocp_socket_service.hpp>
+#else
+# include <boost/asio/detail/reactive_socket_service_ext.hpp>
+#endif
+
+#if defined(BOOST_ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(BOOST_ASIO_HAS_MOVE)
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+#if !defined(BOOST_ASIO_BASIC_SOCKET_EXT_FWD_DECL)
+#define BOOST_ASIO_BASIC_SOCKET_EXT_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Protocol, typename Executor = executor>
+class basic_socket_ext;
+
+#endif // !defined(BOOST_ASIO_BASIC_SOCKET_EXT_FWD_DECL)
+
+/// Provides socket functionality.
+/**
+ * The basic_socket class template provides functionality that is common to both
+ * stream-oriented and datagram-oriented sockets.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ */
+template <typename Protocol, typename Executor>
+class basic_socket_ext
+  : public socket_base
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the socket type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The socket type when rebound to the specified executor.
+    typedef basic_socket_ext<Protocol, Executor1> other;
+  };
+
+  /// The native representation of a socket.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#elif defined(BOOST_ASIO_WINDOWS_RUNTIME)
+  typedef typename detail::null_socket_service<
+    Protocol>::native_handle_type native_handle_type;
+#elif defined(BOOST_ASIO_HAS_IOCP)
+  typedef typename detail::win_iocp_socket_service<
+    Protocol>::native_handle_type native_handle_type;
+#else
+  typedef typename detail::reactive_socket_service_ext<
+    Protocol>::native_handle_type native_handle_type;
+#endif
+
+  /// The protocol type.
+  typedef Protocol protocol_type;
+
+  /// The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+#if !defined(BOOST_ASIO_NO_EXTENSIONS)
+  /// A basic_socket is always the lowest layer.
+  typedef basic_socket_ext<Protocol, Executor> lowest_layer_type;
+#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
+
+  /// Construct a basic_socket without opening it.
+  /**
+   * This constructor creates a socket without opening it.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   */
+  explicit basic_socket_ext(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Construct a basic_socket without opening it.
+  /**
+   * This constructor creates a socket without opening it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   */
+  template <typename ExecutionContext>
+  explicit basic_socket_ext(ExecutionContext& context,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Construct and open a basic_socket.
+  /**
+   * This constructor creates and opens a socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_socket_ext(const executor_type& ex, const protocol_type& protocol)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_socket.
+  /**
+   * This constructor creates and opens a socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_socket_ext(ExecutionContext& context, const protocol_type& protocol,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct a basic_socket, opening it and binding it to the given local
+  /// endpoint.
+  /**
+   * This constructor creates a socket and automatically opens it bound to the
+   * specified endpoint on the local machine. The protocol used is the protocol
+   * associated with the given endpoint.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket will
+   * be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_socket_ext(const executor_type& ex, const endpoint_type& endpoint)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    const protocol_type protocol = endpoint.protocol();
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+  }
+
+  /// Construct a basic_socket, opening it and binding it to the given local
+  /// endpoint.
+  /**
+   * This constructor creates a socket and automatically opens it bound to the
+   * specified endpoint on the local machine. The protocol used is the protocol
+   * associated with the given endpoint.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket will
+   * be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_socket_ext(ExecutionContext& context, const endpoint_type& endpoint,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    const protocol_type protocol = endpoint.protocol();
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+  }
+
+  /// Construct a basic_socket on an existing native socket.
+  /**
+   * This constructor creates a socket object to hold an existing native socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket A native socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_socket_ext(const executor_type& ex, const protocol_type& protocol,
+      const native_handle_type& native_socket)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_socket, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Construct a basic_socket on an existing native socket.
+  /**
+   * This constructor creates a socket object to hold an existing native socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket A native socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_socket_ext(ExecutionContext& context, const protocol_type& protocol,
+      const native_handle_type& native_socket,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_socket, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_socket from another.
+  /**
+   * This constructor moves a socket from one object to another.
+   *
+   * @param other The other basic_socket object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket(const executor_type&) constructor.
+   */
+  basic_socket_ext(basic_socket_ext&& other)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_socket from another.
+  /**
+   * This assignment operator moves a socket from one object to another.
+   *
+   * @param other The other basic_socket object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket(const executor_type&) constructor.
+   */
+  basic_socket_ext& operator=(basic_socket_ext&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+
+  // All sockets have access to each other's implementations.
+  template <typename Protocol1, typename Executor1>
+  friend class basic_socket_ext;
+
+  /// Move-construct a basic_socket from a socket of another protocol type.
+  /**
+   * This constructor moves a socket from one object to another.
+   *
+   * @param other The other basic_socket object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket(const executor_type&) constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  basic_socket_ext(basic_socket_ext<Protocol1, Executor1>&& other,
+      typename enable_if<
+        is_convertible<Protocol1, Protocol>::value
+          && is_convertible<Executor1, Executor>::value
+      >::type* = 0)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_socket from a socket of another protocol type.
+  /**
+   * This assignment operator moves a socket from one object to another.
+   *
+   * @param other The other basic_socket object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket(const executor_type&) constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  typename enable_if<
+    is_convertible<Protocol1, Protocol>::value
+      && is_convertible<Executor1, Executor>::value,
+    basic_socket_ext&
+  >::type operator=(basic_socket_ext<Protocol1, Executor1> && other)
+  {
+    basic_socket_ext tmp(std::move(other));
+    impl_ = std::move(tmp.impl_);
+    return *this;
+  }
+#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() BOOST_ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+#if !defined(BOOST_ASIO_NO_EXTENSIONS)
+  /// Get a reference to the lowest layer.
+  /**
+   * This function returns a reference to the lowest layer in a stack of
+   * layers. Since a basic_socket cannot contain any further layers, it simply
+   * returns a reference to itself.
+   *
+   * @return A reference to the lowest layer in the stack of layers. Ownership
+   * is not transferred to the caller.
+   */
+  lowest_layer_type& lowest_layer()
+  {
+    return *this;
+  }
+
+  /// Get a const reference to the lowest layer.
+  /**
+   * This function returns a const reference to the lowest layer in a stack of
+   * layers. Since a basic_socket cannot contain any further layers, it simply
+   * returns a reference to itself.
+   *
+   * @return A const reference to the lowest layer in the stack of layers.
+   * Ownership is not transferred to the caller.
+   */
+  const lowest_layer_type& lowest_layer() const
+  {
+    return *this;
+  }
+#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
+
+  /// Open the socket using the specified protocol.
+  /**
+   * This function opens the socket so that it will use the specified protocol.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * socket.open(boost::asio::ip::tcp::v4());
+   * @endcode
+   */
+  void open(const protocol_type& protocol = protocol_type())
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Open the socket using the specified protocol.
+  /**
+   * This function opens the socket so that it will use the specified protocol.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::system::error_code ec;
+   * socket.open(boost::asio::ip::tcp::v4(), ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID open(const protocol_type& protocol,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Assign an existing native socket to the socket.
+  /*
+   * This function opens the socket to hold an existing native socket.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param native_socket A native socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  void assign(const protocol_type& protocol,
+      const native_handle_type& native_socket)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_socket, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Assign an existing native socket to the socket.
+  /*
+   * This function opens the socket to hold an existing native socket.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param native_socket A native socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  BOOST_ASIO_SYNC_OP_VOID assign(const protocol_type& protocol,
+      const native_handle_type& native_socket, boost::system::error_code& ec)
+  {
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_socket, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the socket is open.
+  bool is_open() const
+  {
+    return impl_.get_service().is_open(impl_.get_implementation());
+  }
+
+  /// Close the socket.
+  /**
+   * This function is used to close the socket. Any asynchronous send, receive
+   * or connect operations will be cancelled immediately, and will complete
+   * with the boost::asio::error::operation_aborted error.
+   *
+   * @throws boost::system::system_error Thrown on failure. Note that, even if
+   * the function indicates an error, the underlying descriptor is closed.
+   *
+   * @note For portable behaviour with respect to graceful closure of a
+   * connected socket, call shutdown() before closing the socket.
+   */
+  void close()
+  {
+    boost::system::error_code ec;
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "close");
+  }
+
+  /// Close the socket.
+  /**
+   * This function is used to close the socket. Any asynchronous send, receive
+   * or connect operations will be cancelled immediately, and will complete
+   * with the boost::asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any. Note that, even if
+   * the function indicates an error, the underlying descriptor is closed.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * socket.close(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   *
+   * @note For portable behaviour with respect to graceful closure of a
+   * connected socket, call shutdown() before closing the socket.
+   */
+  BOOST_ASIO_SYNC_OP_VOID close(boost::system::error_code& ec)
+  {
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Release ownership of the underlying native socket.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error. Ownership
+   * of the native socket is then transferred to the caller.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note This function is unsupported on Windows versions prior to Windows
+   * 8.1, and will fail with boost::asio::error::operation_not_supported on
+   * these platforms.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0603)
+  __declspec(deprecated("This function always fails with "
+        "operation_not_supported when used on Windows versions "
+        "prior to Windows 8.1."))
+#endif
+  native_handle_type release()
+  {
+    boost::system::error_code ec;
+    native_handle_type s = impl_.get_service().release(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "release");
+    return s;
+  }
+
+  /// Release ownership of the underlying native socket.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error. Ownership
+   * of the native socket is then transferred to the caller.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note This function is unsupported on Windows versions prior to Windows
+   * 8.1, and will fail with boost::asio::error::operation_not_supported on
+   * these platforms.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0603)
+  __declspec(deprecated("This function always fails with "
+        "operation_not_supported when used on Windows versions "
+        "prior to Windows 8.1."))
+#endif
+  native_handle_type release(boost::system::error_code& ec)
+  {
+    return impl_.get_service().release(impl_.get_implementation(), ec);
+  }
+
+  /// Get the native socket representation.
+  /**
+   * This function may be used to obtain the underlying representation of the
+   * socket. This is intended to allow access to native socket functionality
+   * that is not otherwise provided.
+   */
+  native_handle_type native_handle()
+  {
+    return impl_.get_service().native_handle(impl_.get_implementation());
+  }
+
+  /// Cancel all asynchronous operations associated with the socket.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note Calls to cancel() will always fail with
+   * boost::asio::error::operation_not_supported when run on Windows XP, Windows
+   * Server 2003, and earlier versions of Windows, unless
+   * BOOST_ASIO_ENABLE_CANCELIO is defined. However, the CancelIo function has
+   * two issues that should be considered before enabling its use:
+   *
+   * @li It will only cancel asynchronous operations that were initiated in the
+   * current thread.
+   *
+   * @li It can appear to complete without error, but the request to cancel the
+   * unfinished operations may be silently ignored by the operating system.
+   * Whether it works or not seems to depend on the drivers that are installed.
+   *
+   * For portable cancellation, consider using one of the following
+   * alternatives:
+   *
+   * @li Disable asio's I/O completion port backend by defining
+   * BOOST_ASIO_DISABLE_IOCP.
+   *
+   * @li Use the close() function to simultaneously cancel the outstanding
+   * operations and close the socket.
+   *
+   * When running on Windows Vista, Windows Server 2008, and later, the
+   * CancelIoEx function is always used. This function does not have the
+   * problems described above.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0600) \
+  && !defined(BOOST_ASIO_ENABLE_CANCELIO)
+  __declspec(deprecated("By default, this function always fails with "
+        "operation_not_supported when used on Windows XP, Windows Server 2003, "
+        "or earlier. Consult documentation for details."))
+#endif
+  void cancel()
+  {
+    boost::system::error_code ec;
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "cancel");
+  }
+
+  /// Cancel all asynchronous operations associated with the socket.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note Calls to cancel() will always fail with
+   * boost::asio::error::operation_not_supported when run on Windows XP, Windows
+   * Server 2003, and earlier versions of Windows, unless
+   * BOOST_ASIO_ENABLE_CANCELIO is defined. However, the CancelIo function has
+   * two issues that should be considered before enabling its use:
+   *
+   * @li It will only cancel asynchronous operations that were initiated in the
+   * current thread.
+   *
+   * @li It can appear to complete without error, but the request to cancel the
+   * unfinished operations may be silently ignored by the operating system.
+   * Whether it works or not seems to depend on the drivers that are installed.
+   *
+   * For portable cancellation, consider using one of the following
+   * alternatives:
+   *
+   * @li Disable asio's I/O completion port backend by defining
+   * BOOST_ASIO_DISABLE_IOCP.
+   *
+   * @li Use the close() function to simultaneously cancel the outstanding
+   * operations and close the socket.
+   *
+   * When running on Windows Vista, Windows Server 2008, and later, the
+   * CancelIoEx function is always used. This function does not have the
+   * problems described above.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0600) \
+  && !defined(BOOST_ASIO_ENABLE_CANCELIO)
+  __declspec(deprecated("By default, this function always fails with "
+        "operation_not_supported when used on Windows XP, Windows Server 2003, "
+        "or earlier. Consult documentation for details."))
+#endif
+  BOOST_ASIO_SYNC_OP_VOID cancel(boost::system::error_code& ec)
+  {
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the socket is at the out-of-band data mark.
+  /**
+   * This function is used to check whether the socket input is currently
+   * positioned at the out-of-band data mark.
+   *
+   * @return A bool indicating whether the socket is at the out-of-band data
+   * mark.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  bool at_mark() const
+  {
+    boost::system::error_code ec;
+    bool b = impl_.get_service().at_mark(impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "at_mark");
+    return b;
+  }
+
+  /// Determine whether the socket is at the out-of-band data mark.
+  /**
+   * This function is used to check whether the socket input is currently
+   * positioned at the out-of-band data mark.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return A bool indicating whether the socket is at the out-of-band data
+   * mark.
+   */
+  bool at_mark(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().at_mark(impl_.get_implementation(), ec);
+  }
+
+  /// Determine the number of bytes available for reading.
+  /**
+   * This function is used to determine the number of bytes that may be read
+   * without blocking.
+   *
+   * @return The number of bytes that may be read without blocking, or 0 if an
+   * error occurs.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  std::size_t available() const
+  {
+    boost::system::error_code ec;
+    std::size_t s = impl_.get_service().available(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "available");
+    return s;
+  }
+
+  /// Determine the number of bytes available for reading.
+  /**
+   * This function is used to determine the number of bytes that may be read
+   * without blocking.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of bytes that may be read without blocking, or 0 if an
+   * error occurs.
+   */
+  std::size_t available(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().available(impl_.get_implementation(), ec);
+  }
+
+  /// Bind the socket to the given local endpoint.
+  /**
+   * This function binds the socket to the specified endpoint on the local
+   * machine.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket will
+   * be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * socket.open(boost::asio::ip::tcp::v4());
+   * socket.bind(boost::asio::ip::tcp::endpoint(
+   *       boost::asio::ip::tcp::v4(), 12345));
+   * @endcode
+   */
+  void bind(const endpoint_type& endpoint)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+  }
+
+  /// Bind the socket to the given local endpoint.
+  /**
+   * This function binds the socket to the specified endpoint on the local
+   * machine.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket will
+   * be bound.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * socket.open(boost::asio::ip::tcp::v4());
+   * boost::system::error_code ec;
+   * socket.bind(boost::asio::ip::tcp::endpoint(
+   *       boost::asio::ip::tcp::v4(), 12345), ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID bind(const endpoint_type& endpoint,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Connect the socket to the specified endpoint.
+  /**
+   * This function is used to connect a socket to the specified remote endpoint.
+   * The function call will block until the connection is successfully made or
+   * an error occurs.
+   *
+   * The socket is automatically opened if it is not already open. If the
+   * connect fails, and the socket was automatically opened, the socket is
+   * not returned to the closed state.
+   *
+   * @param peer_endpoint The remote endpoint to which the socket will be
+   * connected.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint(
+   *     boost::asio::ip::address::from_string("1.2.3.4"), 12345);
+   * socket.connect(endpoint);
+   * @endcode
+   */
+  void connect(const endpoint_type& peer_endpoint)
+  {
+    boost::system::error_code ec;
+    if (!is_open())
+    {
+      impl_.get_service().open(impl_.get_implementation(),
+          peer_endpoint.protocol(), ec);
+      boost::asio::detail::throw_error(ec, "connect");
+    }
+    impl_.get_service().connect(impl_.get_implementation(), peer_endpoint, ec);
+    boost::asio::detail::throw_error(ec, "connect");
+  }
+
+  /// Connect the socket to the specified endpoint.
+  /**
+   * This function is used to connect a socket to the specified remote endpoint.
+   * The function call will block until the connection is successfully made or
+   * an error occurs.
+   *
+   * The socket is automatically opened if it is not already open. If the
+   * connect fails, and the socket was automatically opened, the socket is
+   * not returned to the closed state.
+   *
+   * @param peer_endpoint The remote endpoint to which the socket will be
+   * connected.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint(
+   *     boost::asio::ip::address::from_string("1.2.3.4"), 12345);
+   * boost::system::error_code ec;
+   * socket.connect(endpoint, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID connect(const endpoint_type& peer_endpoint,
+      boost::system::error_code& ec)
+  {
+    if (!is_open())
+    {
+      impl_.get_service().open(impl_.get_implementation(),
+            peer_endpoint.protocol(), ec);
+      if (ec)
+      {
+        BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+      }
+    }
+
+    impl_.get_service().connect(impl_.get_implementation(), peer_endpoint, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Start an asynchronous connect.
+  /**
+   * This function is used to asynchronously connect a socket to the specified
+   * remote endpoint. The function call always returns immediately.
+   *
+   * The socket is automatically opened if it is not already open. If the
+   * connect fails, and the socket was automatically opened, the socket is
+   * not returned to the closed state.
+   *
+   * @param peer_endpoint The remote endpoint to which the socket will be
+   * connected. Copies will be made of the endpoint object as required.
+   *
+   * @param handler The handler to be called when the connection operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error // Result of operation
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void connect_handler(const boost::system::error_code& error)
+   * {
+   *   if (!error)
+   *   {
+   *     // Connect succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint(
+   *     boost::asio::ip::address::from_string("1.2.3.4"), 12345);
+   * socket.async_connect(endpoint, connect_handler);
+   * @endcode
+   */
+  template <typename ConnectHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ConnectHandler,
+      void (boost::system::error_code))
+  async_connect(const endpoint_type& peer_endpoint,
+      BOOST_ASIO_MOVE_ARG(ConnectHandler) handler)
+  {
+    boost::system::error_code open_ec;
+    if (!is_open())
+    {
+      const protocol_type protocol = peer_endpoint.protocol();
+      impl_.get_service().open(impl_.get_implementation(), protocol, open_ec);
+    }
+
+    return async_initiate<ConnectHandler, void (boost::system::error_code)>(
+        initiate_async_connect(), handler, this, peer_endpoint, open_ec);
+  }
+
+  /// Set an option on the socket.
+  /**
+   * This function is used to set an option on the socket.
+   *
+   * @param option The new option value to be set on the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa SettableSocketOption @n
+   * boost::asio::socket_base::broadcast @n
+   * boost::asio::socket_base::do_not_route @n
+   * boost::asio::socket_base::keep_alive @n
+   * boost::asio::socket_base::linger @n
+   * boost::asio::socket_base::receive_buffer_size @n
+   * boost::asio::socket_base::receive_low_watermark @n
+   * boost::asio::socket_base::reuse_address @n
+   * boost::asio::socket_base::send_buffer_size @n
+   * boost::asio::socket_base::send_low_watermark @n
+   * boost::asio::ip::multicast::join_group @n
+   * boost::asio::ip::multicast::leave_group @n
+   * boost::asio::ip::multicast::enable_loopback @n
+   * boost::asio::ip::multicast::outbound_interface @n
+   * boost::asio::ip::multicast::hops @n
+   * boost::asio::ip::tcp::no_delay
+   *
+   * @par Example
+   * Setting the IPPROTO_TCP/TCP_NODELAY option:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::no_delay option(true);
+   * socket.set_option(option);
+   * @endcode
+   */
+  template <typename SettableSocketOption>
+  void set_option(const SettableSocketOption& option)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().set_option(impl_.get_implementation(), option, ec);
+    boost::asio::detail::throw_error(ec, "set_option");
+  }
+
+  /// Set an option on the socket.
+  /**
+   * This function is used to set an option on the socket.
+   *
+   * @param option The new option value to be set on the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa SettableSocketOption @n
+   * boost::asio::socket_base::broadcast @n
+   * boost::asio::socket_base::do_not_route @n
+   * boost::asio::socket_base::keep_alive @n
+   * boost::asio::socket_base::linger @n
+   * boost::asio::socket_base::receive_buffer_size @n
+   * boost::asio::socket_base::receive_low_watermark @n
+   * boost::asio::socket_base::reuse_address @n
+   * boost::asio::socket_base::send_buffer_size @n
+   * boost::asio::socket_base::send_low_watermark @n
+   * boost::asio::ip::multicast::join_group @n
+   * boost::asio::ip::multicast::leave_group @n
+   * boost::asio::ip::multicast::enable_loopback @n
+   * boost::asio::ip::multicast::outbound_interface @n
+   * boost::asio::ip::multicast::hops @n
+   * boost::asio::ip::tcp::no_delay
+   *
+   * @par Example
+   * Setting the IPPROTO_TCP/TCP_NODELAY option:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::no_delay option(true);
+   * boost::system::error_code ec;
+   * socket.set_option(option, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename SettableSocketOption>
+  BOOST_ASIO_SYNC_OP_VOID set_option(const SettableSocketOption& option,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().set_option(impl_.get_implementation(), option, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get an option from the socket.
+  /**
+   * This function is used to get the current value of an option on the socket.
+   *
+   * @param option The option value to be obtained from the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa GettableSocketOption @n
+   * boost::asio::socket_base::broadcast @n
+   * boost::asio::socket_base::do_not_route @n
+   * boost::asio::socket_base::keep_alive @n
+   * boost::asio::socket_base::linger @n
+   * boost::asio::socket_base::receive_buffer_size @n
+   * boost::asio::socket_base::receive_low_watermark @n
+   * boost::asio::socket_base::reuse_address @n
+   * boost::asio::socket_base::send_buffer_size @n
+   * boost::asio::socket_base::send_low_watermark @n
+   * boost::asio::ip::multicast::join_group @n
+   * boost::asio::ip::multicast::leave_group @n
+   * boost::asio::ip::multicast::enable_loopback @n
+   * boost::asio::ip::multicast::outbound_interface @n
+   * boost::asio::ip::multicast::hops @n
+   * boost::asio::ip::tcp::no_delay
+   *
+   * @par Example
+   * Getting the value of the SOL_SOCKET/SO_KEEPALIVE option:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket::keep_alive option;
+   * socket.get_option(option);
+   * bool is_set = option.value();
+   * @endcode
+   */
+  template <typename GettableSocketOption>
+  void get_option(GettableSocketOption& option) const
+  {
+    boost::system::error_code ec;
+    impl_.get_service().get_option(impl_.get_implementation(), option, ec);
+    boost::asio::detail::throw_error(ec, "get_option");
+  }
+
+  /// Get an option from the socket.
+  /**
+   * This function is used to get the current value of an option on the socket.
+   *
+   * @param option The option value to be obtained from the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa GettableSocketOption @n
+   * boost::asio::socket_base::broadcast @n
+   * boost::asio::socket_base::do_not_route @n
+   * boost::asio::socket_base::keep_alive @n
+   * boost::asio::socket_base::linger @n
+   * boost::asio::socket_base::receive_buffer_size @n
+   * boost::asio::socket_base::receive_low_watermark @n
+   * boost::asio::socket_base::reuse_address @n
+   * boost::asio::socket_base::send_buffer_size @n
+   * boost::asio::socket_base::send_low_watermark @n
+   * boost::asio::ip::multicast::join_group @n
+   * boost::asio::ip::multicast::leave_group @n
+   * boost::asio::ip::multicast::enable_loopback @n
+   * boost::asio::ip::multicast::outbound_interface @n
+   * boost::asio::ip::multicast::hops @n
+   * boost::asio::ip::tcp::no_delay
+   *
+   * @par Example
+   * Getting the value of the SOL_SOCKET/SO_KEEPALIVE option:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket::keep_alive option;
+   * boost::system::error_code ec;
+   * socket.get_option(option, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * bool is_set = option.value();
+   * @endcode
+   */
+  template <typename GettableSocketOption>
+  BOOST_ASIO_SYNC_OP_VOID get_option(GettableSocketOption& option,
+      boost::system::error_code& ec) const
+  {
+    impl_.get_service().get_option(impl_.get_implementation(), option, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Perform an IO control command on the socket.
+  /**
+   * This function is used to execute an IO control command on the socket.
+   *
+   * @param command The IO control command to be performed on the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa IoControlCommand @n
+   * boost::asio::socket_base::bytes_readable @n
+   * boost::asio::socket_base::non_blocking_io
+   *
+   * @par Example
+   * Getting the number of bytes ready to read:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket::bytes_readable command;
+   * socket.io_control(command);
+   * std::size_t bytes_readable = command.get();
+   * @endcode
+   */
+  template <typename IoControlCommand>
+  void io_control(IoControlCommand& command)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().io_control(impl_.get_implementation(), command, ec);
+    boost::asio::detail::throw_error(ec, "io_control");
+  }
+
+  /// Perform an IO control command on the socket.
+  /**
+   * This function is used to execute an IO control command on the socket.
+   *
+   * @param command The IO control command to be performed on the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa IoControlCommand @n
+   * boost::asio::socket_base::bytes_readable @n
+   * boost::asio::socket_base::non_blocking_io
+   *
+   * @par Example
+   * Getting the number of bytes ready to read:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket::bytes_readable command;
+   * boost::system::error_code ec;
+   * socket.io_control(command, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * std::size_t bytes_readable = command.get();
+   * @endcode
+   */
+  template <typename IoControlCommand>
+  BOOST_ASIO_SYNC_OP_VOID io_control(IoControlCommand& command,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().io_control(impl_.get_implementation(), command, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Gets the non-blocking mode of the socket.
+  /**
+   * @returns @c true if the socket's synchronous operations will fail with
+   * boost::asio::error::would_block if they are unable to perform the requested
+   * operation immediately. If @c false, synchronous operations will block
+   * until complete.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  bool non_blocking() const
+  {
+    return impl_.get_service().non_blocking(impl_.get_implementation());
+  }
+
+  /// Sets the non-blocking mode of the socket.
+  /**
+   * @param mode If @c true, the socket's synchronous operations will fail with
+   * boost::asio::error::would_block if they are unable to perform the requested
+   * operation immediately. If @c false, synchronous operations will block
+   * until complete.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  void non_blocking(bool mode)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().non_blocking(impl_.get_implementation(), mode, ec);
+    boost::asio::detail::throw_error(ec, "non_blocking");
+  }
+
+  /// Sets the non-blocking mode of the socket.
+  /**
+   * @param mode If @c true, the socket's synchronous operations will fail with
+   * boost::asio::error::would_block if they are unable to perform the requested
+   * operation immediately. If @c false, synchronous operations will block
+   * until complete.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  BOOST_ASIO_SYNC_OP_VOID non_blocking(
+      bool mode, boost::system::error_code& ec)
+  {
+    impl_.get_service().non_blocking(impl_.get_implementation(), mode, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Gets the non-blocking mode of the native socket implementation.
+  /**
+   * This function is used to retrieve the non-blocking mode of the underlying
+   * native socket. This mode has no effect on the behaviour of the socket
+   * object's synchronous operations.
+   *
+   * @returns @c true if the underlying socket is in non-blocking mode and
+   * direct system calls may fail with boost::asio::error::would_block (or the
+   * equivalent system error).
+   *
+   * @note The current non-blocking mode is cached by the socket object.
+   * Consequently, the return value may be incorrect if the non-blocking mode
+   * was set directly on the native socket.
+   *
+   * @par Example
+   * This function is intended to allow the encapsulation of arbitrary
+   * non-blocking system calls as asynchronous operations, in a way that is
+   * transparent to the user of the socket object. The following example
+   * illustrates how Linux's @c sendfile system call might be encapsulated:
+   * @code template <typename Handler>
+   * struct sendfile_op
+   * {
+   *   tcp::socket& sock_;
+   *   int fd_;
+   *   Handler handler_;
+   *   off_t offset_;
+   *   std::size_t total_bytes_transferred_;
+   *
+   *   // Function call operator meeting WriteHandler requirements.
+   *   // Used as the handler for the async_write_some operation.
+   *   void operator()(boost::system::error_code ec, std::size_t)
+   *   {
+   *     // Put the underlying socket into non-blocking mode.
+   *     if (!ec)
+   *       if (!sock_.native_non_blocking())
+   *         sock_.native_non_blocking(true, ec);
+   *
+   *     if (!ec)
+   *     {
+   *       for (;;)
+   *       {
+   *         // Try the system call.
+   *         errno = 0;
+   *         int n = ::sendfile(sock_.native_handle(), fd_, &offset_, 65536);
+   *         ec = boost::system::error_code(n < 0 ? errno : 0,
+   *             boost::asio::error::get_system_category());
+   *         total_bytes_transferred_ += ec ? 0 : n;
+   *
+   *         // Retry operation immediately if interrupted by signal.
+   *         if (ec == boost::asio::error::interrupted)
+   *           continue;
+   *
+   *         // Check if we need to run the operation again.
+   *         if (ec == boost::asio::error::would_block
+   *             || ec == boost::asio::error::try_again)
+   *         {
+   *           // We have to wait for the socket to become ready again.
+   *           sock_.async_wait(tcp::socket::wait_write, *this);
+   *           return;
+   *         }
+   *
+   *         if (ec || n == 0)
+   *         {
+   *           // An error occurred, or we have reached the end of the file.
+   *           // Either way we must exit the loop so we can call the handler.
+   *           break;
+   *         }
+   *
+   *         // Loop around to try calling sendfile again.
+   *       }
+   *     }
+   *
+   *     // Pass result back to user's handler.
+   *     handler_(ec, total_bytes_transferred_);
+   *   }
+   * };
+   *
+   * template <typename Handler>
+   * void async_sendfile(tcp::socket& sock, int fd, Handler h)
+   * {
+   *   sendfile_op<Handler> op = { sock, fd, h, 0, 0 };
+   *   sock.async_wait(tcp::socket::wait_write, op);
+   * } @endcode
+   */
+  bool native_non_blocking() const
+  {
+    return impl_.get_service().native_non_blocking(impl_.get_implementation());
+  }
+
+  /// Sets the non-blocking mode of the native socket implementation.
+  /**
+   * This function is used to modify the non-blocking mode of the underlying
+   * native socket. It has no effect on the behaviour of the socket object's
+   * synchronous operations.
+   *
+   * @param mode If @c true, the underlying socket is put into non-blocking
+   * mode and direct system calls may fail with boost::asio::error::would_block
+   * (or the equivalent system error).
+   *
+   * @throws boost::system::system_error Thrown on failure. If the @c mode is
+   * @c false, but the current value of @c non_blocking() is @c true, this
+   * function fails with boost::asio::error::invalid_argument, as the
+   * combination does not make sense.
+   *
+   * @par Example
+   * This function is intended to allow the encapsulation of arbitrary
+   * non-blocking system calls as asynchronous operations, in a way that is
+   * transparent to the user of the socket object. The following example
+   * illustrates how Linux's @c sendfile system call might be encapsulated:
+   * @code template <typename Handler>
+   * struct sendfile_op
+   * {
+   *   tcp::socket& sock_;
+   *   int fd_;
+   *   Handler handler_;
+   *   off_t offset_;
+   *   std::size_t total_bytes_transferred_;
+   *
+   *   // Function call operator meeting WriteHandler requirements.
+   *   // Used as the handler for the async_write_some operation.
+   *   void operator()(boost::system::error_code ec, std::size_t)
+   *   {
+   *     // Put the underlying socket into non-blocking mode.
+   *     if (!ec)
+   *       if (!sock_.native_non_blocking())
+   *         sock_.native_non_blocking(true, ec);
+   *
+   *     if (!ec)
+   *     {
+   *       for (;;)
+   *       {
+   *         // Try the system call.
+   *         errno = 0;
+   *         int n = ::sendfile(sock_.native_handle(), fd_, &offset_, 65536);
+   *         ec = boost::system::error_code(n < 0 ? errno : 0,
+   *             boost::asio::error::get_system_category());
+   *         total_bytes_transferred_ += ec ? 0 : n;
+   *
+   *         // Retry operation immediately if interrupted by signal.
+   *         if (ec == boost::asio::error::interrupted)
+   *           continue;
+   *
+   *         // Check if we need to run the operation again.
+   *         if (ec == boost::asio::error::would_block
+   *             || ec == boost::asio::error::try_again)
+   *         {
+   *           // We have to wait for the socket to become ready again.
+   *           sock_.async_wait(tcp::socket::wait_write, *this);
+   *           return;
+   *         }
+   *
+   *         if (ec || n == 0)
+   *         {
+   *           // An error occurred, or we have reached the end of the file.
+   *           // Either way we must exit the loop so we can call the handler.
+   *           break;
+   *         }
+   *
+   *         // Loop around to try calling sendfile again.
+   *       }
+   *     }
+   *
+   *     // Pass result back to user's handler.
+   *     handler_(ec, total_bytes_transferred_);
+   *   }
+   * };
+   *
+   * template <typename Handler>
+   * void async_sendfile(tcp::socket& sock, int fd, Handler h)
+   * {
+   *   sendfile_op<Handler> op = { sock, fd, h, 0, 0 };
+   *   sock.async_wait(tcp::socket::wait_write, op);
+   * } @endcode
+   */
+  void native_non_blocking(bool mode)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().native_non_blocking(
+        impl_.get_implementation(), mode, ec);
+    boost::asio::detail::throw_error(ec, "native_non_blocking");
+  }
+
+  /// Sets the non-blocking mode of the native socket implementation.
+  /**
+   * This function is used to modify the non-blocking mode of the underlying
+   * native socket. It has no effect on the behaviour of the socket object's
+   * synchronous operations.
+   *
+   * @param mode If @c true, the underlying socket is put into non-blocking
+   * mode and direct system calls may fail with boost::asio::error::would_block
+   * (or the equivalent system error).
+   *
+   * @param ec Set to indicate what error occurred, if any. If the @c mode is
+   * @c false, but the current value of @c non_blocking() is @c true, this
+   * function fails with boost::asio::error::invalid_argument, as the
+   * combination does not make sense.
+   *
+   * @par Example
+   * This function is intended to allow the encapsulation of arbitrary
+   * non-blocking system calls as asynchronous operations, in a way that is
+   * transparent to the user of the socket object. The following example
+   * illustrates how Linux's @c sendfile system call might be encapsulated:
+   * @code template <typename Handler>
+   * struct sendfile_op
+   * {
+   *   tcp::socket& sock_;
+   *   int fd_;
+   *   Handler handler_;
+   *   off_t offset_;
+   *   std::size_t total_bytes_transferred_;
+   *
+   *   // Function call operator meeting WriteHandler requirements.
+   *   // Used as the handler for the async_write_some operation.
+   *   void operator()(boost::system::error_code ec, std::size_t)
+   *   {
+   *     // Put the underlying socket into non-blocking mode.
+   *     if (!ec)
+   *       if (!sock_.native_non_blocking())
+   *         sock_.native_non_blocking(true, ec);
+   *
+   *     if (!ec)
+   *     {
+   *       for (;;)
+   *       {
+   *         // Try the system call.
+   *         errno = 0;
+   *         int n = ::sendfile(sock_.native_handle(), fd_, &offset_, 65536);
+   *         ec = boost::system::error_code(n < 0 ? errno : 0,
+   *             boost::asio::error::get_system_category());
+   *         total_bytes_transferred_ += ec ? 0 : n;
+   *
+   *         // Retry operation immediately if interrupted by signal.
+   *         if (ec == boost::asio::error::interrupted)
+   *           continue;
+   *
+   *         // Check if we need to run the operation again.
+   *         if (ec == boost::asio::error::would_block
+   *             || ec == boost::asio::error::try_again)
+   *         {
+   *           // We have to wait for the socket to become ready again.
+   *           sock_.async_wait(tcp::socket::wait_write, *this);
+   *           return;
+   *         }
+   *
+   *         if (ec || n == 0)
+   *         {
+   *           // An error occurred, or we have reached the end of the file.
+   *           // Either way we must exit the loop so we can call the handler.
+   *           break;
+   *         }
+   *
+   *         // Loop around to try calling sendfile again.
+   *       }
+   *     }
+   *
+   *     // Pass result back to user's handler.
+   *     handler_(ec, total_bytes_transferred_);
+   *   }
+   * };
+   *
+   * template <typename Handler>
+   * void async_sendfile(tcp::socket& sock, int fd, Handler h)
+   * {
+   *   sendfile_op<Handler> op = { sock, fd, h, 0, 0 };
+   *   sock.async_wait(tcp::socket::wait_write, op);
+   * } @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID native_non_blocking(
+      bool mode, boost::system::error_code& ec)
+  {
+    impl_.get_service().native_non_blocking(
+        impl_.get_implementation(), mode, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get the local endpoint of the socket.
+  /**
+   * This function is used to obtain the locally bound endpoint of the socket.
+   *
+   * @returns An object that represents the local endpoint of the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint = socket.local_endpoint();
+   * @endcode
+   */
+  endpoint_type local_endpoint() const
+  {
+    boost::system::error_code ec;
+    endpoint_type ep = impl_.get_service().local_endpoint(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "local_endpoint");
+    return ep;
+  }
+
+  /// Get the local endpoint of the socket.
+  /**
+   * This function is used to obtain the locally bound endpoint of the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns An object that represents the local endpoint of the socket.
+   * Returns a default-constructed endpoint object if an error occurred.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * boost::asio::ip::tcp::endpoint endpoint = socket.local_endpoint(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  endpoint_type local_endpoint(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().local_endpoint(impl_.get_implementation(), ec);
+  }
+
+  /// Get the remote endpoint of the socket.
+  /**
+   * This function is used to obtain the remote endpoint of the socket.
+   *
+   * @returns An object that represents the remote endpoint of the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint = socket.remote_endpoint();
+   * @endcode
+   */
+  endpoint_type remote_endpoint() const
+  {
+    boost::system::error_code ec;
+    endpoint_type ep = impl_.get_service().remote_endpoint(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "remote_endpoint");
+    return ep;
+  }
+
+  /// Get the remote endpoint of the socket.
+  /**
+   * This function is used to obtain the remote endpoint of the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns An object that represents the remote endpoint of the socket.
+   * Returns a default-constructed endpoint object if an error occurred.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * boost::asio::ip::tcp::endpoint endpoint = socket.remote_endpoint(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  endpoint_type remote_endpoint(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().remote_endpoint(impl_.get_implementation(), ec);
+  }
+
+  /// Disable sends or receives on the socket.
+  /**
+   * This function is used to disable send operations, receive operations, or
+   * both.
+   *
+   * @param what Determines what types of operation will no longer be allowed.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * Shutting down the send side of the socket:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * socket.shutdown(boost::asio::ip::tcp::socket::shutdown_send);
+   * @endcode
+   */
+  void shutdown(shutdown_type what)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().shutdown(impl_.get_implementation(), what, ec);
+    boost::asio::detail::throw_error(ec, "shutdown");
+  }
+
+  /// Disable sends or receives on the socket.
+  /**
+   * This function is used to disable send operations, receive operations, or
+   * both.
+   *
+   * @param what Determines what types of operation will no longer be allowed.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * Shutting down the send side of the socket:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * socket.shutdown(boost::asio::ip::tcp::socket::shutdown_send, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID shutdown(shutdown_type what,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().shutdown(impl_.get_implementation(), what, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Wait for the socket to become ready to read, ready to write, or to have
+  /// pending error conditions.
+  /**
+   * This function is used to perform a blocking wait for a socket to enter
+   * a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired socket state.
+   *
+   * @par Example
+   * Waiting for a socket to become readable.
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * socket.wait(boost::asio::ip::tcp::socket::wait_read);
+   * @endcode
+   */
+  void wait(wait_type w)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().wait(impl_.get_implementation(), w, ec);
+    boost::asio::detail::throw_error(ec, "wait");
+  }
+
+  /// Wait for the socket to become ready to read, ready to write, or to have
+  /// pending error conditions.
+  /**
+   * This function is used to perform a blocking wait for a socket to enter
+   * a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired socket state.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * Waiting for a socket to become readable.
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * socket.wait(boost::asio::ip::tcp::socket::wait_read, ec);
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID wait(wait_type w, boost::system::error_code& ec)
+  {
+    impl_.get_service().wait(impl_.get_implementation(), w, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Asynchronously wait for the socket to become ready to read, ready to
+  /// write, or to have pending error conditions.
+  /**
+   * This function is used to perform an asynchronous wait for a socket to enter
+   * a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired socket state.
+   *
+   * @param handler The handler to be called when the wait operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error // Result of operation
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void wait_handler(const boost::system::error_code& error)
+   * {
+   *   if (!error)
+   *   {
+   *     // Wait succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * socket.async_wait(boost::asio::ip::tcp::socket::wait_read, wait_handler);
+   * @endcode
+   */
+  template <typename WaitHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WaitHandler,
+      void (boost::system::error_code))
+  async_wait(wait_type w, BOOST_ASIO_MOVE_ARG(WaitHandler) handler)
+  {
+    return async_initiate<WaitHandler, void (boost::system::error_code)>(
+        initiate_async_wait(), handler, this, w);
+  }
+
+protected:
+  /// Protected destructor to prevent deletion through this type.
+  /**
+   * This function destroys the socket, cancelling any outstanding asynchronous
+   * operations associated with the socket as if by calling @c cancel.
+   */
+  ~basic_socket_ext()
+  {
+  }
+
+#if defined(BOOST_ASIO_WINDOWS_RUNTIME)
+  detail::io_object_impl<
+    detail::null_socket_service<Protocol>, Executor> impl_;
+#elif defined(BOOST_ASIO_HAS_IOCP)
+  detail::io_object_impl<
+    detail::win_iocp_socket_service<Protocol>, Executor> impl_;
+#else
+  detail::io_object_impl<
+    detail::reactive_socket_service_ext<Protocol>, Executor> impl_;
+#endif
+
+private:
+  // Disallow copying and assignment.
+  basic_socket_ext(const basic_socket_ext&) BOOST_ASIO_DELETED;
+  basic_socket_ext& operator=(const basic_socket_ext&) BOOST_ASIO_DELETED;
+
+  struct initiate_async_connect
+  {
+    template <typename ConnectHandler>
+    void operator()(BOOST_ASIO_MOVE_ARG(ConnectHandler) handler,
+        basic_socket_ext* self, const endpoint_type& peer_endpoint,
+        const boost::system::error_code& open_ec) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ConnectHandler.
+      BOOST_ASIO_CONNECT_HANDLER_CHECK(ConnectHandler, handler) type_check;
+
+      if (open_ec)
+      {
+          boost::asio::post(self->impl_.get_executor(),
+              boost::asio::detail::bind_handler(
+                BOOST_ASIO_MOVE_CAST(ConnectHandler)(handler), open_ec));
+      }
+      else
+      {
+        detail::non_const_lvalue<ConnectHandler> handler2(handler);
+        self->impl_.get_service().async_connect(
+            self->impl_.get_implementation(), peer_endpoint,
+            handler2.value, self->impl_.get_implementation_executor());
+      }
+    }
+  };
+
+  struct initiate_async_wait
+  {
+    template <typename WaitHandler>
+    void operator()(BOOST_ASIO_MOVE_ARG(WaitHandler) handler,
+        basic_socket_ext* self, wait_type w) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WaitHandler.
+      BOOST_ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;
+
+      detail::non_const_lvalue<WaitHandler> handler2(handler);
+      self->impl_.get_service().async_wait(
+          self->impl_.get_implementation(), w, handler2.value,
+          self->impl_.get_implementation_executor());
+    }
+  };
+};
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_BASIC_SOCKET_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/basic_socket_ext_local.hpp b/implementation/helper/1.76/boost/asio/basic_socket_ext_local.hpp
new file mode 100644
index 0000000..2c898fc
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/basic_socket_ext_local.hpp
@@ -0,0 +1,1859 @@
+//
+// basic_socket_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2018,2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_BASIC_SOCKET_EXT_LOCAL_HPP
+#define BOOST_ASIO_BASIC_SOCKET_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/handler_type_requirements_ext.hpp>
+#include <boost/asio/detail/io_object_impl.hpp>
+#include <boost/asio/detail/non_const_lvalue.hpp>
+#include <boost/asio/detail/throw_error.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/error.hpp>
+#include <boost/asio/execution_context.hpp>
+#include <boost/asio/executor.hpp>
+#include <boost/asio/post.hpp>
+#include <boost/asio/socket_base.hpp>
+
+#if defined(BOOST_ASIO_WINDOWS_RUNTIME)
+# include <boost/asio/detail/null_socket_service.hpp>
+#elif defined(BOOST_ASIO_HAS_IOCP)
+# include <boost/asio/detail/win_iocp_socket_service.hpp>
+#else
+# include <boost/asio/detail/reactive_socket_service_ext_local.hpp>
+#endif
+
+#if defined(BOOST_ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(BOOST_ASIO_HAS_MOVE)
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+#if !defined(BOOST_ASIO_BASIC_SOCKET_EXT_LOCAL_FWD_DECL)
+#define BOOST_ASIO_BASIC_SOCKET_EXT_LOCAL_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Protocol, typename Executor = executor>
+class basic_socket_ext_local;
+
+#endif // !defined(BOOST_ASIO_BASIC_SOCKET_EXT_LOCAL_FWD_DECL)
+
+/// Provides socket functionality.
+/**
+ * The basic_socket class template provides functionality that is common to both
+ * stream-oriented and datagram-oriented sockets.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ */
+template <typename Protocol, typename Executor>
+class basic_socket_ext_local
+  : public socket_base
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the socket type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The socket type when rebound to the specified executor.
+    typedef basic_socket_ext_local<Protocol, Executor1> other;
+  };
+
+  /// The native representation of a socket.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#elif defined(BOOST_ASIO_WINDOWS_RUNTIME)
+  typedef typename detail::null_socket_service<
+    Protocol>::native_handle_type native_handle_type;
+#elif defined(BOOST_ASIO_HAS_IOCP)
+  typedef typename detail::win_iocp_socket_service<
+    Protocol>::native_handle_type native_handle_type;
+#else
+  typedef typename detail::reactive_socket_service_ext_local<
+    Protocol>::native_handle_type native_handle_type;
+#endif
+
+  /// The protocol type.
+  typedef Protocol protocol_type;
+
+  /// The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+#if !defined(BOOST_ASIO_NO_EXTENSIONS)
+  /// A basic_socket is always the lowest layer.
+  typedef basic_socket_ext_local<Protocol, Executor> lowest_layer_type;
+#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
+
+  /// Construct a basic_socket without opening it.
+  /**
+   * This constructor creates a socket without opening it.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   */
+  explicit basic_socket_ext_local(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Construct a basic_socket without opening it.
+  /**
+   * This constructor creates a socket without opening it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   */
+  template <typename ExecutionContext>
+  explicit basic_socket_ext_local(ExecutionContext& context,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Construct and open a basic_socket.
+  /**
+   * This constructor creates and opens a socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_socket_ext_local(const executor_type& ex, const protocol_type& protocol)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_socket.
+  /**
+   * This constructor creates and opens a socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_socket_ext_local(ExecutionContext& context, const protocol_type& protocol,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct a basic_socket, opening it and binding it to the given local
+  /// endpoint.
+  /**
+   * This constructor creates a socket and automatically opens it bound to the
+   * specified endpoint on the local machine. The protocol used is the protocol
+   * associated with the given endpoint.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket will
+   * be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_socket_ext_local(const executor_type& ex, const endpoint_type& endpoint)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    const protocol_type protocol = endpoint.protocol();
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+  }
+
+  /// Construct a basic_socket, opening it and binding it to the given local
+  /// endpoint.
+  /**
+   * This constructor creates a socket and automatically opens it bound to the
+   * specified endpoint on the local machine. The protocol used is the protocol
+   * associated with the given endpoint.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket will
+   * be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_socket_ext_local(ExecutionContext& context, const endpoint_type& endpoint,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    const protocol_type protocol = endpoint.protocol();
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+  }
+
+  /// Construct a basic_socket on an existing native socket.
+  /**
+   * This constructor creates a socket object to hold an existing native socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket A native socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_socket_ext_local(const executor_type& ex, const protocol_type& protocol,
+      const native_handle_type& native_socket)
+    : impl_(0, ex)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_socket, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Construct a basic_socket on an existing native socket.
+  /**
+   * This constructor creates a socket object to hold an existing native socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket A native socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_socket_ext_local(ExecutionContext& context, const protocol_type& protocol,
+      const native_handle_type& native_socket,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : impl_(0, 0, context)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_socket, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_socket from another.
+  /**
+   * This constructor moves a socket from one object to another.
+   *
+   * @param other The other basic_socket object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket(const executor_type&) constructor.
+   */
+  basic_socket_ext_local(basic_socket_ext_local&& other)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_socket from another.
+  /**
+   * This assignment operator moves a socket from one object to another.
+   *
+   * @param other The other basic_socket object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket(const executor_type&) constructor.
+   */
+  basic_socket_ext_local& operator=(basic_socket_ext_local&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+
+  // All sockets have access to each other's implementations.
+  template <typename Protocol1, typename Executor1>
+  friend class basic_socket_ext_local;
+
+  /// Move-construct a basic_socket from a socket of another protocol type.
+  /**
+   * This constructor moves a socket from one object to another.
+   *
+   * @param other The other basic_socket object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket(const executor_type&) constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  basic_socket_ext_local(basic_socket_ext_local<Protocol1, Executor1>&& other,
+      typename enable_if<
+        is_convertible<Protocol1, Protocol>::value
+          && is_convertible<Executor1, Executor>::value
+      >::type* = 0)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_socket from a socket of another protocol type.
+  /**
+   * This assignment operator moves a socket from one object to another.
+   *
+   * @param other The other basic_socket object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_socket(const executor_type&) constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  typename enable_if<
+    is_convertible<Protocol1, Protocol>::value
+      && is_convertible<Executor1, Executor>::value,
+    basic_socket_ext_local&
+  >::type operator=(basic_socket_ext_local<Protocol1, Executor1> && other)
+  {
+    basic_socket_ext_local tmp(std::move(other));
+    impl_ = std::move(tmp.impl_);
+    return *this;
+  }
+#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() BOOST_ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+#if !defined(BOOST_ASIO_NO_EXTENSIONS)
+  /// Get a reference to the lowest layer.
+  /**
+   * This function returns a reference to the lowest layer in a stack of
+   * layers. Since a basic_socket cannot contain any further layers, it simply
+   * returns a reference to itself.
+   *
+   * @return A reference to the lowest layer in the stack of layers. Ownership
+   * is not transferred to the caller.
+   */
+  lowest_layer_type& lowest_layer()
+  {
+    return *this;
+  }
+
+  /// Get a const reference to the lowest layer.
+  /**
+   * This function returns a const reference to the lowest layer in a stack of
+   * layers. Since a basic_socket cannot contain any further layers, it simply
+   * returns a reference to itself.
+   *
+   * @return A const reference to the lowest layer in the stack of layers.
+   * Ownership is not transferred to the caller.
+   */
+  const lowest_layer_type& lowest_layer() const
+  {
+    return *this;
+  }
+#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
+
+  /// Open the socket using the specified protocol.
+  /**
+   * This function opens the socket so that it will use the specified protocol.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * socket.open(boost::asio::ip::tcp::v4());
+   * @endcode
+   */
+  void open(const protocol_type& protocol = protocol_type())
+  {
+    boost::system::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    boost::asio::detail::throw_error(ec, "open");
+  }
+
+  /// Open the socket using the specified protocol.
+  /**
+   * This function opens the socket so that it will use the specified protocol.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::system::error_code ec;
+   * socket.open(boost::asio::ip::tcp::v4(), ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID open(const protocol_type& protocol,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().open(impl_.get_implementation(), protocol, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Assign an existing native socket to the socket.
+  /*
+   * This function opens the socket to hold an existing native socket.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param native_socket A native socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  void assign(const protocol_type& protocol,
+      const native_handle_type& native_socket)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_socket, ec);
+    boost::asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Assign an existing native socket to the socket.
+  /*
+   * This function opens the socket to hold an existing native socket.
+   *
+   * @param protocol An object specifying which protocol is to be used.
+   *
+   * @param native_socket A native socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  BOOST_ASIO_SYNC_OP_VOID assign(const protocol_type& protocol,
+      const native_handle_type& native_socket, boost::system::error_code& ec)
+  {
+    impl_.get_service().assign(impl_.get_implementation(),
+        protocol, native_socket, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the socket is open.
+  bool is_open() const
+  {
+    return impl_.get_service().is_open(impl_.get_implementation());
+  }
+
+  /// Close the socket.
+  /**
+   * This function is used to close the socket. Any asynchronous send, receive
+   * or connect operations will be cancelled immediately, and will complete
+   * with the boost::asio::error::operation_aborted error.
+   *
+   * @throws boost::system::system_error Thrown on failure. Note that, even if
+   * the function indicates an error, the underlying descriptor is closed.
+   *
+   * @note For portable behaviour with respect to graceful closure of a
+   * connected socket, call shutdown() before closing the socket.
+   */
+  void close()
+  {
+    boost::system::error_code ec;
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "close");
+  }
+
+  /// Close the socket.
+  /**
+   * This function is used to close the socket. Any asynchronous send, receive
+   * or connect operations will be cancelled immediately, and will complete
+   * with the boost::asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any. Note that, even if
+   * the function indicates an error, the underlying descriptor is closed.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * socket.close(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   *
+   * @note For portable behaviour with respect to graceful closure of a
+   * connected socket, call shutdown() before closing the socket.
+   */
+  BOOST_ASIO_SYNC_OP_VOID close(boost::system::error_code& ec)
+  {
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Release ownership of the underlying native socket.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error. Ownership
+   * of the native socket is then transferred to the caller.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note This function is unsupported on Windows versions prior to Windows
+   * 8.1, and will fail with boost::asio::error::operation_not_supported on
+   * these platforms.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0603)
+  __declspec(deprecated("This function always fails with "
+        "operation_not_supported when used on Windows versions "
+        "prior to Windows 8.1."))
+#endif
+  native_handle_type release()
+  {
+    boost::system::error_code ec;
+    native_handle_type s = impl_.get_service().release(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "release");
+    return s;
+  }
+
+  /// Release ownership of the underlying native socket.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error. Ownership
+   * of the native socket is then transferred to the caller.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note This function is unsupported on Windows versions prior to Windows
+   * 8.1, and will fail with boost::asio::error::operation_not_supported on
+   * these platforms.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0603)
+  __declspec(deprecated("This function always fails with "
+        "operation_not_supported when used on Windows versions "
+        "prior to Windows 8.1."))
+#endif
+  native_handle_type release(boost::system::error_code& ec)
+  {
+    return impl_.get_service().release(impl_.get_implementation(), ec);
+  }
+
+  /// Get the native socket representation.
+  /**
+   * This function may be used to obtain the underlying representation of the
+   * socket. This is intended to allow access to native socket functionality
+   * that is not otherwise provided.
+   */
+  native_handle_type native_handle()
+  {
+    return impl_.get_service().native_handle(impl_.get_implementation());
+  }
+
+  /// Cancel all asynchronous operations associated with the socket.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note Calls to cancel() will always fail with
+   * boost::asio::error::operation_not_supported when run on Windows XP, Windows
+   * Server 2003, and earlier versions of Windows, unless
+   * BOOST_ASIO_ENABLE_CANCELIO is defined. However, the CancelIo function has
+   * two issues that should be considered before enabling its use:
+   *
+   * @li It will only cancel asynchronous operations that were initiated in the
+   * current thread.
+   *
+   * @li It can appear to complete without error, but the request to cancel the
+   * unfinished operations may be silently ignored by the operating system.
+   * Whether it works or not seems to depend on the drivers that are installed.
+   *
+   * For portable cancellation, consider using one of the following
+   * alternatives:
+   *
+   * @li Disable asio's I/O completion port backend by defining
+   * BOOST_ASIO_DISABLE_IOCP.
+   *
+   * @li Use the close() function to simultaneously cancel the outstanding
+   * operations and close the socket.
+   *
+   * When running on Windows Vista, Windows Server 2008, and later, the
+   * CancelIoEx function is always used. This function does not have the
+   * problems described above.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0600) \
+  && !defined(BOOST_ASIO_ENABLE_CANCELIO)
+  __declspec(deprecated("By default, this function always fails with "
+        "operation_not_supported when used on Windows XP, Windows Server 2003, "
+        "or earlier. Consult documentation for details."))
+#endif
+  void cancel()
+  {
+    boost::system::error_code ec;
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "cancel");
+  }
+
+  /// Cancel all asynchronous operations associated with the socket.
+  /**
+   * This function causes all outstanding asynchronous connect, send and receive
+   * operations to finish immediately, and the handlers for cancelled operations
+   * will be passed the boost::asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note Calls to cancel() will always fail with
+   * boost::asio::error::operation_not_supported when run on Windows XP, Windows
+   * Server 2003, and earlier versions of Windows, unless
+   * BOOST_ASIO_ENABLE_CANCELIO is defined. However, the CancelIo function has
+   * two issues that should be considered before enabling its use:
+   *
+   * @li It will only cancel asynchronous operations that were initiated in the
+   * current thread.
+   *
+   * @li It can appear to complete without error, but the request to cancel the
+   * unfinished operations may be silently ignored by the operating system.
+   * Whether it works or not seems to depend on the drivers that are installed.
+   *
+   * For portable cancellation, consider using one of the following
+   * alternatives:
+   *
+   * @li Disable asio's I/O completion port backend by defining
+   * BOOST_ASIO_DISABLE_IOCP.
+   *
+   * @li Use the close() function to simultaneously cancel the outstanding
+   * operations and close the socket.
+   *
+   * When running on Windows Vista, Windows Server 2008, and later, the
+   * CancelIoEx function is always used. This function does not have the
+   * problems described above.
+   */
+#if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0600) \
+  && !defined(BOOST_ASIO_ENABLE_CANCELIO)
+  __declspec(deprecated("By default, this function always fails with "
+        "operation_not_supported when used on Windows XP, Windows Server 2003, "
+        "or earlier. Consult documentation for details."))
+#endif
+  BOOST_ASIO_SYNC_OP_VOID cancel(boost::system::error_code& ec)
+  {
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the socket is at the out-of-band data mark.
+  /**
+   * This function is used to check whether the socket input is currently
+   * positioned at the out-of-band data mark.
+   *
+   * @return A bool indicating whether the socket is at the out-of-band data
+   * mark.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  bool at_mark() const
+  {
+    boost::system::error_code ec;
+    bool b = impl_.get_service().at_mark(impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "at_mark");
+    return b;
+  }
+
+  /// Determine whether the socket is at the out-of-band data mark.
+  /**
+   * This function is used to check whether the socket input is currently
+   * positioned at the out-of-band data mark.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return A bool indicating whether the socket is at the out-of-band data
+   * mark.
+   */
+  bool at_mark(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().at_mark(impl_.get_implementation(), ec);
+  }
+
+  /// Determine the number of bytes available for reading.
+  /**
+   * This function is used to determine the number of bytes that may be read
+   * without blocking.
+   *
+   * @return The number of bytes that may be read without blocking, or 0 if an
+   * error occurs.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  std::size_t available() const
+  {
+    boost::system::error_code ec;
+    std::size_t s = impl_.get_service().available(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "available");
+    return s;
+  }
+
+  /// Determine the number of bytes available for reading.
+  /**
+   * This function is used to determine the number of bytes that may be read
+   * without blocking.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of bytes that may be read without blocking, or 0 if an
+   * error occurs.
+   */
+  std::size_t available(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().available(impl_.get_implementation(), ec);
+  }
+
+  /// Bind the socket to the given local endpoint.
+  /**
+   * This function binds the socket to the specified endpoint on the local
+   * machine.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket will
+   * be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * socket.open(boost::asio::ip::tcp::v4());
+   * socket.bind(boost::asio::ip::tcp::endpoint(
+   *       boost::asio::ip::tcp::v4(), 12345));
+   * @endcode
+   */
+  void bind(const endpoint_type& endpoint)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    boost::asio::detail::throw_error(ec, "bind");
+  }
+
+  /// Bind the socket to the given local endpoint.
+  /**
+   * This function binds the socket to the specified endpoint on the local
+   * machine.
+   *
+   * @param endpoint An endpoint on the local machine to which the socket will
+   * be bound.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * socket.open(boost::asio::ip::tcp::v4());
+   * boost::system::error_code ec;
+   * socket.bind(boost::asio::ip::tcp::endpoint(
+   *       boost::asio::ip::tcp::v4(), 12345), ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID bind(const endpoint_type& endpoint,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().bind(impl_.get_implementation(), endpoint, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Connect the socket to the specified endpoint.
+  /**
+   * This function is used to connect a socket to the specified remote endpoint.
+   * The function call will block until the connection is successfully made or
+   * an error occurs.
+   *
+   * The socket is automatically opened if it is not already open. If the
+   * connect fails, and the socket was automatically opened, the socket is
+   * not returned to the closed state.
+   *
+   * @param peer_endpoint The remote endpoint to which the socket will be
+   * connected.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint(
+   *     boost::asio::ip::address::from_string("1.2.3.4"), 12345);
+   * socket.connect(endpoint);
+   * @endcode
+   */
+  void connect(const endpoint_type& peer_endpoint)
+  {
+    boost::system::error_code ec;
+    if (!is_open())
+    {
+      impl_.get_service().open(impl_.get_implementation(),
+          peer_endpoint.protocol(), ec);
+      boost::asio::detail::throw_error(ec, "connect");
+    }
+    impl_.get_service().connect(impl_.get_implementation(), peer_endpoint, ec);
+    boost::asio::detail::throw_error(ec, "connect");
+  }
+
+  /// Connect the socket to the specified endpoint.
+  /**
+   * This function is used to connect a socket to the specified remote endpoint.
+   * The function call will block until the connection is successfully made or
+   * an error occurs.
+   *
+   * The socket is automatically opened if it is not already open. If the
+   * connect fails, and the socket was automatically opened, the socket is
+   * not returned to the closed state.
+   *
+   * @param peer_endpoint The remote endpoint to which the socket will be
+   * connected.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint(
+   *     boost::asio::ip::address::from_string("1.2.3.4"), 12345);
+   * boost::system::error_code ec;
+   * socket.connect(endpoint, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID connect(const endpoint_type& peer_endpoint,
+      boost::system::error_code& ec)
+  {
+    if (!is_open())
+    {
+      impl_.get_service().open(impl_.get_implementation(),
+            peer_endpoint.protocol(), ec);
+      if (ec)
+      {
+        BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+      }
+    }
+
+    impl_.get_service().connect(impl_.get_implementation(), peer_endpoint, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Start an asynchronous connect.
+  /**
+   * This function is used to asynchronously connect a socket to the specified
+   * remote endpoint. The function call always returns immediately.
+   *
+   * The socket is automatically opened if it is not already open. If the
+   * connect fails, and the socket was automatically opened, the socket is
+   * not returned to the closed state.
+   *
+   * @param peer_endpoint The remote endpoint to which the socket will be
+   * connected. Copies will be made of the endpoint object as required.
+   *
+   * @param handler The handler to be called when the connection operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error // Result of operation
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void connect_handler(const boost::system::error_code& error)
+   * {
+   *   if (!error)
+   *   {
+   *     // Connect succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * boost::asio::ip::tcp::endpoint endpoint(
+   *     boost::asio::ip::address::from_string("1.2.3.4"), 12345);
+   * socket.async_connect(endpoint, connect_handler);
+   * @endcode
+   */
+  template <typename ConnectHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ConnectHandler,
+      void (boost::system::error_code))
+  async_connect(const endpoint_type& peer_endpoint,
+      BOOST_ASIO_MOVE_ARG(ConnectHandler) handler)
+  {
+    boost::system::error_code open_ec;
+    if (!is_open())
+    {
+      const protocol_type protocol = peer_endpoint.protocol();
+      impl_.get_service().open(impl_.get_implementation(), protocol, open_ec);
+    }
+
+    return async_initiate<ConnectHandler, void (boost::system::error_code)>(
+        initiate_async_connect(), handler, this, peer_endpoint, open_ec);
+  }
+
+  /// Set an option on the socket.
+  /**
+   * This function is used to set an option on the socket.
+   *
+   * @param option The new option value to be set on the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa SettableSocketOption @n
+   * boost::asio::socket_base::broadcast @n
+   * boost::asio::socket_base::do_not_route @n
+   * boost::asio::socket_base::keep_alive @n
+   * boost::asio::socket_base::linger @n
+   * boost::asio::socket_base::receive_buffer_size @n
+   * boost::asio::socket_base::receive_low_watermark @n
+   * boost::asio::socket_base::reuse_address @n
+   * boost::asio::socket_base::send_buffer_size @n
+   * boost::asio::socket_base::send_low_watermark @n
+   * boost::asio::ip::multicast::join_group @n
+   * boost::asio::ip::multicast::leave_group @n
+   * boost::asio::ip::multicast::enable_loopback @n
+   * boost::asio::ip::multicast::outbound_interface @n
+   * boost::asio::ip::multicast::hops @n
+   * boost::asio::ip::tcp::no_delay
+   *
+   * @par Example
+   * Setting the IPPROTO_TCP/TCP_NODELAY option:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::no_delay option(true);
+   * socket.set_option(option);
+   * @endcode
+   */
+  template <typename SettableSocketOption>
+  void set_option(const SettableSocketOption& option)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().set_option(impl_.get_implementation(), option, ec);
+    boost::asio::detail::throw_error(ec, "set_option");
+  }
+
+  /// Set an option on the socket.
+  /**
+   * This function is used to set an option on the socket.
+   *
+   * @param option The new option value to be set on the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa SettableSocketOption @n
+   * boost::asio::socket_base::broadcast @n
+   * boost::asio::socket_base::do_not_route @n
+   * boost::asio::socket_base::keep_alive @n
+   * boost::asio::socket_base::linger @n
+   * boost::asio::socket_base::receive_buffer_size @n
+   * boost::asio::socket_base::receive_low_watermark @n
+   * boost::asio::socket_base::reuse_address @n
+   * boost::asio::socket_base::send_buffer_size @n
+   * boost::asio::socket_base::send_low_watermark @n
+   * boost::asio::ip::multicast::join_group @n
+   * boost::asio::ip::multicast::leave_group @n
+   * boost::asio::ip::multicast::enable_loopback @n
+   * boost::asio::ip::multicast::outbound_interface @n
+   * boost::asio::ip::multicast::hops @n
+   * boost::asio::ip::tcp::no_delay
+   *
+   * @par Example
+   * Setting the IPPROTO_TCP/TCP_NODELAY option:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::no_delay option(true);
+   * boost::system::error_code ec;
+   * socket.set_option(option, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  template <typename SettableSocketOption>
+  BOOST_ASIO_SYNC_OP_VOID set_option(const SettableSocketOption& option,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().set_option(impl_.get_implementation(), option, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get an option from the socket.
+  /**
+   * This function is used to get the current value of an option on the socket.
+   *
+   * @param option The option value to be obtained from the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa GettableSocketOption @n
+   * boost::asio::socket_base::broadcast @n
+   * boost::asio::socket_base::do_not_route @n
+   * boost::asio::socket_base::keep_alive @n
+   * boost::asio::socket_base::linger @n
+   * boost::asio::socket_base::receive_buffer_size @n
+   * boost::asio::socket_base::receive_low_watermark @n
+   * boost::asio::socket_base::reuse_address @n
+   * boost::asio::socket_base::send_buffer_size @n
+   * boost::asio::socket_base::send_low_watermark @n
+   * boost::asio::ip::multicast::join_group @n
+   * boost::asio::ip::multicast::leave_group @n
+   * boost::asio::ip::multicast::enable_loopback @n
+   * boost::asio::ip::multicast::outbound_interface @n
+   * boost::asio::ip::multicast::hops @n
+   * boost::asio::ip::tcp::no_delay
+   *
+   * @par Example
+   * Getting the value of the SOL_SOCKET/SO_KEEPALIVE option:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket::keep_alive option;
+   * socket.get_option(option);
+   * bool is_set = option.value();
+   * @endcode
+   */
+  template <typename GettableSocketOption>
+  void get_option(GettableSocketOption& option) const
+  {
+    boost::system::error_code ec;
+    impl_.get_service().get_option(impl_.get_implementation(), option, ec);
+    boost::asio::detail::throw_error(ec, "get_option");
+  }
+
+  /// Get an option from the socket.
+  /**
+   * This function is used to get the current value of an option on the socket.
+   *
+   * @param option The option value to be obtained from the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa GettableSocketOption @n
+   * boost::asio::socket_base::broadcast @n
+   * boost::asio::socket_base::do_not_route @n
+   * boost::asio::socket_base::keep_alive @n
+   * boost::asio::socket_base::linger @n
+   * boost::asio::socket_base::receive_buffer_size @n
+   * boost::asio::socket_base::receive_low_watermark @n
+   * boost::asio::socket_base::reuse_address @n
+   * boost::asio::socket_base::send_buffer_size @n
+   * boost::asio::socket_base::send_low_watermark @n
+   * boost::asio::ip::multicast::join_group @n
+   * boost::asio::ip::multicast::leave_group @n
+   * boost::asio::ip::multicast::enable_loopback @n
+   * boost::asio::ip::multicast::outbound_interface @n
+   * boost::asio::ip::multicast::hops @n
+   * boost::asio::ip::tcp::no_delay
+   *
+   * @par Example
+   * Getting the value of the SOL_SOCKET/SO_KEEPALIVE option:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket::keep_alive option;
+   * boost::system::error_code ec;
+   * socket.get_option(option, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * bool is_set = option.value();
+   * @endcode
+   */
+  template <typename GettableSocketOption>
+  BOOST_ASIO_SYNC_OP_VOID get_option(GettableSocketOption& option,
+      boost::system::error_code& ec) const
+  {
+    impl_.get_service().get_option(impl_.get_implementation(), option, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Perform an IO control command on the socket.
+  /**
+   * This function is used to execute an IO control command on the socket.
+   *
+   * @param command The IO control command to be performed on the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @sa IoControlCommand @n
+   * boost::asio::socket_base::bytes_readable @n
+   * boost::asio::socket_base::non_blocking_io
+   *
+   * @par Example
+   * Getting the number of bytes ready to read:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket::bytes_readable command;
+   * socket.io_control(command);
+   * std::size_t bytes_readable = command.get();
+   * @endcode
+   */
+  template <typename IoControlCommand>
+  void io_control(IoControlCommand& command)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().io_control(impl_.get_implementation(), command, ec);
+    boost::asio::detail::throw_error(ec, "io_control");
+  }
+
+  /// Perform an IO control command on the socket.
+  /**
+   * This function is used to execute an IO control command on the socket.
+   *
+   * @param command The IO control command to be performed on the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa IoControlCommand @n
+   * boost::asio::socket_base::bytes_readable @n
+   * boost::asio::socket_base::non_blocking_io
+   *
+   * @par Example
+   * Getting the number of bytes ready to read:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::socket::bytes_readable command;
+   * boost::system::error_code ec;
+   * socket.io_control(command, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * std::size_t bytes_readable = command.get();
+   * @endcode
+   */
+  template <typename IoControlCommand>
+  BOOST_ASIO_SYNC_OP_VOID io_control(IoControlCommand& command,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().io_control(impl_.get_implementation(), command, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Gets the non-blocking mode of the socket.
+  /**
+   * @returns @c true if the socket's synchronous operations will fail with
+   * boost::asio::error::would_block if they are unable to perform the requested
+   * operation immediately. If @c false, synchronous operations will block
+   * until complete.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  bool non_blocking() const
+  {
+    return impl_.get_service().non_blocking(impl_.get_implementation());
+  }
+
+  /// Sets the non-blocking mode of the socket.
+  /**
+   * @param mode If @c true, the socket's synchronous operations will fail with
+   * boost::asio::error::would_block if they are unable to perform the requested
+   * operation immediately. If @c false, synchronous operations will block
+   * until complete.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  void non_blocking(bool mode)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().non_blocking(impl_.get_implementation(), mode, ec);
+    boost::asio::detail::throw_error(ec, "non_blocking");
+  }
+
+  /// Sets the non-blocking mode of the socket.
+  /**
+   * @param mode If @c true, the socket's synchronous operations will fail with
+   * boost::asio::error::would_block if they are unable to perform the requested
+   * operation immediately. If @c false, synchronous operations will block
+   * until complete.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note The non-blocking mode has no effect on the behaviour of asynchronous
+   * operations. Asynchronous operations will never fail with the error
+   * boost::asio::error::would_block.
+   */
+  BOOST_ASIO_SYNC_OP_VOID non_blocking(
+      bool mode, boost::system::error_code& ec)
+  {
+    impl_.get_service().non_blocking(impl_.get_implementation(), mode, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Gets the non-blocking mode of the native socket implementation.
+  /**
+   * This function is used to retrieve the non-blocking mode of the underlying
+   * native socket. This mode has no effect on the behaviour of the socket
+   * object's synchronous operations.
+   *
+   * @returns @c true if the underlying socket is in non-blocking mode and
+   * direct system calls may fail with boost::asio::error::would_block (or the
+   * equivalent system error).
+   *
+   * @note The current non-blocking mode is cached by the socket object.
+   * Consequently, the return value may be incorrect if the non-blocking mode
+   * was set directly on the native socket.
+   *
+   * @par Example
+   * This function is intended to allow the encapsulation of arbitrary
+   * non-blocking system calls as asynchronous operations, in a way that is
+   * transparent to the user of the socket object. The following example
+   * illustrates how Linux's @c sendfile system call might be encapsulated:
+   * @code template <typename Handler>
+   * struct sendfile_op
+   * {
+   *   tcp::socket& sock_;
+   *   int fd_;
+   *   Handler handler_;
+   *   off_t offset_;
+   *   std::size_t total_bytes_transferred_;
+   *
+   *   // Function call operator meeting WriteHandler requirements.
+   *   // Used as the handler for the async_write_some operation.
+   *   void operator()(boost::system::error_code ec, std::size_t)
+   *   {
+   *     // Put the underlying socket into non-blocking mode.
+   *     if (!ec)
+   *       if (!sock_.native_non_blocking())
+   *         sock_.native_non_blocking(true, ec);
+   *
+   *     if (!ec)
+   *     {
+   *       for (;;)
+   *       {
+   *         // Try the system call.
+   *         errno = 0;
+   *         int n = ::sendfile(sock_.native_handle(), fd_, &offset_, 65536);
+   *         ec = boost::system::error_code(n < 0 ? errno : 0,
+   *             boost::asio::error::get_system_category());
+   *         total_bytes_transferred_ += ec ? 0 : n;
+   *
+   *         // Retry operation immediately if interrupted by signal.
+   *         if (ec == boost::asio::error::interrupted)
+   *           continue;
+   *
+   *         // Check if we need to run the operation again.
+   *         if (ec == boost::asio::error::would_block
+   *             || ec == boost::asio::error::try_again)
+   *         {
+   *           // We have to wait for the socket to become ready again.
+   *           sock_.async_wait(tcp::socket::wait_write, *this);
+   *           return;
+   *         }
+   *
+   *         if (ec || n == 0)
+   *         {
+   *           // An error occurred, or we have reached the end of the file.
+   *           // Either way we must exit the loop so we can call the handler.
+   *           break;
+   *         }
+   *
+   *         // Loop around to try calling sendfile again.
+   *       }
+   *     }
+   *
+   *     // Pass result back to user's handler.
+   *     handler_(ec, total_bytes_transferred_);
+   *   }
+   * };
+   *
+   * template <typename Handler>
+   * void async_sendfile(tcp::socket& sock, int fd, Handler h)
+   * {
+   *   sendfile_op<Handler> op = { sock, fd, h, 0, 0 };
+   *   sock.async_wait(tcp::socket::wait_write, op);
+   * } @endcode
+   */
+  bool native_non_blocking() const
+  {
+    return impl_.get_service().native_non_blocking(impl_.get_implementation());
+  }
+
+  /// Sets the non-blocking mode of the native socket implementation.
+  /**
+   * This function is used to modify the non-blocking mode of the underlying
+   * native socket. It has no effect on the behaviour of the socket object's
+   * synchronous operations.
+   *
+   * @param mode If @c true, the underlying socket is put into non-blocking
+   * mode and direct system calls may fail with boost::asio::error::would_block
+   * (or the equivalent system error).
+   *
+   * @throws boost::system::system_error Thrown on failure. If the @c mode is
+   * @c false, but the current value of @c non_blocking() is @c true, this
+   * function fails with boost::asio::error::invalid_argument, as the
+   * combination does not make sense.
+   *
+   * @par Example
+   * This function is intended to allow the encapsulation of arbitrary
+   * non-blocking system calls as asynchronous operations, in a way that is
+   * transparent to the user of the socket object. The following example
+   * illustrates how Linux's @c sendfile system call might be encapsulated:
+   * @code template <typename Handler>
+   * struct sendfile_op
+   * {
+   *   tcp::socket& sock_;
+   *   int fd_;
+   *   Handler handler_;
+   *   off_t offset_;
+   *   std::size_t total_bytes_transferred_;
+   *
+   *   // Function call operator meeting WriteHandler requirements.
+   *   // Used as the handler for the async_write_some operation.
+   *   void operator()(boost::system::error_code ec, std::size_t)
+   *   {
+   *     // Put the underlying socket into non-blocking mode.
+   *     if (!ec)
+   *       if (!sock_.native_non_blocking())
+   *         sock_.native_non_blocking(true, ec);
+   *
+   *     if (!ec)
+   *     {
+   *       for (;;)
+   *       {
+   *         // Try the system call.
+   *         errno = 0;
+   *         int n = ::sendfile(sock_.native_handle(), fd_, &offset_, 65536);
+   *         ec = boost::system::error_code(n < 0 ? errno : 0,
+   *             boost::asio::error::get_system_category());
+   *         total_bytes_transferred_ += ec ? 0 : n;
+   *
+   *         // Retry operation immediately if interrupted by signal.
+   *         if (ec == boost::asio::error::interrupted)
+   *           continue;
+   *
+   *         // Check if we need to run the operation again.
+   *         if (ec == boost::asio::error::would_block
+   *             || ec == boost::asio::error::try_again)
+   *         {
+   *           // We have to wait for the socket to become ready again.
+   *           sock_.async_wait(tcp::socket::wait_write, *this);
+   *           return;
+   *         }
+   *
+   *         if (ec || n == 0)
+   *         {
+   *           // An error occurred, or we have reached the end of the file.
+   *           // Either way we must exit the loop so we can call the handler.
+   *           break;
+   *         }
+   *
+   *         // Loop around to try calling sendfile again.
+   *       }
+   *     }
+   *
+   *     // Pass result back to user's handler.
+   *     handler_(ec, total_bytes_transferred_);
+   *   }
+   * };
+   *
+   * template <typename Handler>
+   * void async_sendfile(tcp::socket& sock, int fd, Handler h)
+   * {
+   *   sendfile_op<Handler> op = { sock, fd, h, 0, 0 };
+   *   sock.async_wait(tcp::socket::wait_write, op);
+   * } @endcode
+   */
+  void native_non_blocking(bool mode)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().native_non_blocking(
+        impl_.get_implementation(), mode, ec);
+    boost::asio::detail::throw_error(ec, "native_non_blocking");
+  }
+
+  /// Sets the non-blocking mode of the native socket implementation.
+  /**
+   * This function is used to modify the non-blocking mode of the underlying
+   * native socket. It has no effect on the behaviour of the socket object's
+   * synchronous operations.
+   *
+   * @param mode If @c true, the underlying socket is put into non-blocking
+   * mode and direct system calls may fail with boost::asio::error::would_block
+   * (or the equivalent system error).
+   *
+   * @param ec Set to indicate what error occurred, if any. If the @c mode is
+   * @c false, but the current value of @c non_blocking() is @c true, this
+   * function fails with boost::asio::error::invalid_argument, as the
+   * combination does not make sense.
+   *
+   * @par Example
+   * This function is intended to allow the encapsulation of arbitrary
+   * non-blocking system calls as asynchronous operations, in a way that is
+   * transparent to the user of the socket object. The following example
+   * illustrates how Linux's @c sendfile system call might be encapsulated:
+   * @code template <typename Handler>
+   * struct sendfile_op
+   * {
+   *   tcp::socket& sock_;
+   *   int fd_;
+   *   Handler handler_;
+   *   off_t offset_;
+   *   std::size_t total_bytes_transferred_;
+   *
+   *   // Function call operator meeting WriteHandler requirements.
+   *   // Used as the handler for the async_write_some operation.
+   *   void operator()(boost::system::error_code ec, std::size_t)
+   *   {
+   *     // Put the underlying socket into non-blocking mode.
+   *     if (!ec)
+   *       if (!sock_.native_non_blocking())
+   *         sock_.native_non_blocking(true, ec);
+   *
+   *     if (!ec)
+   *     {
+   *       for (;;)
+   *       {
+   *         // Try the system call.
+   *         errno = 0;
+   *         int n = ::sendfile(sock_.native_handle(), fd_, &offset_, 65536);
+   *         ec = boost::system::error_code(n < 0 ? errno : 0,
+   *             boost::asio::error::get_system_category());
+   *         total_bytes_transferred_ += ec ? 0 : n;
+   *
+   *         // Retry operation immediately if interrupted by signal.
+   *         if (ec == boost::asio::error::interrupted)
+   *           continue;
+   *
+   *         // Check if we need to run the operation again.
+   *         if (ec == boost::asio::error::would_block
+   *             || ec == boost::asio::error::try_again)
+   *         {
+   *           // We have to wait for the socket to become ready again.
+   *           sock_.async_wait(tcp::socket::wait_write, *this);
+   *           return;
+   *         }
+   *
+   *         if (ec || n == 0)
+   *         {
+   *           // An error occurred, or we have reached the end of the file.
+   *           // Either way we must exit the loop so we can call the handler.
+   *           break;
+   *         }
+   *
+   *         // Loop around to try calling sendfile again.
+   *       }
+   *     }
+   *
+   *     // Pass result back to user's handler.
+   *     handler_(ec, total_bytes_transferred_);
+   *   }
+   * };
+   *
+   * template <typename Handler>
+   * void async_sendfile(tcp::socket& sock, int fd, Handler h)
+   * {
+   *   sendfile_op<Handler> op = { sock, fd, h, 0, 0 };
+   *   sock.async_wait(tcp::socket::wait_write, op);
+   * } @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID native_non_blocking(
+      bool mode, boost::system::error_code& ec)
+  {
+    impl_.get_service().native_non_blocking(
+        impl_.get_implementation(), mode, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get the local endpoint of the socket.
+  /**
+   * This function is used to obtain the locally bound endpoint of the socket.
+   *
+   * @returns An object that represents the local endpoint of the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint = socket.local_endpoint();
+   * @endcode
+   */
+  endpoint_type local_endpoint() const
+  {
+    boost::system::error_code ec;
+    endpoint_type ep = impl_.get_service().local_endpoint(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "local_endpoint");
+    return ep;
+  }
+
+  /// Get the local endpoint of the socket.
+  /**
+   * This function is used to obtain the locally bound endpoint of the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns An object that represents the local endpoint of the socket.
+   * Returns a default-constructed endpoint object if an error occurred.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * boost::asio::ip::tcp::endpoint endpoint = socket.local_endpoint(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  endpoint_type local_endpoint(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().local_endpoint(impl_.get_implementation(), ec);
+  }
+
+  /// Get the remote endpoint of the socket.
+  /**
+   * This function is used to obtain the remote endpoint of the socket.
+   *
+   * @returns An object that represents the remote endpoint of the socket.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::asio::ip::tcp::endpoint endpoint = socket.remote_endpoint();
+   * @endcode
+   */
+  endpoint_type remote_endpoint() const
+  {
+    boost::system::error_code ec;
+    endpoint_type ep = impl_.get_service().remote_endpoint(
+        impl_.get_implementation(), ec);
+    boost::asio::detail::throw_error(ec, "remote_endpoint");
+    return ep;
+  }
+
+  /// Get the remote endpoint of the socket.
+  /**
+   * This function is used to obtain the remote endpoint of the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns An object that represents the remote endpoint of the socket.
+   * Returns a default-constructed endpoint object if an error occurred.
+   *
+   * @par Example
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * boost::asio::ip::tcp::endpoint endpoint = socket.remote_endpoint(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  endpoint_type remote_endpoint(boost::system::error_code& ec) const
+  {
+    return impl_.get_service().remote_endpoint(impl_.get_implementation(), ec);
+  }
+
+  /// Disable sends or receives on the socket.
+  /**
+   * This function is used to disable send operations, receive operations, or
+   * both.
+   *
+   * @param what Determines what types of operation will no longer be allowed.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @par Example
+   * Shutting down the send side of the socket:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * socket.shutdown(boost::asio::ip::tcp::socket::shutdown_send);
+   * @endcode
+   */
+  void shutdown(shutdown_type what)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().shutdown(impl_.get_implementation(), what, ec);
+    boost::asio::detail::throw_error(ec, "shutdown");
+  }
+
+  /// Disable sends or receives on the socket.
+  /**
+   * This function is used to disable send operations, receive operations, or
+   * both.
+   *
+   * @param what Determines what types of operation will no longer be allowed.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * Shutting down the send side of the socket:
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * socket.shutdown(boost::asio::ip::tcp::socket::shutdown_send, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID shutdown(shutdown_type what,
+      boost::system::error_code& ec)
+  {
+    impl_.get_service().shutdown(impl_.get_implementation(), what, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Wait for the socket to become ready to read, ready to write, or to have
+  /// pending error conditions.
+  /**
+   * This function is used to perform a blocking wait for a socket to enter
+   * a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired socket state.
+   *
+   * @par Example
+   * Waiting for a socket to become readable.
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * socket.wait(boost::asio::ip::tcp::socket::wait_read);
+   * @endcode
+   */
+  void wait(wait_type w)
+  {
+    boost::system::error_code ec;
+    impl_.get_service().wait(impl_.get_implementation(), w, ec);
+    boost::asio::detail::throw_error(ec, "wait");
+  }
+
+  /// Wait for the socket to become ready to read, ready to write, or to have
+  /// pending error conditions.
+  /**
+   * This function is used to perform a blocking wait for a socket to enter
+   * a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired socket state.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * Waiting for a socket to become readable.
+   * @code
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * boost::system::error_code ec;
+   * socket.wait(boost::asio::ip::tcp::socket::wait_read, ec);
+   * @endcode
+   */
+  BOOST_ASIO_SYNC_OP_VOID wait(wait_type w, boost::system::error_code& ec)
+  {
+    impl_.get_service().wait(impl_.get_implementation(), w, ec);
+    BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Asynchronously wait for the socket to become ready to read, ready to
+  /// write, or to have pending error conditions.
+  /**
+   * This function is used to perform an asynchronous wait for a socket to enter
+   * a ready to read, write or error condition state.
+   *
+   * @param w Specifies the desired socket state.
+   *
+   * @param handler The handler to be called when the wait operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error // Result of operation
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @par Example
+   * @code
+   * void wait_handler(const boost::system::error_code& error)
+   * {
+   *   if (!error)
+   *   {
+   *     // Wait succeeded.
+   *   }
+   * }
+   *
+   * ...
+   *
+   * boost::asio::ip::tcp::socket socket(my_context);
+   * ...
+   * socket.async_wait(boost::asio::ip::tcp::socket::wait_read, wait_handler);
+   * @endcode
+   */
+  template <typename WaitHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WaitHandler,
+      void (boost::system::error_code))
+  async_wait(wait_type w, BOOST_ASIO_MOVE_ARG(WaitHandler) handler)
+  {
+    return async_initiate<WaitHandler, void (boost::system::error_code)>(
+        initiate_async_wait(), handler, this, w);
+  }
+
+protected:
+  /// Protected destructor to prevent deletion through this type.
+  /**
+   * This function destroys the socket, cancelling any outstanding asynchronous
+   * operations associated with the socket as if by calling @c cancel.
+   */
+  ~basic_socket_ext_local()
+  {
+  }
+
+#if defined(BOOST_ASIO_WINDOWS_RUNTIME)
+  detail::io_object_impl<
+    detail::null_socket_service<Protocol>, Executor> impl_;
+#elif defined(BOOST_ASIO_HAS_IOCP)
+  detail::io_object_impl<
+    detail::win_iocp_socket_service<Protocol>, Executor> impl_;
+#else
+  detail::io_object_impl<
+    detail::reactive_socket_service_ext_local<Protocol>, Executor> impl_;
+#endif
+
+private:
+  // Disallow copying and assignment.
+  basic_socket_ext_local(const basic_socket_ext_local&) BOOST_ASIO_DELETED;
+  basic_socket_ext_local& operator=(const basic_socket_ext_local&) BOOST_ASIO_DELETED;
+
+  struct initiate_async_connect
+  {
+    template <typename ConnectHandler>
+    void operator()(BOOST_ASIO_MOVE_ARG(ConnectHandler) handler,
+        basic_socket_ext_local* self, const endpoint_type& peer_endpoint,
+        const boost::system::error_code& open_ec) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ConnectHandler.
+      BOOST_ASIO_CONNECT_HANDLER_CHECK(ConnectHandler, handler) type_check;
+
+      if (open_ec)
+      {
+          boost::asio::post(self->impl_.get_executor(),
+              boost::asio::detail::bind_handler(
+                BOOST_ASIO_MOVE_CAST(ConnectHandler)(handler), open_ec));
+      }
+      else
+      {
+        detail::non_const_lvalue<ConnectHandler> handler2(handler);
+        self->impl_.get_service().async_connect(
+            self->impl_.get_implementation(), peer_endpoint,
+            handler2.value, self->impl_.get_implementation_executor());
+      }
+    }
+  };
+
+  struct initiate_async_wait
+  {
+    template <typename WaitHandler>
+    void operator()(BOOST_ASIO_MOVE_ARG(WaitHandler) handler,
+        basic_socket_ext_local* self, wait_type w) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WaitHandler.
+      BOOST_ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;
+
+      detail::non_const_lvalue<WaitHandler> handler2(handler);
+      self->impl_.get_service().async_wait(
+          self->impl_.get_implementation(), w, handler2.value,
+          self->impl_.get_implementation_executor());
+    }
+  };
+};
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_BASIC_SOCKET_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/basic_stream_socket_ext.hpp b/implementation/helper/1.76/boost/asio/basic_stream_socket_ext.hpp
new file mode 100644
index 0000000..e77f5eb
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/basic_stream_socket_ext.hpp
@@ -0,0 +1,996 @@
+//
+// basic_stream_socket_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_BASIC_STREAM_SOCKET_EXT_HPP
+#define BOOST_ASIO_BASIC_STREAM_SOCKET_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <cstddef>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/basic_socket_ext_local.hpp>
+#include <boost/asio/detail/handler_type_requirements_ext_local.hpp>
+#include <boost/asio/detail/non_const_lvalue.hpp>
+#include <boost/asio/detail/throw_error.hpp>
+#include <boost/asio/error.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+#if !defined(BOOST_ASIO_BASIC_STREAM_SOCKET_EXT_FWD_DECL)
+#define BOOST_ASIO_BASIC_STREAM_SOCKET_EXT_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Protocol, typename Executor = executor>
+class basic_stream_socket_ext;
+
+#endif // !defined(BOOST_ASIO_BASIC_STREAM_SOCKET_EXT_FWD_DECL)
+
+/// Provides stream-oriented socket functionality.
+/**
+ * The basic_stream_socket_ext class template provides asynchronous and blocking
+ * stream-oriented socket functionality.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Concepts:
+ * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream.
+ */
+template <typename Protocol, typename Executor>
+class basic_stream_socket_ext
+  : public basic_socket_ext_local<Protocol, Executor>
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the socket type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The socket type when rebound to the specified executor.
+    typedef basic_stream_socket_ext<Protocol, Executor1> other;
+  };
+
+  /// The native representation of a socket.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#else
+  typedef typename basic_socket<Protocol,
+    Executor>::native_handle_type native_handle_type;
+#endif
+
+  /// The protocol type.
+  typedef Protocol protocol_type;
+
+  /// The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+  /// Construct a basic_stream_socket without opening it.
+  /**
+   * This constructor creates a stream socket without opening it. The socket
+   * needs to be opened and then connected or accepted before data can be sent
+   * or received on it.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   */
+  explicit basic_stream_socket_ext(const executor_type& ex)
+    : basic_socket_ext_local<Protocol, Executor>(ex)
+  {
+  }
+
+  /// Construct a basic_stream_socket without opening it.
+  /**
+   * This constructor creates a stream socket without opening it. The socket
+   * needs to be opened and then connected or accepted before data can be sent
+   * or received on it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   */
+  template <typename ExecutionContext>
+  explicit basic_stream_socket_ext(ExecutionContext& context,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : basic_socket_ext_local<Protocol, Executor>(context)
+  {
+  }
+
+  /// Construct and open a basic_stream_socket.
+  /**
+   * This constructor creates and opens a stream socket. The socket needs to be
+   * connected or accepted before data can be sent or received on it.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_stream_socket_ext(const executor_type& ex, const protocol_type& protocol)
+    : basic_socket_ext_local<Protocol, Executor>(ex, protocol)
+  {
+  }
+
+  /// Construct and open a basic_stream_socket.
+  /**
+   * This constructor creates and opens a stream socket. The socket needs to be
+   * connected or accepted before data can be sent or received on it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_stream_socket_ext(ExecutionContext& context, const protocol_type& protocol,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : basic_socket_ext_local<Protocol, Executor>(context, protocol)
+  {
+  }
+
+  /// Construct a basic_stream_socket, opening it and binding it to the given
+  /// local endpoint.
+  /**
+   * This constructor creates a stream socket and automatically opens it bound
+   * to the specified endpoint on the local machine. The protocol used is the
+   * protocol associated with the given endpoint.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the stream
+   * socket will be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_stream_socket_ext(const executor_type& ex, const endpoint_type& endpoint)
+    : basic_socket_ext_local<Protocol, Executor>(ex, endpoint)
+  {
+  }
+
+  /// Construct a basic_stream_socket, opening it and binding it to the given
+  /// local endpoint.
+  /**
+   * This constructor creates a stream socket and automatically opens it bound
+   * to the specified endpoint on the local machine. The protocol used is the
+   * protocol associated with the given endpoint.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the stream
+   * socket will be bound.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_stream_socket_ext(ExecutionContext& context, const endpoint_type& endpoint,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : basic_socket_ext_local<Protocol, Executor>(context, endpoint)
+  {
+  }
+
+  /// Construct a basic_stream_socket on an existing native socket.
+  /**
+   * This constructor creates a stream socket object to hold an existing native
+   * socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket The new underlying socket implementation.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  basic_stream_socket_ext(const executor_type& ex,
+      const protocol_type& protocol, const native_handle_type& native_socket)
+    : basic_socket_ext_local<Protocol, Executor>(ex, protocol, native_socket)
+  {
+  }
+
+  /// Construct a basic_stream_socket on an existing native socket.
+  /**
+   * This constructor creates a stream socket object to hold an existing native
+   * socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket The new underlying socket implementation.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_stream_socket_ext(ExecutionContext& context,
+      const protocol_type& protocol, const native_handle_type& native_socket,
+      typename enable_if<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type* = 0)
+    : basic_socket_ext_local<Protocol, Executor>(context, protocol, native_socket)
+  {
+  }
+
+#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_stream_socket from another.
+  /**
+   * This constructor moves a stream socket from one object to another.
+   *
+   * @param other The other basic_stream_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_stream_socket(const executor_type&)
+   * constructor.
+   */
+  basic_stream_socket_ext(basic_stream_socket_ext&& other)
+    : basic_socket_ext_local<Protocol, Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_stream_socket from another.
+  /**
+   * This assignment operator moves a stream socket from one object to another.
+   *
+   * @param other The other basic_stream_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_stream_socket(const executor_type&)
+   * constructor.
+   */
+  basic_stream_socket_ext& operator=(basic_stream_socket_ext&& other)
+  {
+    basic_socket_ext_local<Protocol, Executor>::operator=(std::move(other));
+    return *this;
+  }
+
+  /// Move-construct a basic_stream_socket from a socket of another protocol
+  /// type.
+  /**
+   * This constructor moves a stream socket from one object to another.
+   *
+   * @param other The other basic_stream_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_stream_socket(const executor_type&)
+   * constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  basic_stream_socket_ext(basic_stream_socket_ext<Protocol1, Executor1>&& other,
+      typename enable_if<
+        is_convertible<Protocol1, Protocol>::value
+          && is_convertible<Executor1, Executor>::value
+      >::type* = 0)
+    : basic_socket_ext_local<Protocol, Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_stream_socket from a socket of another protocol type.
+  /**
+   * This assignment operator moves a stream socket from one object to another.
+   *
+   * @param other The other basic_stream_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_stream_socket(const executor_type&)
+   * constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  typename enable_if<
+    is_convertible<Protocol1, Protocol>::value
+      && is_convertible<Executor1, Executor>::value,
+    basic_stream_socket_ext&
+  >::type operator=(basic_stream_socket_ext<Protocol1, Executor1>&& other)
+  {
+    basic_socket_ext_local<Protocol, Executor>::operator=(std::move(other));
+    return *this;
+  }
+#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the socket.
+  /**
+   * This function destroys the socket, cancelling any outstanding asynchronous
+   * operations associated with the socket as if by calling @c cancel.
+   */
+  ~basic_stream_socket_ext()
+  {
+  }
+
+  /// Send some data on the socket.
+  /**
+   * This function is used to send data on the stream socket. The function
+   * call will block until one or more bytes of the data has been sent
+   * successfully, or an until error occurs.
+   *
+   * @param buffers One or more data buffers to be sent on the socket.
+   *
+   * @returns The number of bytes sent.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The send operation may not transmit all of the data to the peer.
+   * Consider using the @ref write function if you need to ensure that all data
+   * is written before the blocking operation completes.
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.send(boost::asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send(const ConstBufferSequence& buffers)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, 0, ec);
+    boost::asio::detail::throw_error(ec, "send");
+    return s;
+  }
+
+  /// Send some data on the socket.
+  /**
+   * This function is used to send data on the stream socket. The function
+   * call will block until one or more bytes of the data has been sent
+   * successfully, or an until error occurs.
+   *
+   * @param buffers One or more data buffers to be sent on the socket.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @returns The number of bytes sent.
+   *
+   * @throws boost::system::system_error Thrown on failure.
+   *
+   * @note The send operation may not transmit all of the data to the peer.
+   * Consider using the @ref write function if you need to ensure that all data
+   * is written before the blocking operation completes.
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.send(boost::asio::buffer(data, size), 0);
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, flags, ec);
+    boost::asio::detail::throw_error(ec, "send");
+    return s;
+  }
+
+  /// Send some data on the socket.
+  /**
+   * This function is used to send data on the stream socket. The function
+   * call will block until one or more bytes of the data has been sent
+   * successfully, or an until error occurs.
+   *
+   * @param buffers One or more data buffers to be sent on the socket.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes sent. Returns 0 if an error occurred.
+   *
+   * @note The send operation may not transmit all of the data to the peer.
+   * Consider using the @ref write function if you need to ensure that all data
+   * is written before the blocking operation completes.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags, boost::system::error_code& ec)
+  {
+    return this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, flags, ec);
+  }
+
+  /// Start an asynchronous send.
+  /**
+   * This function is used to asynchronously send data on the stream socket.
+   * The function call always returns immediately.
+   *
+   * @param buffers One or more data buffers to be sent on the socket. Although
+   * the buffers object may be copied as necessary, ownership of the underlying
+   * memory blocks is retained by the caller, which must guarantee that they
+   * remain valid until the handler is called.
+   *
+   * @param handler The handler to be called when the send operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes sent.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The send operation may not transmit all of the data to the peer.
+   * Consider using the @ref async_write function if you need to ensure that all
+   * data is written before the asynchronous operation completes.
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.async_send(boost::asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence, typename WriteHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
+      void (boost::system::error_code, std::size_t))
+  async_send(const ConstBufferSequence& buffers,
+      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
+  {
+    return async_initiate<WriteHandler,
+      void (boost::system::error_code, std::size_t)>(
+        initiate_async_send(), handler, this,
+        buffers, socket_base::message_flags(0));
+  }
+
+  /// Start an asynchronous send.
+  /**
+   * This function is used to asynchronously send data on the stream socket.
+   * The function call always returns immediately.
+   *
+   * @param buffers One or more data buffers to be sent on the socket. Although
+   * the buffers object may be copied as necessary, ownership of the underlying
+   * memory blocks is retained by the caller, which must guarantee that they
+   * remain valid until the handler is called.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @param handler The handler to be called when the send operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes sent.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The send operation may not transmit all of the data to the peer.
+   * Consider using the @ref async_write function if you need to ensure that all
+   * data is written before the asynchronous operation completes.
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.async_send(boost::asio::buffer(data, size), 0, handler);
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence, typename WriteHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
+      void (boost::system::error_code, std::size_t))
+  async_send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags,
+      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
+  {
+    return async_initiate<WriteHandler,
+      void (boost::system::error_code, std::size_t)>(
+        initiate_async_send(), handler, this, buffers, flags);
+  }
+
+  /// Receive some data on the socket.
+  /**
+   * This function is used to receive data on the stream socket. The function
+   * call will block until one or more bytes of data has been received
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @returns The number of bytes received.
+   *
+   * @throws boost::system::system_error Thrown on failure. An error code of
+   * boost::asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The receive operation may not receive all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that the
+   * requested amount of data is read before the blocking operation completes.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.receive(boost::asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().receive(
+        this->impl_.get_implementation(), buffers, 0, ec);
+    boost::asio::detail::throw_error(ec, "receive");
+    return s;
+  }
+
+  /// Receive some data on the socket.
+  /**
+   * This function is used to receive data on the stream socket. The function
+   * call will block until one or more bytes of data has been received
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @returns The number of bytes received.
+   *
+   * @throws boost::system::system_error Thrown on failure. An error code of
+   * boost::asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The receive operation may not receive all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that the
+   * requested amount of data is read before the blocking operation completes.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.receive(boost::asio::buffer(data, size), 0);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags flags)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().receive(
+        this->impl_.get_implementation(), buffers, flags, ec);
+    boost::asio::detail::throw_error(ec, "receive");
+    return s;
+  }
+
+  /// Receive some data on a connected socket.
+  /**
+   * This function is used to receive data on the stream socket. The function
+   * call will block until one or more bytes of data has been received
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes received. Returns 0 if an error occurred.
+   *
+   * @note The receive operation may not receive all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that the
+   * requested amount of data is read before the blocking operation completes.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags flags, boost::system::error_code& ec)
+  {
+    return this->impl_.get_service().receive(
+        this->impl_.get_implementation(), buffers, flags, ec);
+  }
+
+  /// Start an asynchronous receive.
+  /**
+   * This function is used to asynchronously receive data from the stream
+   * socket. The function call always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param handler The handler to be called when the receive operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes received.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The receive operation may not receive all of the requested number of
+   * bytes. Consider using the @ref async_read function if you need to ensure
+   * that the requested amount of data is received before the asynchronous
+   * operation completes.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.async_receive(boost::asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence, typename ReadHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+      void (boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t))
+  async_receive(const MutableBufferSequence& buffers,
+      BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
+  {
+    return async_initiate<ReadHandler,
+      void (boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t)>(
+        initiate_async_receive(), handler, this,
+        buffers, socket_base::message_flags(0));
+  }
+
+  /// Start an asynchronous receive.
+  /**
+   * This function is used to asynchronously receive data from the stream
+   * socket. The function call always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param flags Flags specifying how the receive call is to be made.
+   *
+   * @param handler The handler to be called when the receive operation
+   * completes. Copies will be made of the handler as required. The function
+   * signature of the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes received.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The receive operation may not receive all of the requested number of
+   * bytes. Consider using the @ref async_read function if you need to ensure
+   * that the requested amount of data is received before the asynchronous
+   * operation completes.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.async_receive(boost::asio::buffer(data, size), 0, handler);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence, typename ReadHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+      void (boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t))
+  async_receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags flags,
+      BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
+  {
+    return async_initiate<ReadHandler,
+      void (boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t)>(
+        initiate_async_receive(), handler, this, buffers, flags);
+  }
+
+  /// Write some data to the socket.
+  /**
+   * This function is used to write data to the stream socket. The function call
+   * will block until one or more bytes of the data has been written
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more data buffers to be written to the socket.
+   *
+   * @returns The number of bytes written.
+   *
+   * @throws boost::system::system_error Thrown on failure. An error code of
+   * boost::asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The write_some operation may not transmit all of the data to the
+   * peer. Consider using the @ref write function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.write_some(boost::asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, 0, ec);
+    boost::asio::detail::throw_error(ec, "write_some");
+    return s;
+  }
+
+  /// Write some data to the socket.
+  /**
+   * This function is used to write data to the stream socket. The function call
+   * will block until one or more bytes of the data has been written
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more data buffers to be written to the socket.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes written. Returns 0 if an error occurred.
+   *
+   * @note The write_some operation may not transmit all of the data to the
+   * peer. Consider using the @ref write function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers,
+      boost::system::error_code& ec)
+  {
+    return this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, 0, ec);
+  }
+
+  /// Start an asynchronous write.
+  /**
+   * This function is used to asynchronously write data to the stream socket.
+   * The function call always returns immediately.
+   *
+   * @param buffers One or more data buffers to be written to the socket.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param handler The handler to be called when the write operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes written.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The write operation may not transmit all of the data to the peer.
+   * Consider using the @ref async_write function if you need to ensure that all
+   * data is written before the asynchronous operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.async_write_some(boost::asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence, typename WriteHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
+      void (boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t))
+  async_write_some(const ConstBufferSequence& buffers,
+      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
+  {
+    return async_initiate<WriteHandler,
+      void (boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t)>(
+        initiate_async_send(), handler, this,
+        buffers, socket_base::message_flags(0));
+  }
+
+  /// Read some data from the socket.
+  /**
+   * This function is used to read data from the stream socket. The function
+   * call will block until one or more bytes of data has been read successfully,
+   * or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @returns The number of bytes read.
+   *
+   * @throws boost::system::system_error Thrown on failure. An error code of
+   * boost::asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.read_some(boost::asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers)
+  {
+    boost::system::error_code ec;
+    std::size_t s = this->impl_.get_service().receive(
+        this->impl_.get_implementation(), buffers, 0, ec);
+    boost::asio::detail::throw_error(ec, "read_some");
+    return s;
+  }
+
+  /// Read some data from the socket.
+  /**
+   * This function is used to read data from the stream socket. The function
+   * call will block until one or more bytes of data has been read successfully,
+   * or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes read. Returns 0 if an error occurred.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers,
+      boost::system::error_code& ec)
+  {
+    return this->impl_.get_service().receive(
+        this->impl_.get_implementation(), buffers, 0, ec);
+  }
+
+  /// Start an asynchronous read.
+  /**
+   * This function is used to asynchronously read data from the stream socket.
+   * The function call always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the handler is called.
+   *
+   * @param handler The handler to be called when the read operation completes.
+   * Copies will be made of the handler as required. The function signature of
+   * the handler must be:
+   * @code void handler(
+   *   const boost::system::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred           // Number of bytes read.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the handler will not be invoked from within this function. On
+   * immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using boost::asio::post().
+   *
+   * @note The read operation may not read all of the requested number of bytes.
+   * Consider using the @ref async_read function if you need to ensure that the
+   * requested amount of data is read before the asynchronous operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.async_read_some(boost::asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence, typename ReadHandler>
+  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+      void (boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t))
+  async_read_some(const MutableBufferSequence& buffers,
+      BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
+  {
+    return async_initiate<ReadHandler,
+      void (boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t)>(
+        initiate_async_receive(), handler, this,
+        buffers, socket_base::message_flags(0));
+  }
+
+private:
+  struct initiate_async_send
+  {
+    template <typename WriteHandler, typename ConstBufferSequence>
+    void operator()(BOOST_ASIO_MOVE_ARG(WriteHandler) handler,
+        basic_stream_socket_ext* self, const ConstBufferSequence& buffers,
+        socket_base::message_flags flags) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WriteHandler.
+      BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
+
+      detail::non_const_lvalue<WriteHandler> handler2(handler);
+      self->impl_.get_service().async_send(
+          self->impl_.get_implementation(), buffers, flags,
+          handler2.value, self->impl_.get_executor());
+    }
+  };
+
+  struct initiate_async_receive
+  {
+    template <typename ReadHandler, typename MutableBufferSequence>
+    void operator()(BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
+        basic_stream_socket_ext* self, const MutableBufferSequence& buffers,
+        socket_base::message_flags flags) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ReadHandler.
+      BOOST_ASIO_READ_HANDLER_CHECK_EXT_LOCAL(ReadHandler, handler) type_check;
+
+      detail::non_const_lvalue<ReadHandler> handler2(handler);
+      self->impl_.get_service().async_receive(
+          self->impl_.get_implementation(), buffers, flags,
+          handler2.value, self->impl_.get_executor());
+    }
+  };
+};
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_BASIC_STREAM_SOCKET_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/handler_type_requirements_ext.hpp b/implementation/helper/1.76/boost/asio/detail/handler_type_requirements_ext.hpp
new file mode 100644
index 0000000..67fe6bd
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/handler_type_requirements_ext.hpp
@@ -0,0 +1,586 @@
+//
+// detail/handler_type_requirements_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_HANDLER_TYPE_REQUIREMENTS_EXT_HPP
+#define BOOST_ASIO_DETAIL_HANDLER_TYPE_REQUIREMENTS_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+// Older versions of gcc have difficulty compiling the sizeof expressions where
+// we test the handler type requirements. We'll disable checking of handler type
+// requirements for those compilers, but otherwise enable it by default.
+#if !defined(BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS)
+# if !defined(__GNUC__) || (__GNUC__ >= 4)
+#  define BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS 1
+# endif // !defined(__GNUC__) || (__GNUC__ >= 4)
+#endif // !defined(BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS)
+
+// With C++0x we can use a combination of enhanced SFINAE and static_assert to
+// generate better template error messages. As this technique is not yet widely
+// portable, we'll only enable it for tested compilers.
+#if !defined(BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT)
+# if defined(__GNUC__)
+#  if ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ > 4)
+#   if defined(__GXX_EXPERIMENTAL_CXX0X__)
+#    define BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT 1
+#   endif // defined(__GXX_EXPERIMENTAL_CXX0X__)
+#  endif // ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ > 4)
+# endif // defined(__GNUC__)
+# if defined(BOOST_ASIO_MSVC)
+#  if (_MSC_VER >= 1600)
+#   define BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT 1
+#  endif // (_MSC_VER >= 1600)
+# endif // defined(BOOST_ASIO_MSVC)
+# if defined(__clang__)
+#  if __has_feature(__cxx_static_assert__)
+#   define BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT 1
+#  endif // __has_feature(cxx_static_assert)
+# endif // defined(__clang__)
+#endif // !defined(BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS)
+
+#if defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+# include <boost/asio/async_result.hpp>
+#endif // defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+#if defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+
+# if defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT)
+
+template <typename Handler>
+auto zero_arg_copyable_handler_test(Handler h, void*)
+  -> decltype(
+    sizeof(Handler(static_cast<const Handler&>(h))),
+    ((h)()),
+    char(0));
+
+template <typename Handler>
+char (&zero_arg_copyable_handler_test(Handler, ...))[2];
+
+template <typename Handler, typename Arg1>
+auto one_arg_handler_test(Handler h, Arg1* a1)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1)),
+    char(0));
+
+template <typename Handler>
+char (&one_arg_handler_test(Handler h, ...))[2];
+
+template <typename Handler, typename Arg1, typename Arg2>
+auto two_arg_handler_test(Handler h, Arg1* a1, Arg2* a2)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1, *a2)),
+    char(0));
+
+template <typename Handler>
+char (&two_arg_handler_test(Handler, ...))[2];
+
+template <typename Handler, typename Arg1, typename Arg2>
+auto two_arg_move_handler_test(Handler h, Arg1* a1, Arg2* a2)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1, BOOST_ASIO_MOVE_CAST(Arg2)(*a2))),
+    char(0));
+
+template <typename Handler>
+char (&two_arg_move_handler_test(Handler, ...))[2];
+
+template <typename Handler, typename Arg1, typename Arg2, typename Arg3>
+auto three_arg_handler_test(Handler h, Arg1* a1, Arg2* a2, Arg3* a3)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1, *a2, *a3)),
+    char(0));
+
+template <typename Handler>
+char (&three_arg_handler_test(Handler, ...))[2];
+
+template <typename Handler, typename Arg1, typename Arg2, typename Arg3>
+auto three_arg_move_handler_test(Handler h, Arg1* a1, Arg2* a2, Arg3 *a3)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1, BOOST_ASIO_MOVE_CAST(Arg2)(*a2), BOOST_ASIO_MOVE_CAST(Arg3)(*a3))),
+    char(0));
+
+template <typename Handler>
+char (&three_arg_move_handler_test(Handler, ...))[2];
+
+#  define BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT(expr, msg) \
+     static_assert(expr, msg);
+
+# else // defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT)
+
+#  define BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT(expr, msg)
+
+# endif // defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT)
+
+template <typename T> T& lvref();
+template <typename T> T& lvref(T);
+template <typename T> const T& clvref();
+template <typename T> const T& clvref(T);
+#if defined(BOOST_ASIO_HAS_MOVE)
+template <typename T> T rvref();
+template <typename T> T rvref(T);
+#else // defined(BOOST_ASIO_HAS_MOVE)
+template <typename T> const T& rvref();
+template <typename T> const T& rvref(T);
+#endif // defined(BOOST_ASIO_HAS_MOVE)
+template <typename T> char argbyv(T);
+
+#if 0
+template <int>
+struct handler_type_requirements
+{
+};
+#endif
+
+#define BOOST_ASIO_LEGACY_COMPLETION_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void()) asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::zero_arg_copyable_handler_test( \
+          boost::asio::detail::clvref< \
+            asio_true_handler_type>(), 0)) == 1, \
+      "CompletionHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::clvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()(), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_READ_HANDLER_CHECK_EXT( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, std::size_t, \
+           boost::asio::ip::address)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::three_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const std::size_t*>(0), \
+          static_cast<const boost::asio::ip::address*>(0))) == 1, \
+      "ReadHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const std::size_t>(), \
+            boost::asio::detail::lvref<const boost::asio::ip::address>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_WRITE_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, std::size_t)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const std::size_t*>(0))) == 1, \
+      "WriteHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const std::size_t>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#if 0
+#define BOOST_ASIO_ACCEPT_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "AcceptHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_MOVE_ACCEPT_HANDLER_CHECK( \
+    handler_type, handler, socket_type) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, socket_type)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_move_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<socket_type*>(0))) == 1, \
+      "MoveAcceptHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::rvref<socket_type>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+#endif
+
+#define BOOST_ASIO_CONNECT_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "ConnectHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_RANGE_CONNECT_HANDLER_CHECK( \
+    handler_type, handler, endpoint_type) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, endpoint_type)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const endpoint_type*>(0))) == 1, \
+      "RangeConnectHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const endpoint_type>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_ITERATOR_CONNECT_HANDLER_CHECK( \
+    handler_type, handler, iter_type) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, iter_type)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const iter_type*>(0))) == 1, \
+      "IteratorConnectHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const iter_type>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_RESOLVE_HANDLER_CHECK( \
+    handler_type, handler, range_type) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, range_type)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const range_type*>(0))) == 1, \
+      "ResolveHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const range_type>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_WAIT_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "WaitHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_SIGNAL_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, int)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const int*>(0))) == 1, \
+      "SignalHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const int>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_HANDSHAKE_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "HandshakeHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_BUFFERED_HANDSHAKE_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, std::size_t)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const std::size_t*>(0))) == 1, \
+      "BufferedHandshakeHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+          boost::asio::detail::lvref<const boost::system::error_code>(), \
+          boost::asio::detail::lvref<const std::size_t>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_SHUTDOWN_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "ShutdownHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#else // !defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+
+#define BOOST_ASIO_LEGACY_COMPLETION_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_READ_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_WRITE_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_ACCEPT_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_MOVE_ACCEPT_HANDLER_CHECK( \
+    handler_type, handler, socket_type) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_CONNECT_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_RANGE_CONNECT_HANDLER_CHECK( \
+    handler_type, handler, iter_type) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_ITERATOR_CONNECT_HANDLER_CHECK( \
+    handler_type, handler, iter_type) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_RESOLVE_HANDLER_CHECK( \
+    handler_type, handler, iter_type) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_WAIT_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_SIGNAL_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_HANDSHAKE_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_BUFFERED_HANDSHAKE_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_SHUTDOWN_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#endif // !defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#endif // BOOST_ASIO_DETAIL_HANDLER_TYPE_REQUIREMENTS_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/handler_type_requirements_ext_local.hpp b/implementation/helper/1.76/boost/asio/detail/handler_type_requirements_ext_local.hpp
new file mode 100644
index 0000000..65640ad
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/handler_type_requirements_ext_local.hpp
@@ -0,0 +1,588 @@
+//
+// detail/handler_type_requirements_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_HANDLER_TYPE_REQUIREMENTS_EXT_LOCAL_HPP
+#define BOOST_ASIO_DETAIL_HANDLER_TYPE_REQUIREMENTS_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+// Older versions of gcc have difficulty compiling the sizeof expressions where
+// we test the handler type requirements. We'll disable checking of handler type
+// requirements for those compilers, but otherwise enable it by default.
+#if !defined(BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS)
+# if !defined(__GNUC__) || (__GNUC__ >= 4)
+#  define BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS 1
+# endif // !defined(__GNUC__) || (__GNUC__ >= 4)
+#endif // !defined(BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS)
+
+// With C++0x we can use a combination of enhanced SFINAE and static_assert to
+// generate better template error messages. As this technique is not yet widely
+// portable, we'll only enable it for tested compilers.
+#if !defined(BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT)
+# if defined(__GNUC__)
+#  if ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ > 4)
+#   if defined(__GXX_EXPERIMENTAL_CXX0X__)
+#    define BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT 1
+#   endif // defined(__GXX_EXPERIMENTAL_CXX0X__)
+#  endif // ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ > 4)
+# endif // defined(__GNUC__)
+# if defined(BOOST_ASIO_MSVC)
+#  if (_MSC_VER >= 1600)
+#   define BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT 1
+#  endif // (_MSC_VER >= 1600)
+# endif // defined(BOOST_ASIO_MSVC)
+# if defined(__clang__)
+#  if __has_feature(__cxx_static_assert__)
+#   define BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT 1
+#  endif // __has_feature(cxx_static_assert)
+# endif // defined(__clang__)
+#endif // !defined(BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS)
+
+#if defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+# include <boost/asio/async_result.hpp>
+#endif // defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+#if defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+
+# if defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT)
+
+template <typename Handler>
+auto zero_arg_copyable_handler_test(Handler h, void*)
+  -> decltype(
+    sizeof(Handler(static_cast<const Handler&>(h))),
+    ((h)()),
+    char(0));
+
+template <typename Handler>
+char (&zero_arg_copyable_handler_test(Handler, ...))[2];
+
+template <typename Handler, typename Arg1>
+auto one_arg_handler_test(Handler h, Arg1* a1)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1)),
+    char(0));
+
+template <typename Handler>
+char (&one_arg_handler_test(Handler h, ...))[2];
+
+template <typename Handler, typename Arg1, typename Arg2>
+auto two_arg_handler_test(Handler h, Arg1* a1, Arg2* a2)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1, *a2)),
+    char(0));
+
+template <typename Handler>
+char (&two_arg_handler_test(Handler, ...))[2];
+
+template <typename Handler, typename Arg1, typename Arg2>
+auto two_arg_move_handler_test(Handler h, Arg1* a1, Arg2* a2)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1, BOOST_ASIO_MOVE_CAST(Arg2)(*a2))),
+    char(0));
+
+template <typename Handler>
+char (&two_arg_move_handler_test(Handler, ...))[2];
+
+template <typename Handler, typename Arg1, typename Arg2, typename Arg3, typename Arg4>
+auto four_arg_handler_test(Handler h, Arg1* a1, Arg2* a2, Arg3* a3, Arg4* a4)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1, *a2, *a3, *a4)),
+    char(0));
+
+template <typename Handler>
+char (&four_arg_handler_test(Handler, ...))[2];
+
+template <typename Handler, typename Arg1, typename Arg2,  typename Arg3, typename Arg4>
+auto four_arg_move_handler_test(Handler h, Arg1* a1, Arg2* a2, Arg3* a3, Arg4* a4)
+  -> decltype(
+    sizeof(Handler(BOOST_ASIO_MOVE_CAST(Handler)(h))),
+    ((h)(*a1, BOOST_ASIO_MOVE_CAST(Arg2)(*a2), BOOST_ASIO_MOVE_CAST(Arg3)(*a3), BOOST_ASIO_MOVE_CAST(Arg4)(*a4))),
+    char(0));
+
+template <typename Handler>
+char (&four_arg_move_handler_test(Handler, ...))[2];
+
+#  define BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT(expr, msg) \
+     static_assert(expr, msg);
+
+# else // defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT)
+
+#  define BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT(expr, msg)
+
+# endif // defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS_ASSERT)
+
+template <typename T> T& lvref();
+template <typename T> T& lvref(T);
+template <typename T> const T& clvref();
+template <typename T> const T& clvref(T);
+#if defined(BOOST_ASIO_HAS_MOVE)
+template <typename T> T rvref();
+template <typename T> T rvref(T);
+#else // defined(BOOST_ASIO_HAS_MOVE)
+template <typename T> const T& rvref();
+template <typename T> const T& rvref(T);
+#endif // defined(BOOST_ASIO_HAS_MOVE)
+template <typename T> char argbyv(T);
+
+#if 0
+template <int>
+struct handler_type_requirements
+{
+};
+#endif
+
+#define BOOST_ASIO_LEGACY_COMPLETION_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void()) asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::zero_arg_copyable_handler_test( \
+          boost::asio::detail::clvref< \
+            asio_true_handler_type>(), 0)) == 1, \
+      "CompletionHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::clvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()(), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_READ_HANDLER_CHECK_EXT_LOCAL( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, std::size_t, \
+           std::uint32_t, std::uint32_t)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::four_arg_handler_test( \
+          boost::asio::detail::clvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const std::size_t*>(0), \
+          static_cast<const std::uint32_t*>(0), \
+          static_cast<const std::uint32_t*>(0))) == 1, \
+      "ReadHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::clvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const std::size_t>(), \
+            boost::asio::detail::lvref<const std::uint32_t>(), \
+            boost::asio::detail::lvref<const std::uint32_t>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_WRITE_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, std::size_t)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const std::size_t*>(0))) == 1, \
+      "WriteHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const std::size_t>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#if 0
+#define BOOST_ASIO_ACCEPT_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "AcceptHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_MOVE_ACCEPT_HANDLER_CHECK( \
+    handler_type, handler, socket_type) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, socket_type)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_move_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<socket_type*>(0))) == 1, \
+      "MoveAcceptHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::rvref<socket_type>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+#endif
+
+#define BOOST_ASIO_CONNECT_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "ConnectHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_RANGE_CONNECT_HANDLER_CHECK( \
+    handler_type, handler, endpoint_type) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, endpoint_type)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const endpoint_type*>(0))) == 1, \
+      "RangeConnectHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const endpoint_type>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_ITERATOR_CONNECT_HANDLER_CHECK( \
+    handler_type, handler, iter_type) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, iter_type)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const iter_type*>(0))) == 1, \
+      "IteratorConnectHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const iter_type>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_RESOLVE_HANDLER_CHECK( \
+    handler_type, handler, range_type) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, range_type)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const range_type*>(0))) == 1, \
+      "ResolveHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const range_type>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_WAIT_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "WaitHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_SIGNAL_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, int)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const int*>(0))) == 1, \
+      "SignalHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>(), \
+            boost::asio::detail::lvref<const int>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_HANDSHAKE_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "HandshakeHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_BUFFERED_HANDSHAKE_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code, std::size_t)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::two_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0), \
+          static_cast<const std::size_t*>(0))) == 1, \
+      "BufferedHandshakeHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+          boost::asio::detail::lvref<const boost::system::error_code>(), \
+          boost::asio::detail::lvref<const std::size_t>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_SHUTDOWN_HANDLER_CHECK( \
+    handler_type, handler) \
+  \
+  typedef BOOST_ASIO_HANDLER_TYPE(handler_type, \
+      void(boost::system::error_code)) \
+    asio_true_handler_type; \
+  \
+  BOOST_ASIO_HANDLER_TYPE_REQUIREMENTS_ASSERT( \
+      sizeof(boost::asio::detail::one_arg_handler_test( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>(), \
+          static_cast<const boost::system::error_code*>(0))) == 1, \
+      "ShutdownHandler type requirements not met") \
+  \
+  typedef boost::asio::detail::handler_type_requirements< \
+      sizeof( \
+        boost::asio::detail::argbyv( \
+          boost::asio::detail::rvref< \
+            asio_true_handler_type>())) + \
+      sizeof( \
+        boost::asio::detail::lvref< \
+          asio_true_handler_type>()( \
+            boost::asio::detail::lvref<const boost::system::error_code>()), \
+        char(0))> BOOST_ASIO_UNUSED_TYPEDEF
+
+#else // !defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+
+#define BOOST_ASIO_LEGACY_COMPLETION_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_READ_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_WRITE_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_ACCEPT_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_MOVE_ACCEPT_HANDLER_CHECK( \
+    handler_type, handler, socket_type) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_CONNECT_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_RANGE_CONNECT_HANDLER_CHECK( \
+    handler_type, handler, iter_type) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_ITERATOR_CONNECT_HANDLER_CHECK( \
+    handler_type, handler, iter_type) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_RESOLVE_HANDLER_CHECK( \
+    handler_type, handler, iter_type) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_WAIT_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_SIGNAL_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_HANDSHAKE_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_BUFFERED_HANDSHAKE_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#define BOOST_ASIO_SHUTDOWN_HANDLER_CHECK( \
+    handler_type, handler) \
+  typedef int BOOST_ASIO_UNUSED_TYPEDEF
+
+#endif // !defined(BOOST_ASIO_ENABLE_HANDLER_TYPE_REQUIREMENTS)
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#endif // BOOST_ASIO_DETAIL_HANDLER_TYPE_REQUIREMENTS_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/impl/reactive_socket_service_base_ext.ipp b/implementation/helper/1.76/boost/asio/detail/impl/reactive_socket_service_base_ext.ipp
new file mode 100644
index 0000000..04036ad
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/impl/reactive_socket_service_base_ext.ipp
@@ -0,0 +1,302 @@
+//
+// detail/reactive_socket_service_base_ext.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (C) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_EXT_IPP
+#define BOOST_ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_EXT_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#if !defined(BOOST_ASIO_HAS_IOCP) \
+  && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
+
+#include <boost/asio/detail/reactive_socket_service_base_ext.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+reactive_socket_service_base_ext::reactive_socket_service_base_ext(
+    execution_context& context)
+  : reactor_(use_service<reactor>(context))
+{
+  reactor_.init_task();
+}
+
+void reactive_socket_service_base_ext::base_shutdown()
+{
+}
+
+void reactive_socket_service_base_ext::construct(
+    reactive_socket_service_base_ext::base_implementation_type& impl)
+{
+  impl.socket_ = invalid_socket;
+  impl.state_ = 0;
+}
+
+void reactive_socket_service_base_ext::base_move_construct(
+    reactive_socket_service_base_ext::base_implementation_type& impl,
+    reactive_socket_service_base_ext::base_implementation_type& other_impl)
+{
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = invalid_socket;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  reactor_.move_descriptor(impl.socket_,
+      impl.reactor_data_, other_impl.reactor_data_);
+}
+
+void reactive_socket_service_base_ext::base_move_assign(
+    reactive_socket_service_base_ext::base_implementation_type& impl,
+    reactive_socket_service_base_ext& other_service,
+    reactive_socket_service_base_ext::base_implementation_type& other_impl)
+{
+  destroy(impl);
+
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = invalid_socket;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  other_service.reactor_.move_descriptor(impl.socket_,
+      impl.reactor_data_, other_impl.reactor_data_);
+}
+
+void reactive_socket_service_base_ext::destroy(
+    reactive_socket_service_base_ext::base_implementation_type& impl)
+{
+  if (impl.socket_ != invalid_socket)
+  {
+    BOOST_ASIO_HANDLER_OPERATION((reactor_.context(),
+          "socket", &impl, impl.socket_, "close"));
+
+    reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_,
+        (impl.state_ & socket_ops::possible_dup) == 0);
+
+    boost::system::error_code ignored_ec;
+    socket_ops::close(impl.socket_, impl.state_, true, ignored_ec);
+    
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  }
+}
+
+boost::system::error_code reactive_socket_service_base_ext::close(
+    reactive_socket_service_base_ext::base_implementation_type& impl,
+    boost::system::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    BOOST_ASIO_HANDLER_OPERATION((reactor_.context(),
+          "socket", &impl, impl.socket_, "close"));
+
+    reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_,
+        (impl.state_ & socket_ops::possible_dup) == 0);
+        
+    socket_ops::close(impl.socket_, impl.state_, false, ec);
+    
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  }
+  else
+  {
+    ec = boost::system::error_code();
+  }
+
+  // The descriptor is closed by the OS even if close() returns an error.
+  //
+  // (Actually, POSIX says the state of the descriptor is unspecified. On
+  // Linux the descriptor is apparently closed anyway; e.g. see
+  //   http://lkml.org/lkml/2005/9/10/129
+  // We'll just have to assume that other OSes follow the same behaviour. The
+  // known exception is when Windows's closesocket() function fails with
+  // WSAEWOULDBLOCK, but this case is handled inside socket_ops::close().
+  construct(impl);
+
+  return ec;
+}
+/*
+socket_type reactive_socket_service_base::release(
+    reactive_socket_service_base::base_implementation_type& impl,
+    boost::system::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = boost::asio::error::bad_descriptor;
+    return invalid_socket;
+  }
+
+  BOOST_ASIO_HANDLER_OPERATION((reactor_.context(),
+        "socket", &impl, impl.socket_, "release"));
+
+  reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_, false);
+  reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  socket_type sock = impl.socket_;
+  construct(impl);
+  ec = boost::system::error_code();
+  return sock;
+}
+*/
+boost::system::error_code reactive_socket_service_base_ext::cancel(
+    reactive_socket_service_base_ext::base_implementation_type& impl,
+    boost::system::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = boost::asio::error::bad_descriptor;
+    return ec;
+  }
+
+  BOOST_ASIO_HANDLER_OPERATION((reactor_.context(),
+        "socket", &impl, impl.socket_, "cancel"));
+
+  reactor_.cancel_ops(impl.socket_, impl.reactor_data_);
+  ec = boost::system::error_code();
+  return ec;
+}
+
+boost::system::error_code reactive_socket_service_base_ext::do_open(
+    reactive_socket_service_base_ext::base_implementation_type& impl,
+    int af, int type, int protocol, boost::system::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = boost::asio::error::already_open;
+    return ec;
+  }
+
+  socket_holder sock(socket_ops::socket(af, type, protocol, ec));
+  if (sock.get() == invalid_socket)
+    return ec;
+
+  if (int err = reactor_.register_descriptor(sock.get(), impl.reactor_data_))
+  {
+    ec = boost::system::error_code(err,
+        boost::asio::error::get_system_category());
+    return ec;
+  }
+
+  impl.socket_ = sock.release();
+  switch (type)
+  {
+  case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
+  case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
+  default: impl.state_ = 0; break;
+  }
+  ec = boost::system::error_code();
+  return ec;
+}
+
+boost::system::error_code reactive_socket_service_base_ext::do_assign(
+    reactive_socket_service_base_ext::base_implementation_type& impl, int type,
+    const reactive_socket_service_base_ext::native_handle_type& native_socket,
+    boost::system::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = boost::asio::error::already_open;
+    return ec;
+  }
+
+  if (int err = reactor_.register_descriptor(
+        native_socket, impl.reactor_data_))
+  {
+    ec = boost::system::error_code(err,
+        boost::asio::error::get_system_category());
+    return ec;
+  }
+
+  impl.socket_ = native_socket;
+  switch (type)
+  {
+  case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
+  case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
+  default: impl.state_ = 0; break;
+  }
+  impl.state_ |= socket_ops::possible_dup;
+  ec = boost::system::error_code();
+  return ec;
+}
+
+void reactive_socket_service_base_ext::start_op(
+    reactive_socket_service_base_ext::base_implementation_type& impl,
+    int op_type, reactor_op* op, bool is_continuation,
+    bool is_non_blocking, bool noop)
+{
+  if (!noop)
+  {
+    if ((impl.state_ & socket_ops::non_blocking)
+        || socket_ops::set_internal_non_blocking(
+          impl.socket_, impl.state_, true, op->ec_))
+    {
+      reactor_.start_op(op_type, impl.socket_,
+          impl.reactor_data_, op, is_continuation, is_non_blocking);
+      return;
+    }
+  }
+
+  reactor_.post_immediate_completion(op, is_continuation);
+}
+
+void reactive_socket_service_base_ext::start_accept_op(
+    reactive_socket_service_base_ext::base_implementation_type& impl,
+    reactor_op* op, bool is_continuation, bool peer_is_open)
+{
+  if (!peer_is_open)
+    start_op(impl, reactor::read_op, op, is_continuation, true, false);
+  else
+  {
+    op->ec_ = boost::asio::error::already_open;
+    reactor_.post_immediate_completion(op, is_continuation);
+  }
+}
+
+void reactive_socket_service_base_ext::start_connect_op(
+    reactive_socket_service_base_ext::base_implementation_type& impl,
+    reactor_op* op, bool is_continuation,
+    const socket_addr_type* addr, size_t addrlen)
+{
+  if ((impl.state_ & socket_ops::non_blocking)
+      || socket_ops::set_internal_non_blocking(
+        impl.socket_, impl.state_, true, op->ec_))
+  {
+    if (socket_ops::connect(impl.socket_, addr, addrlen, op->ec_) != 0)
+    {
+      if (op->ec_ == boost::asio::error::in_progress
+          || op->ec_ == boost::asio::error::would_block)
+      {
+        op->ec_ = boost::system::error_code();
+        reactor_.start_op(reactor::connect_op, impl.socket_,
+            impl.reactor_data_, op, is_continuation, false);
+        return;
+      }
+    }
+  }
+
+  reactor_.post_immediate_completion(op, is_continuation);
+}
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // !defined(BOOST_ASIO_HAS_IOCP)
+       //   && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
+
+#endif // BOOST_ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_EXT_IPP
diff --git a/implementation/helper/1.76/boost/asio/detail/impl/reactive_socket_service_base_ext_local.ipp b/implementation/helper/1.76/boost/asio/detail/impl/reactive_socket_service_base_ext_local.ipp
new file mode 100644
index 0000000..288cf19
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/impl/reactive_socket_service_base_ext_local.ipp
@@ -0,0 +1,302 @@
+//
+// detail/reactive_socket_service_base_ext_local.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (C) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_EXT_LOCAL_IPP
+#define BOOST_ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_EXT_LOCAL_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#if !defined(BOOST_ASIO_HAS_IOCP) \
+  && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
+
+#include <boost/asio/detail/reactive_socket_service_base_ext_local.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+reactive_socket_service_base_ext_local::reactive_socket_service_base_ext_local(
+    execution_context& context)
+  : reactor_(use_service<reactor>(context))
+{
+  reactor_.init_task();
+}
+
+void reactive_socket_service_base_ext_local::base_shutdown()
+{
+}
+
+void reactive_socket_service_base_ext_local::construct(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl)
+{
+  impl.socket_ = invalid_socket;
+  impl.state_ = 0;
+}
+
+void reactive_socket_service_base_ext_local::base_move_construct(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl,
+    reactive_socket_service_base_ext_local::base_implementation_type& other_impl)
+{
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = invalid_socket;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  reactor_.move_descriptor(impl.socket_,
+      impl.reactor_data_, other_impl.reactor_data_);
+}
+
+void reactive_socket_service_base_ext_local::base_move_assign(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl,
+    reactive_socket_service_base_ext_local& other_service,
+    reactive_socket_service_base_ext_local::base_implementation_type& other_impl)
+{
+  destroy(impl);
+
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = invalid_socket;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  other_service.reactor_.move_descriptor(impl.socket_,
+      impl.reactor_data_, other_impl.reactor_data_);
+}
+
+void reactive_socket_service_base_ext_local::destroy(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl)
+{
+  if (impl.socket_ != invalid_socket)
+  {
+    BOOST_ASIO_HANDLER_OPERATION((reactor_.context(),
+          "socket", &impl, impl.socket_, "close"));
+
+    reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_,
+        (impl.state_ & socket_ops::possible_dup) == 0);
+
+    boost::system::error_code ignored_ec;
+    socket_ops::close(impl.socket_, impl.state_, true, ignored_ec);
+    
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  }
+}
+
+boost::system::error_code reactive_socket_service_base_ext_local::close(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl,
+    boost::system::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    BOOST_ASIO_HANDLER_OPERATION((reactor_.context(),
+          "socket", &impl, impl.socket_, "close"));
+
+    reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_,
+        (impl.state_ & socket_ops::possible_dup) == 0);
+        
+    socket_ops::close(impl.socket_, impl.state_, false, ec);
+    
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  }
+  else
+  {
+    ec = boost::system::error_code();
+  }
+
+  // The descriptor is closed by the OS even if close() returns an error.
+  //
+  // (Actually, POSIX says the state of the descriptor is unspecified. On
+  // Linux the descriptor is apparently closed anyway; e.g. see
+  //   http://lkml.org/lkml/2005/9/10/129
+  // We'll just have to assume that other OSes follow the same behaviour. The
+  // known exception is when Windows's closesocket() function fails with
+  // WSAEWOULDBLOCK, but this case is handled inside socket_ops::close().
+  construct(impl);
+
+  return ec;
+}
+/*
+socket_type reactive_socket_service_base::release(
+    reactive_socket_service_base::base_implementation_type& impl,
+    boost::system::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = boost::asio::error::bad_descriptor;
+    return invalid_socket;
+  }
+
+  BOOST_ASIO_HANDLER_OPERATION((reactor_.context(),
+        "socket", &impl, impl.socket_, "release"));
+
+  reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_, false);
+  reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  socket_type sock = impl.socket_;
+  construct(impl);
+  ec = boost::system::error_code();
+  return sock;
+}
+*/
+boost::system::error_code reactive_socket_service_base_ext_local::cancel(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl,
+    boost::system::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = boost::asio::error::bad_descriptor;
+    return ec;
+  }
+
+  BOOST_ASIO_HANDLER_OPERATION((reactor_.context(),
+        "socket", &impl, impl.socket_, "cancel"));
+
+  reactor_.cancel_ops(impl.socket_, impl.reactor_data_);
+  ec = boost::system::error_code();
+  return ec;
+}
+
+boost::system::error_code reactive_socket_service_base_ext_local::do_open(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl,
+    int af, int type, int protocol, boost::system::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = boost::asio::error::already_open;
+    return ec;
+  }
+
+  socket_holder sock(socket_ops::socket(af, type, protocol, ec));
+  if (sock.get() == invalid_socket)
+    return ec;
+
+  if (int err = reactor_.register_descriptor(sock.get(), impl.reactor_data_))
+  {
+    ec = boost::system::error_code(err,
+        boost::asio::error::get_system_category());
+    return ec;
+  }
+
+  impl.socket_ = sock.release();
+  switch (type)
+  {
+  case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
+  case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
+  default: impl.state_ = 0; break;
+  }
+  ec = boost::system::error_code();
+  return ec;
+}
+
+boost::system::error_code reactive_socket_service_base_ext_local::do_assign(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl, int type,
+    const reactive_socket_service_base_ext_local::native_handle_type& native_socket,
+    boost::system::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = boost::asio::error::already_open;
+    return ec;
+  }
+
+  if (int err = reactor_.register_descriptor(
+        native_socket, impl.reactor_data_))
+  {
+    ec = boost::system::error_code(err,
+        boost::asio::error::get_system_category());
+    return ec;
+  }
+
+  impl.socket_ = native_socket;
+  switch (type)
+  {
+  case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
+  case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
+  default: impl.state_ = 0; break;
+  }
+  impl.state_ |= socket_ops::possible_dup;
+  ec = boost::system::error_code();
+  return ec;
+}
+
+void reactive_socket_service_base_ext_local::start_op(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl,
+    int op_type, reactor_op* op, bool is_continuation,
+    bool is_non_blocking, bool noop)
+{
+  if (!noop)
+  {
+    if ((impl.state_ & socket_ops::non_blocking)
+        || socket_ops::set_internal_non_blocking(
+          impl.socket_, impl.state_, true, op->ec_))
+    {
+      reactor_.start_op(op_type, impl.socket_,
+          impl.reactor_data_, op, is_continuation, is_non_blocking);
+      return;
+    }
+  }
+
+  reactor_.post_immediate_completion(op, is_continuation);
+}
+
+void reactive_socket_service_base_ext_local::start_accept_op(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl,
+    reactor_op* op, bool is_continuation, bool peer_is_open)
+{
+  if (!peer_is_open)
+    start_op(impl, reactor::read_op, op, is_continuation, true, false);
+  else
+  {
+    op->ec_ = boost::asio::error::already_open;
+    reactor_.post_immediate_completion(op, is_continuation);
+  }
+}
+
+void reactive_socket_service_base_ext_local::start_connect_op(
+    reactive_socket_service_base_ext_local::base_implementation_type& impl,
+    reactor_op* op, bool is_continuation,
+    const socket_addr_type* addr, size_t addrlen)
+{
+  if ((impl.state_ & socket_ops::non_blocking)
+      || socket_ops::set_internal_non_blocking(
+        impl.socket_, impl.state_, true, op->ec_))
+  {
+    if (socket_ops::connect(impl.socket_, addr, addrlen, op->ec_) != 0)
+    {
+      if (op->ec_ == boost::asio::error::in_progress
+          || op->ec_ == boost::asio::error::would_block)
+      {
+        op->ec_ = boost::system::error_code();
+        reactor_.start_op(reactor::connect_op, impl.socket_,
+            impl.reactor_data_, op, is_continuation, false);
+        return;
+      }
+    }
+  }
+
+  reactor_.post_immediate_completion(op, is_continuation);
+}
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // !defined(BOOST_ASIO_HAS_IOCP)
+       //   && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
+
+#endif // BOOST_ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_EXT_LOCAL_IPP
diff --git a/implementation/helper/1.76/boost/asio/detail/impl/socket_ops_ext.ipp b/implementation/helper/1.76/boost/asio/detail/impl/socket_ops_ext.ipp
new file mode 100644
index 0000000..39e2ed8
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/impl/socket_ops_ext.ipp
@@ -0,0 +1,234 @@
+//
+// detail/impl/socket_ops_ext.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (C) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_IPP
+#define BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_IPP
+
+#include <boost/asio/detail/impl/socket_ops.ipp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+namespace socket_ops {
+
+signed_size_type recvfrom(socket_type s, buf* bufs, size_t count,
+    int flags, socket_addr_type* addr, std::size_t* addrlen,
+    boost::system::error_code& ec, boost::asio::ip::address& da)
+{
+
+#if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+  GUID WSARecvMsg_GUID = WSAID_WSARECVMSG;
+  LPFN_WSARECVMSG WSARecvMsg;
+  DWORD NumberOfBytes;
+  signed_size_type result;
+  
+  result = WSAIoctl(s, SIO_GET_EXTENSION_FUNCTION_POINTER,
+		 &WSARecvMsg_GUID, sizeof WSARecvMsg_GUID,
+		 &WSARecvMsg, sizeof WSARecvMsg,
+		 &NumberOfBytes, NULL, NULL);
+  get_last_error(ec, true);
+  if (ec.value() == SOCKET_ERROR) {
+	WSARecvMsg = NULL;
+	return 0;
+  }
+  
+  WSABUF wsaBuf;
+  WSAMSG msg;
+  char controlBuffer[1024];
+  msg.name = addr;
+  msg.namelen = *addrlen;
+  wsaBuf.buf = bufs->buf;
+  wsaBuf.len = bufs->len;
+  msg.lpBuffers = &wsaBuf;
+  msg.dwBufferCount = count;
+  msg.Control.len = sizeof controlBuffer;
+  msg.Control.buf = controlBuffer;
+  msg.dwFlags = flags;
+
+  DWORD dwNumberOfBytesRecvd;
+  result = WSARecvMsg(s, &msg, &dwNumberOfBytesRecvd, NULL, NULL);
+  get_last_error(ec, true);
+  
+  if (result >= 0) {
+    ec = boost::system::error_code();
+
+    // Find destination address
+    for (LPWSACMSGHDR cmsg = WSA_CMSG_FIRSTHDR(&msg);
+         cmsg != NULL;
+         cmsg = WSA_CMSG_NXTHDR(&msg, cmsg))
+    {
+      if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO)
+      {
+        struct in_pktinfo *pi = (struct in_pktinfo *) WSA_CMSG_DATA(cmsg);
+        if (pi)
+        {
+          da = boost::asio::ip::address_v4(ntohl(pi->ipi_addr.s_addr));
+        }
+      } else
+      if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO)
+      {
+        struct in6_pktinfo *pi = (struct in6_pktinfo *) WSA_CMSG_DATA(cmsg);
+        if (pi)
+        {
+          boost::asio::ip::address_v6::bytes_type b;
+          memcpy(b.data(), pi->ipi6_addr.s6_addr, sizeof(pi->ipi6_addr.s6_addr));
+          da = boost::asio::ip::address_v6(b);
+        }
+      }
+    }      
+  } else {
+    dwNumberOfBytesRecvd = -1;
+  }
+  return dwNumberOfBytesRecvd;
+#else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+  char cmbuf[0x100];
+  msghdr msg = msghdr();
+  init_msghdr_msg_name(msg.msg_name, addr);
+  msg.msg_namelen = static_cast<int>(*addrlen);
+  msg.msg_iov = bufs;
+  msg.msg_iovlen = static_cast<int>(count);
+  msg.msg_control = cmbuf;
+  msg.msg_controllen = sizeof(cmbuf);
+  signed_size_type result = ::recvmsg(s, &msg, flags);
+  get_last_error(ec, true);
+  *addrlen = msg.msg_namelen;
+  if (result >= 0) {
+    ec.assign(0, ec.category());
+
+    // Find destination address
+    for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
+         cmsg != NULL;
+         cmsg = CMSG_NXTHDR(&msg, cmsg))
+    {
+      if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO)
+      {
+        struct in_pktinfo *pi = (struct in_pktinfo *) CMSG_DATA(cmsg);
+        if (pi)
+        {
+          da = boost::asio::ip::address_v4(ntohl(pi->ipi_addr.s_addr));
+        }
+      } else
+      if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO)
+      {
+        struct in6_pktinfo *pi = (struct in6_pktinfo *) CMSG_DATA(cmsg);
+        if (pi)
+        {
+          boost::asio::ip::address_v6::bytes_type b;
+          memcpy(b.data(), pi->ipi6_addr.s6_addr, sizeof(pi->ipi6_addr.s6_addr));
+          da = boost::asio::ip::address_v6(b);
+        }
+      }
+    }
+  }
+  return result;
+#endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+size_t sync_recvfrom(socket_type s, state_type state, buf* bufs,
+    size_t count, int flags, socket_addr_type* addr,
+    std::size_t* addrlen, boost::system::error_code& ec, boost::asio::ip::address& da)
+{
+  if (s == invalid_socket)
+  {
+    ec = boost::asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // Read some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    signed_size_type bytes = socket_ops::recvfrom(
+        s, bufs, count, flags, addr, addrlen, ec, da);
+
+    // Check if operation succeeded.
+    if (bytes >= 0)
+      return bytes;
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != boost::asio::error::would_block
+          && ec != boost::asio::error::try_again))
+      return 0;
+
+    // Wait for socket to become ready.
+    if (socket_ops::poll_read(s, 0, -1, ec) < 0)
+      return 0;
+  }
+}
+
+#if defined(BOOST_ASIO_HAS_IOCP)
+
+void complete_iocp_recvfrom(
+    const weak_cancel_token_type& cancel_token,
+    boost::system::error_code& ec, boost::asio::ip::address& da)
+{
+  // Map non-portable errors to their portable counterparts.
+  if (ec.value() == ERROR_NETNAME_DELETED)
+  {
+    if (cancel_token.expired())
+      ec = boost::asio::error::operation_aborted;
+    else
+      ec = boost::asio::error::connection_reset;
+  }
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+  {
+    ec = boost::asio::error::connection_refused;
+  }
+}
+
+#else // defined(BOOST_ASIO_HAS_IOCP)
+
+bool non_blocking_recvfrom(socket_type s,
+    buf* bufs, size_t count, int flags,
+    socket_addr_type* addr, std::size_t* addrlen,
+    boost::system::error_code& ec, size_t& bytes_transferred, boost::asio::ip::address& da)
+{
+  for (;;)
+  {
+    // Read some data.
+    signed_size_type bytes = socket_ops::recvfrom(
+        s, bufs, count, flags, addr, addrlen, ec, da);
+
+    // Retry operation if interrupted by signal.
+    if (ec == boost::asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == boost::asio::error::would_block
+        || ec == boost::asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = boost::system::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+#endif // defined(BOOST_ASIO_HAS_IOCP)
+
+} // namespace socket_ops
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_IPP
diff --git a/implementation/helper/1.76/boost/asio/detail/impl/socket_ops_ext_local.ipp b/implementation/helper/1.76/boost/asio/detail/impl/socket_ops_ext_local.ipp
new file mode 100644
index 0000000..83a673b
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/impl/socket_ops_ext_local.ipp
@@ -0,0 +1,307 @@
+//
+// detail/impl/socket_ops_ext_local.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (C) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_LOCAL_IPP
+#define BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_LOCAL_IPP
+
+#include <boost/asio/detail/impl/socket_ops.ipp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+namespace socket_ops {
+
+signed_size_type recv(socket_type s, buf* bufs, size_t count,
+    int flags, boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid)
+{
+  uid = 0xFFFFFFFF;
+  gid = 0xFFFFFFFF;
+  struct ucred *ucredp;
+
+#if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+  // Receive some data.
+  DWORD recv_buf_count = static_cast<DWORD>(count);
+  DWORD bytes_transferred = 0;
+  DWORD recv_flags = flags;
+  int result = ::WSARecv(s, bufs,
+        recv_buf_count, &bytes_transferred, &recv_flags, 0, 0);
+  get_last_error(ec, true);        
+  if (ec.value() == ERROR_NETNAME_DELETED)
+    ec = boost::asio::error::connection_reset;
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+    ec = boost::asio::error::connection_refused;
+  if (result != 0)
+    return socket_error_retval;
+  ec.assign(0, ec.category());
+  return bytes_transferred;
+#else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+  msghdr msg = msghdr();
+  msg.msg_iov = bufs;
+  msg.msg_iovlen = static_cast<int>(count);
+
+  union {
+    struct cmsghdr cmh;
+    char   control[CMSG_SPACE(sizeof(struct ucred))];
+  } control_un;
+
+  // Set 'control_un' to describe ancillary data that we want to receive
+  control_un.cmh.cmsg_len = CMSG_LEN(sizeof(struct ucred));
+  control_un.cmh.cmsg_level = SOL_SOCKET;
+  control_un.cmh.cmsg_type = SCM_CREDENTIALS;
+
+  // Set 'msg' fields to describe 'control_un'
+  msg.msg_control = control_un.control;
+  msg.msg_controllen = sizeof(control_un.control);
+
+  signed_size_type result = ::recvmsg(s, &msg, flags);
+  get_last_error(ec, true);
+  if (result >= 0) {
+    ec.assign(0, ec.category());
+
+    // Find UID / GID
+    for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
+         cmsg != NULL;
+         cmsg = CMSG_NXTHDR(&msg, cmsg))
+    {
+      if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_CREDENTIALS
+          || cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
+        continue;
+
+      ucredp = (struct ucred *) CMSG_DATA(cmsg);
+      if (ucredp) {
+        uid = ucredp->uid;
+        gid = ucredp->gid;
+      }
+	}
+  }
+  return result;
+#endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+signed_size_type recvfrom(socket_type s, buf* bufs, size_t count,
+    int flags, socket_addr_type* addr, std::size_t* addrlen,
+    boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid)
+{
+  uid = 0xFFFFFFFF;
+  gid = 0xFFFFFFFF;
+  struct ucred *ucredp;
+  clear_last_error();
+#if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+  // Receive some data.
+  DWORD recv_buf_count = static_cast<DWORD>(count);
+  DWORD bytes_transferred = 0;
+  DWORD recv_flags = flags;
+  int tmp_addrlen = (int)*addrlen;
+  int result = ::WSARecvFrom(s, bufs, recv_buf_count,
+        &bytes_transferred, &recv_flags, addr, &tmp_addrlen, 0, 0);
+  get_last_error(ec, true);
+  *addrlen = (std::size_t)tmp_addrlen;
+  if (ec.value() == ERROR_NETNAME_DELETED)
+    ec = boost::asio::error::connection_reset;
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+    ec = boost::asio::error::connection_refused;
+  if (result != 0)
+    return socket_error_retval;
+  ec.assign(0, ec.category());
+  return bytes_transferred;
+#else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+  msghdr msg = msghdr();
+  init_msghdr_msg_name(msg.msg_name, addr);
+  msg.msg_namelen = static_cast<int>(*addrlen);
+  msg.msg_iov = bufs;
+  msg.msg_iovlen = static_cast<int>(count);
+
+  union {
+    struct cmsghdr cmh;
+    char   control[CMSG_SPACE(sizeof(struct ucred))];
+  } control_un;
+
+  // Set 'control_un' to describe ancillary data that we want to receive
+  control_un.cmh.cmsg_len = CMSG_LEN(sizeof(struct ucred));
+  control_un.cmh.cmsg_level = SOL_SOCKET;
+  control_un.cmh.cmsg_type = SCM_CREDENTIALS;
+
+  // Set 'msg' fields to describe 'control_un'
+  msg.msg_control = control_un.control;
+  msg.msg_controllen = sizeof(control_un.control);
+
+  signed_size_type result = ::recvmsg(s, &msg, flags);
+  get_last_error(ec, true);
+  *addrlen = msg.msg_namelen;
+  if (result >= 0) {
+    ec.assign(0, ec.category());
+
+    // Find UID / GID
+    for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
+         cmsg != NULL;
+         cmsg = CMSG_NXTHDR(&msg, cmsg))
+    {
+      if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_CREDENTIALS
+          || cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
+        continue;
+
+      ucredp = (struct ucred *) CMSG_DATA(cmsg);
+      if (ucredp) {
+        uid = ucredp->uid;
+        gid = ucredp->gid;
+      }
+    }
+  }
+  return result;
+#endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+size_t sync_recvfrom(socket_type s, state_type state, buf* bufs,
+    size_t count, int flags, socket_addr_type* addr,
+    std::size_t* addrlen, boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid)
+{
+  if (s == invalid_socket)
+  {
+    ec = boost::asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // Read some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    signed_size_type bytes = socket_ops::recvfrom(
+        s, bufs, count, flags, addr, addrlen, ec, uid, gid);
+
+    // Check if operation succeeded.
+    if (bytes >= 0)
+      return bytes;
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != boost::asio::error::would_block
+          && ec != boost::asio::error::try_again))
+      return 0;
+
+    // Wait for socket to become ready.
+    if (socket_ops::poll_read(s, 0, -1, ec) < 0)
+      return 0;
+  }
+}
+
+#if defined(BOOST_ASIO_HAS_IOCP)
+
+void complete_iocp_recvfrom(
+    const weak_cancel_token_type& cancel_token,
+    boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid)
+{
+  uid = 0xFFFFFFFF;
+  gid = 0xFFFFFFFF;
+  // Map non-portable errors to their portable counterparts.
+  if (ec.value() == ERROR_NETNAME_DELETED)
+  {
+    if (cancel_token.expired())
+      ec = boost::asio::error::operation_aborted;
+    else
+      ec = boost::asio::error::connection_reset;
+  }
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+  {
+    ec = boost::asio::error::connection_refused;
+  }
+}
+
+#else // defined(BOOST_ASIO_HAS_IOCP)
+
+bool non_blocking_recv(socket_type s,
+    buf* bufs, size_t count, int flags, bool is_stream,
+    boost::system::error_code& ec, size_t& bytes_transferred,
+    std::uint32_t& uid, std::uint32_t& gid)
+{
+  for (;;)
+  {
+    // Read some data.
+    signed_size_type bytes = socket_ops::recv(s, bufs, count, flags, ec, uid, gid);
+
+    // Check for end of stream.
+    if (is_stream && bytes == 0)
+    {
+      ec = boost::asio::error::eof;
+      return true;
+    }
+
+    // Retry operation if interrupted by signal.
+    if (ec == boost::asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == boost::asio::error::would_block
+        || ec == boost::asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = boost::system::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+bool non_blocking_recvfrom(socket_type s,
+    buf* bufs, size_t count, int flags,
+    socket_addr_type* addr, std::size_t* addrlen,
+    boost::system::error_code& ec, size_t& bytes_transferred,
+    std::uint32_t& uid, std::uint32_t& gid)
+{
+  for (;;)
+  {
+    // Read some data.
+    signed_size_type bytes = socket_ops::recvfrom(
+        s, bufs, count, flags, addr, addrlen, ec, uid, gid);
+
+    // Retry operation if interrupted by signal.
+    if (ec == boost::asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == boost::asio::error::would_block
+        || ec == boost::asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = boost::system::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+#endif // defined(BOOST_ASIO_HAS_IOCP)
+
+} // namespace socket_ops
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_LOCAL_IPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_recv_op_ext.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recv_op_ext.hpp
new file mode 100644
index 0000000..1167d57
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recv_op_ext.hpp
@@ -0,0 +1,162 @@
+//
+// detail/reactive_socket_recv_op_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECV_OP_EXT_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECV_OP_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/bind_handler.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/fenced_block.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <boost/asio/detail/handler_invoke_helpers.hpp>
+#include <boost/asio/detail/handler_work.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/reactor_op_ext.hpp>
+#include <boost/asio/detail/socket_ops_ext.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename MutableBufferSequence>
+class reactive_socket_recv_op_base_ext : public reactor_op_ext
+{
+public:
+  reactive_socket_recv_op_base_ext(const boost::system::error_code& success_ec,
+      socket_type socket, socket_ops::state_type state,
+      const MutableBufferSequence& buffers,
+      socket_base::message_flags flags, func_type complete_func)
+    : reactor_op_ext(success_ec, &reactive_socket_recv_op_base_ext::do_perform, complete_func),
+      socket_(socket),
+      state_(state),
+      buffers_(buffers),
+      flags_(flags)
+  {
+  }
+
+  static status do_perform(reactor_op* base)
+  {
+    reactive_socket_recv_op_base_ext* o(
+        static_cast<reactive_socket_recv_op_base_ext*>(base));
+
+    typedef buffer_sequence_adapter<boost::asio::mutable_buffer,
+                MutableBufferSequence> bufs_type;
+
+    status result;
+    if (bufs_type::is_single_buffer)
+    {
+      result = socket_ops::non_blocking_recv1(o->socket_,
+          bufs_type::first(o->buffers_).data(),
+          bufs_type::first(o->buffers_).size(), o->flags_,
+          (o->state_ & socket_ops::stream_oriented) != 0,
+          o->ec_, o->bytes_transferred_) ? done : not_done;
+    }
+    else
+    {
+      bufs_type bufs(o->buffers_);
+      result = socket_ops::non_blocking_recv(o->socket_,
+          bufs.buffers(), bufs.count(), o->flags_,
+          (o->state_ & socket_ops::stream_oriented) != 0,
+          o->ec_, o->bytes_transferred_) ? done : not_done;
+    }
+
+    if (result == done)
+      if ((o->state_ & socket_ops::stream_oriented) != 0)
+        if (o->bytes_transferred_ == 0)
+          result = done_and_exhausted;
+
+    BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_recv",
+          o->ec_, o->bytes_transferred_));
+
+    return result;
+  }
+
+private:
+  socket_type socket_;
+  socket_ops::state_type state_;
+  MutableBufferSequence buffers_;
+  socket_base::message_flags flags_;
+};
+
+template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
+class reactive_socket_recv_op_ext :
+  public reactive_socket_recv_op_base_ext<MutableBufferSequence>
+{
+public:
+  BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_recv_op_ext);
+
+  reactive_socket_recv_op_ext(const boost::system::error_code& success_ec,
+      socket_type socket, socket_ops::state_type state,
+      const MutableBufferSequence& buffers, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+    : reactive_socket_recv_op_base_ext<MutableBufferSequence>(success_ec,
+        socket, state, buffers, flags,
+        &reactive_socket_recv_op_ext::do_complete),
+      handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const boost::system::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    reactive_socket_recv_op_ext* o(static_cast<reactive_socket_recv_op_ext*>(base));
+    ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
+
+    BOOST_ASIO_HANDLER_COMPLETION((*o));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+          o->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder3<Handler, boost::system::error_code, std::size_t, boost::asio::ip::address>
+      handler(o->handler_, o->ec_, o->bytes_transferred_, o->da_);
+    p.h = boost::asio::detail::addressof(handler.handler_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_, handler.arg3_));
+      w.complete(handler, handler.handler_);
+      BOOST_ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECV_OP_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_recv_op_ext_local.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recv_op_ext_local.hpp
new file mode 100644
index 0000000..bedbd29
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recv_op_ext_local.hpp
@@ -0,0 +1,162 @@
+//
+// detail/reactive_socket_recv_op_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECV_OP_EXT_LOCAL_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECV_OP_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/bind_handler.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/fenced_block.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <boost/asio/detail/handler_invoke_helpers.hpp>
+#include <boost/asio/detail/handler_work.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/reactor_op_ext_local.hpp>
+#include <boost/asio/detail/socket_ops_ext_local.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename MutableBufferSequence>
+class reactive_socket_recv_op_base_ext_local : public reactor_op_ext_local
+{
+public:
+  reactive_socket_recv_op_base_ext_local(const boost::system::error_code& success_ec,
+      socket_type socket, socket_ops::state_type state,
+      const MutableBufferSequence& buffers,
+      socket_base::message_flags flags, func_type complete_func)
+    : reactor_op_ext_local(success_ec, &reactive_socket_recv_op_base_ext_local::do_perform, complete_func),
+      socket_(socket),
+      state_(state),
+      buffers_(buffers),
+      flags_(flags)
+  {
+  }
+
+  static status do_perform(reactor_op* base)
+  {
+    reactive_socket_recv_op_base_ext_local* o(
+        static_cast<reactive_socket_recv_op_base_ext_local*>(base));
+
+    typedef buffer_sequence_adapter<boost::asio::mutable_buffer,
+            MutableBufferSequence> bufs_type;
+
+    status result;
+    if (bufs_type::is_single_buffer)
+    {
+      result = socket_ops::non_blocking_recv1(o->socket_,
+          bufs_type::first(o->buffers_).data(),
+          bufs_type::first(o->buffers_).size(), o->flags_,
+          (o->state_ & socket_ops::stream_oriented) != 0,
+          o->ec_, o->bytes_transferred_) ? done : not_done;
+    }
+    else
+    {
+      bufs_type bufs(o->buffers_);
+      result = socket_ops::non_blocking_recv(o->socket_,
+          bufs.buffers(), bufs.count(), o->flags_,
+          (o->state_ & socket_ops::stream_oriented) != 0,
+          o->ec_, o->bytes_transferred_) ? done : not_done;
+    }
+
+    if (result == done)
+      if ((o->state_ & socket_ops::stream_oriented) != 0)
+        if (o->bytes_transferred_ == 0)
+          result = done_and_exhausted;
+
+    BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_recv",
+          o->ec_, o->bytes_transferred_));
+
+    return result;
+  }
+
+private:
+  socket_type socket_;
+  socket_ops::state_type state_;
+  MutableBufferSequence buffers_;
+  socket_base::message_flags flags_;
+};
+
+template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
+class reactive_socket_recv_op_ext_local :
+  public reactive_socket_recv_op_base_ext_local<MutableBufferSequence>
+{
+public:
+  BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_recv_op_ext_local);
+
+  reactive_socket_recv_op_ext_local(const boost::system::error_code& success_ec,
+      socket_type socket, socket_ops::state_type state,
+      const MutableBufferSequence& buffers, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+    : reactive_socket_recv_op_base_ext_local<MutableBufferSequence>(success_ec,
+        socket, state, buffers, flags,
+        &reactive_socket_recv_op_ext_local::do_complete),
+      handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const boost::system::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    reactive_socket_recv_op_ext_local* o(static_cast<reactive_socket_recv_op_ext_local*>(base));
+    ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
+
+    BOOST_ASIO_HANDLER_COMPLETION((*o));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+            o->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder4<Handler, boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t>
+      handler(o->handler_, o->ec_, o->bytes_transferred_, o->uid_, o->gid_);
+    p.h = boost::asio::detail::addressof(handler.handler_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_, handler.arg3, handler.arg4));
+      w.complete(handler, handler.handler_);
+      BOOST_ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECV_OP_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvfrom_op_ext.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvfrom_op_ext.hpp
new file mode 100644
index 0000000..875fe14
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvfrom_op_ext.hpp
@@ -0,0 +1,153 @@
+//
+// detail/reactive_socket_recvfrom_op_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVFROM_OP_EXT_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVFROM_OP_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/bind_handler.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/fenced_block.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <boost/asio/detail/handler_invoke_helpers.hpp>
+#include <boost/asio/detail/handler_work.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/reactor_op_ext.hpp>
+#include <boost/asio/detail/socket_ops_ext.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename MutableBufferSequence, typename Endpoint>
+class reactive_socket_recvfrom_op_base_ext : public reactor_op_ext
+{
+public:
+  reactive_socket_recvfrom_op_base_ext(const boost::system::error_code& success_ec,
+      socket_type socket, int protocol_type,
+      const MutableBufferSequence& buffers, Endpoint& endpoint,
+      socket_base::message_flags flags, func_type complete_func)
+    : reactor_op_ext(success_ec, &reactive_socket_recvfrom_op_base_ext::do_perform, complete_func),
+      socket_(socket),
+      protocol_type_(protocol_type),
+      buffers_(buffers),
+      sender_endpoint_(endpoint),
+      flags_(flags)
+  {
+  }
+
+  static status do_perform(reactor_op* base)
+  {
+    reactive_socket_recvfrom_op_base_ext* o(
+        static_cast<reactive_socket_recvfrom_op_base_ext*>(base));
+
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(o->buffers_);
+
+    std::size_t addr_len = o->sender_endpoint_.capacity();
+    status result = socket_ops::non_blocking_recvfrom(o->socket_,
+        bufs.buffers(), bufs.count(), o->flags_,
+        o->sender_endpoint_.data(), &addr_len,
+        o->ec_, o->bytes_transferred_, o->da_) ? done : not_done;
+
+    if (result && !o->ec_)
+      o->sender_endpoint_.resize(addr_len);
+
+    BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_recvfrom",
+          o->ec_, o->bytes_transferred_));
+
+    return result;
+  }
+
+private:
+  socket_type socket_;
+  int protocol_type_;
+  MutableBufferSequence buffers_;
+  Endpoint& sender_endpoint_;
+  socket_base::message_flags flags_;
+};
+
+template <typename MutableBufferSequence, typename Endpoint,
+    typename Handler, typename IoExecutor>
+class reactive_socket_recvfrom_op_ext :
+  public reactive_socket_recvfrom_op_base_ext<MutableBufferSequence, Endpoint>
+{
+public:
+  BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_recvfrom_op_ext);
+
+  reactive_socket_recvfrom_op_ext(const boost::system::error_code& success_ec,
+      socket_type socket, int protocol_type,
+      const MutableBufferSequence& buffers, Endpoint& endpoint,
+      socket_base::message_flags flags, Handler& handler,
+      const IoExecutor& io_ex)
+    : reactive_socket_recvfrom_op_base_ext<MutableBufferSequence, Endpoint>(
+        success_ec, socket, protocol_type, buffers, endpoint, flags,
+        &reactive_socket_recvfrom_op_ext::do_complete),
+      handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const boost::system::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    reactive_socket_recvfrom_op_ext* o(
+        static_cast<reactive_socket_recvfrom_op_ext*>(base));
+    ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
+
+    BOOST_ASIO_HANDLER_COMPLETION((*o));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+          o->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder3<Handler, boost::system::error_code, std::size_t, boost::asio::ip::address>
+      handler(o->handler_, o->ec_, o->bytes_transferred_, o->da_);
+    p.h = boost::asio::detail::addressof(handler.handler_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_, handler.arg3_));
+      w.complete(handler, handler.handler_);
+      BOOST_ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVFROM_OP_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvfrom_op_ext_local.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvfrom_op_ext_local.hpp
new file mode 100644
index 0000000..f9fef2b
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvfrom_op_ext_local.hpp
@@ -0,0 +1,148 @@
+//
+// detail/reactive_socket_recvfrom_op_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVFROM_OP_EXT_LOCAL_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVFROM_OP_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/bind_handler.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/fenced_block.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/reactor_op_ext_local.hpp>
+#include <boost/asio/detail/socket_ops_ext_local.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename MutableBufferSequence, typename Endpoint>
+class reactive_socket_recvfrom_op_base_ext_local : public reactor_op_ext_local
+{
+public:
+  reactive_socket_recvfrom_op_base_ext_local(socket_type socket, int protocol_type,
+      const MutableBufferSequence& buffers, Endpoint& endpoint,
+      socket_base::message_flags flags, func_type complete_func)
+    : reactor_op_ext_local(&reactive_socket_recvfrom_op_base_ext_local::do_perform, complete_func),
+      socket_(socket),
+      protocol_type_(protocol_type),
+      buffers_(buffers),
+      sender_endpoint_(endpoint),
+      flags_(flags)
+  {
+  }
+
+  static status do_perform(reactor_op* base)
+  {
+    reactive_socket_recvfrom_op_base_ext_local* o(
+        static_cast<reactive_socket_recvfrom_op_base_ext_local*>(base));
+
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(o->buffers_);
+
+    std::size_t addr_len = o->sender_endpoint_.capacity();
+    status result = socket_ops::non_blocking_recvfrom(o->socket_,
+        bufs.buffers(), bufs.count(), o->flags_,
+        o->sender_endpoint_.data(), &addr_len,
+        o->ec_, o->bytes_transferred_, o->uid_, o->gid_) ? done : not_done;
+
+    if (result && !o->ec_)
+      o->sender_endpoint_.resize(addr_len);
+
+    BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_recvfrom",
+          o->ec_, o->bytes_transferred_));
+
+    return result;
+  }
+
+private:
+  socket_type socket_;
+  int protocol_type_;
+  MutableBufferSequence buffers_;
+  Endpoint& sender_endpoint_;
+  socket_base::message_flags flags_;
+};
+
+template <typename MutableBufferSequence, typename Endpoint,
+    typename Handler, typename IoExecutor>
+class reactive_socket_recvfrom_op_ext_local :
+  public reactive_socket_recvfrom_op_base_ext_local<MutableBufferSequence, Endpoint>
+{
+public:
+  BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_recvfrom_op_ext_local);
+
+  reactive_socket_recvfrom_op_ext_local(socket_type socket, int protocol_type,
+      const MutableBufferSequence& buffers, Endpoint& endpoint,
+      socket_base::message_flags flags, Handler& handler,
+      const IoExecutor& io_ex)
+    : reactive_socket_recvfrom_op_base_ext_local<MutableBufferSequence, Endpoint>(
+        socket, protocol_type, buffers, endpoint, flags,
+        &reactive_socket_recvfrom_op_ext_local::do_complete),
+      handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const boost::system::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    reactive_socket_recvfrom_op_ext_local* o(
+        static_cast<reactive_socket_recvfrom_op_ext_local*>(base));
+    ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
+
+    BOOST_ASIO_HANDLER_COMPLETION((*o));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+          o->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder4<Handler, boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t>
+      handler(o->handler_, o->ec_, o->bytes_transferred_, o->uid_, o->gid_);
+    p.h = boost::asio::detail::addressof(handler.handler_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_, handler.arg3_, handler.arg4_));
+      w.complete(handler, handler.handler_);
+      BOOST_ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVFROM_OP_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvmsg_op_ext.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvmsg_op_ext.hpp
new file mode 100644
index 0000000..bd315dc
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvmsg_op_ext.hpp
@@ -0,0 +1,144 @@
+//
+// detail/reactive_socket_recvmsg_op_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVMSG_OP_EXT_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVMSG_OP_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/bind_handler.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/fenced_block.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <boost/asio/detail/handler_invoke_helpers.hpp>
+#include <boost/asio/detail/handler_work.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/reactor_op_ext.hpp>
+#include <boost/asio/detail/socket_ops_ext.hpp>
+#include <boost/asio/socket_base.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename MutableBufferSequence>
+class reactive_socket_recvmsg_op_base_ext : public reactor_op_ext
+{
+public:
+  reactive_socket_recvmsg_op_base_ext(const boost::system::error_code& success_ec,
+	  socket_type socket, const MutableBufferSequence& buffers, socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, func_type complete_func)
+    : reactor_op_ext(&reactive_socket_recvmsg_op_base_ext::do_perform, complete_func),
+      socket_(socket),
+      buffers_(buffers),
+      in_flags_(in_flags),
+      out_flags_(out_flags)
+  {
+  }
+
+  static status do_perform(reactor_op* base)
+  {
+    reactive_socket_recvmsg_op_base_ext* o(
+        static_cast<reactive_socket_recvmsg_op_base_ext*>(base));
+
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(o->buffers_);
+
+    status result = socket_ops::non_blocking_recvmsg(o->socket_,
+        bufs.buffers(), bufs.count(),
+        o->in_flags_, o->out_flags_,
+        o->ec_, o->bytes_transferred_) ? done : not_done;
+
+    BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_recvmsg",
+          o->ec_, o->bytes_transferred_));
+
+    return result;
+  }
+
+private:
+  socket_type socket_;
+  MutableBufferSequence buffers_;
+  socket_base::message_flags in_flags_;
+  socket_base::message_flags& out_flags_;
+};
+
+template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
+class reactive_socket_recvmsg_op_ext :
+  public reactive_socket_recvmsg_op_base_ext<MutableBufferSequence>
+{
+public:
+  BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_recvmsg_op_ext);
+
+  reactive_socket_recvmsg_op_ext(const boost::system::error_code& success_ec,
+      socket_type socket, const MutableBufferSequence& buffers, socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, Handler& handler,
+      const IoExecutor& io_ex)
+    : reactive_socket_recvmsg_op_base_ext<MutableBufferSequence>(socket, buffers,
+        in_flags, out_flags, &reactive_socket_recvmsg_op_ext::do_complete),
+      handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const boost::system::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    reactive_socket_recvmsg_op_ext* o(
+        static_cast<reactive_socket_recvmsg_op_ext*>(base));
+    ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
+
+    BOOST_ASIO_HANDLER_COMPLETION((*o));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+            o->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder3<Handler, boost::system::error_code, std::size_t, boost::asio::ip::address>
+      handler(o->handler_, o->ec_, o->bytes_transferred_, o->da_);
+    p.h = boost::asio::detail::addressof(handler.handler_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_, handler.arg3_));
+      w.complete(handler, handler.handler_);
+      BOOST_ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVMSG_OP_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvmsg_op_ext_local.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvmsg_op_ext_local.hpp
new file mode 100644
index 0000000..8148690
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_recvmsg_op_ext_local.hpp
@@ -0,0 +1,145 @@
+//
+// detail/reactive_socket_recvmsg_op_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVMSG_OP_EXT_LOCAL_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVMSG_OP_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/bind_handler.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/fenced_block.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <boost/asio/detail/handler_invoke_helpers.hpp>
+#include <boost/asio/detail/handler_work.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/reactor_op_ext_local.hpp>
+#include <boost/asio/detail/socket_ops_ext_local.hpp>
+#include <boost/asio/socket_base.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename MutableBufferSequence>
+class reactive_socket_recvmsg_op_base_ext_local : public reactor_op_ext_local
+{
+public:
+  reactive_socket_recvmsg_op_base_ext_local(const boost::system::error_code& success_ec,
+      socket_type socket, const MutableBufferSequence& buffers, socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, func_type complete_func)
+    : reactor_op_ext_local(success_ec, &reactive_socket_recvmsg_op_base_ext_local::do_perform, complete_func),
+      socket_(socket),
+      buffers_(buffers),
+      in_flags_(in_flags),
+      out_flags_(out_flags)
+  {
+  }
+
+  static status do_perform(reactor_op* base)
+  {
+    reactive_socket_recvmsg_op_base_ext_local* o(
+        static_cast<reactive_socket_recvmsg_op_base_ext_local*>(base));
+
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(o->buffers_);
+
+    status result = socket_ops::non_blocking_recvmsg(o->socket_,
+        bufs.buffers(), bufs.count(),
+        o->in_flags_, o->out_flags_,
+        o->ec_, o->bytes_transferred_) ? done : not_done;
+
+    BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_recvmsg",
+          o->ec_, o->bytes_transferred_));
+
+    return result;
+  }
+
+private:
+  socket_type socket_;
+  MutableBufferSequence buffers_;
+  socket_base::message_flags in_flags_;
+  socket_base::message_flags& out_flags_;
+};
+
+template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
+class reactive_socket_recvmsg_op_ext_local :
+  public reactive_socket_recvmsg_op_base_ext_local<MutableBufferSequence>
+{
+public:
+  BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_recvmsg_op_ext_local);
+
+  reactive_socket_recvmsg_op_ext_local(const boost::system::error_code& success_ec,
+      socket_type socket, const MutableBufferSequence& buffers, socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, Handler& handler,
+      const IoExecutor& io_ex)
+    : reactive_socket_recvmsg_op_base_ext_local<MutableBufferSequence>(success_ec,
+        socket, buffers, in_flags, out_flags,
+        &reactive_socket_recvmsg_op_ext_local::do_complete),
+      handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const boost::system::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    reactive_socket_recvmsg_op_ext_local* o(
+        static_cast<reactive_socket_recvmsg_op_ext_local*>(base));
+    ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
+
+    BOOST_ASIO_HANDLER_COMPLETION((*o));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+          o->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder4<Handler, boost::system::error_code, std::size_t, std::uint32_t, std::uint32_t>
+      handler(o->handler_, o->ec_, o->bytes_transferred_, o->uid_, o->gid_);
+    p.h = boost::asio::detail::addressof(handler.handler_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_, handler.arg3_, handler.arg4_));
+      w.complete(handler, handler.handler_);
+      BOOST_ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVMSG_OP_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_base_ext.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_base_ext.hpp
new file mode 100644
index 0000000..2e68a87
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_base_ext.hpp
@@ -0,0 +1,524 @@
+//
+// detail/reactive_socket_service_base.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_BASE_EXT_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_BASE_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#if !defined(BOOST_ASIO_HAS_IOCP) \
+  && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
+
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/error.hpp>
+#include <boost/asio/execution_context.hpp>
+#include <boost/asio/socket_base.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/reactive_null_buffers_op.hpp>
+#include <boost/asio/detail/reactive_socket_recv_op_ext.hpp>
+#include <boost/asio/detail/reactive_socket_recvmsg_op_ext.hpp>
+#include <boost/asio/detail/reactive_socket_send_op.hpp>
+#include <boost/asio/detail/reactive_wait_op.hpp>
+#include <boost/asio/detail/reactor.hpp>
+#include <boost/asio/detail/reactor_op.hpp>
+#include <boost/asio/detail/socket_holder.hpp>
+#include <boost/asio/detail/socket_ops_ext.hpp>
+#include <boost/asio/detail/socket_types.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+class reactive_socket_service_base_ext
+{
+public:
+  // The native type of a socket.
+  typedef socket_type native_handle_type;
+
+  // The implementation type of the socket.
+  struct base_implementation_type
+  {
+    // The native socket representation.
+    socket_type socket_;
+
+    // The current state of the socket.
+    socket_ops::state_type state_;
+
+    // Per-descriptor data used by the reactor.
+    reactor::per_descriptor_data reactor_data_;
+  };
+
+  // Constructor.
+  BOOST_ASIO_DECL reactive_socket_service_base_ext(execution_context& context);
+
+  // Destroy all user-defined handler objects owned by the service.
+  BOOST_ASIO_DECL void base_shutdown();
+
+  // Construct a new socket implementation.
+  BOOST_ASIO_DECL void construct(base_implementation_type& impl);
+
+  // Move-construct a new socket implementation.
+  BOOST_ASIO_DECL void base_move_construct(base_implementation_type& impl,
+      base_implementation_type& other_impl);
+
+  // Move-assign from another socket implementation.
+  BOOST_ASIO_DECL void base_move_assign(base_implementation_type& impl,
+      reactive_socket_service_base_ext& other_service,
+      base_implementation_type& other_impl);
+
+  // Destroy a socket implementation.
+  BOOST_ASIO_DECL void destroy(base_implementation_type& impl);
+
+  // Determine whether the socket is open.
+  bool is_open(const base_implementation_type& impl) const
+  {
+    return impl.socket_ != invalid_socket;
+  }
+
+  // Destroy a socket implementation.
+  BOOST_ASIO_DECL boost::system::error_code close(
+      base_implementation_type& impl, boost::system::error_code& ec);
+
+  // Release ownership of the socket.
+  BOOST_ASIO_DECL socket_type release(
+      base_implementation_type& impl, boost::system::error_code& ec);
+
+  // Get the native socket representation.
+  native_handle_type native_handle(base_implementation_type& impl)
+  {
+    return impl.socket_;
+  }
+
+  // Cancel all operations associated with the socket.
+  BOOST_ASIO_DECL boost::system::error_code cancel(
+      base_implementation_type& impl, boost::system::error_code& ec);
+
+  // Determine whether the socket is at the out-of-band data mark.
+  bool at_mark(const base_implementation_type& impl,
+      boost::system::error_code& ec) const
+  {
+    return socket_ops::sockatmark(impl.socket_, ec);
+  }
+
+  // Determine the number of bytes available for reading.
+  std::size_t available(const base_implementation_type& impl,
+      boost::system::error_code& ec) const
+  {
+    return socket_ops::available(impl.socket_, ec);
+  }
+
+  // Place the socket into the state where it will listen for new connections.
+  boost::system::error_code listen(base_implementation_type& impl,
+      int backlog, boost::system::error_code& ec)
+  {
+    socket_ops::listen(impl.socket_, backlog, ec);
+    return ec;
+  }
+
+  // Perform an IO control command on the socket.
+  template <typename IO_Control_Command>
+  boost::system::error_code io_control(base_implementation_type& impl,
+      IO_Control_Command& command, boost::system::error_code& ec)
+  {
+    socket_ops::ioctl(impl.socket_, impl.state_, command.name(),
+        static_cast<ioctl_arg_type*>(command.data()), ec);
+    return ec;
+  }
+
+  // Gets the non-blocking mode of the socket.
+  bool non_blocking(const base_implementation_type& impl) const
+  {
+    return (impl.state_ & socket_ops::user_set_non_blocking) != 0;
+  }
+
+  // Sets the non-blocking mode of the socket.
+  boost::system::error_code non_blocking(base_implementation_type& impl,
+      bool mode, boost::system::error_code& ec)
+  {
+    socket_ops::set_user_non_blocking(impl.socket_, impl.state_, mode, ec);
+    return ec;
+  }
+
+  // Gets the non-blocking mode of the native socket implementation.
+  bool native_non_blocking(const base_implementation_type& impl) const
+  {
+    return (impl.state_ & socket_ops::internal_non_blocking) != 0;
+  }
+
+  // Sets the non-blocking mode of the native socket implementation.
+  boost::system::error_code native_non_blocking(base_implementation_type& impl,
+      bool mode, boost::system::error_code& ec)
+  {
+    socket_ops::set_internal_non_blocking(impl.socket_, impl.state_, mode, ec);
+    return ec;
+  }
+
+  // Wait for the socket to become ready to read, ready to write, or to have
+  // pending error conditions.
+  boost::system::error_code wait(base_implementation_type& impl,
+      socket_base::wait_type w, boost::system::error_code& ec)
+  {
+    switch (w)
+    {
+    case socket_base::wait_read:
+      socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
+      break;
+    case socket_base::wait_write:
+      socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);
+      break;
+    case socket_base::wait_error:
+      socket_ops::poll_error(impl.socket_, impl.state_, -1, ec);
+      break;
+    default:
+      ec = boost::asio::error::invalid_argument;
+      break;
+    }
+
+    return ec;
+  }
+
+  // Asynchronously wait for the socket to become ready to read, ready to
+  // write, or to have pending error conditions.
+  template <typename Handler, typename IoExecutor>
+  void async_wait(base_implementation_type& impl,
+      socket_base::wait_type w, Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_wait_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_wait"));
+
+    int op_type;
+    switch (w)
+    {
+      case socket_base::wait_read:
+        op_type = reactor::read_op;
+        break;
+      case socket_base::wait_write:
+        op_type = reactor::write_op;
+        break;
+      case socket_base::wait_error:
+        op_type = reactor::except_op;
+        break;
+      default:
+        p.p->ec_ = boost::asio::error::invalid_argument;
+        reactor_.post_immediate_completion(p.p, is_continuation);
+        p.v = p.p = 0;
+        return;
+    }
+
+    start_op(impl, op_type, p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Send the given data to the peer.
+  template <typename ConstBufferSequence>
+  size_t send(base_implementation_type& impl,
+      const ConstBufferSequence& buffers,
+      socket_base::message_flags flags, boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::const_buffer,
+        ConstBufferSequence> bufs(buffers);
+
+    return socket_ops::sync_send(impl.socket_, impl.state_,
+        bufs.buffers(), bufs.count(), flags, bufs.all_empty(), ec);
+  }
+
+  // Wait until data can be sent without blocking.
+  size_t send(base_implementation_type& impl, const null_buffers&,
+      socket_base::message_flags, boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);
+
+    return 0;
+  }
+
+  // Start an asynchronous send. The data being sent must be valid for the
+  // lifetime of the asynchronous operation.
+  template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
+  void async_send(base_implementation_type& impl,
+      const ConstBufferSequence& buffers, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_send_op<
+        ConstBufferSequence, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, impl.state_,
+        buffers, flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_send"));
+
+    start_op(impl, reactor::write_op, p.p, is_continuation, true,
+        ((impl.state_ & socket_ops::stream_oriented)
+          && buffer_sequence_adapter<boost::asio::const_buffer,
+            ConstBufferSequence>::all_empty(buffers)));
+    p.v = p.p = 0;
+  }
+
+  // Start an asynchronous wait until data can be sent without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_send(base_implementation_type& impl, const null_buffers&,
+      socket_base::message_flags, Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_send(null_buffers)"));
+
+    start_op(impl, reactor::write_op, p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Receive some data from the peer. Returns the number of bytes received.
+  template <typename MutableBufferSequence>
+  size_t receive(base_implementation_type& impl,
+      const MutableBufferSequence& buffers,
+      socket_base::message_flags flags, boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(buffers);
+
+    return socket_ops::sync_recv(impl.socket_, impl.state_,
+        bufs.buffers(), bufs.count(), flags, bufs.all_empty(), ec);
+  }
+
+  // Wait until data can be received without blocking.
+  size_t receive(base_implementation_type& impl, const null_buffers&,
+      socket_base::message_flags, boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
+
+    return 0;
+  }
+
+  // Start an asynchronous receive. The buffer for the data being received
+  // must be valid for the lifetime of the asynchronous operation.
+  template <typename MutableBufferSequence,
+      typename Handler, typename IoExecutor>
+  void async_receive(base_implementation_type& impl,
+      const MutableBufferSequence& buffers, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_recv_op_ext<
+        MutableBufferSequence, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, impl.state_,
+        buffers, flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive"));
+
+    start_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation,
+        (flags & socket_base::message_out_of_band) == 0,
+        ((impl.state_ & socket_ops::stream_oriented)
+          && buffer_sequence_adapter<boost::asio::mutable_buffer,
+            MutableBufferSequence>::all_empty(buffers)));
+    p.v = p.p = 0;
+  }
+
+  // Wait until data can be received without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_receive(base_implementation_type& impl,
+      const null_buffers&, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive(null_buffers)"));
+
+    start_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Receive some data with associated flags. Returns the number of bytes
+  // received.
+  template <typename MutableBufferSequence>
+  size_t receive_with_flags(base_implementation_type& impl,
+      const MutableBufferSequence& buffers,
+      socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(buffers);
+
+    return socket_ops::sync_recvmsg(impl.socket_, impl.state_,
+        bufs.buffers(), bufs.count(), in_flags, out_flags, ec);
+  }
+
+  // Wait until data can be received without blocking.
+  size_t receive_with_flags(base_implementation_type& impl,
+      const null_buffers&, socket_base::message_flags,
+      socket_base::message_flags& out_flags, boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
+
+    // Clear out_flags, since we cannot give it any other sensible value when
+    // performing a null_buffers operation.
+    out_flags = 0;
+
+    return 0;
+  }
+
+  // Start an asynchronous receive. The buffer for the data being received
+  // must be valid for the lifetime of the asynchronous operation.
+  template <typename MutableBufferSequence,
+      typename Handler, typename IoExecutor>
+  void async_receive_with_flags(base_implementation_type& impl,
+      const MutableBufferSequence& buffers, socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, Handler& handler,
+      const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_recvmsg_op_ext<
+        MutableBufferSequence, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, buffers,
+        in_flags, out_flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive_with_flags"));
+
+    start_op(impl,
+        (in_flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation,
+        (in_flags & socket_base::message_out_of_band) == 0, false);
+    p.v = p.p = 0;
+  }
+
+  // Wait until data can be received without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_receive_with_flags(base_implementation_type& impl,
+      const null_buffers&, socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, Handler& handler,
+      const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive_with_flags(null_buffers)"));
+
+    // Clear out_flags, since we cannot give it any other sensible value when
+    // performing a null_buffers operation.
+    out_flags = 0;
+
+    start_op(impl,
+        (in_flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+protected:
+  // Open a new socket implementation.
+  BOOST_ASIO_DECL boost::system::error_code do_open(
+      base_implementation_type& impl, int af,
+      int type, int protocol, boost::system::error_code& ec);
+
+  // Assign a native socket to a socket implementation.
+  BOOST_ASIO_DECL boost::system::error_code do_assign(
+      base_implementation_type& impl, int type,
+      const native_handle_type& native_socket, boost::system::error_code& ec);
+
+  // Start the asynchronous read or write operation.
+  BOOST_ASIO_DECL void start_op(base_implementation_type& impl, int op_type,
+      reactor_op* op, bool is_continuation, bool is_non_blocking, bool noop);
+
+  // Start the asynchronous accept operation.
+  BOOST_ASIO_DECL void start_accept_op(base_implementation_type& impl,
+      reactor_op* op, bool is_continuation, bool peer_is_open);
+
+  // Start the asynchronous connect operation.
+  BOOST_ASIO_DECL void start_connect_op(base_implementation_type& impl,
+      reactor_op* op, bool is_continuation,
+      const socket_addr_type* addr, size_t addrlen);
+
+  // The selector that performs event demultiplexing for the service.
+  reactor& reactor_;
+
+  // Cached success value to avoid accessing category singleton.
+  const boost::system::error_code success_ec_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#if defined(BOOST_ASIO_HEADER_ONLY)
+# include <boost/asio/detail/impl/reactive_socket_service_base_ext.ipp>
+#endif // defined(BOOST_ASIO_HEADER_ONLY)
+
+#endif // !defined(BOOST_ASIO_HAS_IOCP)
+       //   && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_BASE_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_base_ext_local.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_base_ext_local.hpp
new file mode 100644
index 0000000..a71fce5
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_base_ext_local.hpp
@@ -0,0 +1,524 @@
+//
+// detail/reactive_socket_service_base_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_BASE_EXT_LOCAL_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_BASE_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#if !defined(BOOST_ASIO_HAS_IOCP) \
+  && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
+
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/error.hpp>
+#include <boost/asio/execution_context.hpp>
+#include <boost/asio/socket_base.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/reactive_null_buffers_op.hpp>
+#include <boost/asio/detail/reactive_socket_recv_op_ext_local.hpp>
+#include <boost/asio/detail/reactive_socket_recvmsg_op_ext_local.hpp>
+#include <boost/asio/detail/reactive_socket_send_op.hpp>
+#include <boost/asio/detail/reactive_wait_op.hpp>
+#include <boost/asio/detail/reactor.hpp>
+#include <boost/asio/detail/reactor_op.hpp>
+#include <boost/asio/detail/socket_holder.hpp>
+#include <boost/asio/detail/socket_ops_ext_local.hpp>
+#include <boost/asio/detail/socket_types.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+class reactive_socket_service_base_ext_local
+{
+public:
+  // The native type of a socket.
+  typedef socket_type native_handle_type;
+
+  // The implementation type of the socket.
+  struct base_implementation_type
+  {
+    // The native socket representation.
+    socket_type socket_;
+
+    // The current state of the socket.
+    socket_ops::state_type state_;
+
+    // Per-descriptor data used by the reactor.
+    reactor::per_descriptor_data reactor_data_;
+  };
+
+  // Constructor.
+  BOOST_ASIO_DECL reactive_socket_service_base_ext_local(execution_context& context);
+
+  // Destroy all user-defined handler objects owned by the service.
+  BOOST_ASIO_DECL void base_shutdown();
+
+  // Construct a new socket implementation.
+  BOOST_ASIO_DECL void construct(base_implementation_type& impl);
+
+  // Move-construct a new socket implementation.
+  BOOST_ASIO_DECL void base_move_construct(base_implementation_type& impl,
+      base_implementation_type& other_impl);
+
+  // Move-assign from another socket implementation.
+  BOOST_ASIO_DECL void base_move_assign(base_implementation_type& impl,
+      reactive_socket_service_base_ext_local& other_service,
+      base_implementation_type& other_impl);
+
+  // Destroy a socket implementation.
+  BOOST_ASIO_DECL void destroy(base_implementation_type& impl);
+
+  // Determine whether the socket is open.
+  bool is_open(const base_implementation_type& impl) const
+  {
+    return impl.socket_ != invalid_socket;
+  }
+
+  // Destroy a socket implementation.
+  BOOST_ASIO_DECL boost::system::error_code close(
+      base_implementation_type& impl, boost::system::error_code& ec);
+
+  // Release ownership of the socket.
+  BOOST_ASIO_DECL socket_type release(
+      base_implementation_type& impl, boost::system::error_code& ec);
+
+  // Get the native socket representation.
+  native_handle_type native_handle(base_implementation_type& impl)
+  {
+    return impl.socket_;
+  }
+
+  // Cancel all operations associated with the socket.
+  BOOST_ASIO_DECL boost::system::error_code cancel(
+      base_implementation_type& impl, boost::system::error_code& ec);
+
+  // Determine whether the socket is at the out-of-band data mark.
+  bool at_mark(const base_implementation_type& impl,
+      boost::system::error_code& ec) const
+  {
+    return socket_ops::sockatmark(impl.socket_, ec);
+  }
+
+  // Determine the number of bytes available for reading.
+  std::size_t available(const base_implementation_type& impl,
+      boost::system::error_code& ec) const
+  {
+    return socket_ops::available(impl.socket_, ec);
+  }
+
+  // Place the socket into the state where it will listen for new connections.
+  boost::system::error_code listen(base_implementation_type& impl,
+      int backlog, boost::system::error_code& ec)
+  {
+    socket_ops::listen(impl.socket_, backlog, ec);
+    return ec;
+  }
+
+  // Perform an IO control command on the socket.
+  template <typename IO_Control_Command>
+  boost::system::error_code io_control(base_implementation_type& impl,
+      IO_Control_Command& command, boost::system::error_code& ec)
+  {
+    socket_ops::ioctl(impl.socket_, impl.state_, command.name(),
+        static_cast<ioctl_arg_type*>(command.data()), ec);
+    return ec;
+  }
+
+  // Gets the non-blocking mode of the socket.
+  bool non_blocking(const base_implementation_type& impl) const
+  {
+    return (impl.state_ & socket_ops::user_set_non_blocking) != 0;
+  }
+
+  // Sets the non-blocking mode of the socket.
+  boost::system::error_code non_blocking(base_implementation_type& impl,
+      bool mode, boost::system::error_code& ec)
+  {
+    socket_ops::set_user_non_blocking(impl.socket_, impl.state_, mode, ec);
+    return ec;
+  }
+
+  // Gets the non-blocking mode of the native socket implementation.
+  bool native_non_blocking(const base_implementation_type& impl) const
+  {
+    return (impl.state_ & socket_ops::internal_non_blocking) != 0;
+  }
+
+  // Sets the non-blocking mode of the native socket implementation.
+  boost::system::error_code native_non_blocking(base_implementation_type& impl,
+      bool mode, boost::system::error_code& ec)
+  {
+    socket_ops::set_internal_non_blocking(impl.socket_, impl.state_, mode, ec);
+    return ec;
+  }
+
+  // Wait for the socket to become ready to read, ready to write, or to have
+  // pending error conditions.
+  boost::system::error_code wait(base_implementation_type& impl,
+      socket_base::wait_type w, boost::system::error_code& ec)
+  {
+    switch (w)
+    {
+    case socket_base::wait_read:
+      socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
+      break;
+    case socket_base::wait_write:
+      socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);
+      break;
+    case socket_base::wait_error:
+      socket_ops::poll_error(impl.socket_, impl.state_, -1, ec);
+      break;
+    default:
+      ec = boost::asio::error::invalid_argument;
+      break;
+    }
+
+    return ec;
+  }
+
+  // Asynchronously wait for the socket to become ready to read, ready to
+  // write, or to have pending error conditions.
+  template <typename Handler, typename IoExecutor>
+  void async_wait(base_implementation_type& impl,
+      socket_base::wait_type w, Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_wait_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_wait"));
+
+    int op_type;
+    switch (w)
+    {
+      case socket_base::wait_read:
+        op_type = reactor::read_op;
+        break;
+      case socket_base::wait_write:
+        op_type = reactor::write_op;
+        break;
+      case socket_base::wait_error:
+        op_type = reactor::except_op;
+        break;
+      default:
+        p.p->ec_ = boost::asio::error::invalid_argument;
+        reactor_.post_immediate_completion(p.p, is_continuation);
+        p.v = p.p = 0;
+        return;
+    }
+
+    start_op(impl, op_type, p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Send the given data to the peer.
+  template <typename ConstBufferSequence>
+  size_t send(base_implementation_type& impl,
+      const ConstBufferSequence& buffers,
+      socket_base::message_flags flags, boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::const_buffer,
+        ConstBufferSequence> bufs(buffers);
+
+    return socket_ops::sync_send(impl.socket_, impl.state_,
+        bufs.buffers(), bufs.count(), flags, bufs.all_empty(), ec);
+  }
+
+  // Wait until data can be sent without blocking.
+  size_t send(base_implementation_type& impl, const null_buffers&,
+      socket_base::message_flags, boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);
+
+    return 0;
+  }
+
+  // Start an asynchronous send. The data being sent must be valid for the
+  // lifetime of the asynchronous operation.
+  template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
+  void async_send(base_implementation_type& impl,
+      const ConstBufferSequence& buffers, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_send_op<
+        ConstBufferSequence, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, impl.state_,
+        buffers, flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_send"));
+
+    start_op(impl, reactor::write_op, p.p, is_continuation, true,
+        ((impl.state_ & socket_ops::stream_oriented)
+          && buffer_sequence_adapter<boost::asio::const_buffer,
+            ConstBufferSequence>::all_empty(buffers)));
+    p.v = p.p = 0;
+  }
+
+  // Start an asynchronous wait until data can be sent without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_send(base_implementation_type& impl, const null_buffers&,
+      socket_base::message_flags, Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_send(null_buffers)"));
+
+    start_op(impl, reactor::write_op, p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Receive some data from the peer. Returns the number of bytes received.
+  template <typename MutableBufferSequence>
+  size_t receive(base_implementation_type& impl,
+      const MutableBufferSequence& buffers,
+      socket_base::message_flags flags, boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(buffers);
+
+    return socket_ops::sync_recv(impl.socket_, impl.state_,
+        bufs.buffers(), bufs.count(), flags, bufs.all_empty(), ec);
+  }
+
+  // Wait until data can be received without blocking.
+  size_t receive(base_implementation_type& impl, const null_buffers&,
+      socket_base::message_flags, boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
+
+    return 0;
+  }
+
+  // Start an asynchronous receive. The buffer for the data being received
+  // must be valid for the lifetime of the asynchronous operation.
+  template <typename MutableBufferSequence,
+      typename Handler, typename IoExecutor>
+  void async_receive(base_implementation_type& impl,
+      const MutableBufferSequence& buffers, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_recv_op_ext_local<
+        MutableBufferSequence, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, impl.state_,
+        buffers, flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive"));
+
+    start_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation,
+        (flags & socket_base::message_out_of_band) == 0,
+        ((impl.state_ & socket_ops::stream_oriented)
+          && buffer_sequence_adapter<boost::asio::mutable_buffer,
+            MutableBufferSequence>::all_empty(buffers)));
+    p.v = p.p = 0;
+  }
+
+  // Wait until data can be received without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_receive(base_implementation_type& impl,
+      const null_buffers&, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive(null_buffers)"));
+
+    start_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Receive some data with associated flags. Returns the number of bytes
+  // received.
+  template <typename MutableBufferSequence>
+  size_t receive_with_flags(base_implementation_type& impl,
+      const MutableBufferSequence& buffers,
+      socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(buffers);
+
+    return socket_ops::sync_recvmsg(impl.socket_, impl.state_,
+        bufs.buffers(), bufs.count(), in_flags, out_flags, ec);
+  }
+
+  // Wait until data can be received without blocking.
+  size_t receive_with_flags(base_implementation_type& impl,
+      const null_buffers&, socket_base::message_flags,
+      socket_base::message_flags& out_flags, boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
+
+    // Clear out_flags, since we cannot give it any other sensible value when
+    // performing a null_buffers operation.
+    out_flags = 0;
+
+    return 0;
+  }
+
+  // Start an asynchronous receive. The buffer for the data being received
+  // must be valid for the lifetime of the asynchronous operation.
+  template <typename MutableBufferSequence,
+      typename Handler, typename IoExecutor>
+  void async_receive_with_flags(base_implementation_type& impl,
+      const MutableBufferSequence& buffers, socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, Handler& handler,
+      const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_recvmsg_op_ext_local<
+        MutableBufferSequence, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, buffers,
+        in_flags, out_flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive_with_flags"));
+
+    start_op(impl,
+        (in_flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation,
+        (in_flags & socket_base::message_out_of_band) == 0, false);
+    p.v = p.p = 0;
+  }
+
+  // Wait until data can be received without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_receive_with_flags(base_implementation_type& impl,
+      const null_buffers&, socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, Handler& handler,
+      const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive_with_flags(null_buffers)"));
+
+    // Clear out_flags, since we cannot give it any other sensible value when
+    // performing a null_buffers operation.
+    out_flags = 0;
+
+    start_op(impl,
+        (in_flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+protected:
+  // Open a new socket implementation.
+  BOOST_ASIO_DECL boost::system::error_code do_open(
+      base_implementation_type& impl, int af,
+      int type, int protocol, boost::system::error_code& ec);
+
+  // Assign a native socket to a socket implementation.
+  BOOST_ASIO_DECL boost::system::error_code do_assign(
+      base_implementation_type& impl, int type,
+      const native_handle_type& native_socket, boost::system::error_code& ec);
+
+  // Start the asynchronous read or write operation.
+  BOOST_ASIO_DECL void start_op(base_implementation_type& impl, int op_type,
+      reactor_op* op, bool is_continuation, bool is_non_blocking, bool noop);
+
+  // Start the asynchronous accept operation.
+  BOOST_ASIO_DECL void start_accept_op(base_implementation_type& impl,
+      reactor_op* op, bool is_continuation, bool peer_is_open);
+
+  // Start the asynchronous connect operation.
+  BOOST_ASIO_DECL void start_connect_op(base_implementation_type& impl,
+      reactor_op* op, bool is_continuation,
+      const socket_addr_type* addr, size_t addrlen);
+
+  // The selector that performs event demultiplexing for the service.
+  reactor& reactor_;
+
+  // Cached success value to avoid accessing category singleton.
+  const boost::system::error_code success_ec_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#if defined(BOOST_ASIO_HEADER_ONLY)
+# include <boost/asio/detail/impl/reactive_socket_service_base_ext_local.ipp>
+#endif // defined(BOOST_ASIO_HEADER_ONLY)
+
+#endif // !defined(BOOST_ASIO_HAS_IOCP)
+       //   && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_BASE_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_ext.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_ext.hpp
new file mode 100644
index 0000000..7254ccd
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_ext.hpp
@@ -0,0 +1,508 @@
+//
+// detail/reactive_socket_service_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_EXT_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#if !defined(BOOST_ASIO_HAS_IOCP)
+
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/error.hpp>
+#include <boost/asio/execution_context.hpp>
+#include <boost/asio/socket_base.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/noncopyable.hpp>
+#include <boost/asio/detail/reactive_null_buffers_op.hpp>
+#include <boost/asio/detail/reactive_socket_accept_op.hpp>
+#include <boost/asio/detail/reactive_socket_connect_op.hpp>
+#include <boost/asio/detail/reactive_socket_recvfrom_op_ext.hpp>
+#include <boost/asio/detail/reactive_socket_sendto_op.hpp>
+#include <boost/asio/detail/reactive_socket_service_base_ext.hpp>
+#include <boost/asio/detail/reactor.hpp>
+#include <boost/asio/detail/reactor_op.hpp>
+#include <boost/asio/detail/socket_holder.hpp>
+#include <boost/asio/detail/socket_ops.hpp>
+#include <boost/asio/detail/socket_types.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Protocol>
+class reactive_socket_service_ext :
+  public execution_context_service_base<reactive_socket_service_ext<Protocol> >,
+  public reactive_socket_service_base_ext
+{
+public:
+  // The protocol type.
+  typedef Protocol protocol_type;
+
+  // The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+  // The native type of a socket.
+  typedef socket_type native_handle_type;
+
+  // The implementation type of the socket.
+  struct implementation_type :
+    reactive_socket_service_base_ext::base_implementation_type
+  {
+    // Default constructor.
+    implementation_type()
+      : protocol_(endpoint_type().protocol())
+    {
+    }
+
+    // The protocol associated with the socket.
+    protocol_type protocol_;
+  };
+
+  // Constructor.
+  reactive_socket_service_ext(execution_context& context)
+    : execution_context_service_base<
+        reactive_socket_service_ext<Protocol> >(context),
+      reactive_socket_service_base_ext(context)
+  {
+  }
+
+  // Destroy all user-defined handler objects owned by the service.
+  void shutdown()
+  {
+    this->base_shutdown();
+  }
+
+  // Move-construct a new socket implementation.
+  void move_construct(implementation_type& impl,
+      implementation_type& other_impl)
+  {
+    this->base_move_construct(impl, other_impl);
+
+    impl.protocol_ = other_impl.protocol_;
+    other_impl.protocol_ = endpoint_type().protocol();
+  }
+
+  // Move-assign from another socket implementation.
+  void move_assign(implementation_type& impl,
+      reactive_socket_service_base_ext& other_service,
+      implementation_type& other_impl)
+  {
+    this->base_move_assign(impl, other_service, other_impl);
+
+    impl.protocol_ = other_impl.protocol_;
+    other_impl.protocol_ = endpoint_type().protocol();
+  }
+
+  // Move-construct a new socket implementation from another protocol type.
+  template <typename Protocol1>
+  void converting_move_construct(implementation_type& impl,
+      reactive_socket_service_ext<Protocol1>&,
+      typename reactive_socket_service_ext<
+        Protocol1>::implementation_type& other_impl)
+  {
+    this->base_move_construct(impl, other_impl);
+
+    impl.protocol_ = protocol_type(other_impl.protocol_);
+    other_impl.protocol_ = typename Protocol1::endpoint().protocol();
+  }
+
+  // Open a new socket implementation.
+  boost::system::error_code open(implementation_type& impl,
+      const protocol_type& protocol, boost::system::error_code& ec)
+  {
+    if (!do_open(impl, protocol.family(),
+          protocol.type(), protocol.protocol(), ec))
+      impl.protocol_ = protocol;
+    return ec;
+  }
+
+  // Assign a native socket to a socket implementation.
+  boost::system::error_code assign(implementation_type& impl,
+      const protocol_type& protocol, const native_handle_type& native_socket,
+      boost::system::error_code& ec)
+  {
+    if (!do_assign(impl, protocol.type(), native_socket, ec))
+      impl.protocol_ = protocol;
+    return ec;
+  }
+
+  // Get the native socket representation.
+  native_handle_type native_handle(implementation_type& impl)
+  {
+    return impl.socket_;
+  }
+
+  // Bind the socket to the specified local endpoint.
+  boost::system::error_code bind(implementation_type& impl,
+      const endpoint_type& endpoint, boost::system::error_code& ec)
+  {
+    socket_ops::bind(impl.socket_, endpoint.data(), endpoint.size(), ec);
+    return ec;
+  }
+
+  // Set a socket option.
+  template <typename Option>
+  boost::system::error_code set_option(implementation_type& impl,
+      const Option& option, boost::system::error_code& ec)
+  {
+    socket_ops::setsockopt(impl.socket_, impl.state_,
+        option.level(impl.protocol_), option.name(impl.protocol_),
+        option.data(impl.protocol_), option.size(impl.protocol_), ec);
+    return ec;
+  }
+
+  // Set a socket option.
+  template <typename Option>
+  boost::system::error_code get_option(const implementation_type& impl,
+      Option& option, boost::system::error_code& ec) const
+  {
+    std::size_t size = option.size(impl.protocol_);
+    socket_ops::getsockopt(impl.socket_, impl.state_,
+        option.level(impl.protocol_), option.name(impl.protocol_),
+        option.data(impl.protocol_), &size, ec);
+    if (!ec)
+      option.resize(impl.protocol_, size);
+    return ec;
+  }
+
+  // Get the local endpoint.
+  endpoint_type local_endpoint(const implementation_type& impl,
+      boost::system::error_code& ec) const
+  {
+    endpoint_type endpoint;
+    std::size_t addr_len = endpoint.capacity();
+    if (socket_ops::getsockname(impl.socket_, endpoint.data(), &addr_len, ec))
+      return endpoint_type();
+    endpoint.resize(addr_len);
+    return endpoint;
+  }
+
+  // Get the remote endpoint.
+  endpoint_type remote_endpoint(const implementation_type& impl,
+      boost::system::error_code& ec) const
+  {
+    endpoint_type endpoint;
+    std::size_t addr_len = endpoint.capacity();
+    if (socket_ops::getpeername(impl.socket_,
+          endpoint.data(), &addr_len, false, ec))
+      return endpoint_type();
+    endpoint.resize(addr_len);
+    return endpoint;
+  }
+
+  // Disable sends or receives on the socket.
+  boost::system::error_code shutdown(base_implementation_type& impl,
+      socket_base::shutdown_type what, boost::system::error_code& ec)
+  {
+    socket_ops::shutdown(impl.socket_, what, ec);
+    return ec;
+  }
+
+  // Send a datagram to the specified endpoint. Returns the number of bytes
+  // sent.
+  template <typename ConstBufferSequence>
+  size_t send_to(implementation_type& impl, const ConstBufferSequence& buffers,
+      const endpoint_type& destination, socket_base::message_flags flags,
+      boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::const_buffer,
+        ConstBufferSequence> bufs(buffers);
+
+    return socket_ops::sync_sendto(impl.socket_, impl.state_,
+        bufs.buffers(), bufs.count(), flags,
+        destination.data(), destination.size(), ec);
+  }
+
+  // Wait until data can be sent without blocking.
+  size_t send_to(implementation_type& impl, const null_buffers&,
+      const endpoint_type&, socket_base::message_flags,
+      boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);
+
+    return 0;
+  }
+
+  // Start an asynchronous send. The data being sent must be valid for the
+  // lifetime of the asynchronous operation.
+  template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
+  void async_send_to(implementation_type& impl,
+      const ConstBufferSequence& buffers,
+      const endpoint_type& destination, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_sendto_op<ConstBufferSequence,
+        endpoint_type, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, buffers,
+        destination, flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_send_to"));
+
+    start_op(impl, reactor::write_op, p.p, is_continuation, true, false);
+    p.v = p.p = 0;
+  }
+
+  // Start an asynchronous wait until data can be sent without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_send_to(implementation_type& impl, const null_buffers&,
+      const endpoint_type&, socket_base::message_flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_send_to(null_buffers)"));
+
+    start_op(impl, reactor::write_op, p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Receive a datagram with the endpoint of the sender. Returns the number of
+  // bytes received.
+  template <typename MutableBufferSequence>
+  size_t receive_from(implementation_type& impl,
+      const MutableBufferSequence& buffers,
+      endpoint_type& sender_endpoint, socket_base::message_flags flags,
+      boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(buffers);
+
+    std::size_t addr_len = sender_endpoint.capacity();
+    std::size_t bytes_recvd = socket_ops::sync_recvfrom(
+        impl.socket_, impl.state_, bufs.buffers(), bufs.count(),
+        flags, sender_endpoint.data(), &addr_len, ec);
+
+    if (!ec)
+      sender_endpoint.resize(addr_len);
+
+    return bytes_recvd;
+  }
+
+  // Wait until data can be received without blocking.
+  size_t receive_from(implementation_type& impl, const null_buffers&,
+      endpoint_type& sender_endpoint, socket_base::message_flags,
+      boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
+
+    // Reset endpoint since it can be given no sensible value at this time.
+    sender_endpoint = endpoint_type();
+
+    return 0;
+  }
+
+  // Start an asynchronous receive. The buffer for the data being received and
+  // the sender_endpoint object must both be valid for the lifetime of the
+  // asynchronous operation.
+  template <typename MutableBufferSequence,
+      typename Handler, typename IoExecutor>
+  void async_receive_from(implementation_type& impl,
+      const MutableBufferSequence& buffers, endpoint_type& sender_endpoint,
+      socket_base::message_flags flags, Handler& handler,
+      const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_recvfrom_op_ext<MutableBufferSequence,
+        endpoint_type, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    int protocol = impl.protocol_.type();
+    p.p = new (p.v) op(success_ec_, impl.socket_, protocol, buffers,
+        sender_endpoint, flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive_from"));
+
+    start_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation, true, false);
+    p.v = p.p = 0;
+  }
+
+  // Wait until data can be received without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_receive_from(implementation_type& impl, const null_buffers&,
+      endpoint_type& sender_endpoint, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive_from(null_buffers)"));
+
+    // Reset endpoint since it can be given no sensible value at this time.
+    sender_endpoint = endpoint_type();
+
+    start_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Accept a new connection.
+  template <typename Socket>
+  boost::system::error_code accept(implementation_type& impl,
+      Socket& peer, endpoint_type* peer_endpoint, boost::system::error_code& ec)
+  {
+    // We cannot accept a socket that is already open.
+    if (peer.is_open())
+    {
+      ec = boost::asio::error::already_open;
+      return ec;
+    }
+
+    std::size_t addr_len = peer_endpoint ? peer_endpoint->capacity() : 0;
+    socket_holder new_socket(socket_ops::sync_accept(impl.socket_,
+          impl.state_, peer_endpoint ? peer_endpoint->data() : 0,
+          peer_endpoint ? &addr_len : 0, ec));
+
+    // On success, assign new connection to peer socket object.
+    if (new_socket.get() != invalid_socket)
+    {
+      if (peer_endpoint)
+        peer_endpoint->resize(addr_len);
+      peer.assign(impl.protocol_, new_socket.get(), ec);
+      if (!ec)
+        new_socket.release();
+    }
+
+    return ec;
+  }
+
+  // Start an asynchronous accept. The peer and peer_endpoint objects must be
+  // valid until the accept's handler is invoked.
+  template <typename Socket, typename Handler, typename IoExecutor>
+  void async_accept(implementation_type& impl, Socket& peer,
+      endpoint_type* peer_endpoint, Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_accept_op<Socket, Protocol, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, impl.state_, peer,
+        impl.protocol_, peer_endpoint, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_accept"));
+
+    start_accept_op(impl, p.p, is_continuation, peer.is_open());
+    p.v = p.p = 0;
+  }
+
+#if defined(BOOST_ASIO_HAS_MOVE)
+  // Start an asynchronous accept. The peer_endpoint object must be valid until
+  // the accept's handler is invoked.
+  template <typename PeerIoExecutor, typename Handler, typename IoExecutor>
+  void async_move_accept(implementation_type& impl,
+      const PeerIoExecutor& peer_io_ex, endpoint_type* peer_endpoint,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_move_accept_op<Protocol,
+        PeerIoExecutor, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, peer_io_ex, impl.socket_, impl.state_,
+        impl.protocol_, peer_endpoint, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_accept"));
+
+    start_accept_op(impl, p.p, is_continuation, false);
+    p.v = p.p = 0;
+  }
+#endif // defined(BOOST_ASIO_HAS_MOVE)
+
+  // Connect the socket to the specified endpoint.
+  boost::system::error_code connect(implementation_type& impl,
+      const endpoint_type& peer_endpoint, boost::system::error_code& ec)
+  {
+    socket_ops::sync_connect(impl.socket_,
+        peer_endpoint.data(), peer_endpoint.size(), ec);
+    return ec;
+  }
+
+  // Start an asynchronous connect.
+  template <typename Handler, typename IoExecutor>
+  void async_connect(implementation_type& impl,
+      const endpoint_type& peer_endpoint,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_connect_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_connect"));
+
+    start_connect_op(impl, p.p, is_continuation,
+        peer_endpoint.data(), peer_endpoint.size());
+    p.v = p.p = 0;
+  }
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // !defined(BOOST_ASIO_HAS_IOCP)
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_ext_local.hpp b/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_ext_local.hpp
new file mode 100644
index 0000000..8ac3265
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactive_socket_service_ext_local.hpp
@@ -0,0 +1,508 @@
+//
+// detail/reactive_socket_service_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_EXT_LOCAL_HPP
+#define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#if !defined(BOOST_ASIO_HAS_IOCP)
+
+#include <boost/asio/buffer.hpp>
+#include <boost/asio/error.hpp>
+#include <boost/asio/execution_context.hpp>
+#include <boost/asio/socket_base.hpp>
+#include <boost/asio/detail/buffer_sequence_adapter.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/noncopyable.hpp>
+#include <boost/asio/detail/reactive_null_buffers_op.hpp>
+#include <boost/asio/detail/reactive_socket_accept_op.hpp>
+#include <boost/asio/detail/reactive_socket_connect_op.hpp>
+#include <boost/asio/detail/reactive_socket_recvfrom_op_ext_local.hpp>
+#include <boost/asio/detail/reactive_socket_sendto_op.hpp>
+#include <boost/asio/detail/reactive_socket_service_base_ext_local.hpp>
+#include <boost/asio/detail/reactor.hpp>
+#include <boost/asio/detail/reactor_op.hpp>
+#include <boost/asio/detail/socket_holder.hpp>
+#include <boost/asio/detail/socket_ops.hpp>
+#include <boost/asio/detail/socket_types.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Protocol>
+class reactive_socket_service_ext_local :
+  public execution_context_service_base<reactive_socket_service_ext_local<Protocol> >,
+  public reactive_socket_service_base_ext_local
+{
+public:
+  // The protocol type.
+  typedef Protocol protocol_type;
+
+  // The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+  // The native type of a socket.
+  typedef socket_type native_handle_type;
+
+  // The implementation type of the socket.
+  struct implementation_type :
+    reactive_socket_service_base_ext_local::base_implementation_type
+  {
+    // Default constructor.
+    implementation_type()
+      : protocol_(endpoint_type().protocol())
+    {
+    }
+
+    // The protocol associated with the socket.
+    protocol_type protocol_;
+  };
+
+  // Constructor.
+  reactive_socket_service_ext_local(execution_context& context)
+    : execution_context_service_base<
+        reactive_socket_service_ext_local<Protocol> >(context),
+      reactive_socket_service_base_ext_local(context)
+  {
+  }
+
+  // Destroy all user-defined handler objects owned by the service.
+  void shutdown()
+  {
+    this->base_shutdown();
+  }
+
+  // Move-construct a new socket implementation.
+  void move_construct(implementation_type& impl,
+      implementation_type& other_impl)
+  {
+    this->base_move_construct(impl, other_impl);
+
+    impl.protocol_ = other_impl.protocol_;
+    other_impl.protocol_ = endpoint_type().protocol();
+  }
+
+  // Move-assign from another socket implementation.
+  void move_assign(implementation_type& impl,
+      reactive_socket_service_base_ext_local& other_service,
+      implementation_type& other_impl)
+  {
+    this->base_move_assign(impl, other_service, other_impl);
+
+    impl.protocol_ = other_impl.protocol_;
+    other_impl.protocol_ = endpoint_type().protocol();
+  }
+
+  // Move-construct a new socket implementation from another protocol type.
+  template <typename Protocol1>
+  void converting_move_construct(implementation_type& impl,
+      reactive_socket_service_ext_local<Protocol1>&,
+      typename reactive_socket_service_ext_local<
+        Protocol1>::implementation_type& other_impl)
+  {
+    this->base_move_construct(impl, other_impl);
+
+    impl.protocol_ = protocol_type(other_impl.protocol_);
+    other_impl.protocol_ = typename Protocol1::endpoint().protocol();
+  }
+
+  // Open a new socket implementation.
+  boost::system::error_code open(implementation_type& impl,
+      const protocol_type& protocol, boost::system::error_code& ec)
+  {
+    if (!do_open(impl, protocol.family(),
+          protocol.type(), protocol.protocol(), ec))
+      impl.protocol_ = protocol;
+    return ec;
+  }
+
+  // Assign a native socket to a socket implementation.
+  boost::system::error_code assign(implementation_type& impl,
+      const protocol_type& protocol, const native_handle_type& native_socket,
+      boost::system::error_code& ec)
+  {
+    if (!do_assign(impl, protocol.type(), native_socket, ec))
+      impl.protocol_ = protocol;
+    return ec;
+  }
+
+  // Get the native socket representation.
+  native_handle_type native_handle(implementation_type& impl)
+  {
+    return impl.socket_;
+  }
+
+  // Bind the socket to the specified local endpoint.
+  boost::system::error_code bind(implementation_type& impl,
+      const endpoint_type& endpoint, boost::system::error_code& ec)
+  {
+    socket_ops::bind(impl.socket_, endpoint.data(), endpoint.size(), ec);
+    return ec;
+  }
+
+  // Set a socket option.
+  template <typename Option>
+  boost::system::error_code set_option(implementation_type& impl,
+      const Option& option, boost::system::error_code& ec)
+  {
+    socket_ops::setsockopt(impl.socket_, impl.state_,
+        option.level(impl.protocol_), option.name(impl.protocol_),
+        option.data(impl.protocol_), option.size(impl.protocol_), ec);
+    return ec;
+  }
+
+  // Set a socket option.
+  template <typename Option>
+  boost::system::error_code get_option(const implementation_type& impl,
+      Option& option, boost::system::error_code& ec) const
+  {
+    std::size_t size = option.size(impl.protocol_);
+    socket_ops::getsockopt(impl.socket_, impl.state_,
+        option.level(impl.protocol_), option.name(impl.protocol_),
+        option.data(impl.protocol_), &size, ec);
+    if (!ec)
+      option.resize(impl.protocol_, size);
+    return ec;
+  }
+
+  // Get the local endpoint.
+  endpoint_type local_endpoint(const implementation_type& impl,
+      boost::system::error_code& ec) const
+  {
+    endpoint_type endpoint;
+    std::size_t addr_len = endpoint.capacity();
+    if (socket_ops::getsockname(impl.socket_, endpoint.data(), &addr_len, ec))
+      return endpoint_type();
+    endpoint.resize(addr_len);
+    return endpoint;
+  }
+
+  // Get the remote endpoint.
+  endpoint_type remote_endpoint(const implementation_type& impl,
+      boost::system::error_code& ec) const
+  {
+    endpoint_type endpoint;
+    std::size_t addr_len = endpoint.capacity();
+    if (socket_ops::getpeername(impl.socket_,
+          endpoint.data(), &addr_len, false, ec))
+      return endpoint_type();
+    endpoint.resize(addr_len);
+    return endpoint;
+  }
+
+  // Disable sends or receives on the socket.
+  boost::system::error_code shutdown(base_implementation_type& impl,
+      socket_base::shutdown_type what, boost::system::error_code& ec)
+  {
+    socket_ops::shutdown(impl.socket_, what, ec);
+    return ec;
+  }
+
+  // Send a datagram to the specified endpoint. Returns the number of bytes
+  // sent.
+  template <typename ConstBufferSequence>
+  size_t send_to(implementation_type& impl, const ConstBufferSequence& buffers,
+      const endpoint_type& destination, socket_base::message_flags flags,
+      boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::const_buffer,
+        ConstBufferSequence> bufs(buffers);
+
+    return socket_ops::sync_sendto(impl.socket_, impl.state_,
+        bufs.buffers(), bufs.count(), flags,
+        destination.data(), destination.size(), ec);
+  }
+
+  // Wait until data can be sent without blocking.
+  size_t send_to(implementation_type& impl, const null_buffers&,
+      const endpoint_type&, socket_base::message_flags,
+      boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_write(impl.socket_, impl.state_, -1, ec);
+
+    return 0;
+  }
+
+  // Start an asynchronous send. The data being sent must be valid for the
+  // lifetime of the asynchronous operation.
+  template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
+  void async_send_to(implementation_type& impl,
+      const ConstBufferSequence& buffers,
+      const endpoint_type& destination, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_sendto_op<ConstBufferSequence,
+        endpoint_type, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, buffers,
+        destination, flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_send_to"));
+
+    start_op(impl, reactor::write_op, p.p, is_continuation, true, false);
+    p.v = p.p = 0;
+  }
+
+  // Start an asynchronous wait until data can be sent without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_send_to(implementation_type& impl, const null_buffers&,
+      const endpoint_type&, socket_base::message_flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_send_to(null_buffers)"));
+
+    start_op(impl, reactor::write_op, p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Receive a datagram with the endpoint of the sender. Returns the number of
+  // bytes received.
+  template <typename MutableBufferSequence>
+  size_t receive_from(implementation_type& impl,
+      const MutableBufferSequence& buffers,
+      endpoint_type& sender_endpoint, socket_base::message_flags flags,
+      boost::system::error_code& ec)
+  {
+    buffer_sequence_adapter<boost::asio::mutable_buffer,
+        MutableBufferSequence> bufs(buffers);
+
+    std::size_t addr_len = sender_endpoint.capacity();
+    std::size_t bytes_recvd = socket_ops::sync_recvfrom(
+        impl.socket_, impl.state_, bufs.buffers(), bufs.count(),
+        flags, sender_endpoint.data(), &addr_len, ec);
+
+    if (!ec)
+      sender_endpoint.resize(addr_len);
+
+    return bytes_recvd;
+  }
+
+  // Wait until data can be received without blocking.
+  size_t receive_from(implementation_type& impl, const null_buffers&,
+      endpoint_type& sender_endpoint, socket_base::message_flags,
+      boost::system::error_code& ec)
+  {
+    // Wait for socket to become ready.
+    socket_ops::poll_read(impl.socket_, impl.state_, -1, ec);
+
+    // Reset endpoint since it can be given no sensible value at this time.
+    sender_endpoint = endpoint_type();
+
+    return 0;
+  }
+
+  // Start an asynchronous receive. The buffer for the data being received and
+  // the sender_endpoint object must both be valid for the lifetime of the
+  // asynchronous operation.
+  template <typename MutableBufferSequence,
+      typename Handler, typename IoExecutor>
+  void async_receive_from(implementation_type& impl,
+      const MutableBufferSequence& buffers, endpoint_type& sender_endpoint,
+      socket_base::message_flags flags, Handler& handler,
+      const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_recvfrom_op_ext_local<MutableBufferSequence,
+        endpoint_type, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    int protocol = impl.protocol_.type();
+    p.p = new (p.v) op(success_ec_, impl.socket_, protocol, buffers,
+        sender_endpoint, flags, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive_from"));
+
+    start_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation, true, false);
+    p.v = p.p = 0;
+  }
+
+  // Wait until data can be received without blocking.
+  template <typename Handler, typename IoExecutor>
+  void async_receive_from(implementation_type& impl, const null_buffers&,
+      endpoint_type& sender_endpoint, socket_base::message_flags flags,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_null_buffers_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_receive_from(null_buffers)"));
+
+    // Reset endpoint since it can be given no sensible value at this time.
+    sender_endpoint = endpoint_type();
+
+    start_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? reactor::except_op : reactor::read_op,
+        p.p, is_continuation, false, false);
+    p.v = p.p = 0;
+  }
+
+  // Accept a new connection.
+  template <typename Socket>
+  boost::system::error_code accept(implementation_type& impl,
+      Socket& peer, endpoint_type* peer_endpoint, boost::system::error_code& ec)
+  {
+    // We cannot accept a socket that is already open.
+    if (peer.is_open())
+    {
+      ec = boost::asio::error::already_open;
+      return ec;
+    }
+
+    std::size_t addr_len = peer_endpoint ? peer_endpoint->capacity() : 0;
+    socket_holder new_socket(socket_ops::sync_accept(impl.socket_,
+          impl.state_, peer_endpoint ? peer_endpoint->data() : 0,
+          peer_endpoint ? &addr_len : 0, ec));
+
+    // On success, assign new connection to peer socket object.
+    if (new_socket.get() != invalid_socket)
+    {
+      if (peer_endpoint)
+        peer_endpoint->resize(addr_len);
+      peer.assign(impl.protocol_, new_socket.get(), ec);
+      if (!ec)
+        new_socket.release();
+    }
+
+    return ec;
+  }
+
+  // Start an asynchronous accept. The peer and peer_endpoint objects must be
+  // valid until the accept's handler is invoked.
+  template <typename Socket, typename Handler, typename IoExecutor>
+  void async_accept(implementation_type& impl, Socket& peer,
+      endpoint_type* peer_endpoint, Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_accept_op<Socket, Protocol, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, impl.state_, peer,
+        impl.protocol_, peer_endpoint, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_accept"));
+
+    start_accept_op(impl, p.p, is_continuation, peer.is_open());
+    p.v = p.p = 0;
+  }
+
+#if defined(BOOST_ASIO_HAS_MOVE)
+  // Start an asynchronous accept. The peer_endpoint object must be valid until
+  // the accept's handler is invoked.
+  template <typename PeerIoExecutor, typename Handler, typename IoExecutor>
+  void async_move_accept(implementation_type& impl,
+      const PeerIoExecutor& peer_io_ex, endpoint_type* peer_endpoint,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_move_accept_op<Protocol,
+        PeerIoExecutor, Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, peer_io_ex, impl.socket_, impl.state_,
+        impl.protocol_, peer_endpoint, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_accept"));
+
+    start_accept_op(impl, p.p, is_continuation, false);
+    p.v = p.p = 0;
+  }
+#endif // defined(BOOST_ASIO_HAS_MOVE)
+
+  // Connect the socket to the specified endpoint.
+  boost::system::error_code connect(implementation_type& impl,
+      const endpoint_type& peer_endpoint, boost::system::error_code& ec)
+  {
+    socket_ops::sync_connect(impl.socket_,
+        peer_endpoint.data(), peer_endpoint.size(), ec);
+    return ec;
+  }
+
+  // Start an asynchronous connect.
+  template <typename Handler, typename IoExecutor>
+  void async_connect(implementation_type& impl,
+      const endpoint_type& peer_endpoint,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    bool is_continuation =
+      boost_asio_handler_cont_helpers::is_continuation(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef reactive_socket_connect_op<Handler, IoExecutor> op;
+    typename op::ptr p = { boost::asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(success_ec_, impl.socket_, handler, io_ex);
+
+    BOOST_ASIO_HANDLER_CREATION((reactor_.context(), *p.p, "socket",
+          &impl, impl.socket_, "async_connect"));
+
+    start_connect_op(impl, p.p, is_continuation,
+        peer_endpoint.data(), peer_endpoint.size());
+    p.v = p.p = 0;
+  }
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // !defined(BOOST_ASIO_HAS_IOCP)
+
+#endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SERVICE_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactor_op_ext.hpp b/implementation/helper/1.76/boost/asio/detail/reactor_op_ext.hpp
new file mode 100644
index 0000000..697cd9f
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactor_op_ext.hpp
@@ -0,0 +1,43 @@
+//
+// detail/reactor_op_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTOR_OP_EXT_HPP
+#define BOOST_ASIO_DETAIL_REACTOR_OP_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/reactor_op.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+class reactor_op_ext
+  : public reactor_op
+{
+public:
+    // The destination address
+    boost::asio::ip::address da_;
+
+    reactor_op_ext(const boost::system::error_code& success_ec,
+        perform_func_type perform_func, func_type complete_func)
+        : reactor_op(success_ec, perform_func, complete_func)
+    {
+    }
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#endif // BOOST_ASIO_DETAIL_REACTOR_OP_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/reactor_op_ext_local.hpp b/implementation/helper/1.76/boost/asio/detail/reactor_op_ext_local.hpp
new file mode 100644
index 0000000..3d9ae5f
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/reactor_op_ext_local.hpp
@@ -0,0 +1,44 @@
+//
+// detail/reactor_op_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_REACTOR_OP_EXT_LOCAL_HPP
+#define BOOST_ASIO_DETAIL_REACTOR_OP_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/reactor_op.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+class reactor_op_ext_local
+  : public reactor_op
+{
+public:
+    // Credentials
+    std::uint32_t uid_;
+    std::uint32_t gid_;
+
+    reactor_op_ext_local(const boost::system::error_code& success_ec,
+    		perform_func_type perform_func, func_type complete_func)
+      : reactor_op(success_ec, perform_func, complete_func)
+    {
+    }
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#endif // BOOST_ASIO_DETAIL_REACTOR_OP_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/socket_ops_ext.hpp b/implementation/helper/1.76/boost/asio/detail/socket_ops_ext.hpp
new file mode 100644
index 0000000..9285fed
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/socket_ops_ext.hpp
@@ -0,0 +1,62 @@
+//
+// detail/socket_ops_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (C) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_HPP
+#define BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/socket_ops.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+namespace socket_ops {
+
+BOOST_ASIO_DECL signed_size_type recvfrom(socket_type s, buf* bufs,
+    size_t count, int flags, socket_addr_type* addr,
+    std::size_t* addrlen, boost::system::error_code& ec,
+    boost::asio::ip::address& da);
+
+BOOST_ASIO_DECL size_t sync_recvfrom(socket_type s, state_type state,
+    buf* bufs, size_t count, int flags, socket_addr_type* addr,
+    std::size_t* addrlen, boost::system::error_code& ec, boost::asio::ip::address& da);
+
+#if defined(BOOST_ASIO_HAS_IOCP)
+
+BOOST_ASIO_DECL void complete_iocp_recvfrom(
+    const weak_cancel_token_type& cancel_token,
+    boost::system::error_code& ec,
+    boost::asio::ip::address& da);
+
+#else // defined(BOOST_ASIO_HAS_IOCP)
+
+BOOST_ASIO_DECL bool non_blocking_recvfrom(socket_type s,
+    buf* bufs, size_t count, int flags,
+    socket_addr_type* addr, std::size_t* addrlen,
+    boost::system::error_code& ec, size_t& bytes_transferred,
+    boost::asio::ip::address& da);
+
+#endif // defined(BOOST_ASIO_HAS_IOCP)
+
+} // namespace socket_ops
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+
+#if defined(BOOST_ASIO_HEADER_ONLY)
+# include <boost/asio/detail/impl/socket_ops_ext.ipp>
+#endif // defined(BOOST_ASIO_HEADER_ONLY)
+
+#endif // BOOST_EXT_ASIO_DETAIL_SOCKET_OPS_HPP
diff --git a/implementation/helper/1.76/boost/asio/detail/socket_ops_ext_local.hpp b/implementation/helper/1.76/boost/asio/detail/socket_ops_ext_local.hpp
new file mode 100644
index 0000000..a937bb6
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/detail/socket_ops_ext_local.hpp
@@ -0,0 +1,95 @@
+//
+// detail/socket_ops_ext_local.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (C) 2016-2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_LOCAL_HPP
+#define BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_LOCAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#include <boost/system/error_code.hpp>
+#include <boost/asio/detail/memory.hpp>
+#include <boost/asio/detail/socket_types.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+namespace socket_ops {
+
+BOOST_ASIO_DECL signed_size_type recv(socket_type s, buf* bufs,
+    size_t count, int flags, boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid);
+
+BOOST_ASIO_DECL size_t sync_recv(socket_type s, state_type state, buf* bufs,
+    size_t count, int flags, bool all_empty, boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid);
+
+#if defined(BOOST_ASIO_HAS_IOCP)
+
+BOOST_ASIO_DECL void complete_iocp_recv(state_type state,
+    const weak_cancel_token_type& cancel_token, bool all_empty,
+    boost::system::error_code& ec, size_t bytes_transferred,
+    std::uint32_t& uid, std::uint32_t& gid);
+
+#else // defined(BOOST_ASIO_HAS_IOCP)
+
+BOOST_ASIO_DECL bool non_blocking_recv(socket_type s,
+    buf* bufs, size_t count, int flags, bool is_stream,
+    boost::system::error_code& ec, size_t& bytes_transferred,
+    std::uint32_t& uid, std::uint32_t& gid);
+
+#endif // defined(BOOST_ASIO_HAS_IOCP)
+
+BOOST_ASIO_DECL signed_size_type recvfrom(socket_type s, buf* bufs,
+    size_t count, int flags, socket_addr_type* addr,
+    std::size_t* addrlen, boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid);
+
+BOOST_ASIO_DECL size_t sync_recvfrom(socket_type s, state_type state,
+    buf* bufs, size_t count, int flags, socket_addr_type* addr,
+    std::size_t* addrlen, boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid);
+
+#if defined(BOOST_ASIO_HAS_IOCP)
+
+BOOST_ASIO_DECL void complete_iocp_recvfrom(
+    const weak_cancel_token_type& cancel_token,
+    boost::system::error_code& ec,
+    std::uint32_t& uid, std::uint32_t& gid);
+
+#else // defined(BOOST_ASIO_HAS_IOCP)
+
+BOOST_ASIO_DECL bool non_blocking_recvfrom(socket_type s,
+    buf* bufs, size_t count, int flags,
+    socket_addr_type* addr, std::size_t* addrlen,
+    boost::system::error_code& ec, size_t& bytes_transferred,
+    std::uint32_t& uid, std::uint32_t& gid);
+
+#endif // defined(BOOST_ASIO_HAS_IOCP)
+
+
+} // namespace socket_ops
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#if defined(BOOST_ASIO_HEADER_ONLY)
+# include <boost/asio/detail/impl/socket_ops_ext_local.ipp>
+#endif // defined(BOOST_ASIO_HEADER_ONLY)
+
+#endif // BOOST_ASIO_DETAIL_SOCKET_OPS_EXT_LOCAL_HPP
diff --git a/implementation/helper/1.76/boost/asio/ip/udp_ext.hpp b/implementation/helper/1.76/boost/asio/ip/udp_ext.hpp
new file mode 100644
index 0000000..6ce2ac4
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/ip/udp_ext.hpp
@@ -0,0 +1,115 @@
+//
+// ip/udp_ext.hpp
+// ~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2017 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (C) 2016-2018 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_boost or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_IP_UDP_EXT_HPP
+#define BOOST_ASIO_IP_UDP_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/basic_datagram_socket_ext.hpp>
+#include <boost/asio/detail/socket_types.hpp>
+#include <boost/asio/ip/basic_endpoint.hpp>
+#include <boost/asio/ip/basic_resolver.hpp>
+#include <boost/asio/ip/basic_resolver_iterator.hpp>
+#include <boost/asio/ip/basic_resolver_query.hpp>
+#include <boost/asio/ip/udp.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace ip {
+
+/// Encapsulates the flags needed for UDP.
+/**
+ * The boost::asio::ip::udp_ext class contains flags necessary for UDP sockets.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Safe.
+ *
+ * @par Concepts:
+ * Protocol, InternetProtocol.
+ */
+class udp_ext
+{
+public:
+  /// The type of a UDP endpoint.
+  typedef basic_endpoint<udp> endpoint;
+
+  /// Construct to represent the IPv4 UDP protocol.
+  static udp_ext v4()
+  {
+    return udp_ext(BOOST_ASIO_OS_DEF(AF_INET));
+  }
+
+  /// Construct to represent the IPv6 UDP protocol.
+  static udp_ext v6()
+  {
+    return udp_ext(BOOST_ASIO_OS_DEF(AF_INET6));
+  }
+
+  /// Obtain an identifier for the type of the protocol.
+  int type() const
+  {
+    return BOOST_ASIO_OS_DEF(SOCK_DGRAM);
+  }
+
+  /// Obtain an identifier for the protocol.
+  int protocol() const
+  {
+    return BOOST_ASIO_OS_DEF(IPPROTO_UDP);
+  }
+
+  /// Obtain an identifier for the protocol family.
+  int family() const
+  {
+    return family_;
+  }
+
+  /// The UDP socket type.
+  typedef basic_datagram_socket_ext<udp> socket;
+
+  /// The UDP resolver type.
+  typedef basic_resolver<udp> resolver;
+
+  /// Compare two protocols for equality.
+  friend bool operator==(const udp_ext& p1, const udp_ext& p2)
+  {
+    return p1.family_ == p2.family_;
+  }
+
+  /// Compare two protocols for inequality.
+  friend bool operator!=(const udp_ext& p1, const udp_ext& p2)
+  {
+    return p1.family_ != p2.family_;
+  }
+
+private:
+  // Construct with a specific family.
+  explicit udp_ext(int protocol_family)
+    : family_(protocol_family)
+  {
+  }
+
+  int family_;
+};
+
+} // namespace ip
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_IP_UDP_EXT_HPP
diff --git a/implementation/helper/1.76/boost/asio/local/stream_protocol_ext.hpp b/implementation/helper/1.76/boost/asio/local/stream_protocol_ext.hpp
new file mode 100644
index 0000000..7c57c62
--- /dev/null
+++ b/implementation/helper/1.76/boost/asio/local/stream_protocol_ext.hpp
@@ -0,0 +1,93 @@
+//
+// local/stream_protocol_ext.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2019 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_LOCAL_STREAM_PROTOCOL_EXT_HPP
+#define BOOST_ASIO_LOCAL_STREAM_PROTOCOL_EXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#if defined(BOOST_ASIO_HAS_LOCAL_SOCKETS) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include <boost/asio/basic_socket_acceptor_ext.hpp>
+#include <boost/asio/basic_socket_iostream.hpp>
+#include <boost/asio/basic_stream_socket_ext.hpp>
+#include <boost/asio/detail/socket_types.hpp>
+#include <boost/asio/local/basic_endpoint.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace local {
+
+/// Encapsulates the flags needed for stream-oriented UNIX sockets.
+/**
+ * The boost::asio::local::stream_protocol class contains flags necessary for
+ * stream-oriented UNIX domain sockets.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Safe.
+ *
+ * @par Concepts:
+ * Protocol.
+ */
+class stream_protocol_ext
+{
+public:
+  /// Obtain an identifier for the type of the protocol.
+  int type() const
+  {
+    return SOCK_STREAM;
+  }
+
+  /// Obtain an identifier for the protocol.
+  int protocol() const
+  {
+    return 0;
+  }
+
+  /// Obtain an identifier for the protocol family.
+  int family() const
+  {
+    return AF_UNIX;
+  }
+
+  /// The type of a UNIX domain endpoint.
+  typedef basic_endpoint<stream_protocol_ext> endpoint;
+
+  /// The UNIX domain socket type.
+  typedef basic_stream_socket_ext<stream_protocol_ext> socket;
+
+  /// The UNIX domain acceptor type.
+  typedef basic_socket_acceptor_ext<stream_protocol_ext> acceptor;
+
+#if !defined(BOOST_ASIO_NO_IOSTREAM)
+  /// The UNIX domain iostream type.
+  typedef basic_socket_iostream<stream_protocol_ext> iostream;
+#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
+};
+
+} // namespace local
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // defined(BOOST_ASIO_HAS_LOCAL_SOCKETS)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // BOOST_ASIO_LOCAL_STREAM_PROTOCOL_EXT_HPP