From 4ea281c750c5afcc68f2832bb42d98a1cbce6735 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Konstantin=20Ka=CC=88fer?= <mail@kkaefer.com>
Date: Wed, 16 Jul 2014 18:53:56 -0700
Subject: rename llmr => mbgl

---
 include/mbgl/util/variant.hpp | 731 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 731 insertions(+)
 create mode 100644 include/mbgl/util/variant.hpp

(limited to 'include/mbgl/util/variant.hpp')

diff --git a/include/mbgl/util/variant.hpp b/include/mbgl/util/variant.hpp
new file mode 100644
index 0000000000..ddc82ee311
--- /dev/null
+++ b/include/mbgl/util/variant.hpp
@@ -0,0 +1,731 @@
+#ifndef MAPBOX_UTIL_VARIANT_HPP
+#define MAPBOX_UTIL_VARIANT_HPP
+
+#include <utility>
+#include <typeinfo>
+#include <type_traits>
+#include <algorithm> // std::move/swap
+#include <stdexcept> // runtime_error
+#include <new> // operator new
+#include <cstddef> // size_t
+#include <iosfwd>
+#include <string>
+
+#include "recursive_wrapper.hpp"
+
+#ifdef _MSC_VER
+ // http://msdn.microsoft.com/en-us/library/z8y1yy88.aspx
+ #ifdef NDEBUG
+  #define VARIANT_INLINE __forceinline
+ #else
+  #define VARIANT_INLINE __declspec(noinline)
+ #endif
+#else
+ #ifdef NDEBUG
+  #define VARIANT_INLINE inline __attribute__((always_inline))
+ #else
+  #define VARIANT_INLINE __attribute__((noinline))
+ #endif
+#endif
+
+#define VARIANT_MAJOR_VERSION 0
+#define VARIANT_MINOR_VERSION 1
+#define VARIANT_PATCH_VERSION 0
+
+// translates to 100
+#define VARIANT_VERSION (VARIANT_MAJOR_VERSION*100000) + (VARIANT_MINOR_VERSION*100) + (VARIANT_PATCH_VERSION)
+
+namespace mbgl { namespace util { namespace detail {
+
+static constexpr std::size_t invalid_value = std::size_t(-1);
+
+template <typename T, typename...Types>
+struct direct_type;
+
+template <typename T, typename First, typename...Types>
+struct direct_type<T, First, Types...>
+{
+    static constexpr std::size_t index = std::is_same<T, First>::value
+        ? sizeof...(Types) : direct_type<T, Types...>::index;
+};
+
+template <typename T>
+struct direct_type<T>
+{
+    static constexpr std::size_t index = invalid_value;
+};
+
+template <typename T, typename...Types>
+struct convertible_type;
+
+template <typename T, typename First, typename...Types>
+struct convertible_type<T, First, Types...>
+{
+    static constexpr std::size_t index = std::is_convertible<T, First>::value
+        ? sizeof...(Types) : convertible_type<T, Types...>::index;
+};
+
+template <typename T>
+struct convertible_type<T>
+{
+    static constexpr std::size_t index = invalid_value;
+};
+
+template <typename T, typename...Types>
+struct value_traits
+{
+    static constexpr std::size_t direct_index = direct_type<T, Types...>::index;
+    static constexpr std::size_t index =
+        (direct_index == invalid_value) ? convertible_type<T, Types...>::index : direct_index;
+};
+
+template <typename T, typename...Types>
+struct is_valid_type;
+
+template <typename T, typename First, typename... Types>
+struct is_valid_type<T, First, Types...>
+{
+    static constexpr bool value = std::is_convertible<T, First>::value
+        || is_valid_type<T, Types...>::value;
+};
+
+template <typename T>
+struct is_valid_type<T> : std::false_type {};
+
+template <std::size_t N, typename ... Types>
+struct select_type
+{
+    static_assert(N < sizeof...(Types), "index out of bounds");
+};
+
+template <std::size_t N, typename T, typename ... Types>
+struct select_type<N, T, Types...>
+{
+    using type = typename select_type<N - 1, Types...>::type;
+};
+
+template <typename T, typename ... Types>
+struct select_type<0, T, Types...>
+{
+    using type = T;
+};
+
+} // namespace detail
+
+// static visitor
+template <typename R = void>
+struct static_visitor
+{
+    using result_type = R;
+protected:
+    static_visitor() {}
+    ~static_visitor() {}
+};
+
+
+template <std::size_t arg1, std::size_t ... others>
+struct static_max;
+
+template <std::size_t arg>
+struct static_max<arg>
+{
+    static const std::size_t value = arg;
+};
+
+template <std::size_t arg1, std::size_t arg2, std::size_t ... others>
+struct static_max<arg1, arg2, others...>
+{
+    static const std::size_t value = arg1 >= arg2 ? static_max<arg1, others...>::value :
+        static_max<arg2, others...>::value;
+};
+
+template<typename... Types>
+struct variant_helper;
+
+template<typename T, typename... Types>
+struct variant_helper<T, Types...>
+{
+    VARIANT_INLINE static void destroy(const std::size_t id, void * data)
+    {
+        if (id == sizeof...(Types))
+        {
+            reinterpret_cast<T*>(data)->~T();
+        }
+        else
+        {
+            variant_helper<Types...>::destroy(id, data);
+        }
+    }
+
+    VARIANT_INLINE static void move(const std::size_t old_id, void * old_value, void * new_value)
+    {
+        if (old_id == sizeof...(Types))
+        {
+            new (new_value) T(std::move(*reinterpret_cast<T*>(old_value)));
+            //std::memcpy(new_value, old_value, sizeof(T));
+            // ^^  DANGER: this should only be considered for relocatable types e.g built-in types
+            // Also, I don't see any measurable performance benefit just yet
+        }
+        else
+        {
+            variant_helper<Types...>::move(old_id, old_value, new_value);
+        }
+    }
+
+    VARIANT_INLINE static void copy(const std::size_t old_id, const void * old_value, void * new_value)
+    {
+        if (old_id == sizeof...(Types))
+        {
+            new (new_value) T(*reinterpret_cast<const T*>(old_value));
+        }
+        else
+        {
+            variant_helper<Types...>::copy(old_id, old_value, new_value);
+        }
+    }
+};
+
+template<> struct variant_helper<>
+{
+    VARIANT_INLINE static void destroy(const std::size_t, void *) {}
+    VARIANT_INLINE static void move(const std::size_t, void *, void *) {}
+    VARIANT_INLINE static void copy(const std::size_t, const void *, void *) {}
+};
+
+namespace detail {
+
+template <typename T>
+struct unwrapper
+{
+    T const& operator() (T const& obj) const
+    {
+        return obj;
+    }
+
+    T& operator() (T & obj) const
+    {
+        return obj;
+    }
+};
+
+
+template <typename T>
+struct unwrapper<recursive_wrapper<T>>
+{
+    auto operator() (recursive_wrapper<T> const& obj) const
+        -> typename recursive_wrapper<T>::type const&
+    {
+        return obj.get();
+    }
+};
+
+
+template <typename F, typename V, typename...Types>
+struct dispatcher;
+
+template <typename F, typename V, typename T, typename...Types>
+struct dispatcher<F, V, T, Types...>
+{
+    using result_type = typename F::result_type;
+    VARIANT_INLINE static result_type apply_const(V const& v, F f)
+    {
+        if (v.get_type_index() == sizeof...(Types))
+        {
+            return f(unwrapper<T>()(v. template get<T>()));
+        }
+        else
+        {
+            return dispatcher<F, V, Types...>::apply_const(v, f);
+        }
+    }
+
+    VARIANT_INLINE static result_type apply(V & v, F f)
+    {
+        if (v.get_type_index() == sizeof...(Types))
+        {
+            return f(unwrapper<T>()(v. template get<T>()));
+        }
+        else
+        {
+            return dispatcher<F, V, Types...>::apply(v, f);
+        }
+    }
+};
+
+template<typename F, typename V>
+struct dispatcher<F, V>
+{
+    using result_type = typename F::result_type;
+    VARIANT_INLINE static result_type apply_const(V const&, F)
+    {
+        throw std::runtime_error(std::string("unary dispatch: FAIL ") + typeid(V).name());
+    }
+
+    VARIANT_INLINE static result_type apply(V &, F)
+    {
+        throw std::runtime_error(std::string("unary dispatch: FAIL ") + typeid(V).name());
+    }
+};
+
+
+template <typename F, typename V, typename T, typename...Types>
+struct binary_dispatcher_rhs;
+
+template <typename F, typename V, typename T0, typename T1, typename...Types>
+struct binary_dispatcher_rhs<F, V, T0, T1, Types...>
+{
+    using result_type = typename F::result_type;
+    VARIANT_INLINE static result_type apply_const(V const& lhs, V const& rhs, F f)
+    {
+        if (rhs.get_type_index() == sizeof...(Types)) // call binary functor
+        {
+            return f(unwrapper<T0>()(lhs. template get<T0>()),
+                     unwrapper<T1>()(rhs. template get<T1>()));
+        }
+        else
+        {
+            return binary_dispatcher_rhs<F, V, T0, Types...>::apply_const(lhs, rhs, f);
+        }
+    }
+
+    VARIANT_INLINE static result_type apply(V & lhs, V & rhs, F f)
+    {
+        if (rhs.get_type_index() == sizeof...(Types)) // call binary functor
+        {
+            return f(unwrapper<T0>()(lhs. template get<T0>()),
+                     unwrapper<T1>()(rhs. template get<T1>()));
+        }
+        else
+        {
+            return binary_dispatcher_rhs<F, V, T0, Types...>::apply(lhs, rhs, f);
+        }
+    }
+
+};
+
+template<typename F, typename V, typename T>
+struct binary_dispatcher_rhs<F, V, T>
+{
+    using result_type = typename F::result_type;
+    VARIANT_INLINE static result_type apply_const(V const&, V const&, F)
+    {
+        throw std::runtime_error("binary dispatch: FAIL");
+    }
+    VARIANT_INLINE static result_type apply(V &, V &, F)
+    {
+        throw std::runtime_error("binary dispatch: FAIL");
+    }
+};
+
+
+template <typename F, typename V, typename T, typename...Types>
+struct binary_dispatcher_lhs;
+
+template <typename F, typename V, typename T0, typename T1, typename...Types>
+struct binary_dispatcher_lhs<F, V, T0, T1, Types...>
+{
+    using result_type = typename F::result_type;
+    VARIANT_INLINE static result_type apply_const(V const& lhs, V const& rhs, F f)
+    {
+        if (lhs.get_type_index() == sizeof...(Types)) // call binary functor
+        {
+            return f(lhs. template get<T1>(), rhs. template get<T0>());
+        }
+        else
+        {
+            return binary_dispatcher_lhs<F, V, T0, Types...>::apply_const(lhs, rhs, f);
+        }
+    }
+
+    VARIANT_INLINE static result_type apply(V & lhs, V & rhs, F f)
+    {
+        if (lhs.get_type_index() == sizeof...(Types)) // call binary functor
+        {
+            return f(lhs. template get<T1>(), rhs. template get<T0>());
+        }
+        else
+        {
+            return binary_dispatcher_lhs<F, V, T0, Types...>::apply(lhs, rhs, f);
+        }
+    }
+
+};
+
+template<typename F, typename V, typename T>
+struct binary_dispatcher_lhs<F, V, T>
+{
+    using result_type = typename F::result_type;
+    VARIANT_INLINE static result_type apply_const(V const&, V const&, F)
+    {
+        throw std::runtime_error("binary dispatch: FAIL");
+    }
+
+    VARIANT_INLINE static result_type apply(V &, V &, F)
+    {
+        throw std::runtime_error("binary dispatch: FAIL");
+    }
+};
+
+template <typename F, typename V, typename...Types>
+struct binary_dispatcher;
+
+template <typename F, typename V, typename T, typename...Types>
+struct binary_dispatcher<F, V, T, Types...>
+{
+    using result_type = typename F::result_type;
+    VARIANT_INLINE static result_type apply_const(V const& v0, V const& v1, F f)
+    {
+        if (v0.get_type_index() == sizeof...(Types))
+        {
+            if (v0.get_type_index() == v1.get_type_index())
+            {
+                return f(v0. template get<T>(), v1. template get<T>()); // call binary functor
+            }
+            else
+            {
+                return binary_dispatcher_rhs<F, V, T, Types...>::apply_const(v0, v1, f);
+            }
+        }
+        else if (v1.get_type_index() == sizeof...(Types))
+        {
+            return binary_dispatcher_lhs<F, V, T, Types...>::apply_const(v0, v1, f);
+        }
+        return binary_dispatcher<F, V, Types...>::apply_const(v0, v1, f);
+    }
+
+    VARIANT_INLINE static result_type apply(V & v0, V & v1, F f)
+    {
+        if (v0.get_type_index() == sizeof...(Types))
+        {
+            if (v0.get_type_index() == v1.get_type_index())
+            {
+                return f(v0. template get<T>(), v1. template get<T>()); // call binary functor
+            }
+            else
+            {
+                return binary_dispatcher_rhs<F, V, T, Types...>::apply(v0, v1, f);
+            }
+        }
+        else if (v1.get_type_index() == sizeof...(Types))
+        {
+            return binary_dispatcher_lhs<F, V, T, Types...>::apply(v0, v1, f);
+        }
+        return binary_dispatcher<F, V, Types...>::apply(v0, v1, f);
+    }
+};
+
+template<typename F, typename V>
+struct binary_dispatcher<F, V>
+{
+    using result_type = typename F::result_type;
+    VARIANT_INLINE static result_type apply_const(V const&, V const&, F)
+    {
+        throw std::runtime_error("binary dispatch: FAIL");
+    }
+
+    VARIANT_INLINE static result_type apply(V &, V &, F)
+    {
+        throw std::runtime_error("binary dispatch: FAIL");
+    }
+};
+
+// comparator functors
+struct equal_comp
+{
+    template <typename T>
+    bool operator()(T const& lhs, T const& rhs) const
+    {
+        return lhs == rhs;
+    }
+};
+
+struct less_comp
+{
+    template <typename T>
+    bool operator()(T const& lhs, T const& rhs) const
+    {
+        return lhs < rhs;
+    }
+};
+
+template <typename Variant, typename Comp>
+class comparer : public static_visitor<bool>
+{
+public:
+    explicit comparer(Variant const& lhs) noexcept
+        : lhs_(lhs) {}
+    comparer& operator=(comparer const&) = delete;
+    // visitor
+    template<typename T>
+    bool operator()(T const& rhs_content) const
+    {
+        T const& lhs_content = lhs_.template get<T>();
+        return Comp()(lhs_content, rhs_content);
+    }
+private:
+    Variant const& lhs_;
+};
+
+// operator<< helper
+template <typename Out>
+class printer : public static_visitor<>
+{
+public:
+    explicit printer(Out & out)
+        : out_(out) {}
+    printer& operator=(printer const&) = delete;
+
+// visitor
+    template <typename T>
+    void operator()(T const& operand) const
+    {
+        out_ << operand;
+    }
+private:
+    Out & out_;
+};
+
+} // namespace detail
+
+template<typename... Types>
+class variant
+{
+private:
+
+    static const std::size_t data_size = static_max<sizeof(Types)...>::value;
+    static const std::size_t data_align = static_max<alignof(Types)...>::value;
+
+    using data_type = typename std::aligned_storage<data_size, data_align>::type;
+    using helper_type = variant_helper<Types...>;
+
+    std::size_t type_index;
+    data_type data;
+
+public:
+
+    VARIANT_INLINE variant()
+        : type_index(sizeof...(Types) - 1)
+    {
+        new (&data) typename detail::select_type<0, Types...>::type();
+    }
+
+    template <typename T, class = typename std::enable_if<
+                         detail::is_valid_type<T, Types...>::value>::type>
+    VARIANT_INLINE explicit variant(T const& val) noexcept
+        : type_index(detail::value_traits<T, Types...>::index)
+    {
+        constexpr std::size_t index = sizeof...(Types) - detail::value_traits<T, Types...>::index - 1;
+        using target_type = typename detail::select_type<index, Types...>::type;
+        new (&data) target_type(val);
+    }
+
+    template <typename T, class = typename std::enable_if<
+                          detail::is_valid_type<T, Types...>::value>::type>
+    VARIANT_INLINE variant(T && val) noexcept
+        : type_index(detail::value_traits<T, Types...>::index)
+    {
+        constexpr std::size_t index = sizeof...(Types) - detail::value_traits<T, Types...>::index - 1;
+        using target_type = typename detail::select_type<index, Types...>::type;
+        new (&data) target_type(std::forward<T>(val)); // nothrow
+    }
+
+    VARIANT_INLINE variant(variant<Types...> const& old)
+        : type_index(old.type_index)
+    {
+        helper_type::copy(old.type_index, &old.data, &data);
+    }
+
+    VARIANT_INLINE variant(variant<Types...>&& old) noexcept
+        : type_index(old.type_index)
+    {
+        helper_type::move(old.type_index, &old.data, &data);
+    }
+
+    friend void swap(variant<Types...> & first, variant<Types...> & second)
+    {
+        using std::swap; //enable ADL
+        swap(first.type_index, second.type_index);
+        swap(first.data, second.data);
+    }
+
+    VARIANT_INLINE variant<Types...>& operator=(variant<Types...> other)
+    {
+        swap(*this, other);
+        return *this;
+    }
+
+    // conversions
+    // move-assign
+    template <typename T>
+    VARIANT_INLINE variant<Types...>& operator=(T && rhs) noexcept
+    {
+        variant<Types...> temp(std::move(rhs));
+        swap(*this, temp);
+        return *this;
+    }
+
+    // copy-assign
+    template <typename T>
+    VARIANT_INLINE variant<Types...>& operator=(T const& rhs)
+    {
+        variant<Types...> temp(rhs);
+        swap(*this, temp);
+        return *this;
+    }
+
+    template<typename T>
+    VARIANT_INLINE bool is() const
+    {
+        return (type_index == detail::direct_type<T, Types...>::index);
+    }
+
+    VARIANT_INLINE bool valid() const
+    {
+        return (type_index != detail::invalid_value);
+    }
+
+    template<typename T, typename... Args>
+    VARIANT_INLINE void set(Args&&... args)
+    {
+        helper_type::destroy(type_index, &data);
+        new (&data) T(std::forward<Args>(args)...);
+        type_index = detail::direct_type<T, Types...>::index;
+    }
+
+    template<typename T>
+    VARIANT_INLINE T& get()
+    {
+        if (type_index == detail::direct_type<T, Types...>::index)
+        {
+            return *reinterpret_cast<T*>(&data);
+        }
+        else
+        {
+            throw std::runtime_error("in get()");
+        }
+    }
+
+    template<typename T>
+    VARIANT_INLINE T const& get() const
+    {
+        if (type_index == detail::direct_type<T, Types...>::index)
+        {
+            return *reinterpret_cast<T const*>(&data);
+        }
+        else
+        {
+            throw std::runtime_error("in get()");
+        }
+    }
+
+    VARIANT_INLINE std::size_t get_type_index() const
+    {
+        return type_index;
+    }
+
+    // visitor
+    // unary
+    template <typename F, typename V>
+    auto VARIANT_INLINE
+    static visit(V const& v, F f)
+        -> decltype(detail::dispatcher<F, V, Types...>::apply_const(v, f))
+    {
+        return detail::dispatcher<F, V, Types...>::apply_const(v, f);
+    }
+    // non-const
+    template <typename F, typename V>
+    auto VARIANT_INLINE
+    static visit(V & v, F f)
+        -> decltype(detail::dispatcher<F, V, Types...>::apply(v, f))
+    {
+        return detail::dispatcher<F, V, Types...>::apply(v, f);
+    }
+
+    // binary
+    // const
+    template <typename F, typename V>
+    auto VARIANT_INLINE
+    static binary_visit(V const& v0, V const& v1, F f)
+        -> decltype(detail::binary_dispatcher<F, V, Types...>::apply_const(v0, v1, f))
+    {
+        return detail::binary_dispatcher<F, V, Types...>::apply_const(v0, v1, f);
+    }
+    // non-const
+    template <typename F, typename V>
+    auto VARIANT_INLINE
+    static binary_visit(V& v0, V& v1, F f)
+        -> decltype(detail::binary_dispatcher<F, V, Types...>::apply(v0, v1, f))
+    {
+        return detail::binary_dispatcher<F, V, Types...>::apply(v0, v1, f);
+    }
+
+    ~variant() noexcept
+    {
+        helper_type::destroy(type_index, &data);
+    }
+
+    // comparison operators
+    // equality
+    VARIANT_INLINE bool operator==(variant const& rhs) const
+    {
+        if (this->get_type_index() != rhs.get_type_index())
+            return false;
+        detail::comparer<variant, detail::equal_comp> visitor(*this);
+        return visit(rhs, visitor);
+    }
+    // less than
+    VARIANT_INLINE bool operator<(variant const& rhs) const
+    {
+        if (this->get_type_index() != rhs.get_type_index())
+        {
+            return this->get_type_index() < rhs.get_type_index();
+            // ^^ borrowed from boost::variant
+        }
+        detail::comparer<variant, detail::less_comp> visitor(*this);
+        return visit(rhs, visitor);
+    }
+};
+
+// unary visitor interface
+
+// const
+template <typename V, typename F>
+auto VARIANT_INLINE static apply_visitor(F f, V const& v) -> decltype(V::visit(v, f))
+{
+    return V::visit(v, f);
+}
+// non-const
+template <typename V, typename F>
+auto VARIANT_INLINE static apply_visitor(F f, V & v) -> decltype(V::visit(v, f))
+{
+    return V::visit(v, f);
+}
+
+// binary visitor interface
+// const
+template <typename V, typename F>
+auto VARIANT_INLINE static apply_visitor(F f, V const& v0, V const& v1) -> decltype(V::binary_visit(v0, v1, f))
+{
+    return V::binary_visit(v0, v1, f);
+}
+// non-const
+template <typename V, typename F>
+auto VARIANT_INLINE static apply_visitor(F f, V & v0, V & v1) -> decltype(V::binary_visit(v0, v1, f))
+{
+    return V::binary_visit(v0, v1, f);
+}
+
+
+// operator<<
+template <typename charT, typename traits, typename Variant>
+VARIANT_INLINE std::basic_ostream<charT, traits>&
+operator<< (std::basic_ostream<charT, traits>& out, Variant const& rhs)
+{
+    detail::printer<std::basic_ostream<charT, traits>> visitor(out);
+    apply_visitor(visitor, rhs);
+    return out;
+}
+
+}}
+
+#endif  // MAPBOX_UTIL_VARIANT_HPP
-- 
cgit v1.2.1