summaryrefslogtreecommitdiff
path: root/include
diff options
context:
space:
mode:
authorAsheem Mamoowala <asheem.mamoowala@mapbox.com>2017-11-16 18:38:27 -0800
committerAsheem Mamoowala <asheem.mamoowala@mapbox.com>2017-11-22 13:56:38 -0800
commit3067b77c650f5dea0c00a7a92a9fc927e028c742 (patch)
tree407bf2b4bf19678f1e7c2418f4fd0b4e18fbfef6 /include
parentba63d06cfc09b016ce0ddfcaaa297bd259cadf09 (diff)
downloadqtlocation-mapboxgl-3067b77c650f5dea0c00a7a92a9fc927e028c742.tar.gz
[core, ios, macos] Implement unique_any and remove linb::any
Diffstat (limited to 'include')
-rw-r--r--include/mbgl/style/layer.hpp4
-rw-r--r--include/mbgl/style/source.hpp4
-rw-r--r--include/mbgl/util/any.hpp10
-rw-r--r--include/mbgl/util/unique_any.hpp275
4 files changed, 279 insertions, 14 deletions
diff --git a/include/mbgl/style/layer.hpp b/include/mbgl/style/layer.hpp
index c6a3c0e735..eb2dbf830b 100644
--- a/include/mbgl/style/layer.hpp
+++ b/include/mbgl/style/layer.hpp
@@ -1,7 +1,7 @@
#pragma once
#include <mbgl/util/noncopyable.hpp>
-#include <mbgl/util/any.hpp>
+#include <mbgl/util/unique_any.hpp>
#include <mbgl/util/immutable.hpp>
#include <mbgl/style/layer_type.hpp>
#include <mbgl/style/types.hpp>
@@ -126,7 +126,7 @@ public:
// For use in SDK bindings, which store a reference to a platform-native peer
// object here, so that separately-obtained references to this object share
// identical platform-native peers.
- any peer;
+ util::unique_any peer;
};
} // namespace style
diff --git a/include/mbgl/style/source.hpp b/include/mbgl/style/source.hpp
index cec9619451..0b6a6c72d9 100644
--- a/include/mbgl/style/source.hpp
+++ b/include/mbgl/style/source.hpp
@@ -2,7 +2,7 @@
#include <mbgl/util/noncopyable.hpp>
#include <mbgl/util/optional.hpp>
-#include <mbgl/util/any.hpp>
+#include <mbgl/util/unique_any.hpp>
#include <mbgl/util/immutable.hpp>
#include <mbgl/style/types.hpp>
@@ -76,7 +76,7 @@ public:
// For use in SDK bindings, which store a reference to a platform-native peer
// object here, so that separately-obtained references to this object share
// identical platform-native peers.
- any peer;
+ util::unique_any peer;
};
} // namespace style
diff --git a/include/mbgl/util/any.hpp b/include/mbgl/util/any.hpp
deleted file mode 100644
index eea64b188a..0000000000
--- a/include/mbgl/util/any.hpp
+++ /dev/null
@@ -1,10 +0,0 @@
-#pragma once
-
-#include <linb/any.hpp>
-
-namespace mbgl {
-
-using linb::any;
-using linb::any_cast;
-
-} // namespace mbgl
diff --git a/include/mbgl/util/unique_any.hpp b/include/mbgl/util/unique_any.hpp
new file mode 100644
index 0000000000..d488930a03
--- /dev/null
+++ b/include/mbgl/util/unique_any.hpp
@@ -0,0 +1,275 @@
+#pragma once
+
+#include <typeinfo>
+#include <type_traits>
+#include <stdexcept>
+namespace mbgl {
+namespace util {
+
+class bad_any_cast : public std::bad_cast {
+public:
+ const char* what() const noexcept override {
+ return "bad any_cast<>()";
+ }
+};
+/**
+ * A variant of `std::any` for non-copyable types.
+ *
+ * Use `unique_any` for non-copyable types (e.g. `std::unique_ptr<T>`)
+ * or to ensure that no copies are made of copyable types that are
+ * moved in.
+ *
+ * `uniqe_any` differs from `std::any` in that it does not support copy construction
+ * or copy assignment. It also does not require the contained type to be copy
+ * constructible.
+ *
+ * The `any_cast<T>()` methods work similar to `std::any_cast<T>()` except that
+ * non-copyable types may only be cast to references.
+ *
+ * Example usage:
+ * unique_any u1(3);
+ * auto u2 = unique_any(std::move(u1)); // u1 is moved from
+ * int i = any_cast<int>(u2);
+ *
+ * unique_any u2;
+ * u2 = std::unique_ptr<int>(new int);
+ * std::unique_ptr<int> iPtr = any_cast<std::unique_ptr<int>>(std::move(u2));
+ *
+ * Inspired by linb::any (https://github.com/thelink2012/any) and the
+ * libc++ implementation (https://github.com/llvm-mirror/libcxx).
+ */
+class unique_any final
+{
+public:
+ unique_any() = default;
+
+ //Copy constructor (deleted)
+ unique_any(const unique_any& rhs) = delete;
+
+ unique_any(unique_any&& rhs) : vtable(rhs.vtable) {
+ if (vtable) {
+ vtable->move(std::move(rhs.storage), storage);
+ }
+ rhs.vtable = nullptr;
+ }
+
+ // Constructs with a direct-initilizated object of type ValueType
+ template <typename ValueType,
+ typename _Vt = std::decay_t<ValueType>,
+ typename = std::enable_if_t<!std::is_same<_Vt, unique_any>::value> >
+ unique_any(ValueType&& value) {
+ create(std::forward<ValueType>(value));
+ }
+
+ ~unique_any() {
+ reset();
+ }
+
+ unique_any& operator=(unique_any&& rhs) {
+ unique_any(std::move(rhs)).swap(*this);
+ return *this;
+ }
+
+ template <class ValueType,
+ typename = std::enable_if_t<!std::is_same<std::decay_t<ValueType>, unique_any>::value> >
+ unique_any& operator=(ValueType&& rhs) {
+ unique_any(std::forward<ValueType>(rhs)).swap(*this);
+ return *this;
+ }
+
+ void reset() {
+ if (vtable) {
+ vtable->destroy(storage);
+ vtable = nullptr;
+ }
+ }
+
+ void swap(unique_any& rhs) {
+ if (this == &rhs) {
+ return;
+ } else {
+ unique_any tmp(std::move(rhs));
+ rhs.vtable = vtable;
+ if (rhs.vtable) {
+ rhs.vtable->move(std::move(storage), rhs.storage);
+ }
+ vtable = tmp.vtable;
+ if (vtable) {
+ vtable->move(std::move(tmp.storage), storage);
+ }
+ }
+ }
+
+ const std::type_info& type() const {
+ return !has_value()? typeid(void) : vtable->type();
+ }
+
+ bool has_value() const {
+ return vtable != nullptr;
+ }
+
+private:
+
+ union Storage {
+ using StackStorage = std::aligned_storage_t<3*sizeof(void*), std::alignment_of<void*>::value>;
+ Storage() = default;
+
+ void * dynamic { nullptr };
+ StackStorage stack;
+ };
+
+ template<typename T>
+ struct AllocateOnStack : std::integral_constant<bool,
+ sizeof(T) <= sizeof(Storage::stack)
+ && std::alignment_of<T>::value <= std::alignment_of<Storage::StackStorage>::value
+ && std::is_nothrow_move_constructible<T>::value> {
+ };
+
+ struct VTable {
+ virtual ~VTable() = default;
+ virtual void move(Storage&& src, Storage& dest) = 0;
+ virtual void destroy(Storage&) = 0;
+ virtual const std::type_info& type() = 0;
+ };
+
+ template <typename ValueType>
+ struct VTableHeap : public VTable {
+ void move(Storage&& src, Storage& dest) override {
+ destroy(dest);
+ dest.dynamic = src.dynamic;
+ }
+
+ void destroy(Storage& s) override {
+ if (s.dynamic) {
+ delete reinterpret_cast<ValueType*>(s.dynamic);
+ }
+ s.dynamic = nullptr;
+ }
+
+ const std::type_info& type() override {
+ return typeid(ValueType);
+ }
+ };
+
+ template <typename ValueType>
+ struct VTableStack : public VTable {
+ void move(Storage&& src, Storage& dest) override {
+ auto srcValue = reinterpret_cast<ValueType&&>(src.stack);
+ new (static_cast<void*>(&dest.stack)) ValueType(std::move(srcValue));
+ srcValue.~ValueType();
+ }
+
+ void destroy(Storage& s) override {
+ reinterpret_cast<ValueType&>(s.stack).~ValueType();
+ }
+
+ const std::type_info& type() override {
+ return typeid(ValueType);
+ }
+ };
+
+ template <typename ValueType>
+ static VTable* vtableForType() {
+ using VTableType = std::conditional_t<AllocateOnStack<ValueType>::value, VTableStack<ValueType>, VTableHeap<ValueType> >;
+ static VTableType vtable;
+ return &vtable;
+ }
+
+ template <typename ValueType, typename _Vt>
+ std::enable_if_t<AllocateOnStack<_Vt>::value>
+ createStorage(ValueType&& value) {
+ new (static_cast<void*>(&storage.stack)) _Vt(std::forward<ValueType>(value));
+ }
+
+ template <typename ValueType, typename _Vt>
+ std::enable_if_t<!AllocateOnStack<_Vt>::value>
+ createStorage(ValueType&& value) {
+ storage.dynamic = static_cast<void*>(new _Vt(std::forward<ValueType>(value)));
+ }
+
+ template <typename ValueType>
+ void create(ValueType&& value) {
+ using _Vt = std::decay_t<ValueType>;
+ vtable = vtableForType<_Vt>();
+ createStorage<ValueType, _Vt>(std::forward<ValueType>(value));
+ }
+
+ VTable* vtable { nullptr };
+ Storage storage;
+
+protected:
+ template<class ValueType>
+ friend const ValueType* any_cast(const unique_any* operand) ;
+
+ template<class ValueType>
+ friend ValueType* any_cast(unique_any* operand) ;
+
+ template<typename ValueType, typename _Vt = std::decay_t<ValueType> >
+ ValueType* cast()
+ {
+ return reinterpret_cast<ValueType *>(
+ AllocateOnStack<_Vt>::value ? &storage.stack : storage.dynamic);
+ }
+};
+
+template<typename ValueType>
+inline const ValueType* any_cast(const unique_any* any)
+{
+ return any_cast<ValueType>(const_cast<unique_any *>(any));
+}
+
+template<typename ValueType>
+inline ValueType* any_cast(unique_any* any)
+{
+ if(any == nullptr || any->type() != typeid(ValueType))
+ return nullptr;
+ else
+ return any->cast<ValueType>();
+}
+
+template<typename ValueType, typename _Vt = std::decay_t<ValueType> >
+inline ValueType any_cast(const unique_any& any)
+{
+ static_assert(std::is_constructible<ValueType, const _Vt&>::value,
+ "any_cast type can't construct copy of contained object");
+ auto temp = any_cast<_Vt>(&any);
+ if (temp == nullptr) {
+ throw bad_any_cast();
+ }
+ return static_cast<ValueType>(*temp);
+}
+
+template<typename ValueType, typename _Vt = std::decay_t<ValueType> >
+inline ValueType any_cast(unique_any& any)
+{
+ static_assert(std::is_constructible<ValueType, const _Vt&>::value,
+ "any_cast type can't construct copy of contained object");
+ auto temp = any_cast<_Vt>(&any);
+ if (temp == nullptr) {
+ throw bad_any_cast();
+ }
+ return static_cast<ValueType>(*temp);
+}
+
+template<typename ValueType, typename _Vt = std::remove_cv_t<ValueType> >
+inline ValueType any_cast(unique_any&& any)
+{
+ auto temp = any_cast<_Vt>(&any);
+ if (temp == nullptr) {
+ throw bad_any_cast();
+ }
+ auto retValue = static_cast<ValueType>(std::move(*temp));
+ any.reset();
+ return std::move(retValue);
+}
+
+} // namespace util
+} // namespace mbgl
+
+namespace std {
+
+inline void swap(mbgl::util::unique_any& lhs, mbgl::util::unique_any& rhs) {
+ lhs.swap(rhs);
+}
+
+} // namespace std