diff options
Diffstat (limited to 'libstdc++-v3/include/bits/alloc_traits.h')
| -rw-r--r-- | libstdc++-v3/include/bits/alloc_traits.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/libstdc++-v3/include/bits/alloc_traits.h b/libstdc++-v3/include/bits/alloc_traits.h index 34412583064..05b584f742f 100644 --- a/libstdc++-v3/include/bits/alloc_traits.h +++ b/libstdc++-v3/include/bits/alloc_traits.h @@ -559,6 +559,110 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { return __rhs; } }; + /// Explicit specialization for std::allocator<void>. + template<> + struct allocator_traits<allocator<void>> + { + /// The allocator type + using allocator_type = allocator<void>; + + /// The allocated type + using value_type = void; + + /// The allocator's pointer type. + using pointer = void*; + + /// The allocator's const pointer type. + using const_pointer = const void*; + + /// The allocator's void pointer type. + using void_pointer = void*; + + /// The allocator's const void pointer type. + using const_void_pointer = const void*; + + /// The allocator's difference type + using difference_type = std::ptrdiff_t; + + /// The allocator's size type + using size_type = std::size_t; + + /// How the allocator is propagated on copy assignment + using propagate_on_container_copy_assignment = false_type; + + /// How the allocator is propagated on move assignment + using propagate_on_container_move_assignment = true_type; + + /// How the allocator is propagated on swap + using propagate_on_container_swap = false_type; + + /// Whether all instances of the allocator type compare equal. + using is_always_equal = true_type; + + template<typename _Up> + using rebind_alloc = allocator<_Up>; + + template<typename _Up> + using rebind_traits = allocator_traits<allocator<_Up>>; + + /// allocate is ill-formed for allocator<void> + static void* + allocate(allocator_type&, size_type, const void* = nullptr) = delete; + + /// deallocate is ill-formed for allocator<void> + static void + deallocate(allocator_type&, void*, size_type) = delete; + + /** + * @brief Construct an object of type `_Up` + * @param __a An allocator. + * @param __p Pointer to memory of suitable size and alignment for + * an object of type `_Up`. + * @param __args Constructor arguments. + * + * Calls `__a.construct(__p, std::forward<_Args>(__args)...)` + * in C++11, C++14 and C++17. Changed in C++20 to call + * `std::construct_at(__p, std::forward<_Args>(__args)...)` instead. + */ + template<typename _Up, typename... _Args> + static _GLIBCXX20_CONSTEXPR void + construct(allocator_type&, _Up* __p, _Args&&... __args) + noexcept(std::is_nothrow_constructible<_Up, _Args...>::value) + { +#if __cplusplus <= 201703L + ::new((void *)__p) _Up(std::forward<_Args>(__args)...); +#else + std::construct_at(__p, std::forward<_Args>(__args)...); +#endif + } + + /** + * @brief Destroy an object of type `_Up` + * @param __a An allocator. + * @param __p Pointer to the object to destroy + * + * Invokes the destructor for `*__p`. + */ + template<typename _Up> + static _GLIBCXX20_CONSTEXPR void + destroy(allocator_type&, _Up* __p) + noexcept(is_nothrow_destructible<_Up>::value) + { std::_Destroy(__p); } + + /// max_size is ill-formed for allocator<void> + static size_type + max_size(const allocator_type&) = delete; + + /** + * @brief Obtain an allocator to use when copying a container. + * @param __rhs An allocator. + * @return `__rhs` + */ + static _GLIBCXX20_CONSTEXPR allocator_type + select_on_container_copy_construction(const allocator_type& __rhs) + { return __rhs; } + }; + #if __cplusplus < 201703L template<typename _Alloc> inline void |