diff options
Diffstat (limited to 'contrib/llvm-project/libcxx/include/__memory/construct_at.h')
-rw-r--r-- | contrib/llvm-project/libcxx/include/__memory/construct_at.h | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__memory/construct_at.h b/contrib/llvm-project/libcxx/include/__memory/construct_at.h new file mode 100644 index 000000000000..91d17134db01 --- /dev/null +++ b/contrib/llvm-project/libcxx/include/__memory/construct_at.h @@ -0,0 +1,128 @@ +// -*- C++ -*- +//===----------------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef _LIBCPP___MEMORY_CONSTRUCT_AT_H +#define _LIBCPP___MEMORY_CONSTRUCT_AT_H + +#include <__assert> +#include <__config> +#include <__iterator/access.h> +#include <__memory/addressof.h> +#include <__memory/voidify.h> +#include <__type_traits/enable_if.h> +#include <__type_traits/is_array.h> +#include <__utility/declval.h> +#include <__utility/forward.h> +#include <__utility/move.h> +#include <new> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +# pragma GCC system_header +#endif + +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + +_LIBCPP_BEGIN_NAMESPACE_STD + +// construct_at + +#if _LIBCPP_STD_VER >= 20 + +template <class _Tp, class... _Args, class = decltype(::new(std::declval<void*>()) _Tp(std::declval<_Args>()...))> +_LIBCPP_HIDE_FROM_ABI constexpr _Tp* construct_at(_Tp* __location, _Args&&... __args) { + _LIBCPP_ASSERT_NON_NULL(__location != nullptr, "null pointer given to construct_at"); + return ::new (std::__voidify(*__location)) _Tp(std::forward<_Args>(__args)...); +} + +#endif + +template <class _Tp, class... _Args, class = decltype(::new(std::declval<void*>()) _Tp(std::declval<_Args>()...))> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp* __construct_at(_Tp* __location, _Args&&... __args) { +#if _LIBCPP_STD_VER >= 20 + return std::construct_at(__location, std::forward<_Args>(__args)...); +#else + return _LIBCPP_ASSERT_NON_NULL(__location != nullptr, "null pointer given to construct_at"), + ::new (std::__voidify(*__location)) _Tp(std::forward<_Args>(__args)...); +#endif +} + +// destroy_at + +// The internal functions are available regardless of the language version (with the exception of the `__destroy_at` +// taking an array). + +template <class _ForwardIterator> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator __destroy(_ForwardIterator, _ForwardIterator); + +template <class _Tp, __enable_if_t<!is_array<_Tp>::value, int> = 0> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __destroy_at(_Tp* __loc) { + _LIBCPP_ASSERT_NON_NULL(__loc != nullptr, "null pointer given to destroy_at"); + __loc->~_Tp(); +} + +#if _LIBCPP_STD_VER >= 20 +template <class _Tp, __enable_if_t<is_array<_Tp>::value, int> = 0> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __destroy_at(_Tp* __loc) { + _LIBCPP_ASSERT_NON_NULL(__loc != nullptr, "null pointer given to destroy_at"); + std::__destroy(std::begin(*__loc), std::end(*__loc)); +} +#endif + +template <class _ForwardIterator> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator +__destroy(_ForwardIterator __first, _ForwardIterator __last) { + for (; __first != __last; ++__first) + std::__destroy_at(std::addressof(*__first)); + return __first; +} + +template <class _BidirectionalIterator> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _BidirectionalIterator +__reverse_destroy(_BidirectionalIterator __first, _BidirectionalIterator __last) { + while (__last != __first) { + --__last; + std::__destroy_at(std::addressof(*__last)); + } + return __last; +} + +#if _LIBCPP_STD_VER >= 17 + +template <class _Tp, enable_if_t<!is_array_v<_Tp>, int> = 0> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void destroy_at(_Tp* __loc) { + std::__destroy_at(__loc); +} + +# if _LIBCPP_STD_VER >= 20 +template <class _Tp, enable_if_t<is_array_v<_Tp>, int> = 0> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void destroy_at(_Tp* __loc) { + std::__destroy_at(__loc); +} +# endif + +template <class _ForwardIterator> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void destroy(_ForwardIterator __first, _ForwardIterator __last) { + (void)std::__destroy(std::move(__first), std::move(__last)); +} + +template <class _ForwardIterator, class _Size> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) { + for (; __n > 0; (void)++__first, --__n) + std::__destroy_at(std::addressof(*__first)); + return __first; +} + +#endif // _LIBCPP_STD_VER >= 17 + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___MEMORY_CONSTRUCT_AT_H |