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1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___MEMORY_TEMP_VALUE_H10#define _LIBCPP___MEMORY_TEMP_VALUE_H11 12#include <__config>13#include <__memory/addressof.h>14#include <__memory/allocator_traits.h>15#include <__utility/forward.h>16 17#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)18# pragma GCC system_header19#endif20 21_LIBCPP_BEGIN_NAMESPACE_STD22 23template <class _Tp, class _Alloc>24struct __temp_value {25 typedef allocator_traits<_Alloc> _Traits;26 27#ifdef _LIBCPP_CXX03_LANG28 _ALIGNAS_TYPE(_Tp) char __v[sizeof(_Tp)];29#else30 union {31 _Tp __v;32 };33#endif34 _Alloc& __a;35 36 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp* __addr() {37#ifdef _LIBCPP_CXX03_LANG38 return reinterpret_cast<_Tp*>(std::addressof(__v));39#else40 return std::addressof(__v);41#endif42 }43 44 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp& get() { return *__addr(); }45 46 template <class... _Args>47 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI _LIBCPP_CONSTEXPR_SINCE_CXX20 __temp_value(_Alloc& __alloc, _Args&&... __args)48 : __a(__alloc) {49 _Traits::construct(__a, __addr(), std::forward<_Args>(__args)...);50 }51 52 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 ~__temp_value() { _Traits::destroy(__a, __addr()); }53};54 55_LIBCPP_END_NAMESPACE_STD56 57#endif // _LIBCPP___MEMORY_TEMP_VALUE_H58