| // -*- 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_BASE_H |
| #define _LIBCPP___MEMORY_BASE_H |
| |
| #include <__config> |
| #include <__debug> |
| #include <type_traits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| #pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| // addressof |
| #ifndef _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF |
| |
| template <class _Tp> |
| inline _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| _LIBCPP_NO_CFI _LIBCPP_INLINE_VISIBILITY |
| _Tp* |
| addressof(_Tp& __x) _NOEXCEPT |
| { |
| return __builtin_addressof(__x); |
| } |
| |
| #else |
| |
| template <class _Tp> |
| inline _LIBCPP_NO_CFI _LIBCPP_INLINE_VISIBILITY |
| _Tp* |
| addressof(_Tp& __x) _NOEXCEPT |
| { |
| return reinterpret_cast<_Tp *>( |
| const_cast<char *>(&reinterpret_cast<const volatile char &>(__x))); |
| } |
| |
| #endif // _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF |
| |
| #if defined(_LIBCPP_HAS_OBJC_ARC) && !defined(_LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF) |
| // Objective-C++ Automatic Reference Counting uses qualified pointers |
| // that require special addressof() signatures. When |
| // _LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF is defined, the compiler |
| // itself is providing these definitions. Otherwise, we provide them. |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY |
| __strong _Tp* |
| addressof(__strong _Tp& __x) _NOEXCEPT |
| { |
| return &__x; |
| } |
| |
| #ifdef _LIBCPP_HAS_OBJC_ARC_WEAK |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY |
| __weak _Tp* |
| addressof(__weak _Tp& __x) _NOEXCEPT |
| { |
| return &__x; |
| } |
| #endif |
| |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY |
| __autoreleasing _Tp* |
| addressof(__autoreleasing _Tp& __x) _NOEXCEPT |
| { |
| return &__x; |
| } |
| |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY |
| __unsafe_unretained _Tp* |
| addressof(__unsafe_unretained _Tp& __x) _NOEXCEPT |
| { |
| return &__x; |
| } |
| #endif |
| |
| #if !defined(_LIBCPP_CXX03_LANG) |
| template <class _Tp> _Tp* addressof(const _Tp&&) noexcept = delete; |
| #endif |
| |
| // construct_at |
| |
| #if _LIBCPP_STD_VER > 17 |
| |
| template<class _Tp, class ..._Args, class = decltype( |
| ::new (_VSTD::declval<void*>()) _Tp(_VSTD::declval<_Args>()...) |
| )> |
| _LIBCPP_INLINE_VISIBILITY |
| constexpr _Tp* construct_at(_Tp* __location, _Args&& ...__args) { |
| _LIBCPP_ASSERT(__location, "null pointer given to construct_at"); |
| return ::new ((void*)__location) _Tp(_VSTD::forward<_Args>(__args)...); |
| } |
| |
| #endif |
| |
| // destroy_at |
| |
| #if _LIBCPP_STD_VER > 14 |
| |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| void destroy_at(_Tp* __loc) { |
| _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at"); |
| __loc->~_Tp(); |
| } |
| |
| #endif |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___MEMORY_BASE_H |