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Diffstat (limited to 'libcxx/include/__memory/addressof.h')
-rw-r--r-- | libcxx/include/__memory/addressof.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/libcxx/include/__memory/addressof.h b/libcxx/include/__memory/addressof.h new file mode 100644 index 000000000000..5efdb5878625 --- /dev/null +++ b/libcxx/include/__memory/addressof.h @@ -0,0 +1,96 @@ +// -*- 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_ADDRESSOF_H +#define _LIBCPP___MEMORY_ADDRESSOF_H + +#include <__config> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +#pragma GCC system_header +#endif + +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + +_LIBCPP_BEGIN_NAMESPACE_STD + +#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 + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___MEMORY_ADDRESSOF_H |