libcxx/include/__memory/addressof.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef _LIBCPP___MEMORY_ADDRESSOF_H
  11 #define _LIBCPP___MEMORY_ADDRESSOF_H
  12
  13 #include <__config>
  14
  15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  16 #  pragma GCC system_header
  17 #endif
  18
  19 _LIBCPP_BEGIN_NAMESPACE_STD
  20
  21 template <class _Tp>
  22 inline _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_NO_CFI _LIBCPP_HIDE_FROM_ABI _Tp* addressof(_Tp& __x) _NOEXCEPT {
  23   return __builtin_addressof(__x);
  24 }
  25
  26 #if _LIBCPP_HAS_OBJC_ARC
  27 // Objective-C++ Automatic Reference Counting uses qualified pointers
  28 // that require special addressof() signatures.
  29 template <class _Tp>
  30 inline _LIBCPP_HIDE_FROM_ABI __strong _Tp* addressof(__strong _Tp& __x) _NOEXCEPT {
  31   return &__x;
  32 }
  33
  34 #  if _LIBCPP_HAS_OBJC_ARC_WEAK
  35 template <class _Tp>
  36 inline _LIBCPP_HIDE_FROM_ABI __weak _Tp* addressof(__weak _Tp& __x) _NOEXCEPT {
  37   return &__x;
  38 }
  39 #  endif
  40
  41 template <class _Tp>
  42 inline _LIBCPP_HIDE_FROM_ABI __autoreleasing _Tp* addressof(__autoreleasing _Tp& __x) _NOEXCEPT {
  43   return &__x;
  44 }
  45
  46 template <class _Tp>
  47 inline _LIBCPP_HIDE_FROM_ABI __unsafe_unretained _Tp* addressof(__unsafe_unretained _Tp& __x) _NOEXCEPT {
  48   return &__x;
  49 }
  50 #endif
  51
  52 #if !defined(_LIBCPP_CXX03_LANG)
  53 template <class _Tp>
  54 _Tp* addressof(const _Tp&&) noexcept = delete;
  55 #endif
  56
  57 _LIBCPP_END_NAMESPACE_STD
  58
  59 #endif // _LIBCPP___MEMORY_ADDRESSOF_H