libcxx/include/__cxx03/__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___CXX03___MEMORY_ADDRESSOF_H
  11 #define _LIBCPP___CXX03___MEMORY_ADDRESSOF_H
  12
  13 #include <__cxx03/__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 defined(_LIBCPP_HAS_OBJC_ARC) && !defined(_LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF)
  27 // Objective-C++ Automatic Reference Counting uses qualified pointers
  28 // that require special addressof() signatures. When
  29 // _LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF is defined, the compiler
  30 // itself is providing these definitions. Otherwise, we provide them.
  31 template <class _Tp>
  32 inline _LIBCPP_HIDE_FROM_ABI __strong _Tp* addressof(__strong _Tp& __x) _NOEXCEPT {
  33   return &__x;
  34 }
  35
  36 #  ifdef _LIBCPP_HAS_OBJC_ARC_WEAK
  37 template <class _Tp>
  38 inline _LIBCPP_HIDE_FROM_ABI __weak _Tp* addressof(__weak _Tp& __x) _NOEXCEPT {
  39   return &__x;
  40 }
  41 #  endif
  42
  43 template <class _Tp>
  44 inline _LIBCPP_HIDE_FROM_ABI __autoreleasing _Tp* addressof(__autoreleasing _Tp& __x) _NOEXCEPT {
  45   return &__x;
  46 }
  47
  48 template <class _Tp>
  49 inline _LIBCPP_HIDE_FROM_ABI __unsafe_unretained _Tp* addressof(__unsafe_unretained _Tp& __x) _NOEXCEPT {
  50   return &__x;
  51 }
  52 #endif
  53
  54 #if !defined(_LIBCPP_CXX03_LANG)
  55 template <class _Tp>
  56 _Tp* addressof(const _Tp&&) noexcept = delete;
  57 #endif
  58
  59 _LIBCPP_END_NAMESPACE_STD
  60
  61 #endif // _LIBCPP___CXX03___MEMORY_ADDRESSOF_H