xref: /freebsd/contrib/llvm-project/libcxx/include/__memory/addressof.h (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
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 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___MEMORY_ADDRESSOF_H
62