1 // <experimental/memory> -*- C++ -*- 2 3 // Copyright (C) 2015-2024 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 3, or (at your option) 9 // any later version. 10 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 16 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /** @file experimental/memory 26 * This is a TS C++ Library header. 27 * @ingroup libfund-ts 28 */ 29 30 // 31 // N4336 Working Draft, C++ Extensions for Library Fundamentals, Version 2 32 // 33 34 #ifndef _GLIBCXX_EXPERIMENTAL_MEMORY 35 #define _GLIBCXX_EXPERIMENTAL_MEMORY 1 36 37 #pragma GCC system_header 38 39 #include <bits/requires_hosted.h> // experimental is currently omitted 40 41 #if __cplusplus >= 201402L 42 43 #include <memory> 44 #include <type_traits> 45 #include <experimental/bits/shared_ptr.h> 46 #include <bits/functional_hash.h> 47 48 namespace std _GLIBCXX_VISIBILITY(default) 49 { 50 _GLIBCXX_BEGIN_NAMESPACE_VERSION 51 52 namespace experimental 53 { 54 inline namespace fundamentals_v2 55 { 56 #define __cpp_lib_experimental_observer_ptr 201411 57 58 template <typename _Tp> 59 class observer_ptr 60 { 61 public: 62 // publish our template parameter and variations thereof 63 using element_type = _Tp; 64 using __pointer = add_pointer_t<_Tp>; // exposition-only 65 using __reference = add_lvalue_reference_t<_Tp>; // exposition-only 66 67 // 3.2.2, observer_ptr constructors 68 // default c'tor 69 constexpr observer_ptr() noexcept 70 : __t() 71 { } 72 73 // pointer-accepting c'tors 74 constexpr observer_ptr(nullptr_t) noexcept 75 : __t() 76 { } 77 78 constexpr explicit observer_ptr(__pointer __p) noexcept 79 : __t(__p) 80 { } 81 82 // copying c'tors (in addition to compiler-generated copy c'tor) 83 template <typename _Up, 84 typename = typename enable_if< 85 is_convertible<typename add_pointer<_Up>::type, __pointer 86 >::value 87 >::type> 88 constexpr observer_ptr(observer_ptr<_Up> __p) noexcept 89 : __t(__p.get()) 90 { 91 } 92 93 // 3.2.3, observer_ptr observers 94 constexpr __pointer 95 get() const noexcept 96 { 97 return __t; 98 } 99 100 constexpr __reference 101 operator*() const 102 { 103 return *get(); 104 } 105 106 constexpr __pointer 107 operator->() const noexcept 108 { 109 return get(); 110 } 111 112 constexpr explicit operator bool() const noexcept 113 { 114 return get() != nullptr; 115 } 116 117 // 3.2.4, observer_ptr conversions 118 constexpr explicit operator __pointer() const noexcept 119 { 120 return get(); 121 } 122 123 // 3.2.5, observer_ptr modifiers 124 constexpr __pointer 125 release() noexcept 126 { 127 __pointer __tmp = get(); 128 reset(); 129 return __tmp; 130 } 131 132 constexpr void 133 reset(__pointer __p = nullptr) noexcept 134 { 135 __t = __p; 136 } 137 138 constexpr void 139 swap(observer_ptr& __p) noexcept 140 { 141 std::swap(__t, __p.__t); 142 } 143 144 private: 145 __pointer __t; 146 }; // observer_ptr<> 147 148 template<typename _Tp> 149 void 150 swap(observer_ptr<_Tp>& __p1, observer_ptr<_Tp>& __p2) noexcept 151 { 152 __p1.swap(__p2); 153 } 154 155 template<typename _Tp> 156 observer_ptr<_Tp> 157 make_observer(_Tp* __p) noexcept 158 { 159 return observer_ptr<_Tp>(__p); 160 } 161 162 template<typename _Tp, typename _Up> 163 bool 164 operator==(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) 165 { 166 return __p1.get() == __p2.get(); 167 } 168 169 template<typename _Tp, typename _Up> 170 bool 171 operator!=(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) 172 { 173 return !(__p1 == __p2); 174 } 175 176 template<typename _Tp> 177 bool 178 operator==(observer_ptr<_Tp> __p, nullptr_t) noexcept 179 { 180 return !__p; 181 } 182 183 template<typename _Tp> 184 bool 185 operator==(nullptr_t, observer_ptr<_Tp> __p) noexcept 186 { 187 return !__p; 188 } 189 190 template<typename _Tp> 191 bool 192 operator!=(observer_ptr<_Tp> __p, nullptr_t) noexcept 193 { 194 return bool(__p); 195 } 196 197 template<typename _Tp> 198 bool 199 operator!=(nullptr_t, observer_ptr<_Tp> __p) noexcept 200 { 201 return bool(__p); 202 } 203 204 template<typename _Tp, typename _Up> 205 bool 206 operator<(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) 207 { 208 return std::less<typename common_type<typename add_pointer<_Tp>::type, 209 typename add_pointer<_Up>::type 210 >::type 211 >{}(__p1.get(), __p2.get()); 212 } 213 214 template<typename _Tp, typename _Up> 215 bool 216 operator>(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) 217 { 218 return __p2 < __p1; 219 } 220 221 template<typename _Tp, typename _Up> 222 bool 223 operator<=(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) 224 { 225 return !(__p2 < __p1); 226 } 227 228 template<typename _Tp, typename _Up> 229 bool 230 operator>=(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) 231 { 232 return !(__p1 < __p2); 233 } 234 } // namespace fundamentals_v2 235 } // namespace experimental 236 237 template <typename _Tp> 238 struct hash<experimental::observer_ptr<_Tp>> 239 { 240 using result_type = size_t; 241 using argument_type = experimental::observer_ptr<_Tp>; 242 243 size_t 244 operator()(const experimental::observer_ptr<_Tp>& __t) const 245 noexcept(noexcept(hash<typename add_pointer<_Tp>::type> {}(__t.get()))) 246 { 247 return hash<typename add_pointer<_Tp>::type> {}(__t.get()); 248 } 249 }; 250 251 252 _GLIBCXX_END_NAMESPACE_VERSION 253 } // namespace std 254 255 #endif // __cplusplus <= 201103L 256 257 #endif // _GLIBCXX_EXPERIMENTAL_MEMORY 258
Indexes created Tue Feb 24 08:35:24 UTC 2026