1 // <concepts> -*- C++ -*- 2 3 // Copyright (C) 2019-2024 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 include/concepts 26 * This is a Standard C++ Library header. 27 * @ingroup concepts 28 */ 29 30 #ifndef _GLIBCXX_CONCEPTS 31 #define _GLIBCXX_CONCEPTS 1 32 33 #pragma GCC system_header 34 35 #define __glibcxx_want_concepts 36 #include <bits/version.h> 37 38 #ifdef __cpp_lib_concepts // C++ >= 20 && concepts 39 /** 40 * @defgroup concepts Concepts 41 * @ingroup utilities 42 * 43 * Concepts for checking type requirements. 44 */ 45 46 #include <type_traits> 47 48 namespace std _GLIBCXX_VISIBILITY(default) 49 { 50 _GLIBCXX_BEGIN_NAMESPACE_VERSION 51 52 // [concepts.lang], language-related concepts 53 54 namespace __detail 55 { 56 template<typename _Tp, typename _Up> 57 concept __same_as = std::is_same_v<_Tp, _Up>; 58 } // namespace __detail 59 60 /// [concept.same], concept same_as 61 template<typename _Tp, typename _Up> 62 concept same_as 63 = __detail::__same_as<_Tp, _Up> && __detail::__same_as<_Up, _Tp>; 64 65 namespace __detail 66 { 67 template<typename _Tp, typename _Up> 68 concept __different_from 69 = !same_as<remove_cvref_t<_Tp>, remove_cvref_t<_Up>>; 70 } // namespace __detail 71 72 /// [concept.derived], concept derived_from 73 template<typename _Derived, typename _Base> 74 concept derived_from = __is_base_of(_Base, _Derived) 75 && is_convertible_v<const volatile _Derived*, const volatile _Base*>; 76 77 /// [concept.convertible], concept convertible_to 78 template<typename _From, typename _To> 79 concept convertible_to = is_convertible_v<_From, _To> 80 && requires { static_cast<_To>(std::declval<_From>()); }; 81 82 /// [concept.commonref], concept common_reference_with 83 template<typename _Tp, typename _Up> 84 concept common_reference_with 85 = same_as<common_reference_t<_Tp, _Up>, common_reference_t<_Up, _Tp>> 86 && convertible_to<_Tp, common_reference_t<_Tp, _Up>> 87 && convertible_to<_Up, common_reference_t<_Tp, _Up>>; 88 89 /// [concept.common], concept common_with 90 template<typename _Tp, typename _Up> 91 concept common_with 92 = same_as<common_type_t<_Tp, _Up>, common_type_t<_Up, _Tp>> 93 && requires { 94 static_cast<common_type_t<_Tp, _Up>>(std::declval<_Tp>()); 95 static_cast<common_type_t<_Tp, _Up>>(std::declval<_Up>()); 96 } 97 && common_reference_with<add_lvalue_reference_t<const _Tp>, 98 add_lvalue_reference_t<const _Up>> 99 && common_reference_with<add_lvalue_reference_t<common_type_t<_Tp, _Up>>, 100 common_reference_t< 101 add_lvalue_reference_t<const _Tp>, 102 add_lvalue_reference_t<const _Up>>>; 103 104 // [concepts.arithmetic], arithmetic concepts 105 106 template<typename _Tp> 107 concept integral = is_integral_v<_Tp>; 108 109 template<typename _Tp> 110 concept signed_integral = integral<_Tp> && is_signed_v<_Tp>; 111 112 template<typename _Tp> 113 concept unsigned_integral = integral<_Tp> && !signed_integral<_Tp>; 114 115 template<typename _Tp> 116 concept floating_point = is_floating_point_v<_Tp>; 117 118 namespace __detail 119 { 120 template<typename _Tp> 121 using __cref = const remove_reference_t<_Tp>&; 122 123 template<typename _Tp> 124 concept __class_or_enum 125 = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>; 126 127 template<typename _Tp> 128 constexpr bool __destructible_impl = false; 129 template<typename _Tp> 130 requires requires(_Tp& __t) { { __t.~_Tp() } noexcept; } 131 constexpr bool __destructible_impl<_Tp> = true; 132 133 template<typename _Tp> 134 constexpr bool __destructible = __destructible_impl<_Tp>; 135 template<typename _Tp> 136 constexpr bool __destructible<_Tp&> = true; 137 template<typename _Tp> 138 constexpr bool __destructible<_Tp&&> = true; 139 template<typename _Tp, size_t _Nm> 140 constexpr bool __destructible<_Tp[_Nm]> = __destructible<_Tp>; 141 142 } // namespace __detail 143 144 /// [concept.assignable], concept assignable_from 145 template<typename _Lhs, typename _Rhs> 146 concept assignable_from 147 = is_lvalue_reference_v<_Lhs> 148 && common_reference_with<__detail::__cref<_Lhs>, __detail::__cref<_Rhs>> 149 && requires(_Lhs __lhs, _Rhs&& __rhs) { 150 { __lhs = static_cast<_Rhs&&>(__rhs) } -> same_as<_Lhs>; 151 }; 152 153 /// [concept.destructible], concept destructible 154 template<typename _Tp> 155 concept destructible = __detail::__destructible<_Tp>; 156 157 /// [concept.constructible], concept constructible_from 158 template<typename _Tp, typename... _Args> 159 concept constructible_from 160 = destructible<_Tp> && is_constructible_v<_Tp, _Args...>; 161 162 /// [concept.defaultinitializable], concept default_initializable 163 template<typename _Tp> 164 concept default_initializable = constructible_from<_Tp> 165 && requires 166 { 167 _Tp{}; 168 (void) ::new _Tp; 169 }; 170 171 /// [concept.moveconstructible], concept move_constructible 172 template<typename _Tp> 173 concept move_constructible 174 = constructible_from<_Tp, _Tp> && convertible_to<_Tp, _Tp>; 175 176 /// [concept.copyconstructible], concept copy_constructible 177 template<typename _Tp> 178 concept copy_constructible 179 = move_constructible<_Tp> 180 && constructible_from<_Tp, _Tp&> && convertible_to<_Tp&, _Tp> 181 && constructible_from<_Tp, const _Tp&> && convertible_to<const _Tp&, _Tp> 182 && constructible_from<_Tp, const _Tp> && convertible_to<const _Tp, _Tp>; 183 184 // [concept.swappable], concept swappable 185 186 namespace ranges 187 { 188 /// @cond undocumented 189 namespace __swap 190 { 191 template<typename _Tp> void swap(_Tp&, _Tp&) = delete; 192 193 template<typename _Tp, typename _Up> 194 concept __adl_swap 195 = (std::__detail::__class_or_enum<remove_reference_t<_Tp>> 196 || std::__detail::__class_or_enum<remove_reference_t<_Up>>) 197 && requires(_Tp&& __t, _Up&& __u) { 198 swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); 199 }; 200 201 struct _Swap 202 { 203 private: 204 template<typename _Tp, typename _Up> 205 static constexpr bool 206 _S_noexcept() 207 { 208 if constexpr (__adl_swap<_Tp, _Up>) 209 return noexcept(swap(std::declval<_Tp>(), std::declval<_Up>())); 210 else 211 return is_nothrow_move_constructible_v<remove_reference_t<_Tp>> 212 && is_nothrow_move_assignable_v<remove_reference_t<_Tp>>; 213 } 214 215 public: 216 template<typename _Tp, typename _Up> 217 requires __adl_swap<_Tp, _Up> 218 || (same_as<_Tp, _Up> && is_lvalue_reference_v<_Tp> 219 && move_constructible<remove_reference_t<_Tp>> 220 && assignable_from<_Tp, remove_reference_t<_Tp>>) 221 constexpr void 222 operator()(_Tp&& __t, _Up&& __u) const 223 noexcept(_S_noexcept<_Tp, _Up>()) 224 { 225 if constexpr (__adl_swap<_Tp, _Up>) 226 swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); 227 else 228 { 229 auto __tmp = static_cast<remove_reference_t<_Tp>&&>(__t); 230 __t = static_cast<remove_reference_t<_Tp>&&>(__u); 231 __u = static_cast<remove_reference_t<_Tp>&&>(__tmp); 232 } 233 } 234 235 template<typename _Tp, typename _Up, size_t _Num> 236 requires requires(const _Swap& __swap, _Tp& __e1, _Up& __e2) { 237 __swap(__e1, __e2); 238 } 239 constexpr void 240 operator()(_Tp (&__e1)[_Num], _Up (&__e2)[_Num]) const 241 noexcept(noexcept(std::declval<const _Swap&>()(*__e1, *__e2))) 242 { 243 for (size_t __n = 0; __n < _Num; ++__n) 244 (*this)(__e1[__n], __e2[__n]); 245 } 246 }; 247 } // namespace __swap 248 /// @endcond 249 250 inline namespace _Cpo { 251 inline constexpr __swap::_Swap swap{}; 252 } 253 } // namespace ranges 254 255 template<typename _Tp> 256 concept swappable 257 = requires(_Tp& __a, _Tp& __b) { ranges::swap(__a, __b); }; 258 259 template<typename _Tp, typename _Up> 260 concept swappable_with = common_reference_with<_Tp, _Up> 261 && requires(_Tp&& __t, _Up&& __u) { 262 ranges::swap(static_cast<_Tp&&>(__t), static_cast<_Tp&&>(__t)); 263 ranges::swap(static_cast<_Up&&>(__u), static_cast<_Up&&>(__u)); 264 ranges::swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); 265 ranges::swap(static_cast<_Up&&>(__u), static_cast<_Tp&&>(__t)); 266 }; 267 268 // [concepts.object], Object concepts 269 270 template<typename _Tp> 271 concept movable = is_object_v<_Tp> && move_constructible<_Tp> 272 && assignable_from<_Tp&, _Tp> && swappable<_Tp>; 273 274 template<typename _Tp> 275 concept copyable = copy_constructible<_Tp> && movable<_Tp> 276 && assignable_from<_Tp&, _Tp&> && assignable_from<_Tp&, const _Tp&> 277 && assignable_from<_Tp&, const _Tp>; 278 279 template<typename _Tp> 280 concept semiregular = copyable<_Tp> && default_initializable<_Tp>; 281 282 // [concepts.compare], comparison concepts 283 284 // [concept.booleantestable], Boolean testability 285 namespace __detail 286 { 287 template<typename _Tp> 288 concept __boolean_testable_impl = convertible_to<_Tp, bool>; 289 290 template<typename _Tp> 291 concept __boolean_testable 292 = __boolean_testable_impl<_Tp> 293 && requires(_Tp&& __t) 294 { { !static_cast<_Tp&&>(__t) } -> __boolean_testable_impl; }; 295 } // namespace __detail 296 297 // [concept.equalitycomparable], concept equality_comparable 298 299 namespace __detail 300 { 301 template<typename _Tp, typename _Up> 302 concept __weakly_eq_cmp_with 303 = requires(__detail::__cref<_Tp> __t, __detail::__cref<_Up> __u) { 304 { __t == __u } -> __boolean_testable; 305 { __t != __u } -> __boolean_testable; 306 { __u == __t } -> __boolean_testable; 307 { __u != __t } -> __boolean_testable; 308 }; 309 } // namespace __detail 310 311 template<typename _Tp> 312 concept equality_comparable = __detail::__weakly_eq_cmp_with<_Tp, _Tp>; 313 314 template<typename _Tp, typename _Up> 315 concept equality_comparable_with 316 = equality_comparable<_Tp> && equality_comparable<_Up> 317 && common_reference_with<__detail::__cref<_Tp>, __detail::__cref<_Up>> 318 && equality_comparable<common_reference_t<__detail::__cref<_Tp>, 319 __detail::__cref<_Up>>> 320 && __detail::__weakly_eq_cmp_with<_Tp, _Up>; 321 322 namespace __detail 323 { 324 template<typename _Tp, typename _Up> 325 concept __partially_ordered_with 326 = requires(const remove_reference_t<_Tp>& __t, 327 const remove_reference_t<_Up>& __u) { 328 { __t < __u } -> __boolean_testable; 329 { __t > __u } -> __boolean_testable; 330 { __t <= __u } -> __boolean_testable; 331 { __t >= __u } -> __boolean_testable; 332 { __u < __t } -> __boolean_testable; 333 { __u > __t } -> __boolean_testable; 334 { __u <= __t } -> __boolean_testable; 335 { __u >= __t } -> __boolean_testable; 336 }; 337 } // namespace __detail 338 339 // [concept.totallyordered], concept totally_ordered 340 template<typename _Tp> 341 concept totally_ordered 342 = equality_comparable<_Tp> 343 && __detail::__partially_ordered_with<_Tp, _Tp>; 344 345 template<typename _Tp, typename _Up> 346 concept totally_ordered_with 347 = totally_ordered<_Tp> && totally_ordered<_Up> 348 && equality_comparable_with<_Tp, _Up> 349 && totally_ordered<common_reference_t<__detail::__cref<_Tp>, 350 __detail::__cref<_Up>>> 351 && __detail::__partially_ordered_with<_Tp, _Up>; 352 353 template<typename _Tp> 354 concept regular = semiregular<_Tp> && equality_comparable<_Tp>; 355 356 // [concepts.callable], callable concepts 357 358 /// [concept.invocable], concept invocable 359 template<typename _Fn, typename... _Args> 360 concept invocable = is_invocable_v<_Fn, _Args...>; 361 362 /// [concept.regularinvocable], concept regular_invocable 363 template<typename _Fn, typename... _Args> 364 concept regular_invocable = invocable<_Fn, _Args...>; 365 366 /// [concept.predicate], concept predicate 367 template<typename _Fn, typename... _Args> 368 concept predicate = regular_invocable<_Fn, _Args...> 369 && __detail::__boolean_testable<invoke_result_t<_Fn, _Args...>>; 370 371 /// [concept.relation], concept relation 372 template<typename _Rel, typename _Tp, typename _Up> 373 concept relation 374 = predicate<_Rel, _Tp, _Tp> && predicate<_Rel, _Up, _Up> 375 && predicate<_Rel, _Tp, _Up> && predicate<_Rel, _Up, _Tp>; 376 377 /// [concept.equiv], concept equivalence_relation 378 template<typename _Rel, typename _Tp, typename _Up> 379 concept equivalence_relation = relation<_Rel, _Tp, _Up>; 380 381 /// [concept.strictweakorder], concept strict_weak_order 382 template<typename _Rel, typename _Tp, typename _Up> 383 concept strict_weak_order = relation<_Rel, _Tp, _Up>; 384 385 _GLIBCXX_END_NAMESPACE_VERSION 386 } // namespace 387 #endif // __cpp_lib_concepts 388 389 #endif /* _GLIBCXX_CONCEPTS */ 390
Indexes created Sun Mar 01 05:31:48 UTC 2026