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1 | // <concepts> -*- C++ -*- |
2 | ||
7adcbafe | 3 | // Copyright (C) 2019-2022 Free Software Foundation, Inc. |
cfc219ae JW |
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 | ||
7dbf96e2 JW |
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; | |
cfc219ae JW |
22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
23 | // <http://www.gnu.org/licenses/>. | |
24 | ||
25 | /** @file include/concepts | |
44af818f | 26 | * This is a Standard C++ Library header. |
cfc219ae JW |
27 | * @ingroup concepts |
28 | */ | |
29 | ||
30 | #ifndef _GLIBCXX_CONCEPTS | |
31 | #define _GLIBCXX_CONCEPTS 1 | |
32 | ||
b8a28a06 | 33 | #if __cplusplus > 201703L && __cpp_concepts >= 201907L |
cfc219ae JW |
34 | |
35 | #pragma GCC system_header | |
36 | ||
37 | /** | |
38 | * @defgroup concepts Concepts | |
39 | * @ingroup utilities | |
40 | * | |
41 | * Concepts for checking type requirements. | |
42 | */ | |
43 | ||
44 | #include <type_traits> | |
45 | ||
46 | namespace std _GLIBCXX_VISIBILITY(default) | |
47 | { | |
48 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
49 | ||
c9313582 | 50 | #define __cpp_lib_concepts 202002L |
cfc219ae JW |
51 | |
52 | // [concepts.lang], language-related concepts | |
53 | ||
54 | namespace __detail | |
55 | { | |
56 | template<typename _Tp, typename _Up> | |
44af818f | 57 | concept __same_as = std::is_same_v<_Tp, _Up>; |
cfc219ae JW |
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 | /// [concept.derived], concept derived_from | |
66 | template<typename _Derived, typename _Base> | |
67 | concept derived_from = __is_base_of(_Base, _Derived) | |
68 | && is_convertible_v<const volatile _Derived*, const volatile _Base*>; | |
69 | ||
70 | /// [concept.convertible], concept convertible_to | |
71 | template<typename _From, typename _To> | |
72 | concept convertible_to = is_convertible_v<_From, _To> | |
83faf7ea | 73 | && requires { static_cast<_To>(std::declval<_From>()); }; |
cfc219ae JW |
74 | |
75 | /// [concept.commonref], concept common_reference_with | |
76 | template<typename _Tp, typename _Up> | |
77 | concept common_reference_with | |
78 | = same_as<common_reference_t<_Tp, _Up>, common_reference_t<_Up, _Tp>> | |
79 | && convertible_to<_Tp, common_reference_t<_Tp, _Up>> | |
80 | && convertible_to<_Up, common_reference_t<_Tp, _Up>>; | |
81 | ||
82 | /// [concept.common], concept common_with | |
83 | template<typename _Tp, typename _Up> | |
84 | concept common_with | |
85 | = same_as<common_type_t<_Tp, _Up>, common_type_t<_Up, _Tp>> | |
86 | && requires { | |
87 | static_cast<common_type_t<_Tp, _Up>>(std::declval<_Tp>()); | |
88 | static_cast<common_type_t<_Tp, _Up>>(std::declval<_Up>()); | |
89 | } | |
90 | && common_reference_with<add_lvalue_reference_t<const _Tp>, | |
91 | add_lvalue_reference_t<const _Up>> | |
92 | && common_reference_with<add_lvalue_reference_t<common_type_t<_Tp, _Up>>, | |
93 | common_reference_t< | |
94 | add_lvalue_reference_t<const _Tp>, | |
95 | add_lvalue_reference_t<const _Up>>>; | |
96 | ||
97 | // [concepts.arithmetic], arithmetic concepts | |
98 | ||
99 | template<typename _Tp> | |
100 | concept integral = is_integral_v<_Tp>; | |
101 | ||
102 | template<typename _Tp> | |
103 | concept signed_integral = integral<_Tp> && is_signed_v<_Tp>; | |
104 | ||
105 | template<typename _Tp> | |
106 | concept unsigned_integral = integral<_Tp> && !signed_integral<_Tp>; | |
107 | ||
108 | template<typename _Tp> | |
109 | concept floating_point = is_floating_point_v<_Tp>; | |
110 | ||
111 | namespace __detail | |
112 | { | |
113 | template<typename _Tp> | |
114 | using __cref = const remove_reference_t<_Tp>&; | |
6d0dff49 JW |
115 | |
116 | template<typename _Tp> | |
117 | concept __class_or_enum | |
118 | = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>; | |
cfc219ae JW |
119 | } // namespace __detail |
120 | ||
121 | /// [concept.assignable], concept assignable_from | |
122 | template<typename _Lhs, typename _Rhs> | |
123 | concept assignable_from | |
124 | = is_lvalue_reference_v<_Lhs> | |
125 | && common_reference_with<__detail::__cref<_Lhs>, __detail::__cref<_Rhs>> | |
126 | && requires(_Lhs __lhs, _Rhs&& __rhs) { | |
127 | { __lhs = static_cast<_Rhs&&>(__rhs) } -> same_as<_Lhs>; | |
128 | }; | |
129 | ||
130 | /// [concept.destructible], concept destructible | |
131 | template<typename _Tp> | |
132 | concept destructible = is_nothrow_destructible_v<_Tp>; | |
133 | ||
134 | /// [concept.constructible], concept constructible_from | |
135 | template<typename _Tp, typename... _Args> | |
136 | concept constructible_from | |
137 | = destructible<_Tp> && is_constructible_v<_Tp, _Args...>; | |
138 | ||
a31517cb | 139 | /// [concept.defaultinitializable], concept default_initializable |
cfc219ae | 140 | template<typename _Tp> |
a31517cb JW |
141 | concept default_initializable = constructible_from<_Tp> |
142 | && requires | |
143 | { | |
144 | _Tp{}; | |
145 | (void) ::new _Tp; | |
146 | }; | |
cfc219ae JW |
147 | |
148 | /// [concept.moveconstructible], concept move_constructible | |
149 | template<typename _Tp> | |
150 | concept move_constructible | |
151 | = constructible_from<_Tp, _Tp> && convertible_to<_Tp, _Tp>; | |
152 | ||
153 | /// [concept.copyconstructible], concept copy_constructible | |
154 | template<typename _Tp> | |
155 | concept copy_constructible | |
156 | = move_constructible<_Tp> | |
157 | && constructible_from<_Tp, _Tp&> && convertible_to<_Tp&, _Tp> | |
158 | && constructible_from<_Tp, const _Tp&> && convertible_to<const _Tp&, _Tp> | |
159 | && constructible_from<_Tp, const _Tp> && convertible_to<const _Tp, _Tp>; | |
160 | ||
161 | // [concept.swappable], concept swappable | |
162 | ||
163 | namespace ranges | |
164 | { | |
165 | namespace __cust_swap | |
166 | { | |
167 | template<typename _Tp> void swap(_Tp&, _Tp&) = delete; | |
168 | ||
cfc219ae JW |
169 | template<typename _Tp, typename _Up> |
170 | concept __adl_swap | |
6d0dff49 JW |
171 | = (__detail::__class_or_enum<remove_reference_t<_Tp>> |
172 | || __detail::__class_or_enum<remove_reference_t<_Up>>) | |
cfc219ae JW |
173 | && requires(_Tp&& __t, _Up&& __u) { |
174 | swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); | |
175 | }; | |
176 | ||
177 | struct _Swap | |
178 | { | |
ce001b30 JW |
179 | private: |
180 | template<typename _Tp, typename _Up> | |
181 | static constexpr bool | |
182 | _S_noexcept() | |
183 | { | |
184 | if constexpr (__adl_swap<_Tp, _Up>) | |
185 | return noexcept(swap(std::declval<_Tp>(), std::declval<_Up>())); | |
186 | else | |
187 | return is_nothrow_move_constructible_v<remove_reference_t<_Tp>> | |
188 | && is_nothrow_move_assignable_v<remove_reference_t<_Tp>>; | |
189 | } | |
190 | ||
191 | public: | |
cfc219ae JW |
192 | template<typename _Tp, typename _Up> |
193 | requires __adl_swap<_Tp, _Up> | |
ce001b30 JW |
194 | || (same_as<_Tp, _Up> && is_lvalue_reference_v<_Tp> |
195 | && move_constructible<remove_reference_t<_Tp>> | |
196 | && assignable_from<_Tp, remove_reference_t<_Tp>>) | |
6d0dff49 JW |
197 | constexpr void |
198 | operator()(_Tp&& __t, _Up&& __u) const | |
ce001b30 JW |
199 | noexcept(_S_noexcept<_Tp, _Up>()) |
200 | { | |
201 | if constexpr (__adl_swap<_Tp, _Up>) | |
202 | swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); | |
203 | else | |
204 | { | |
205 | auto __tmp = static_cast<remove_reference_t<_Tp>&&>(__t); | |
206 | __t = static_cast<remove_reference_t<_Tp>&&>(__u); | |
207 | __u = static_cast<remove_reference_t<_Tp>&&>(__tmp); | |
208 | } | |
209 | } | |
cfc219ae JW |
210 | |
211 | template<typename _Tp, typename _Up, size_t _Num> | |
212 | requires requires(const _Swap& __swap, _Tp& __e1, _Up& __e2) { | |
213 | __swap(__e1, __e2); | |
214 | } | |
215 | constexpr void | |
216 | operator()(_Tp (&__e1)[_Num], _Up (&__e2)[_Num]) const | |
217 | noexcept(noexcept(std::declval<const _Swap&>()(*__e1, *__e2))) | |
218 | { | |
219 | for (size_t __n = 0; __n < _Num; ++__n) | |
220 | (*this)(__e1[__n], __e2[__n]); | |
221 | } | |
cfc219ae JW |
222 | }; |
223 | } // namespace __cust_swap | |
224 | ||
225 | inline namespace __cust | |
226 | { | |
227 | inline constexpr __cust_swap::_Swap swap{}; | |
228 | } // inline namespace __cust | |
229 | } // namespace ranges | |
230 | ||
231 | template<typename _Tp> | |
232 | concept swappable | |
233 | = requires(_Tp& __a, _Tp& __b) { ranges::swap(__a, __b); }; | |
234 | ||
235 | template<typename _Tp, typename _Up> | |
236 | concept swappable_with = common_reference_with<_Tp, _Up> | |
237 | && requires(_Tp&& __t, _Up&& __u) { | |
238 | ranges::swap(static_cast<_Tp&&>(__t), static_cast<_Tp&&>(__t)); | |
239 | ranges::swap(static_cast<_Up&&>(__u), static_cast<_Up&&>(__u)); | |
240 | ranges::swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); | |
241 | ranges::swap(static_cast<_Up&&>(__u), static_cast<_Tp&&>(__t)); | |
242 | }; | |
243 | ||
244 | // [concepts.object], Object concepts | |
245 | ||
246 | template<typename _Tp> | |
247 | concept movable = is_object_v<_Tp> && move_constructible<_Tp> | |
248 | && assignable_from<_Tp&, _Tp> && swappable<_Tp>; | |
249 | ||
250 | template<typename _Tp> | |
251 | concept copyable = copy_constructible<_Tp> && movable<_Tp> | |
d6dfa3da JW |
252 | && assignable_from<_Tp&, _Tp&> && assignable_from<_Tp&, const _Tp&> |
253 | && assignable_from<_Tp&, const _Tp>; | |
cfc219ae JW |
254 | |
255 | template<typename _Tp> | |
a31517cb | 256 | concept semiregular = copyable<_Tp> && default_initializable<_Tp>; |
cfc219ae JW |
257 | |
258 | // [concepts.compare], comparison concepts | |
259 | ||
c5e1c1d3 JW |
260 | // [concept.booleantestable], Boolean testability |
261 | namespace __detail | |
262 | { | |
263 | template<typename _Tp> | |
264 | concept __boolean_testable_impl = convertible_to<_Tp, bool>; | |
265 | ||
266 | template<typename _Tp> | |
267 | concept __boolean_testable | |
268 | = __boolean_testable_impl<_Tp> | |
269 | && requires(_Tp&& __t) | |
270 | { { !static_cast<_Tp&&>(__t) } -> __boolean_testable_impl; }; | |
271 | } // namespace __detail | |
cfc219ae JW |
272 | |
273 | // [concept.equalitycomparable], concept equality_comparable | |
274 | ||
275 | namespace __detail | |
276 | { | |
277 | template<typename _Tp, typename _Up> | |
278 | concept __weakly_eq_cmp_with | |
279 | = requires(__detail::__cref<_Tp> __t, __detail::__cref<_Up> __u) { | |
c5e1c1d3 JW |
280 | { __t == __u } -> __boolean_testable; |
281 | { __t != __u } -> __boolean_testable; | |
282 | { __u == __t } -> __boolean_testable; | |
283 | { __u != __t } -> __boolean_testable; | |
cfc219ae JW |
284 | }; |
285 | } // namespace __detail | |
286 | ||
287 | template<typename _Tp> | |
288 | concept equality_comparable = __detail::__weakly_eq_cmp_with<_Tp, _Tp>; | |
289 | ||
290 | template<typename _Tp, typename _Up> | |
291 | concept equality_comparable_with | |
292 | = equality_comparable<_Tp> && equality_comparable<_Up> | |
293 | && common_reference_with<__detail::__cref<_Tp>, __detail::__cref<_Up>> | |
294 | && equality_comparable<common_reference_t<__detail::__cref<_Tp>, | |
295 | __detail::__cref<_Up>>> | |
296 | && __detail::__weakly_eq_cmp_with<_Tp, _Up>; | |
297 | ||
0294dc5f JW |
298 | namespace __detail |
299 | { | |
300 | template<typename _Tp, typename _Up> | |
301 | concept __partially_ordered_with | |
302 | = requires(const remove_reference_t<_Tp>& __t, | |
303 | const remove_reference_t<_Up>& __u) { | |
304 | { __t < __u } -> __boolean_testable; | |
305 | { __t > __u } -> __boolean_testable; | |
306 | { __t <= __u } -> __boolean_testable; | |
307 | { __t >= __u } -> __boolean_testable; | |
308 | { __u < __t } -> __boolean_testable; | |
309 | { __u > __t } -> __boolean_testable; | |
310 | { __u <= __t } -> __boolean_testable; | |
311 | { __u >= __t } -> __boolean_testable; | |
312 | }; | |
313 | } // namespace __detail | |
314 | ||
cfc219ae JW |
315 | // [concept.totallyordered], concept totally_ordered |
316 | template<typename _Tp> | |
317 | concept totally_ordered | |
318 | = equality_comparable<_Tp> | |
0294dc5f | 319 | && __detail::__partially_ordered_with<_Tp, _Tp>; |
cfc219ae JW |
320 | |
321 | template<typename _Tp, typename _Up> | |
322 | concept totally_ordered_with | |
323 | = totally_ordered<_Tp> && totally_ordered<_Up> | |
241ed965 | 324 | && equality_comparable_with<_Tp, _Up> |
cfc219ae JW |
325 | && totally_ordered<common_reference_t<__detail::__cref<_Tp>, |
326 | __detail::__cref<_Up>>> | |
0294dc5f | 327 | && __detail::__partially_ordered_with<_Tp, _Up>; |
cfc219ae JW |
328 | |
329 | template<typename _Tp> | |
330 | concept regular = semiregular<_Tp> && equality_comparable<_Tp>; | |
331 | ||
332 | // [concepts.callable], callable concepts | |
333 | ||
270082a7 | 334 | /// [concept.invocable], concept invocable |
cfc219ae JW |
335 | template<typename _Fn, typename... _Args> |
336 | concept invocable = is_invocable_v<_Fn, _Args...>; | |
337 | ||
270082a7 | 338 | /// [concept.regularinvocable], concept regular_invocable |
cfc219ae JW |
339 | template<typename _Fn, typename... _Args> |
340 | concept regular_invocable = invocable<_Fn, _Args...>; | |
341 | ||
270082a7 | 342 | /// [concept.predicate], concept predicate |
cfc219ae JW |
343 | template<typename _Fn, typename... _Args> |
344 | concept predicate = regular_invocable<_Fn, _Args...> | |
c5e1c1d3 | 345 | && __detail::__boolean_testable<invoke_result_t<_Fn, _Args...>>; |
cfc219ae | 346 | |
270082a7 | 347 | /// [concept.relation], concept relation |
cfc219ae JW |
348 | template<typename _Rel, typename _Tp, typename _Up> |
349 | concept relation | |
350 | = predicate<_Rel, _Tp, _Tp> && predicate<_Rel, _Up, _Up> | |
351 | && predicate<_Rel, _Tp, _Up> && predicate<_Rel, _Up, _Tp>; | |
352 | ||
270082a7 JW |
353 | /// [concept.equiv], concept equivalence_relation |
354 | template<typename _Rel, typename _Tp, typename _Up> | |
355 | concept equivalence_relation = relation<_Rel, _Tp, _Up>; | |
356 | ||
357 | /// [concept.strictweakorder], concept strict_weak_order | |
cfc219ae JW |
358 | template<typename _Rel, typename _Tp, typename _Up> |
359 | concept strict_weak_order = relation<_Rel, _Tp, _Up>; | |
360 | ||
361 | _GLIBCXX_END_NAMESPACE_VERSION | |
362 | } // namespace | |
363 | #endif // C++2a | |
364 | ||
365 | #endif /* _GLIBCXX_CONCEPTS */ |