master
1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___UTILITY_PAIR_H
10#define _LIBCPP___UTILITY_PAIR_H
11
12#include <__compare/common_comparison_category.h>
13#include <__compare/synth_three_way.h>
14#include <__concepts/boolean_testable.h>
15#include <__concepts/different_from.h>
16#include <__config>
17#include <__cstddef/size_t.h>
18#include <__fwd/array.h>
19#include <__fwd/pair.h>
20#include <__fwd/tuple.h>
21#include <__tuple/tuple_indices.h>
22#include <__tuple/tuple_like_no_subrange.h>
23#include <__tuple/tuple_size.h>
24#include <__type_traits/common_reference.h>
25#include <__type_traits/common_type.h>
26#include <__type_traits/conditional.h>
27#include <__type_traits/enable_if.h>
28#include <__type_traits/integral_constant.h>
29#include <__type_traits/is_assignable.h>
30#include <__type_traits/is_constructible.h>
31#include <__type_traits/is_convertible.h>
32#include <__type_traits/is_implicitly_default_constructible.h>
33#include <__type_traits/is_nothrow_assignable.h>
34#include <__type_traits/is_nothrow_constructible.h>
35#include <__type_traits/is_replaceable.h>
36#include <__type_traits/is_same.h>
37#include <__type_traits/is_swappable.h>
38#include <__type_traits/is_trivially_relocatable.h>
39#include <__type_traits/nat.h>
40#include <__type_traits/unwrap_ref.h>
41#include <__utility/declval.h>
42#include <__utility/forward.h>
43#include <__utility/move.h>
44#include <__utility/piecewise_construct.h>
45
46#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
47# pragma GCC system_header
48#endif
49
50_LIBCPP_PUSH_MACROS
51#include <__undef_macros>
52
53_LIBCPP_BEGIN_NAMESPACE_STD
54
55#ifndef _LIBCPP_CXX03_LANG
56
57template <class _T1, class _T2>
58struct __check_pair_construction {
59 template <int&...>
60 static _LIBCPP_HIDE_FROM_ABI constexpr bool __enable_implicit_default() {
61 return __is_implicitly_default_constructible<_T1>::value && __is_implicitly_default_constructible<_T2>::value;
62 }
63
64 template <int&...>
65 static _LIBCPP_HIDE_FROM_ABI constexpr bool __enable_default() {
66 return is_default_constructible<_T1>::value && is_default_constructible<_T2>::value;
67 }
68
69 template <class _U1, class _U2>
70 static _LIBCPP_HIDE_FROM_ABI constexpr bool __is_pair_constructible() {
71 return is_constructible<_T1, _U1>::value && is_constructible<_T2, _U2>::value;
72 }
73
74 template <class _U1, class _U2>
75 static _LIBCPP_HIDE_FROM_ABI constexpr bool __is_implicit() {
76 return is_convertible<_U1, _T1>::value && is_convertible<_U2, _T2>::value;
77 }
78};
79
80#endif
81
82template <class, class>
83struct __non_trivially_copyable_base {
84 _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI __non_trivially_copyable_base() _NOEXCEPT {}
85 _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI
86 __non_trivially_copyable_base(__non_trivially_copyable_base const&) _NOEXCEPT {}
87};
88
89template <class _T1, class _T2>
90struct pair
91#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
92 : private __non_trivially_copyable_base<_T1, _T2>
93#endif
94{
95 using first_type = _T1;
96 using second_type = _T2;
97
98 _T1 first;
99 _T2 second;
100
101 using __trivially_relocatable _LIBCPP_NODEBUG =
102 __conditional_t<__libcpp_is_trivially_relocatable<_T1>::value && __libcpp_is_trivially_relocatable<_T2>::value,
103 pair,
104 void>;
105 using __replaceable _LIBCPP_NODEBUG = __conditional_t<__is_replaceable_v<_T1> && __is_replaceable_v<_T2>, pair, void>;
106
107 _LIBCPP_HIDE_FROM_ABI pair(pair const&) = default;
108 _LIBCPP_HIDE_FROM_ABI pair(pair&&) = default;
109
110#ifdef _LIBCPP_CXX03_LANG
111 _LIBCPP_HIDE_FROM_ABI pair() : first(), second() {}
112
113 _LIBCPP_HIDE_FROM_ABI pair(_T1 const& __t1, _T2 const& __t2) : first(__t1), second(__t2) {}
114
115 template <class _U1, class _U2>
116 _LIBCPP_HIDE_FROM_ABI pair(const pair<_U1, _U2>& __p) : first(__p.first), second(__p.second) {}
117
118 _LIBCPP_HIDE_FROM_ABI pair& operator=(pair const& __p) {
119 first = __p.first;
120 second = __p.second;
121 return *this;
122 }
123
124 // Extension: This is provided in C++03 because it allows properly handling the
125 // assignment to a pair containing references, which would be a hard
126 // error otherwise.
127 template <
128 class _U1,
129 class _U2,
130 __enable_if_t<is_assignable<first_type&, _U1 const&>::value && is_assignable<second_type&, _U2 const&>::value,
131 int> = 0>
132 _LIBCPP_HIDE_FROM_ABI pair& operator=(pair<_U1, _U2> const& __p) {
133 first = __p.first;
134 second = __p.second;
135 return *this;
136 }
137#else
138 template <class _CheckArgsDep = __check_pair_construction<_T1, _T2>,
139 __enable_if_t<_CheckArgsDep::__enable_default(), int> = 0>
140 explicit(!_CheckArgsDep::__enable_implicit_default()) _LIBCPP_HIDE_FROM_ABI constexpr pair() noexcept(
141 is_nothrow_default_constructible<first_type>::value && is_nothrow_default_constructible<second_type>::value)
142 : first(), second() {}
143
144 template <class _CheckArgsDep = __check_pair_construction<_T1, _T2>,
145 __enable_if_t<_CheckArgsDep::template __is_pair_constructible<_T1 const&, _T2 const&>(), int> = 0>
146 _LIBCPP_HIDE_FROM_ABI
147 _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(!_CheckArgsDep::template __is_implicit<_T1 const&, _T2 const&>())
148 pair(_T1 const& __t1, _T2 const& __t2) noexcept(is_nothrow_copy_constructible<first_type>::value &&
149 is_nothrow_copy_constructible<second_type>::value)
150 : first(__t1), second(__t2) {}
151
152 template <
153# if _LIBCPP_STD_VER >= 23 // http://wg21.link/P1951
154 class _U1 = _T1,
155 class _U2 = _T2,
156# else
157 class _U1,
158 class _U2,
159# endif
160 __enable_if_t<__check_pair_construction<_T1, _T2>::template __is_pair_constructible<_U1, _U2>(), int> = 0 >
161 _LIBCPP_HIDE_FROM_ABI
162 _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(!__check_pair_construction<_T1, _T2>::template __is_implicit<_U1, _U2>())
163 pair(_U1&& __u1, _U2&& __u2) noexcept(is_nothrow_constructible<first_type, _U1>::value &&
164 is_nothrow_constructible<second_type, _U2>::value)
165 : first(std::forward<_U1>(__u1)), second(std::forward<_U2>(__u2)) {
166 }
167
168# if _LIBCPP_STD_VER >= 23
169 template <class _U1,
170 class _U2,
171 __enable_if_t<__check_pair_construction<_T1, _T2>::template __is_pair_constructible<_U1&, _U2&>(), int> = 0>
172 _LIBCPP_HIDE_FROM_ABI constexpr explicit(!__check_pair_construction<_T1, _T2>::template __is_implicit<_U1&, _U2&>())
173 pair(pair<_U1, _U2>& __p) noexcept((is_nothrow_constructible<first_type, _U1&>::value &&
174 is_nothrow_constructible<second_type, _U2&>::value))
175 : first(__p.first), second(__p.second) {}
176# endif
177
178 template <
179 class _U1,
180 class _U2,
181 __enable_if_t<__check_pair_construction<_T1, _T2>::template __is_pair_constructible<_U1 const&, _U2 const&>(),
182 int> = 0>
183 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(
184 !__check_pair_construction<_T1, _T2>::template __is_implicit<_U1 const&, _U2 const&>())
185 pair(pair<_U1, _U2> const& __p) noexcept(is_nothrow_constructible<first_type, _U1 const&>::value &&
186 is_nothrow_constructible<second_type, _U2 const&>::value)
187 : first(__p.first), second(__p.second) {}
188
189 template <class _U1,
190 class _U2,
191 __enable_if_t<__check_pair_construction<_T1, _T2>::template __is_pair_constructible<_U1, _U2>(), int> = 0>
192 _LIBCPP_HIDE_FROM_ABI
193 _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit(!__check_pair_construction<_T1, _T2>::template __is_implicit<_U1, _U2>())
194 pair(pair<_U1, _U2>&& __p) noexcept(is_nothrow_constructible<first_type, _U1&&>::value &&
195 is_nothrow_constructible<second_type, _U2&&>::value)
196 : first(std::forward<_U1>(__p.first)), second(std::forward<_U2>(__p.second)) {}
197
198# if _LIBCPP_STD_VER >= 23
199 template <
200 class _U1,
201 class _U2,
202 __enable_if_t<__check_pair_construction<_T1, _T2>::template __is_pair_constructible<const _U1&&, const _U2&&>(),
203 int> = 0>
204 _LIBCPP_HIDE_FROM_ABI constexpr explicit(
205 !__check_pair_construction<_T1, _T2>::template __is_implicit<const _U1&&, const _U2&&>())
206 pair(const pair<_U1, _U2>&& __p) noexcept(is_nothrow_constructible<first_type, const _U1&&>::value &&
207 is_nothrow_constructible<second_type, const _U2&&>::value)
208 : first(std::move(__p.first)), second(std::move(__p.second)) {}
209# endif
210
211# if _LIBCPP_STD_VER >= 23
212 template <__pair_like_no_subrange _PairLike>
213 requires(is_constructible_v<first_type, decltype(std::get<0>(std::declval<_PairLike &&>()))> &&
214 is_constructible_v<second_type, decltype(std::get<1>(std::declval<_PairLike &&>()))>)
215 _LIBCPP_HIDE_FROM_ABI constexpr explicit(
216 !is_convertible_v<decltype(std::get<0>(std::declval<_PairLike&&>())), first_type> ||
217 !is_convertible_v<decltype(std::get<1>(std::declval<_PairLike&&>())), second_type>) pair(_PairLike&& __p)
218 : first(std::get<0>(std::forward<_PairLike>(__p))), second(std::get<1>(std::forward<_PairLike>(__p))) {}
219# endif
220
221 template <class... _Args1, class... _Args2>
222 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
223 pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args, tuple<_Args2...> __second_args) noexcept(
224 is_nothrow_constructible<first_type, _Args1...>::value && is_nothrow_constructible<second_type, _Args2...>::value)
225 : pair(__pc,
226 __first_args,
227 __second_args,
228 typename __make_tuple_indices<sizeof...(_Args1)>::type(),
229 typename __make_tuple_indices<sizeof...(_Args2) >::type()) {}
230
231 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair&
232 operator=(__conditional_t<is_copy_assignable<first_type>::value && is_copy_assignable<second_type>::value,
233 pair,
234 __nat> const& __p) noexcept(is_nothrow_copy_assignable<first_type>::value &&
235 is_nothrow_copy_assignable<second_type>::value) {
236 first = __p.first;
237 second = __p.second;
238 return *this;
239 }
240
241 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair& operator=(
242 __conditional_t<is_move_assignable<first_type>::value && is_move_assignable<second_type>::value, pair, __nat>&&
243 __p) noexcept(is_nothrow_move_assignable<first_type>::value &&
244 is_nothrow_move_assignable<second_type>::value) {
245 first = std::forward<first_type>(__p.first);
246 second = std::forward<second_type>(__p.second);
247 return *this;
248 }
249
250 template <
251 class _U1,
252 class _U2,
253 __enable_if_t<is_assignable<first_type&, _U1 const&>::value && is_assignable<second_type&, _U2 const&>::value,
254 int> = 0>
255 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair& operator=(pair<_U1, _U2> const& __p) {
256 first = __p.first;
257 second = __p.second;
258 return *this;
259 }
260
261 template <class _U1,
262 class _U2,
263 __enable_if_t<is_assignable<first_type&, _U1>::value && is_assignable<second_type&, _U2>::value, int> = 0>
264 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair& operator=(pair<_U1, _U2>&& __p) {
265 first = std::forward<_U1>(__p.first);
266 second = std::forward<_U2>(__p.second);
267 return *this;
268 }
269
270# if _LIBCPP_STD_VER >= 23
271 template <class = void>
272 _LIBCPP_HIDE_FROM_ABI constexpr const pair& operator=(pair const& __p) const
273 noexcept(is_nothrow_copy_assignable_v<const first_type> && is_nothrow_copy_assignable_v<const second_type>)
274 requires(is_copy_assignable_v<const first_type> && is_copy_assignable_v<const second_type>)
275 {
276 first = __p.first;
277 second = __p.second;
278 return *this;
279 }
280
281 template <class = void>
282 _LIBCPP_HIDE_FROM_ABI constexpr const pair& operator=(pair&& __p) const
283 noexcept(is_nothrow_assignable_v<const first_type&, first_type> &&
284 is_nothrow_assignable_v<const second_type&, second_type>)
285 requires(is_assignable_v<const first_type&, first_type> && is_assignable_v<const second_type&, second_type>)
286 {
287 first = std::forward<first_type>(__p.first);
288 second = std::forward<second_type>(__p.second);
289 return *this;
290 }
291
292 template <class _U1, class _U2>
293 _LIBCPP_HIDE_FROM_ABI constexpr const pair& operator=(const pair<_U1, _U2>& __p) const
294 requires(is_assignable_v<const first_type&, const _U1&> && is_assignable_v<const second_type&, const _U2&>)
295 {
296 first = __p.first;
297 second = __p.second;
298 return *this;
299 }
300
301 template <class _U1, class _U2>
302 _LIBCPP_HIDE_FROM_ABI constexpr const pair& operator=(pair<_U1, _U2>&& __p) const
303 requires(is_assignable_v<const first_type&, _U1> && is_assignable_v<const second_type&, _U2>)
304 {
305 first = std::forward<_U1>(__p.first);
306 second = std::forward<_U2>(__p.second);
307 return *this;
308 }
309
310 template <__pair_like_no_subrange _PairLike>
311 requires(__different_from<_PairLike, pair> &&
312 is_assignable_v<first_type&, decltype(std::get<0>(std::declval<_PairLike>()))> &&
313 is_assignable_v<second_type&, decltype(std::get<1>(std::declval<_PairLike>()))>)
314 _LIBCPP_HIDE_FROM_ABI constexpr pair& operator=(_PairLike&& __p) {
315 first = std::get<0>(std::forward<_PairLike>(__p));
316 second = std::get<1>(std::forward<_PairLike>(__p));
317 return *this;
318 }
319
320 template <__pair_like_no_subrange _PairLike>
321 requires(__different_from<_PairLike, pair> &&
322 is_assignable_v<first_type const&, decltype(std::get<0>(std::declval<_PairLike>()))> &&
323 is_assignable_v<second_type const&, decltype(std::get<1>(std::declval<_PairLike>()))>)
324 _LIBCPP_HIDE_FROM_ABI constexpr pair const& operator=(_PairLike&& __p) const {
325 first = std::get<0>(std::forward<_PairLike>(__p));
326 second = std::get<1>(std::forward<_PairLike>(__p));
327 return *this;
328 }
329# endif // _LIBCPP_STD_VER >= 23
330
331 // Prior to C++23, we provide an approximation of constructors and assignment operators from
332 // pair-like types. This was historically provided as an extension.
333# if _LIBCPP_STD_VER < 23
334 // from std::tuple
335 template <class _U1,
336 class _U2,
337 __enable_if_t<is_convertible<_U1 const&, _T1>::value && is_convertible<_U2 const&, _T2>::value, int> = 0>
338 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair(tuple<_U1, _U2> const& __p)
339 : first(std::get<0>(__p)), second(std::get<1>(__p)) {}
340
341 template < class _U1,
342 class _U2,
343 __enable_if_t<is_constructible<_T1, _U1 const&>::value && is_constructible<_T2, _U2 const&>::value &&
344 !(is_convertible<_U1 const&, _T1>::value && is_convertible<_U2 const&, _T2>::value),
345 int> = 0>
346 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit pair(tuple<_U1, _U2> const& __p)
347 : first(std::get<0>(__p)), second(std::get<1>(__p)) {}
348
349 template <class _U1,
350 class _U2,
351 __enable_if_t<is_convertible<_U1, _T1>::value && is_convertible<_U2, _T2>::value, int> = 0>
352 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair(tuple<_U1, _U2>&& __p)
353 : first(std::get<0>(std::move(__p))), second(std::get<1>(std::move(__p))) {}
354
355 template <class _U1,
356 class _U2,
357 __enable_if_t<is_constructible<_T1, _U1>::value && is_constructible<_T2, _U2>::value &&
358 !(is_convertible<_U1, _T1>::value && is_convertible<_U2, _T2>::value) > = 0>
359 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit pair(tuple<_U1, _U2>&& __p)
360 : first(std::get<0>(std::move(__p))), second(std::get<1>(std::move(__p))) {}
361
362 template <class _U1,
363 class _U2,
364 __enable_if_t<is_assignable<_T1&, _U1 const&>::value && is_assignable<_T2&, _U2 const&>::value, int> = 0>
365 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair& operator=(tuple<_U1, _U2> const& __p) {
366 first = std::get<0>(__p);
367 second = std::get<1>(__p);
368 return *this;
369 }
370
371 template <class _U1,
372 class _U2,
373 __enable_if_t<is_assignable<_T1&, _U1&&>::value && is_assignable<_T2&, _U2&&>::value, int> = 0>
374 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair& operator=(tuple<_U1, _U2>&& __p) {
375 first = std::get<0>(std::move(__p));
376 second = std::get<1>(std::move(__p));
377 return *this;
378 }
379
380 // from std::array
381 template <class _Up,
382 __enable_if_t<is_convertible<_Up const&, _T1>::value && is_convertible<_Up const&, _T2>::value, int> = 0>
383 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair(array<_Up, 2> const& __p) : first(__p[0]), second(__p[1]) {}
384
385 template <class _Up,
386 __enable_if_t<is_constructible<_T1, _Up const&>::value && is_constructible<_T2, _Up const&>::value &&
387 !(is_convertible<_Up const&, _T1>::value && is_convertible<_Up const&, _T2>::value),
388 int> = 0>
389 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit pair(array<_Up, 2> const& __p)
390 : first(__p[0]), second(__p[1]) {}
391
392 template <class _Up, __enable_if_t< is_convertible<_Up, _T1>::value && is_convertible<_Up, _T2>::value, int> = 0>
393 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair(array<_Up, 2>&& __p)
394 : first(std::move(__p)[0]), second(std::move(__p)[1]) {}
395
396 template <class _Up,
397 __enable_if_t<is_constructible<_T1, _Up>::value && is_constructible<_T2, _Up>::value &&
398 !(is_convertible<_Up, _T1>::value && is_convertible<_Up, _T2>::value),
399 int> = 0>
400 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit pair(array<_Up, 2>&& __p)
401 : first(std::move(__p)[0]), second(std::move(__p)[1]) {}
402
403 template <class _Up,
404 __enable_if_t<is_assignable<_T1&, _Up const&>::value && is_assignable<_T2&, _Up const&>::value, int> = 0>
405 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair& operator=(array<_Up, 2> const& __p) {
406 first = std::get<0>(__p);
407 second = std::get<1>(__p);
408 return *this;
409 }
410
411 template <class _Up, __enable_if_t<is_assignable<_T1&, _Up>::value && is_assignable<_T2&, _Up>::value, int> = 0>
412 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair& operator=(array<_Up, 2>&& __p) {
413 first = std::get<0>(std::move(__p));
414 second = std::get<1>(std::move(__p));
415 return *this;
416 }
417# endif // _LIBCPP_STD_VER < 23
418#endif // _LIBCPP_CXX03_LANG
419
420 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(pair& __p)
421 _NOEXCEPT_(__is_nothrow_swappable_v<first_type>&& __is_nothrow_swappable_v<second_type>) {
422 using std::swap;
423 swap(first, __p.first);
424 swap(second, __p.second);
425 }
426
427#if _LIBCPP_STD_VER >= 23
428 _LIBCPP_HIDE_FROM_ABI constexpr void swap(const pair& __p) const
429 noexcept(__is_nothrow_swappable_v<const first_type> && __is_nothrow_swappable_v<const second_type>) {
430 using std::swap;
431 swap(first, __p.first);
432 swap(second, __p.second);
433 }
434#endif
435
436private:
437#ifndef _LIBCPP_CXX03_LANG
438 template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
439 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
440 pair(piecewise_construct_t,
441 tuple<_Args1...>& __first_args,
442 tuple<_Args2...>& __second_args,
443 __tuple_indices<_I1...>,
444 __tuple_indices<_I2...>)
445 : first(std::forward<_Args1>(std::get<_I1>(__first_args))...),
446 second(std::forward<_Args2>(std::get<_I2>(__second_args))...) {}
447#endif
448};
449
450#if _LIBCPP_STD_VER >= 17
451template <class _T1, class _T2>
452pair(_T1, _T2) -> pair<_T1, _T2>;
453#endif
454
455// [pairs.spec], specialized algorithms
456
457template <class _T1, class _T2, class _U1, class _U2>
458inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
459operator==(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y)
460#if _LIBCPP_STD_VER >= 26
461 requires requires {
462 { __x.first == __y.first } -> __boolean_testable;
463 { __x.second == __y.second } -> __boolean_testable;
464 }
465#endif
466{
467 return __x.first == __y.first && __x.second == __y.second;
468}
469
470#if _LIBCPP_STD_VER >= 20
471
472template <class _T1, class _T2, class _U1, class _U2>
473_LIBCPP_HIDE_FROM_ABI constexpr common_comparison_category_t< __synth_three_way_result<_T1, _U1>,
474 __synth_three_way_result<_T2, _U2> >
475operator<=>(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y) {
476 if (auto __c = std::__synth_three_way(__x.first, __y.first); __c != 0) {
477 return __c;
478 }
479 return std::__synth_three_way(__x.second, __y.second);
480}
481
482#else // _LIBCPP_STD_VER >= 20
483
484template <class _T1, class _T2, class _U1, class _U2>
485inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
486operator!=(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y) {
487 return !(__x == __y);
488}
489
490template <class _T1, class _T2, class _U1, class _U2>
491inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
492operator<(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y) {
493 return __x.first < __y.first || (!(__y.first < __x.first) && __x.second < __y.second);
494}
495
496template <class _T1, class _T2, class _U1, class _U2>
497inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
498operator>(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y) {
499 return __y < __x;
500}
501
502template <class _T1, class _T2, class _U1, class _U2>
503inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
504operator>=(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y) {
505 return !(__x < __y);
506}
507
508template <class _T1, class _T2, class _U1, class _U2>
509inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
510operator<=(const pair<_T1, _T2>& __x, const pair<_U1, _U2>& __y) {
511 return !(__y < __x);
512}
513
514#endif // _LIBCPP_STD_VER >= 20
515
516#if _LIBCPP_STD_VER >= 23
517template <class _T1, class _T2, class _U1, class _U2, template <class> class _TQual, template <class> class _UQual>
518 requires requires {
519 typename pair<common_reference_t<_TQual<_T1>, _UQual<_U1>>, common_reference_t<_TQual<_T2>, _UQual<_U2>>>;
520 }
521struct basic_common_reference<pair<_T1, _T2>, pair<_U1, _U2>, _TQual, _UQual> {
522 using type _LIBCPP_NODEBUG =
523 pair<common_reference_t<_TQual<_T1>, _UQual<_U1>>, common_reference_t<_TQual<_T2>, _UQual<_U2>>>;
524};
525
526template <class _T1, class _T2, class _U1, class _U2>
527 requires requires { typename pair<common_type_t<_T1, _U1>, common_type_t<_T2, _U2>>; }
528struct common_type<pair<_T1, _T2>, pair<_U1, _U2>> {
529 using type _LIBCPP_NODEBUG = pair<common_type_t<_T1, _U1>, common_type_t<_T2, _U2>>;
530};
531#endif // _LIBCPP_STD_VER >= 23
532
533template <class _T1, class _T2, __enable_if_t<__is_swappable_v<_T1> && __is_swappable_v<_T2>, int> = 0>
534inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
535 _NOEXCEPT_(__is_nothrow_swappable_v<_T1>&& __is_nothrow_swappable_v<_T2>) {
536 __x.swap(__y);
537}
538
539#if _LIBCPP_STD_VER >= 23
540template <class _T1, class _T2>
541 requires(__is_swappable_v<const _T1> && __is_swappable_v<const _T2>)
542_LIBCPP_HIDE_FROM_ABI constexpr void
543swap(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) noexcept(noexcept(__x.swap(__y))) {
544 __x.swap(__y);
545}
546#endif
547
548template <class _T1, class _T2>
549inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<__unwrap_ref_decay_t<_T1>, __unwrap_ref_decay_t<_T2> >
550make_pair(_T1&& __t1, _T2&& __t2) {
551 return pair<__unwrap_ref_decay_t<_T1>, __unwrap_ref_decay_t<_T2> >(std::forward<_T1>(__t1), std::forward<_T2>(__t2));
552}
553
554template <class _T1, class _T2>
555struct tuple_size<pair<_T1, _T2> > : public integral_constant<size_t, 2> {};
556
557template <size_t _Ip, class _T1, class _T2>
558struct tuple_element<_Ip, pair<_T1, _T2> > {
559 static_assert(_Ip < 2, "Index out of bounds in std::tuple_element<std::pair<T1, T2>>");
560};
561
562template <class _T1, class _T2>
563struct tuple_element<0, pair<_T1, _T2> > {
564 using type _LIBCPP_NODEBUG = _T1;
565};
566
567template <class _T1, class _T2>
568struct tuple_element<1, pair<_T1, _T2> > {
569 using type _LIBCPP_NODEBUG = _T2;
570};
571
572template <size_t _Ip>
573struct __get_pair;
574
575template <>
576struct __get_pair<0> {
577 template <class _T1, class _T2>
578 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _T1& get(pair<_T1, _T2>& __p) _NOEXCEPT {
579 return __p.first;
580 }
581
582 template <class _T1, class _T2>
583 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const _T1& get(const pair<_T1, _T2>& __p) _NOEXCEPT {
584 return __p.first;
585 }
586
587 template <class _T1, class _T2>
588 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _T1&& get(pair<_T1, _T2>&& __p) _NOEXCEPT {
589 return std::forward<_T1>(__p.first);
590 }
591
592 template <class _T1, class _T2>
593 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const _T1&& get(const pair<_T1, _T2>&& __p) _NOEXCEPT {
594 return std::forward<const _T1>(__p.first);
595 }
596};
597
598template <>
599struct __get_pair<1> {
600 template <class _T1, class _T2>
601 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _T2& get(pair<_T1, _T2>& __p) _NOEXCEPT {
602 return __p.second;
603 }
604
605 template <class _T1, class _T2>
606 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const _T2& get(const pair<_T1, _T2>& __p) _NOEXCEPT {
607 return __p.second;
608 }
609
610 template <class _T1, class _T2>
611 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _T2&& get(pair<_T1, _T2>&& __p) _NOEXCEPT {
612 return std::forward<_T2>(__p.second);
613 }
614
615 template <class _T1, class _T2>
616 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const _T2&& get(const pair<_T1, _T2>&& __p) _NOEXCEPT {
617 return std::forward<const _T2>(__p.second);
618 }
619};
620
621template <size_t _Ip, class _T1, class _T2>
622inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename tuple_element<_Ip, pair<_T1, _T2> >::type&
623get(pair<_T1, _T2>& __p) _NOEXCEPT {
624 return __get_pair<_Ip>::get(__p);
625}
626
627template <size_t _Ip, class _T1, class _T2>
628inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
629get(const pair<_T1, _T2>& __p) _NOEXCEPT {
630 return __get_pair<_Ip>::get(__p);
631}
632
633template <size_t _Ip, class _T1, class _T2>
634inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
635get(pair<_T1, _T2>&& __p) _NOEXCEPT {
636 return __get_pair<_Ip>::get(std::move(__p));
637}
638
639template <size_t _Ip, class _T1, class _T2>
640inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
641get(const pair<_T1, _T2>&& __p) _NOEXCEPT {
642 return __get_pair<_Ip>::get(std::move(__p));
643}
644
645#if _LIBCPP_STD_VER >= 14
646template <class _T1, class _T2>
647inline _LIBCPP_HIDE_FROM_ABI constexpr _T1& get(pair<_T1, _T2>& __p) _NOEXCEPT {
648 return __p.first;
649}
650
651template <class _T1, class _T2>
652inline _LIBCPP_HIDE_FROM_ABI constexpr _T1 const& get(pair<_T1, _T2> const& __p) _NOEXCEPT {
653 return __p.first;
654}
655
656template <class _T1, class _T2>
657inline _LIBCPP_HIDE_FROM_ABI constexpr _T1&& get(pair<_T1, _T2>&& __p) _NOEXCEPT {
658 return std::forward<_T1&&>(__p.first);
659}
660
661template <class _T1, class _T2>
662inline _LIBCPP_HIDE_FROM_ABI constexpr _T1 const&& get(pair<_T1, _T2> const&& __p) _NOEXCEPT {
663 return std::forward<_T1 const&&>(__p.first);
664}
665
666template <class _T2, class _T1>
667inline _LIBCPP_HIDE_FROM_ABI constexpr _T2& get(pair<_T1, _T2>& __p) _NOEXCEPT {
668 return __p.second;
669}
670
671template <class _T2, class _T1>
672inline _LIBCPP_HIDE_FROM_ABI constexpr _T2 const& get(pair<_T1, _T2> const& __p) _NOEXCEPT {
673 return __p.second;
674}
675
676template <class _T2, class _T1>
677inline _LIBCPP_HIDE_FROM_ABI constexpr _T2&& get(pair<_T1, _T2>&& __p) _NOEXCEPT {
678 return std::forward<_T2&&>(__p.second);
679}
680
681template <class _T2, class _T1>
682inline _LIBCPP_HIDE_FROM_ABI constexpr _T2 const&& get(pair<_T1, _T2> const&& __p) _NOEXCEPT {
683 return std::forward<_T2 const&&>(__p.second);
684}
685
686#endif // _LIBCPP_STD_VER >= 14
687
688_LIBCPP_END_NAMESPACE_STD
689
690_LIBCPP_POP_MACROS
691
692#endif // _LIBCPP___UTILITY_PAIR_H