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_ALGORITHM
11#define _LIBCPP_ALGORITHM
12
13/*
14    algorithm synopsis
15
16#include <initializer_list>
17
18namespace std
19{
20
21namespace ranges {
22
23  // [algorithms.results], algorithm result types
24  template <class I, class F>
25    struct in_fun_result;     // since C++20
26
27  template <class I1, class I2>
28    struct in_in_result;      // since C++20
29
30  template <class I, class O>
31    struct in_out_result;  // since C++20
32
33  template <class I1, class I2, class O>
34    struct in_in_out_result;  // since C++20
35
36  template <class I, class O1, class O2>
37    struct in_out_out_result; // since C++20
38
39  template <class I1, class I2>
40    struct min_max_result;    // since C++20
41
42  template <class I>
43    struct in_found_result;   // since C++20
44
45  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
46    indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>             // since C++20
47  constexpr I min_element(I first, S last, Comp comp = {}, Proj proj = {});
48
49  template<forward_range R, class Proj = identity,
50    indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less> // since C++20
51  constexpr borrowed_iterator_t<R> min_element(R&& r, Comp comp = {}, Proj proj = {});
52
53  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
54    indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
55  constexpr I ranges::max_element(I first, S last, Comp comp = {}, Proj proj = {});                        // since C++20
56
57  template<forward_range R, class Proj = identity,
58    indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
59  constexpr borrowed_iterator_t<R> ranges::max_element(R&& r, Comp comp = {}, Proj proj = {});             // since C++20
60
61  template<class I1, class I2>
62    using mismatch_result = in_in_result<I1, I2>;
63
64  template <input_iterator I1, sentinel_for<_I1> S1, input_iterator I2, sentinel_for<_I2> S2,
65          class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
66    requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
67  constexpr mismatch_result<_I1, _I2>
68  mismatch()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) // since C++20
69
70  template <input_range R1, input_range R2,
71          class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
72    requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
73  constexpr mismatch_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
74  mismatch(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {})                           // since C++20
75
76    requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
77    constexpr I find(I first, S last, const T& value, Proj proj = {});              // since C++20
78
79  template<input_range R, class T, class Proj = identity>
80    requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
81    constexpr borrowed_iterator_t<R>
82      find(R&& r, const T& value, Proj proj = {});                                  // since C++20
83
84  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
85           indirect_unary_predicate<projected<I, Proj>> Pred>
86    constexpr I find_if(I first, S last, Pred pred, Proj proj = {});                // since C++20
87
88  template<input_range R, class Proj = identity,
89           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
90    constexpr borrowed_iterator_t<R>
91      find_if(R&& r, Pred pred, Proj proj = {});                                    // since C++20
92
93  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
94           indirect_unary_predicate<projected<I, Proj>> Pred>
95    constexpr I find_if_not(I first, S last, Pred pred, Proj proj = {});            // since C++20
96
97  template<input_range R, class Proj = identity,
98           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
99    constexpr borrowed_iterator_t<R>
100      find_if_not(R&& r, Pred pred, Proj proj = {});                                // since C++20
101
102  template<class T, class Proj = identity,
103           indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
104    constexpr const T& min(const T& a, const T& b, Comp comp = {}, Proj proj = {}); // since C++20
105
106  template<copyable T, class Proj = identity,
107           indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
108    constexpr T min(initializer_list<T> r, Comp comp = {}, Proj proj = {});         // since C++20
109
110 template<input_range R, class Proj = identity,
111          indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
112   requires indirectly_copyable_storable<iterator_t<R>, range_value_t<R>*>
113   constexpr range_value_t<R>
114     min(R&& r, Comp comp = {}, Proj proj = {});                                    // since C++20
115
116  template<class T, class Proj = identity,
117           indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
118    constexpr const T& max(const T& a, const T& b, Comp comp = {}, Proj proj = {}); // since C++20
119
120  template<copyable T, class Proj = identity,
121           indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
122    constexpr T max(initializer_list<T> r, Comp comp = {}, Proj proj = {});         // since C++20
123
124  template<input_range R, class Proj = identity,
125           indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
126    requires indirectly_copyable_storable<iterator_t<R>, range_value_t<R>*>
127    constexpr range_value_t<R>
128      max(R&& r, Comp comp = {}, Proj proj = {});                                   // since C++20
129
130  template<class I, class O>
131    using unary_transform_result = in_out_result<I, O>;                             // since C++20
132
133  template<class I1, class I2, class O>
134    using binary_transform_result = in_in_out_result<I1, I2, O>;                    // since C++20
135
136  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O,
137           copy_constructible F, class Proj = identity>
138    requires indirectly_writable<O, indirect_result_t<F&, projected<I, Proj>>>
139    constexpr ranges::unary_transform_result<I, O>
140      transform(I first1, S last1, O result, F op, Proj proj = {});                 // since C++20
141
142  template<input_range R, weakly_incrementable O, copy_constructible F,
143           class Proj = identity>
144    requires indirectly_writable<O, indirect_result_t<F&, projected<iterator_t<R>, Proj>>>
145    constexpr ranges::unary_transform_result<borrowed_iterator_t<R>, O>
146      transform(R&& r, O result, F op, Proj proj = {});                             // since C++20
147
148  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
149           weakly_incrementable O, copy_constructible F, class Proj1 = identity,
150           class Proj2 = identity>
151    requires indirectly_writable<O, indirect_result_t<F&, projected<I1, Proj1>,
152                                           projected<I2, Proj2>>>
153    constexpr ranges::binary_transform_result<I1, I2, O>
154      transform(I1 first1, S1 last1, I2 first2, S2 last2, O result,
155                        F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {});           // since C++20
156
157  template<input_range R1, input_range R2, weakly_incrementable O,
158           copy_constructible F, class Proj1 = identity, class Proj2 = identity>
159    requires indirectly_writable<O, indirect_result_t<F&, projected<iterator_t<R1>, Proj1>,
160                                           projected<iterator_t<R2>, Proj2>>>
161    constexpr ranges::binary_transform_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
162      transform(R1&& r1, R2&& r2, O result,
163                        F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {});           // since C++20
164
165  template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity>
166    requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
167    constexpr iter_difference_t<I>
168      count(I first, S last, const T& value, Proj proj = {});                       // since C++20
169
170  template<input_range R, class T, class Proj = identity>
171    requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
172    constexpr range_difference_t<R>
173      count(R&& r, const T& value, Proj proj = {});                                 // since C++20
174
175  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
176           indirect_unary_predicate<projected<I, Proj>> Pred>
177    constexpr iter_difference_t<I>
178      count_if(I first, S last, Pred pred, Proj proj = {});                         // since C++20
179
180  template<input_range R, class Proj = identity,
181           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
182    constexpr range_difference_t<R>
183      count_if(R&& r, Pred pred, Proj proj = {});                                   // since C++20
184
185  template<class T>
186  using minmax_result = min_max_result<T>;
187
188  template<class T, class Proj = identity,
189           indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
190    constexpr ranges::minmax_result<const T&>
191      minmax(const T& a, const T& b, Comp comp = {}, Proj proj = {});                     // since C++20
192
193  template<copyable T, class Proj = identity,
194           indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
195    constexpr ranges::minmax_result<T>
196      minmax(initializer_list<T> r, Comp comp = {}, Proj proj = {});                      // since C++20
197
198  template<input_range R, class Proj = identity,
199           indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
200    requires indirectly_copyable_storable<iterator_t<R>, range_value_t<R>*>
201    constexpr ranges::minmax_result<range_value_t<R>>
202      minmax(R&& r, Comp comp = {}, Proj proj = {});                                      // since C++20
203
204  template<class I>
205  using minmax_element_result = min_max_result<I>;
206
207  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
208           indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
209    constexpr ranges::minmax_element_result<I>
210      minmax_element(I first, S last, Comp comp = {}, Proj proj = {});                    // since C++20
211
212  template<forward_range R, class Proj = identity,
213           indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
214    constexpr ranges::minmax_element_result<borrowed_iterator_t<R>>
215      minmax_element(R&& r, Comp comp = {}, Proj proj = {});                              // since C++20
216
217  template<class I, class O>
218    using copy_result = in_out_result<I, O>;                                              // since C++20
219
220  template<class I, class O>
221    using copy_n_result = in_out_result<I, O>;                                            // since C++20
222
223  template<class I, class O>
224    using copy_if_result = in_out_result<I, O>;                                             // since C++20
225
226  template<class I1, class I2>
227    using copy_backward_result = in_out_result<I1, I2>;                                     // since C++20
228
229  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O>
230    requires indirectly_copyable<I, O>
231    constexpr ranges::copy_result<I, O> ranges::copy(I first, S last, O result);            // since C++20
232
233  template<input_range R, weakly_incrementable O>
234    requires indirectly_copyable<iterator_t<R>, O>
235    constexpr ranges::copy_result<borrowed_iterator_t<R>, O> ranges::copy(R&& r, O result); // since C++20
236
237  template<input_iterator I, weakly_incrementable O>
238    requires indirectly_copyable<I, O>
239    constexpr ranges::copy_n_result<I, O>
240      ranges::copy_n(I first, iter_difference_t<I> n, O result);                            // since C++20
241
242  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O, class Proj = identity,
243           indirect_unary_predicate<projected<I, Proj>> Pred>
244    requires indirectly_copyable<I, O>
245    constexpr ranges::copy_if_result<I, O>
246      ranges::copy_if(I first, S last, O result, Pred pred, Proj proj = {});                // since C++20
247
248  template<input_range R, weakly_incrementable O, class Proj = identity,
249           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
250    requires indirectly_copyable<iterator_t<R>, O>
251    constexpr ranges::copy_if_result<borrowed_iterator_t<R>, O>
252      ranges::copy_if(R&& r, O result, Pred pred, Proj proj = {});                          // since C++20
253
254  template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2>
255    requires indirectly_copyable<I1, I2>
256    constexpr ranges::copy_backward_result<I1, I2>
257      ranges::copy_backward(I1 first, S1 last, I2 result);                                  // since C++20
258
259  template<bidirectional_range R, bidirectional_iterator I>
260    requires indirectly_copyable<iterator_t<R>, I>
261    constexpr ranges::copy_backward_result<borrowed_iterator_t<R>, I>
262      ranges::copy_backward(R&& r, I result);                                               // since C++20
263
264  template<class I, class F>
265    using for_each_result = in_fun_result<I, F>;                                            // since C++20
266
267  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
268           indirectly_unary_invocable<projected<I, Proj>> Fun>
269    constexpr ranges::for_each_result<I, Fun>
270      ranges::for_each(I first, S last, Fun f, Proj proj = {});                             // since C++20
271
272  template<input_range R, class Proj = identity,
273           indirectly_unary_invocable<projected<iterator_t<R>, Proj>> Fun>
274    constexpr ranges::for_each_result<borrowed_iterator_t<R>, Fun>
275      ranges::for_each(R&& r, Fun f, Proj proj = {});                                       // since C++20
276
277  template<input_iterator I, class Proj = identity,
278           indirectly_unary_invocable<projected<I, Proj>> Fun>
279    constexpr ranges::for_each_n_result<I, Fun>
280      ranges::for_each_n(I first, iter_difference_t<I> n, Fun f, Proj proj = {});           // since C++20
281
282  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
283           indirect_unary_predicate<projected<I, Proj>> Pred>
284    constexpr bool ranges::is_partitioned(I first, S last, Pred pred, Proj proj = {});      // since C++20
285
286  template<input_range R, class Proj = identity,
287           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
288    constexpr bool ranges::is_partitioned(R&& r, Pred pred, Proj proj = {});                // since C++20
289
290  template<bidirectional_iterator I, sentinel_for<I> S>
291    requires permutable<I>
292    constexpr I ranges::reverse(I first, S last);                                           // since C++20
293
294  template<bidirectional_range R>
295    requires permutable<iterator_t<R>>
296    constexpr borrowed_iterator_t<R> ranges::reverse(R&& r);                                // since C++20
297
298  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
299            class Proj = identity>
300    requires sortable<I, Comp, Proj>
301    constexpr I
302      ranges::sort(I first, S last, Comp comp = {}, Proj proj = {});                        // since C++20
303
304  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
305    requires sortable<iterator_t<R>, Comp, Proj>
306    constexpr borrowed_iterator_t<R>
307      ranges::sort(R&& r, Comp comp = {}, Proj proj = {});                                  // since C++20
308
309  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
310          class Proj = identity>
311    requires sortable<I, Comp, Proj>
312    I ranges::stable_sort(I first, S last, Comp comp = {}, Proj proj = {});                 // since C++20
313
314  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
315    requires sortable<iterator_t<R>, Comp, Proj>
316    borrowed_iterator_t<R>
317      ranges::stable_sort(R&& r, Comp comp = {}, Proj proj = {});                           // since C++20
318
319  template<class T, output_iterator<const T&> O, sentinel_for<O> S>
320    constexpr O ranges::fill(O first, S last, const T& value);                              // since C++20
321
322  template<class T, output_range<const T&> R>
323    constexpr borrowed_iterator_t<R> ranges::fill(R&& r, const T& value);                   // since C++20
324
325  template<class T, output_iterator<const T&> O>
326    constexpr O ranges::fill_n(O first, iter_difference_t<O> n, const T& value);            // since C++20
327
328 template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
329          class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
330   requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
331   constexpr bool ranges::equal(I1 first1, S1 last1, I2 first2, S2 last2,
332                                Pred pred = {},
333                                Proj1 proj1 = {}, Proj2 proj2 = {});                        // since C++20
334
335 template<input_range R1, input_range R2, class Pred = ranges::equal_to,
336          class Proj1 = identity, class Proj2 = identity>
337   requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
338   constexpr bool ranges::equal(R1&& r1, R2&& r2, Pred pred = {},
339                                Proj1 proj1 = {}, Proj2 proj2 = {});                        // since C++20
340
341  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
342           indirect_unary_predicate<projected<I, Proj>> Pred>
343    constexpr bool ranges::all_of(I first, S last, Pred pred, Proj proj = {});      // since C++20
344
345  template<input_range R, class Proj = identity,
346           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
347    constexpr bool ranges::all_of(R&& r, Pred pred, Proj proj = {});                // since C++20
348
349  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
350           indirect_unary_predicate<projected<I, Proj>> Pred>
351    constexpr bool ranges::any_of(I first, S last, Pred pred, Proj proj = {});      // since C++20
352
353  template<input_range R, class Proj = identity,
354           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
355    constexpr bool ranges::any_of(R&& r, Pred pred, Proj proj = {});                // since C++20
356
357  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
358           indirect_unary_predicate<projected<I, Proj>> Pred>
359    constexpr bool ranges::none_of(I first, S last, Pred pred, Proj proj = {});     // since C++20
360
361  template<input_range R, class Proj = identity,
362           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
363    constexpr bool ranges::none_of(R&& r, Pred pred, Proj proj = {});               // since C++20
364
365  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
366           indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
367    constexpr bool ranges::is_sorted(I first, S last, Comp comp = {}, Proj proj = {});      // since C++20
368
369  template<forward_range R, class Proj = identity,
370           indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
371    constexpr bool ranges::is_sorted(R&& r, Comp comp = {}, Proj proj = {});                // since C++20
372
373  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
374           indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
375    constexpr I ranges::is_sorted_until(I first, S last, Comp comp = {}, Proj proj = {});   // since C++20
376
377  template<forward_range R, class Proj = identity,
378           indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
379    constexpr borrowed_iterator_t<R>
380      ranges::is_sorted_until(R&& r, Comp comp = {}, Proj proj = {});                       // since C++20
381
382  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
383          class Proj = identity>
384    requires sortable<I, Comp, Proj>
385    constexpr I
386      ranges::nth_element(I first, I nth, S last, Comp comp = {}, Proj proj = {});            // since C++20
387
388  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
389    requires sortable<iterator_t<R>, Comp, Proj>
390    constexpr borrowed_iterator_t<R>
391      ranges::nth_element(R&& r, iterator_t<R> nth, Comp comp = {}, Proj proj = {});          // since C++20
392
393  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
394           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
395    constexpr I upper_bound(I first, S last, const T& value, Comp comp = {}, Proj proj = {}); // since C++20
396
397  template<forward_range R, class T, class Proj = identity,
398           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
399             ranges::less>
400    constexpr borrowed_iterator_t<R>
401      upper_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});                     // since C++20
402
403  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
404           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
405    constexpr I lower_bound(I first, S last, const T& value, Comp comp = {},
406                                    Proj proj = {});                                          // since C++20
407  template<forward_range R, class T, class Proj = identity,
408           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
409             ranges::less>
410    constexpr borrowed_iterator_t<R>
411      lower_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});                     // since C++20
412
413  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
414           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
415    constexpr bool binary_search(I first, S last, const T& value, Comp comp = {},
416                                         Proj proj = {});                                     // since C++20
417
418  template<forward_range R, class T, class Proj = identity,
419           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
420             ranges::less>
421    constexpr bool binary_search(R&& r, const T& value, Comp comp = {},
422                                         Proj proj = {});                                     // since C++20
423  template<input_iterator I1, sentinel_for<I1> S1, forward_iterator I2, sentinel_for<I2> S2,
424           class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
425    requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
426    constexpr I1 ranges::find_first_of(I1 first1, S1 last1, I2 first2, S2 last2,
427                                       Pred pred = {},
428                                       Proj1 proj1 = {}, Proj2 proj2 = {});                 // since C++20
429
430  template<input_range R1, forward_range R2,
431           class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
432    requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
433    constexpr borrowed_iterator_t<R1>
434      ranges::find_first_of(R1&& r1, R2&& r2,
435                            Pred pred = {},
436                            Proj1 proj1 = {}, Proj2 proj2 = {});                            // since C++20
437
438  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
439           indirect_binary_predicate<projected<I, Proj>,
440                                     projected<I, Proj>> Pred = ranges::equal_to>
441    constexpr I ranges::adjacent_find(I first, S last, Pred pred = {}, Proj proj = {});     // since C+20
442
443  template<forward_range R, class Proj = identity,
444           indirect_binary_predicate<projected<iterator_t<R>, Proj>,
445                                     projected<iterator_t<R>, Proj>> Pred = ranges::equal_to>
446    constexpr borrowed_iterator_t<R> ranges::adjacent_find(R&& r, Pred pred = {}, Proj proj = {});  // since C++20
447
448  template<input_iterator I, sentinel_for<I> S, class T1, class T2, class Proj = identity>
449    requires indirectly_writable<I, const T2&> &&
450             indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T1*>
451    constexpr I
452      ranges::replace(I first, S last, const T1& old_value, const T2& new_value, Proj proj = {});   // since C++20
453
454  template<input_range R, class T1, class T2, class Proj = identity>
455    requires indirectly_writable<iterator_t<R>, const T2&> &&
456             indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T1*>
457    constexpr borrowed_iterator_t<R>
458      ranges::replace(R&& r, const T1& old_value, const T2& new_value, Proj proj = {});             // since C++20
459
460  template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity,
461           indirect_unary_predicate<projected<I, Proj>> Pred>
462    requires indirectly_writable<I, const T&>
463    constexpr I ranges::replace_if(I first, S last, Pred pred, const T& new_value, Proj proj = {}); // since C++20
464
465  template<input_range R, class T, class Proj = identity,
466           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
467    requires indirectly_writable<iterator_t<R>, const T&>
468    constexpr borrowed_iterator_t<R>
469      ranges::replace_if(R&& r, Pred pred, const T& new_value, Proj proj = {});                     // since C++20
470
471  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
472           class Proj1 = identity, class Proj2 = identity,
473           indirect_strict_weak_order<projected<I1, Proj1>,
474                                      projected<I2, Proj2>> Comp = ranges::less>
475    constexpr bool
476      ranges::lexicographical_compare(I1 first1, S1 last1, I2 first2, S2 last2,
477                                      Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});    // since C++20
478
479  template<input_range R1, input_range R2, class Proj1 = identity,
480           class Proj2 = identity,
481           indirect_strict_weak_order<projected<iterator_t<R1>, Proj1>,
482                                      projected<iterator_t<R2>, Proj2>> Comp = ranges::less>
483    constexpr bool
484      ranges::lexicographical_compare(R1&& r1, R2&& r2, Comp comp = {},
485                                      Proj1 proj1 = {}, Proj2 proj2 = {});                    // since C++20
486
487  template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2>
488    requires indirectly_movable<I1, I2>
489    constexpr ranges::move_backward_result<I1, I2>
490      ranges::move_backward(I1 first, S1 last, I2 result);                                          // since C++20
491
492  template<bidirectional_range R, bidirectional_iterator I>
493    requires indirectly_movable<iterator_t<R>, I>
494    constexpr ranges::move_backward_result<borrowed_iterator_t<R>, I>
495      ranges::move_backward(R&& r, I result);                                                       // since C++20
496
497  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O>
498    requires indirectly_movable<I, O>
499    constexpr ranges::move_result<I, O>
500      ranges::move(I first, S last, O result);                                                      // since C++20
501
502  template<input_range R, weakly_incrementable O>
503    requires indirectly_movable<iterator_t<R>, O>
504    constexpr ranges::move_result<borrowed_iterator_t<R>, O>
505      ranges::move(R&& r, O result);                                                                // since C++20
506
507  template<class I1, class I2, class O>
508    using merge_result = in_in_out_result<I1, I2, O>;                                               // since C++20
509
510  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
511           weakly_incrementable O, class Comp = ranges::less, class Proj1 = identity,
512           class Proj2 = identity>
513    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
514    constexpr merge_result<I1, I2, O>
515      merge(I1 first1, S1 last1, I2 first2, S2 last2, O result,
516            Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                                    // since C++20
517
518  template<input_range R1, input_range R2, weakly_incrementable O, class Comp = ranges::less,
519           class Proj1 = identity, class Proj2 = identity>
520    requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
521    constexpr merge_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
522      merge(R1&& r1, R2&& r2, O result,
523            Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                                    // since C++20
524
525  template<permutable I, sentinel_for<I> S, class T, class Proj = identity>
526    requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
527    constexpr subrange<I> ranges::remove(I first, S last, const T& value, Proj proj = {});          // since C++20
528
529  template<forward_range R, class T, class Proj = identity>
530    requires permutable<iterator_t<R>> &&
531             indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
532    constexpr borrowed_subrange_t<R>
533      ranges::remove(R&& r, const T& value, Proj proj = {});                                        // since C++20
534
535  template<permutable I, sentinel_for<I> S, class Proj = identity,
536           indirect_unary_predicate<projected<I, Proj>> Pred>
537    constexpr subrange<I> ranges::remove_if(I first, S last, Pred pred, Proj proj = {});            // since C++20
538
539  template<forward_range R, class Proj = identity,
540           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
541    requires permutable<iterator_t<R>>
542    constexpr borrowed_subrange_t<R>
543      ranges::remove_if(R&& r, Pred pred, Proj proj = {});                                          // since C++20
544
545  template<class I, class O>
546    using set_difference_result = in_out_result<I, O>;                                              // since C++20
547
548  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
549           weakly_incrementable O, class Comp = ranges::less,
550           class Proj1 = identity, class Proj2 = identity>
551    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
552    constexpr set_difference_result<I1, O>
553      set_difference(I1 first1, S1 last1, I2 first2, S2 last2, O result,
554                     Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                           // since C++20
555
556  template<input_range R1, input_range R2, weakly_incrementable O,
557           class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
558    requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
559    constexpr set_difference_result<borrowed_iterator_t<R1>, O>
560      set_difference(R1&& r1, R2&& r2, O result,
561                     Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                           // since C++20
562
563}
564
565    constexpr bool     // constexpr in C++20
566    all_of(InputIterator first, InputIterator last, Predicate pred);
567
568template <class InputIterator, class Predicate>
569    constexpr bool     // constexpr in C++20
570    any_of(InputIterator first, InputIterator last, Predicate pred);
571
572template <class InputIterator, class Predicate>
573    constexpr bool     // constexpr in C++20
574    none_of(InputIterator first, InputIterator last, Predicate pred);
575
576template <class InputIterator, class Function>
577    constexpr Function          // constexpr in C++20
578    for_each(InputIterator first, InputIterator last, Function f);
579
580template<class InputIterator, class Size, class Function>
581    constexpr InputIterator     // constexpr in C++20
582    for_each_n(InputIterator first, Size n, Function f); // C++17
583
584template <class InputIterator, class T>
585    constexpr InputIterator     // constexpr in C++20
586    find(InputIterator first, InputIterator last, const T& value);
587
588template <class InputIterator, class Predicate>
589    constexpr InputIterator     // constexpr in C++20
590    find_if(InputIterator first, InputIterator last, Predicate pred);
591
592template<class InputIterator, class Predicate>
593    constexpr InputIterator     // constexpr in C++20
594    find_if_not(InputIterator first, InputIterator last, Predicate pred);
595
596template <class ForwardIterator1, class ForwardIterator2>
597    constexpr ForwardIterator1  // constexpr in C++20
598    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
599             ForwardIterator2 first2, ForwardIterator2 last2);
600
601template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
602    constexpr ForwardIterator1  // constexpr in C++20
603    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
604             ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
605
606template <class ForwardIterator1, class ForwardIterator2>
607    constexpr ForwardIterator1  // constexpr in C++20
608    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
609                  ForwardIterator2 first2, ForwardIterator2 last2);
610
611template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
612    constexpr ForwardIterator1  // constexpr in C++20
613    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
614                  ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
615
616template <class ForwardIterator>
617    constexpr ForwardIterator   // constexpr in C++20
618    adjacent_find(ForwardIterator first, ForwardIterator last);
619
620template <class ForwardIterator, class BinaryPredicate>
621    constexpr ForwardIterator   // constexpr in C++20
622    adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
623
624template <class InputIterator, class T>
625    constexpr typename iterator_traits<InputIterator>::difference_type  // constexpr in C++20
626    count(InputIterator first, InputIterator last, const T& value);
627
628template <class InputIterator, class Predicate>
629    constexpr typename iterator_traits<InputIterator>::difference_type // constexpr in C++20
630    count_if(InputIterator first, InputIterator last, Predicate pred);
631
632template <class InputIterator1, class InputIterator2>
633    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
634    mismatch(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
635
636template <class InputIterator1, class InputIterator2>
637    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
638    mismatch(InputIterator1 first1, InputIterator1 last1,
639             InputIterator2 first2, InputIterator2 last2); // **C++14**
640
641template <class InputIterator1, class InputIterator2, class BinaryPredicate>
642    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
643    mismatch(InputIterator1 first1, InputIterator1 last1,
644             InputIterator2 first2, BinaryPredicate pred);
645
646template <class InputIterator1, class InputIterator2, class BinaryPredicate>
647    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
648    mismatch(InputIterator1 first1, InputIterator1 last1,
649             InputIterator2 first2, InputIterator2 last2,
650             BinaryPredicate pred); // **C++14**
651
652template <class InputIterator1, class InputIterator2>
653    constexpr bool      // constexpr in C++20
654    equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
655
656template <class InputIterator1, class InputIterator2>
657    constexpr bool      // constexpr in C++20
658    equal(InputIterator1 first1, InputIterator1 last1,
659          InputIterator2 first2, InputIterator2 last2); // **C++14**
660
661template <class InputIterator1, class InputIterator2, class BinaryPredicate>
662    constexpr bool      // constexpr in C++20
663    equal(InputIterator1 first1, InputIterator1 last1,
664          InputIterator2 first2, BinaryPredicate pred);
665
666template <class InputIterator1, class InputIterator2, class BinaryPredicate>
667    constexpr bool      // constexpr in C++20
668    equal(InputIterator1 first1, InputIterator1 last1,
669          InputIterator2 first2, InputIterator2 last2,
670          BinaryPredicate pred); // **C++14**
671
672template<class ForwardIterator1, class ForwardIterator2>
673    constexpr bool      // constexpr in C++20
674    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
675                   ForwardIterator2 first2);
676
677template<class ForwardIterator1, class ForwardIterator2>
678    constexpr bool      // constexpr in C++20
679    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
680                   ForwardIterator2 first2, ForwardIterator2 last2); // **C++14**
681
682template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
683    constexpr bool      // constexpr in C++20
684    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
685                   ForwardIterator2 first2, BinaryPredicate pred);
686
687template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
688    constexpr bool      // constexpr in C++20
689    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
690                   ForwardIterator2 first2, ForwardIterator2 last2,
691                   BinaryPredicate pred);  // **C++14**
692
693template <class ForwardIterator1, class ForwardIterator2>
694    constexpr ForwardIterator1      // constexpr in C++20
695    search(ForwardIterator1 first1, ForwardIterator1 last1,
696           ForwardIterator2 first2, ForwardIterator2 last2);
697
698template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
699    constexpr ForwardIterator1      // constexpr in C++20
700    search(ForwardIterator1 first1, ForwardIterator1 last1,
701           ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
702
703template <class ForwardIterator, class Size, class T>
704    constexpr ForwardIterator       // constexpr in C++20
705    search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value);
706
707template <class ForwardIterator, class Size, class T, class BinaryPredicate>
708    constexpr ForwardIterator       // constexpr in C++20
709    search_n(ForwardIterator first, ForwardIterator last,
710             Size count, const T& value, BinaryPredicate pred);
711
712template <class InputIterator, class OutputIterator>
713    constexpr OutputIterator      // constexpr in C++20
714    copy(InputIterator first, InputIterator last, OutputIterator result);
715
716template<class InputIterator, class OutputIterator, class Predicate>
717    constexpr OutputIterator      // constexpr in C++20
718    copy_if(InputIterator first, InputIterator last,
719            OutputIterator result, Predicate pred);
720
721template<class InputIterator, class Size, class OutputIterator>
722    constexpr OutputIterator      // constexpr in C++20
723    copy_n(InputIterator first, Size n, OutputIterator result);
724
725template <class BidirectionalIterator1, class BidirectionalIterator2>
726    constexpr BidirectionalIterator2      // constexpr in C++20
727    copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
728                  BidirectionalIterator2 result);
729
730// [alg.move], move
731template<class InputIterator, class OutputIterator>
732    constexpr OutputIterator move(InputIterator first, InputIterator last,
733                                OutputIterator result);
734
735template<class BidirectionalIterator1, class BidirectionalIterator2>
736    constexpr BidirectionalIterator2
737    move_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
738                  BidirectionalIterator2 result);
739
740template <class ForwardIterator1, class ForwardIterator2>
741    constexpr ForwardIterator2    // constexpr in C++20
742    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
743
744namespace ranges {
745    template<class I1, class I2>
746    using swap_ranges_result = in_in_result<I1, I2>;
747
748template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2>
749        requires indirectly_swappable<I1, I2>
750    constexpr ranges::swap_ranges_result<I1, I2>
751        swap_ranges(I1 first1, S1 last1, I2 first2, S2 last2);
752
753template<input_range R1, input_range R2>
754        requires indirectly_swappable<iterator_t<R1>, iterator_t<R2>>
755    constexpr ranges::swap_ranges_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
756        swap_ranges(R1&& r1, R2&& r2);
757}
758
759template <class ForwardIterator1, class ForwardIterator2>
760    constexpr void                // constexpr in C++20
761    iter_swap(ForwardIterator1 a, ForwardIterator2 b);
762
763template <class InputIterator, class OutputIterator, class UnaryOperation>
764    constexpr OutputIterator      // constexpr in C++20
765    transform(InputIterator first, InputIterator last, OutputIterator result, UnaryOperation op);
766
767template <class InputIterator1, class InputIterator2, class OutputIterator, class BinaryOperation>
768    constexpr OutputIterator      // constexpr in C++20
769    transform(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
770              OutputIterator result, BinaryOperation binary_op);
771
772template <class ForwardIterator, class T>
773    constexpr void      // constexpr in C++20
774    replace(ForwardIterator first, ForwardIterator last, const T& old_value, const T& new_value);
775
776template <class ForwardIterator, class Predicate, class T>
777    constexpr void      // constexpr in C++20
778    replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, const T& new_value);
779
780template <class InputIterator, class OutputIterator, class T>
781    constexpr OutputIterator      // constexpr in C++20
782    replace_copy(InputIterator first, InputIterator last, OutputIterator result,
783                 const T& old_value, const T& new_value);
784
785template <class InputIterator, class OutputIterator, class Predicate, class T>
786    constexpr OutputIterator      // constexpr in C++20
787    replace_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred, const T& new_value);
788
789template <class ForwardIterator, class T>
790    constexpr void      // constexpr in C++20
791    fill(ForwardIterator first, ForwardIterator last, const T& value);
792
793template <class OutputIterator, class Size, class T>
794    constexpr OutputIterator      // constexpr in C++20
795    fill_n(OutputIterator first, Size n, const T& value);
796
797template <class ForwardIterator, class Generator>
798    constexpr void      // constexpr in C++20
799    generate(ForwardIterator first, ForwardIterator last, Generator gen);
800
801template <class OutputIterator, class Size, class Generator>
802    constexpr OutputIterator      // constexpr in C++20
803    generate_n(OutputIterator first, Size n, Generator gen);
804
805template <class ForwardIterator, class T>
806    constexpr ForwardIterator     // constexpr in C++20
807    remove(ForwardIterator first, ForwardIterator last, const T& value);
808
809template <class ForwardIterator, class Predicate>
810    constexpr ForwardIterator     // constexpr in C++20
811    remove_if(ForwardIterator first, ForwardIterator last, Predicate pred);
812
813template <class InputIterator, class OutputIterator, class T>
814    constexpr OutputIterator     // constexpr in C++20
815    remove_copy(InputIterator first, InputIterator last, OutputIterator result, const T& value);
816
817template <class InputIterator, class OutputIterator, class Predicate>
818    constexpr OutputIterator     // constexpr in C++20
819    remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred);
820
821template <class ForwardIterator>
822    constexpr ForwardIterator    // constexpr in C++20
823    unique(ForwardIterator first, ForwardIterator last);
824
825template <class ForwardIterator, class BinaryPredicate>
826    constexpr ForwardIterator    // constexpr in C++20
827    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
828
829template <class InputIterator, class OutputIterator>
830    constexpr OutputIterator     // constexpr in C++20
831    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
832
833template <class InputIterator, class OutputIterator, class BinaryPredicate>
834    constexpr OutputIterator     // constexpr in C++20
835    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
836
837template <class BidirectionalIterator>
838    constexpr void               // constexpr in C++20
839    reverse(BidirectionalIterator first, BidirectionalIterator last);
840
841template <class BidirectionalIterator, class OutputIterator>
842    constexpr OutputIterator       // constexpr in C++20
843    reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result);
844
845template <class ForwardIterator>
846    constexpr ForwardIterator      // constexpr in C++20
847    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
848
849template <class ForwardIterator, class OutputIterator>
850    constexpr OutputIterator       // constexpr in C++20
851    rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result);
852
853template <class RandomAccessIterator>
854    void
855    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14, removed in C++17
856
857template <class RandomAccessIterator, class RandomNumberGenerator>
858    void
859    random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
860                   RandomNumberGenerator& rand);  // deprecated in C++14, removed in C++17
861
862template<class PopulationIterator, class SampleIterator,
863         class Distance, class UniformRandomBitGenerator>
864    SampleIterator sample(PopulationIterator first, PopulationIterator last,
865                          SampleIterator out, Distance n,
866                          UniformRandomBitGenerator&& g); // C++17
867
868template<class RandomAccessIterator, class UniformRandomNumberGenerator>
869    void shuffle(RandomAccessIterator first, RandomAccessIterator last,
870                 UniformRandomNumberGenerator&& g);
871
872template<class ForwardIterator>
873  constexpr ForwardIterator
874    shift_left(ForwardIterator first, ForwardIterator last,
875               typename iterator_traits<ForwardIterator>::difference_type n); // C++20
876
877template<class ForwardIterator>
878  constexpr ForwardIterator
879    shift_right(ForwardIterator first, ForwardIterator last,
880                typename iterator_traits<ForwardIterator>::difference_type n); // C++20
881
882template <class InputIterator, class Predicate>
883    constexpr bool  // constexpr in C++20
884    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
885
886template <class ForwardIterator, class Predicate>
887    constexpr ForwardIterator  // constexpr in C++20
888    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
889
890template <class InputIterator, class OutputIterator1,
891          class OutputIterator2, class Predicate>
892    constexpr pair<OutputIterator1, OutputIterator2>   // constexpr in C++20
893    partition_copy(InputIterator first, InputIterator last,
894                   OutputIterator1 out_true, OutputIterator2 out_false,
895                   Predicate pred);
896
897template <class ForwardIterator, class Predicate>
898    ForwardIterator
899    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
900
901template<class ForwardIterator, class Predicate>
902    constexpr ForwardIterator  // constexpr in C++20
903    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
904
905template <class ForwardIterator>
906    constexpr bool  // constexpr in C++20
907    is_sorted(ForwardIterator first, ForwardIterator last);
908
909template <class ForwardIterator, class Compare>
910    constexpr bool  // constexpr in C++20
911    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
912
913template<class ForwardIterator>
914    constexpr ForwardIterator    // constexpr in C++20
915    is_sorted_until(ForwardIterator first, ForwardIterator last);
916
917template <class ForwardIterator, class Compare>
918    constexpr ForwardIterator    // constexpr in C++20
919    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
920
921template <class RandomAccessIterator>
922    constexpr void               // constexpr in C++20
923    sort(RandomAccessIterator first, RandomAccessIterator last);
924
925template <class RandomAccessIterator, class Compare>
926    constexpr void               // constexpr in C++20
927    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
928
929template <class RandomAccessIterator>
930    void
931    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
932
933template <class RandomAccessIterator, class Compare>
934    void
935    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
936
937template <class RandomAccessIterator>
938    constexpr void                    // constexpr in C++20
939    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
940
941template <class RandomAccessIterator, class Compare>
942    constexpr void                    // constexpr in C++20
943    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
944
945template <class InputIterator, class RandomAccessIterator>
946    constexpr RandomAccessIterator    // constexpr in C++20
947    partial_sort_copy(InputIterator first, InputIterator last,
948                      RandomAccessIterator result_first, RandomAccessIterator result_last);
949
950template <class InputIterator, class RandomAccessIterator, class Compare>
951    constexpr RandomAccessIterator    // constexpr in C++20
952    partial_sort_copy(InputIterator first, InputIterator last,
953                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
954
955template <class RandomAccessIterator>
956    constexpr void                    // constexpr in C++20
957    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
958
959template <class RandomAccessIterator, class Compare>
960    constexpr void                    // constexpr in C++20
961    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
962
963template <class ForwardIterator, class T>
964    constexpr ForwardIterator                         // constexpr in C++20
965    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
966
967template <class ForwardIterator, class T, class Compare>
968    constexpr ForwardIterator                         // constexpr in C++20
969    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
970
971template <class ForwardIterator, class T>
972    constexpr ForwardIterator                         // constexpr in C++20
973    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
974
975template <class ForwardIterator, class T, class Compare>
976    constexpr ForwardIterator                         // constexpr in C++20
977    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
978
979template <class ForwardIterator, class T>
980    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
981    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
982
983template <class ForwardIterator, class T, class Compare>
984    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
985    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
986
987template <class ForwardIterator, class T>
988    constexpr bool                                    // constexpr in C++20
989    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
990
991template <class ForwardIterator, class T, class Compare>
992    constexpr bool                                    // constexpr in C++20
993    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
994
995template <class InputIterator1, class InputIterator2, class OutputIterator>
996    constexpr OutputIterator                          // constexpr in C++20
997    merge(InputIterator1 first1, InputIterator1 last1,
998          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
999
1000template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1001    constexpr OutputIterator                          // constexpr in C++20
1002    merge(InputIterator1 first1, InputIterator1 last1,
1003          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1004
1005template <class BidirectionalIterator>
1006    void
1007    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
1008
1009template <class BidirectionalIterator, class Compare>
1010    void
1011    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
1012
1013template <class InputIterator1, class InputIterator2>
1014    constexpr bool                                    // constexpr in C++20
1015    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
1016
1017template <class InputIterator1, class InputIterator2, class Compare>
1018    constexpr bool                                    // constexpr in C++20
1019    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
1020
1021template <class InputIterator1, class InputIterator2, class OutputIterator>
1022    constexpr OutputIterator                          // constexpr in C++20
1023    set_union(InputIterator1 first1, InputIterator1 last1,
1024              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1025
1026template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1027    constexpr OutputIterator                          // constexpr in C++20
1028    set_union(InputIterator1 first1, InputIterator1 last1,
1029              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1030
1031template <class InputIterator1, class InputIterator2, class OutputIterator>
1032    constexpr OutputIterator                         // constexpr in C++20
1033    set_intersection(InputIterator1 first1, InputIterator1 last1,
1034                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1035
1036template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1037    constexpr OutputIterator                         // constexpr in C++20
1038    set_intersection(InputIterator1 first1, InputIterator1 last1,
1039                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1040
1041template <class InputIterator1, class InputIterator2, class OutputIterator>
1042    constexpr OutputIterator                         // constexpr in C++20
1043    set_difference(InputIterator1 first1, InputIterator1 last1,
1044                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1045
1046template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1047    constexpr OutputIterator                         // constexpr in C++20
1048    set_difference(InputIterator1 first1, InputIterator1 last1,
1049                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1050
1051template <class InputIterator1, class InputIterator2, class OutputIterator>
1052    constexpr OutputIterator                         // constexpr in C++20
1053    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
1054                             InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1055
1056template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1057    constexpr OutputIterator                         // constexpr in C++20
1058    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
1059                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1060
1061template <class RandomAccessIterator>
1062    constexpr void                                   // constexpr in C++20
1063    push_heap(RandomAccessIterator first, RandomAccessIterator last);
1064
1065template <class RandomAccessIterator, class Compare>
1066    constexpr void                                   // constexpr in C++20
1067    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1068
1069template <class RandomAccessIterator>
1070    constexpr void                                   // constexpr in C++20
1071    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
1072
1073template <class RandomAccessIterator, class Compare>
1074    constexpr void                                   // constexpr in C++20
1075    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1076
1077template <class RandomAccessIterator>
1078    constexpr void                                   // constexpr in C++20
1079    make_heap(RandomAccessIterator first, RandomAccessIterator last);
1080
1081template <class RandomAccessIterator, class Compare>
1082    constexpr void                                   // constexpr in C++20
1083    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1084
1085template <class RandomAccessIterator>
1086    constexpr void                                   // constexpr in C++20
1087    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
1088
1089template <class RandomAccessIterator, class Compare>
1090    constexpr void                                   // constexpr in C++20
1091    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1092
1093template <class RandomAccessIterator>
1094    constexpr bool   // constexpr in C++20
1095    is_heap(RandomAccessIterator first, RandomAccessiterator last);
1096
1097template <class RandomAccessIterator, class Compare>
1098    constexpr bool   // constexpr in C++20
1099    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
1100
1101template <class RandomAccessIterator>
1102    constexpr RandomAccessIterator   // constexpr in C++20
1103    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
1104
1105template <class RandomAccessIterator, class Compare>
1106    constexpr RandomAccessIterator   // constexpr in C++20
1107    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
1108
1109template <class ForwardIterator>
1110    constexpr ForwardIterator        // constexpr in C++14
1111    min_element(ForwardIterator first, ForwardIterator last);
1112
1113template <class ForwardIterator, class Compare>
1114    constexpr ForwardIterator        // constexpr in C++14
1115    min_element(ForwardIterator first, ForwardIterator last, Compare comp);
1116
1117template <class T>
1118    constexpr const T&               // constexpr in C++14
1119    min(const T& a, const T& b);
1120
1121template <class T, class Compare>
1122    constexpr const T&               // constexpr in C++14
1123    min(const T& a, const T& b, Compare comp);
1124
1125template<class T>
1126    constexpr T                      // constexpr in C++14
1127    min(initializer_list<T> t);
1128
1129template<class T, class Compare>
1130    constexpr T                      // constexpr in C++14
1131    min(initializer_list<T> t, Compare comp);
1132
1133template<class T>
1134    constexpr const T& clamp(const T& v, const T& lo, const T& hi);               // C++17
1135
1136template<class T, class Compare>
1137    constexpr const T& clamp(const T& v, const T& lo, const T& hi, Compare comp); // C++17
1138
1139template <class ForwardIterator>
1140    constexpr ForwardIterator        // constexpr in C++14
1141    max_element(ForwardIterator first, ForwardIterator last);
1142
1143template <class ForwardIterator, class Compare>
1144    constexpr ForwardIterator        // constexpr in C++14
1145    max_element(ForwardIterator first, ForwardIterator last, Compare comp);
1146
1147template <class T>
1148    constexpr const T&               // constexpr in C++14
1149    max(const T& a, const T& b);
1150
1151template <class T, class Compare>
1152    constexpr const T&               // constexpr in C++14
1153    max(const T& a, const T& b, Compare comp);
1154
1155template<class T>
1156    constexpr T                      // constexpr in C++14
1157    max(initializer_list<T> t);
1158
1159template<class T, class Compare>
1160    constexpr T                      // constexpr in C++14
1161    max(initializer_list<T> t, Compare comp);
1162
1163template<class ForwardIterator>
1164    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++14
1165    minmax_element(ForwardIterator first, ForwardIterator last);
1166
1167template<class ForwardIterator, class Compare>
1168    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++14
1169    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);
1170
1171template<class T>
1172    constexpr pair<const T&, const T&>  // constexpr in C++14
1173    minmax(const T& a, const T& b);
1174
1175template<class T, class Compare>
1176    constexpr pair<const T&, const T&>  // constexpr in C++14
1177    minmax(const T& a, const T& b, Compare comp);
1178
1179template<class T>
1180    constexpr pair<T, T>                // constexpr in C++14
1181    minmax(initializer_list<T> t);
1182
1183template<class T, class Compare>
1184    constexpr pair<T, T>                // constexpr in C++14
1185    minmax(initializer_list<T> t, Compare comp);
1186
1187template <class InputIterator1, class InputIterator2>
1188    constexpr bool     // constexpr in C++20
1189    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
1190
1191template <class InputIterator1, class InputIterator2, class Compare>
1192    constexpr bool     // constexpr in C++20
1193    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
1194                            InputIterator2 first2, InputIterator2 last2, Compare comp);
1195
1196template <class BidirectionalIterator>
1197    constexpr bool     // constexpr in C++20
1198    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
1199
1200template <class BidirectionalIterator, class Compare>
1201    constexpr bool     // constexpr in C++20
1202    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
1203
1204template <class BidirectionalIterator>
1205    constexpr bool     // constexpr in C++20
1206    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
1207
1208template <class BidirectionalIterator, class Compare>
1209    constexpr bool     // constexpr in C++20
1210    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
1211}  // std
1212
1213*/
1214
1215#include <__assert> // all public C++ headers provide the assertion handler
1216#include <__bits>
1217#include <__config>
1218#include <__debug>
1219#include <cstddef>
1220#include <cstring>
1221#include <memory>
1222#include <type_traits>
1223#include <version>
1224
1225#include <__algorithm/adjacent_find.h>
1226#include <__algorithm/all_of.h>
1227#include <__algorithm/any_of.h>
1228#include <__algorithm/binary_search.h>
1229#include <__algorithm/clamp.h>
1230#include <__algorithm/comp.h>
1231#include <__algorithm/comp_ref_type.h>
1232#include <__algorithm/copy.h>
1233#include <__algorithm/copy_backward.h>
1234#include <__algorithm/copy_if.h>
1235#include <__algorithm/copy_n.h>
1236#include <__algorithm/count.h>
1237#include <__algorithm/count_if.h>
1238#include <__algorithm/equal.h>
1239#include <__algorithm/equal_range.h>
1240#include <__algorithm/fill.h>
1241#include <__algorithm/fill_n.h>
1242#include <__algorithm/find.h>
1243#include <__algorithm/find_end.h>
1244#include <__algorithm/find_first_of.h>
1245#include <__algorithm/find_if.h>
1246#include <__algorithm/find_if_not.h>
1247#include <__algorithm/for_each.h>
1248#include <__algorithm/for_each_n.h>
1249#include <__algorithm/generate.h>
1250#include <__algorithm/generate_n.h>
1251#include <__algorithm/half_positive.h>
1252#include <__algorithm/in_found_result.h>
1253#include <__algorithm/in_fun_result.h>
1254#include <__algorithm/in_in_out_result.h>
1255#include <__algorithm/in_in_result.h>
1256#include <__algorithm/in_out_out_result.h>
1257#include <__algorithm/in_out_result.h>
1258#include <__algorithm/includes.h>
1259#include <__algorithm/inplace_merge.h>
1260#include <__algorithm/is_heap.h>
1261#include <__algorithm/is_heap_until.h>
1262#include <__algorithm/is_partitioned.h>
1263#include <__algorithm/is_permutation.h>
1264#include <__algorithm/is_sorted.h>
1265#include <__algorithm/is_sorted_until.h>
1266#include <__algorithm/iter_swap.h>
1267#include <__algorithm/lexicographical_compare.h>
1268#include <__algorithm/lower_bound.h>
1269#include <__algorithm/make_heap.h>
1270#include <__algorithm/max.h>
1271#include <__algorithm/max_element.h>
1272#include <__algorithm/merge.h>
1273#include <__algorithm/min.h>
1274#include <__algorithm/min_element.h>
1275#include <__algorithm/min_max_result.h>
1276#include <__algorithm/minmax.h>
1277#include <__algorithm/minmax_element.h>
1278#include <__algorithm/mismatch.h>
1279#include <__algorithm/move.h>
1280#include <__algorithm/move_backward.h>
1281#include <__algorithm/next_permutation.h>
1282#include <__algorithm/none_of.h>
1283#include <__algorithm/nth_element.h>
1284#include <__algorithm/partial_sort.h>
1285#include <__algorithm/partial_sort_copy.h>
1286#include <__algorithm/partition.h>
1287#include <__algorithm/partition_copy.h>
1288#include <__algorithm/partition_point.h>
1289#include <__algorithm/pop_heap.h>
1290#include <__algorithm/prev_permutation.h>
1291#include <__algorithm/push_heap.h>
1292#include <__algorithm/ranges_adjacent_find.h>
1293#include <__algorithm/ranges_all_of.h>
1294#include <__algorithm/ranges_any_of.h>
1295#include <__algorithm/ranges_binary_search.h>
1296#include <__algorithm/ranges_copy.h>
1297#include <__algorithm/ranges_copy_backward.h>
1298#include <__algorithm/ranges_copy_if.h>
1299#include <__algorithm/ranges_copy_n.h>
1300#include <__algorithm/ranges_count.h>
1301#include <__algorithm/ranges_count_if.h>
1302#include <__algorithm/ranges_equal.h>
1303#include <__algorithm/ranges_fill.h>
1304#include <__algorithm/ranges_fill_n.h>
1305#include <__algorithm/ranges_find.h>
1306#include <__algorithm/ranges_find_first_of.h>
1307#include <__algorithm/ranges_find_if.h>
1308#include <__algorithm/ranges_find_if_not.h>
1309#include <__algorithm/ranges_for_each.h>
1310#include <__algorithm/ranges_for_each_n.h>
1311#include <__algorithm/ranges_is_partitioned.h>
1312#include <__algorithm/ranges_is_sorted.h>
1313#include <__algorithm/ranges_is_sorted_until.h>
1314#include <__algorithm/ranges_lexicographical_compare.h>
1315#include <__algorithm/ranges_lower_bound.h>
1316#include <__algorithm/ranges_max.h>
1317#include <__algorithm/ranges_max_element.h>
1318#include <__algorithm/ranges_merge.h>
1319#include <__algorithm/ranges_min.h>
1320#include <__algorithm/ranges_min_element.h>
1321#include <__algorithm/ranges_minmax.h>
1322#include <__algorithm/ranges_minmax_element.h>
1323#include <__algorithm/ranges_mismatch.h>
1324#include <__algorithm/ranges_move.h>
1325#include <__algorithm/ranges_move_backward.h>
1326#include <__algorithm/ranges_none_of.h>
1327#include <__algorithm/ranges_nth_element.h>
1328#include <__algorithm/ranges_remove.h>
1329#include <__algorithm/ranges_remove_if.h>
1330#include <__algorithm/ranges_replace.h>
1331#include <__algorithm/ranges_replace_if.h>
1332#include <__algorithm/ranges_reverse.h>
1333#include <__algorithm/ranges_set_difference.h>
1334#include <__algorithm/ranges_sort.h>
1335#include <__algorithm/ranges_stable_sort.h>
1336#include <__algorithm/ranges_swap_ranges.h>
1337#include <__algorithm/ranges_transform.h>
1338#include <__algorithm/ranges_upper_bound.h>
1339#include <__algorithm/remove.h>
1340#include <__algorithm/remove_copy.h>
1341#include <__algorithm/remove_copy_if.h>
1342#include <__algorithm/remove_if.h>
1343#include <__algorithm/replace.h>
1344#include <__algorithm/replace_copy.h>
1345#include <__algorithm/replace_copy_if.h>
1346#include <__algorithm/replace_if.h>
1347#include <__algorithm/reverse.h>
1348#include <__algorithm/reverse_copy.h>
1349#include <__algorithm/rotate.h>
1350#include <__algorithm/rotate_copy.h>
1351#include <__algorithm/sample.h>
1352#include <__algorithm/search.h>
1353#include <__algorithm/search_n.h>
1354#include <__algorithm/set_difference.h>
1355#include <__algorithm/set_intersection.h>
1356#include <__algorithm/set_symmetric_difference.h>
1357#include <__algorithm/set_union.h>
1358#include <__algorithm/shift_left.h>
1359#include <__algorithm/shift_right.h>
1360#include <__algorithm/shuffle.h>
1361#include <__algorithm/sift_down.h>
1362#include <__algorithm/sort.h>
1363#include <__algorithm/sort_heap.h>
1364#include <__algorithm/stable_partition.h>
1365#include <__algorithm/stable_sort.h>
1366#include <__algorithm/swap_ranges.h>
1367#include <__algorithm/transform.h>
1368#include <__algorithm/unique.h>
1369#include <__algorithm/unique_copy.h>
1370#include <__algorithm/unwrap_iter.h>
1371#include <__algorithm/upper_bound.h>
1372
1373#ifndef _LIBCPP_REMOVE_TRANSITIVE_INCLUDES
1374#  include <chrono>
1375#  include <iterator>
1376#  include <utility>
1377#endif
1378
1379// standard-mandated includes
1380#include <initializer_list>
1381
1382#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1383#  pragma GCC system_header
1384#endif
1385
1386#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
1387#   include <__pstl_algorithm>
1388#endif
1389
1390#endif // _LIBCPP_ALGORITHM
1391