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<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
383           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
384    constexpr I upper_bound(I first, S last, const T& value, Comp comp = {}, Proj proj = {}); // since C++20
385
386  template<forward_range R, class T, class Proj = identity,
387           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
388             ranges::less>
389    constexpr borrowed_iterator_t<R>
390      upper_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});                     // since C++20
391
392  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
393           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
394    constexpr I lower_bound(I first, S last, const T& value, Comp comp = {},
395                                    Proj proj = {});                                          // since C++20
396  template<forward_range R, class T, class Proj = identity,
397           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
398             ranges::less>
399    constexpr borrowed_iterator_t<R>
400      lower_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});                     // since C++20
401
402  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
403           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
404    constexpr bool binary_search(I first, S last, const T& value, Comp comp = {},
405                                         Proj proj = {});                                     // since C++20
406
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 bool binary_search(R&& r, const T& value, Comp comp = {},
411                                         Proj proj = {});                                     // since C++20
412  template<input_iterator I1, sentinel_for<I1> S1, forward_iterator I2, sentinel_for<I2> S2,
413           class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
414    requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
415    constexpr I1 ranges::find_first_of(I1 first1, S1 last1, I2 first2, S2 last2,
416                                       Pred pred = {},
417                                       Proj1 proj1 = {}, Proj2 proj2 = {});                 // since C++20
418
419  template<input_range R1, forward_range R2,
420           class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
421    requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
422    constexpr borrowed_iterator_t<R1>
423      ranges::find_first_of(R1&& r1, R2&& r2,
424                            Pred pred = {},
425                            Proj1 proj1 = {}, Proj2 proj2 = {});                            // since C++20
426
427  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
428           indirect_binary_predicate<projected<I, Proj>,
429                                     projected<I, Proj>> Pred = ranges::equal_to>
430    constexpr I ranges::adjacent_find(I first, S last, Pred pred = {}, Proj proj = {});     // since C+20
431
432  template<forward_range R, class Proj = identity,
433           indirect_binary_predicate<projected<iterator_t<R>, Proj>,
434                                     projected<iterator_t<R>, Proj>> Pred = ranges::equal_to>
435    constexpr borrowed_iterator_t<R> ranges::adjacent_find(R&& r, Pred pred = {}, Proj proj = {});  // since C++20
436
437  template<input_iterator I, sentinel_for<I> S, class T1, class T2, class Proj = identity>
438    requires indirectly_writable<I, const T2&> &&
439             indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T1*>
440    constexpr I
441      ranges::replace(I first, S last, const T1& old_value, const T2& new_value, Proj proj = {});   // since C++20
442
443  template<input_range R, class T1, class T2, class Proj = identity>
444    requires indirectly_writable<iterator_t<R>, const T2&> &&
445             indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T1*>
446    constexpr borrowed_iterator_t<R>
447      ranges::replace(R&& r, const T1& old_value, const T2& new_value, Proj proj = {});             // since C++20
448
449  template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity,
450           indirect_unary_predicate<projected<I, Proj>> Pred>
451    requires indirectly_writable<I, const T&>
452    constexpr I ranges::replace_if(I first, S last, Pred pred, const T& new_value, Proj proj = {}); // since C++20
453
454  template<input_range R, class T, class Proj = identity,
455           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
456    requires indirectly_writable<iterator_t<R>, const T&>
457    constexpr borrowed_iterator_t<R>
458      ranges::replace_if(R&& r, Pred pred, const T& new_value, Proj proj = {});                     // since C++20
459
460  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
461           class Proj1 = identity, class Proj2 = identity,
462           indirect_strict_weak_order<projected<I1, Proj1>,
463                                      projected<I2, Proj2>> Comp = ranges::less>
464    constexpr bool
465      ranges::lexicographical_compare(I1 first1, S1 last1, I2 first2, S2 last2,
466                                      Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});    // since C++20
467
468  template<input_range R1, input_range R2, class Proj1 = identity,
469           class Proj2 = identity,
470           indirect_strict_weak_order<projected<iterator_t<R1>, Proj1>,
471                                      projected<iterator_t<R2>, Proj2>> Comp = ranges::less>
472    constexpr bool
473      ranges::lexicographical_compare(R1&& r1, R2&& r2, Comp comp = {},
474                                      Proj1 proj1 = {}, Proj2 proj2 = {});                    // since C++20
475
476  template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2>
477    requires indirectly_movable<I1, I2>
478    constexpr ranges::move_backward_result<I1, I2>
479      ranges::move_backward(I1 first, S1 last, I2 result);                                          // since C++20
480
481  template<bidirectional_range R, bidirectional_iterator I>
482    requires indirectly_movable<iterator_t<R>, I>
483    constexpr ranges::move_backward_result<borrowed_iterator_t<R>, I>
484      ranges::move_backward(R&& r, I result);                                                       // since C++20
485
486  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O>
487    requires indirectly_movable<I, O>
488    constexpr ranges::move_result<I, O>
489      ranges::move(I first, S last, O result);                                                      // since C++20
490
491  template<input_range R, weakly_incrementable O>
492    requires indirectly_movable<iterator_t<R>, O>
493    constexpr ranges::move_result<borrowed_iterator_t<R>, O>
494      ranges::move(R&& r, O result);                                                                // since C++20
495
496  template<class I1, class I2, class O>
497    using merge_result = in_in_out_result<I1, I2, O>;                                               // since C++20
498
499  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
500           weakly_incrementable O, class Comp = ranges::less, class Proj1 = identity,
501           class Proj2 = identity>
502    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
503    constexpr merge_result<I1, I2, O>
504      merge(I1 first1, S1 last1, I2 first2, S2 last2, O result,
505            Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                                    // since C++20
506
507  template<input_range R1, input_range R2, weakly_incrementable O, class Comp = ranges::less,
508           class Proj1 = identity, class Proj2 = identity>
509    requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
510    constexpr merge_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
511      merge(R1&& r1, R2&& r2, O result,
512            Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                                    // since C++20
513
514  template<permutable I, sentinel_for<I> S, class T, class Proj = identity>
515    requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
516    constexpr subrange<I> ranges::remove(I first, S last, const T& value, Proj proj = {});          // since C++20
517
518  template<forward_range R, class T, class Proj = identity>
519    requires permutable<iterator_t<R>> &&
520             indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
521    constexpr borrowed_subrange_t<R>
522      ranges::remove(R&& r, const T& value, Proj proj = {});                                        // since C++20
523
524  template<permutable I, sentinel_for<I> S, class Proj = identity,
525           indirect_unary_predicate<projected<I, Proj>> Pred>
526    constexpr subrange<I> ranges::remove_if(I first, S last, Pred pred, Proj proj = {});            // since C++20
527
528  template<forward_range R, class Proj = identity,
529           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
530    requires permutable<iterator_t<R>>
531    constexpr borrowed_subrange_t<R>
532      ranges::remove_if(R&& r, Pred pred, Proj proj = {});                                          // since C++20
533
534}
535
536    constexpr bool     // constexpr in C++20
537    all_of(InputIterator first, InputIterator last, Predicate pred);
538
539template <class InputIterator, class Predicate>
540    constexpr bool     // constexpr in C++20
541    any_of(InputIterator first, InputIterator last, Predicate pred);
542
543template <class InputIterator, class Predicate>
544    constexpr bool     // constexpr in C++20
545    none_of(InputIterator first, InputIterator last, Predicate pred);
546
547template <class InputIterator, class Function>
548    constexpr Function          // constexpr in C++20
549    for_each(InputIterator first, InputIterator last, Function f);
550
551template<class InputIterator, class Size, class Function>
552    constexpr InputIterator     // constexpr in C++20
553    for_each_n(InputIterator first, Size n, Function f); // C++17
554
555template <class InputIterator, class T>
556    constexpr InputIterator     // constexpr in C++20
557    find(InputIterator first, InputIterator last, const T& value);
558
559template <class InputIterator, class Predicate>
560    constexpr InputIterator     // constexpr in C++20
561    find_if(InputIterator first, InputIterator last, Predicate pred);
562
563template<class InputIterator, class Predicate>
564    constexpr InputIterator     // constexpr in C++20
565    find_if_not(InputIterator first, InputIterator last, Predicate pred);
566
567template <class ForwardIterator1, class ForwardIterator2>
568    constexpr ForwardIterator1  // constexpr in C++20
569    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
570             ForwardIterator2 first2, ForwardIterator2 last2);
571
572template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
573    constexpr ForwardIterator1  // constexpr in C++20
574    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
575             ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
576
577template <class ForwardIterator1, class ForwardIterator2>
578    constexpr ForwardIterator1  // constexpr in C++20
579    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
580                  ForwardIterator2 first2, ForwardIterator2 last2);
581
582template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
583    constexpr ForwardIterator1  // constexpr in C++20
584    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
585                  ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
586
587template <class ForwardIterator>
588    constexpr ForwardIterator   // constexpr in C++20
589    adjacent_find(ForwardIterator first, ForwardIterator last);
590
591template <class ForwardIterator, class BinaryPredicate>
592    constexpr ForwardIterator   // constexpr in C++20
593    adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
594
595template <class InputIterator, class T>
596    constexpr typename iterator_traits<InputIterator>::difference_type  // constexpr in C++20
597    count(InputIterator first, InputIterator last, const T& value);
598
599template <class InputIterator, class Predicate>
600    constexpr typename iterator_traits<InputIterator>::difference_type // constexpr in C++20
601    count_if(InputIterator first, InputIterator last, Predicate pred);
602
603template <class InputIterator1, class InputIterator2>
604    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
605    mismatch(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
606
607template <class InputIterator1, class InputIterator2>
608    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
609    mismatch(InputIterator1 first1, InputIterator1 last1,
610             InputIterator2 first2, InputIterator2 last2); // **C++14**
611
612template <class InputIterator1, class InputIterator2, class BinaryPredicate>
613    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
614    mismatch(InputIterator1 first1, InputIterator1 last1,
615             InputIterator2 first2, BinaryPredicate pred);
616
617template <class InputIterator1, class InputIterator2, class BinaryPredicate>
618    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
619    mismatch(InputIterator1 first1, InputIterator1 last1,
620             InputIterator2 first2, InputIterator2 last2,
621             BinaryPredicate pred); // **C++14**
622
623template <class InputIterator1, class InputIterator2>
624    constexpr bool      // constexpr in C++20
625    equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
626
627template <class InputIterator1, class InputIterator2>
628    constexpr bool      // constexpr in C++20
629    equal(InputIterator1 first1, InputIterator1 last1,
630          InputIterator2 first2, InputIterator2 last2); // **C++14**
631
632template <class InputIterator1, class InputIterator2, class BinaryPredicate>
633    constexpr bool      // constexpr in C++20
634    equal(InputIterator1 first1, InputIterator1 last1,
635          InputIterator2 first2, BinaryPredicate pred);
636
637template <class InputIterator1, class InputIterator2, class BinaryPredicate>
638    constexpr bool      // constexpr in C++20
639    equal(InputIterator1 first1, InputIterator1 last1,
640          InputIterator2 first2, InputIterator2 last2,
641          BinaryPredicate pred); // **C++14**
642
643template<class ForwardIterator1, class ForwardIterator2>
644    constexpr bool      // constexpr in C++20
645    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
646                   ForwardIterator2 first2);
647
648template<class ForwardIterator1, class ForwardIterator2>
649    constexpr bool      // constexpr in C++20
650    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
651                   ForwardIterator2 first2, ForwardIterator2 last2); // **C++14**
652
653template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
654    constexpr bool      // constexpr in C++20
655    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
656                   ForwardIterator2 first2, BinaryPredicate pred);
657
658template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
659    constexpr bool      // constexpr in C++20
660    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
661                   ForwardIterator2 first2, ForwardIterator2 last2,
662                   BinaryPredicate pred);  // **C++14**
663
664template <class ForwardIterator1, class ForwardIterator2>
665    constexpr ForwardIterator1      // constexpr in C++20
666    search(ForwardIterator1 first1, ForwardIterator1 last1,
667           ForwardIterator2 first2, ForwardIterator2 last2);
668
669template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
670    constexpr ForwardIterator1      // constexpr in C++20
671    search(ForwardIterator1 first1, ForwardIterator1 last1,
672           ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
673
674template <class ForwardIterator, class Size, class T>
675    constexpr ForwardIterator       // constexpr in C++20
676    search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value);
677
678template <class ForwardIterator, class Size, class T, class BinaryPredicate>
679    constexpr ForwardIterator       // constexpr in C++20
680    search_n(ForwardIterator first, ForwardIterator last,
681             Size count, const T& value, BinaryPredicate pred);
682
683template <class InputIterator, class OutputIterator>
684    constexpr OutputIterator      // constexpr in C++20
685    copy(InputIterator first, InputIterator last, OutputIterator result);
686
687template<class InputIterator, class OutputIterator, class Predicate>
688    constexpr OutputIterator      // constexpr in C++20
689    copy_if(InputIterator first, InputIterator last,
690            OutputIterator result, Predicate pred);
691
692template<class InputIterator, class Size, class OutputIterator>
693    constexpr OutputIterator      // constexpr in C++20
694    copy_n(InputIterator first, Size n, OutputIterator result);
695
696template <class BidirectionalIterator1, class BidirectionalIterator2>
697    constexpr BidirectionalIterator2      // constexpr in C++20
698    copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
699                  BidirectionalIterator2 result);
700
701// [alg.move], move
702template<class InputIterator, class OutputIterator>
703    constexpr OutputIterator move(InputIterator first, InputIterator last,
704                                OutputIterator result);
705
706template<class BidirectionalIterator1, class BidirectionalIterator2>
707    constexpr BidirectionalIterator2
708    move_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
709                  BidirectionalIterator2 result);
710
711template <class ForwardIterator1, class ForwardIterator2>
712    constexpr ForwardIterator2    // constexpr in C++20
713    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
714
715namespace ranges {
716    template<class I1, class I2>
717    using swap_ranges_result = in_in_result<I1, I2>;
718
719template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2>
720        requires indirectly_swappable<I1, I2>
721    constexpr ranges::swap_ranges_result<I1, I2>
722        swap_ranges(I1 first1, S1 last1, I2 first2, S2 last2);
723
724template<input_range R1, input_range R2>
725        requires indirectly_swappable<iterator_t<R1>, iterator_t<R2>>
726    constexpr ranges::swap_ranges_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
727        swap_ranges(R1&& r1, R2&& r2);
728}
729
730template <class ForwardIterator1, class ForwardIterator2>
731    constexpr void                // constexpr in C++20
732    iter_swap(ForwardIterator1 a, ForwardIterator2 b);
733
734template <class InputIterator, class OutputIterator, class UnaryOperation>
735    constexpr OutputIterator      // constexpr in C++20
736    transform(InputIterator first, InputIterator last, OutputIterator result, UnaryOperation op);
737
738template <class InputIterator1, class InputIterator2, class OutputIterator, class BinaryOperation>
739    constexpr OutputIterator      // constexpr in C++20
740    transform(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
741              OutputIterator result, BinaryOperation binary_op);
742
743template <class ForwardIterator, class T>
744    constexpr void      // constexpr in C++20
745    replace(ForwardIterator first, ForwardIterator last, const T& old_value, const T& new_value);
746
747template <class ForwardIterator, class Predicate, class T>
748    constexpr void      // constexpr in C++20
749    replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, const T& new_value);
750
751template <class InputIterator, class OutputIterator, class T>
752    constexpr OutputIterator      // constexpr in C++20
753    replace_copy(InputIterator first, InputIterator last, OutputIterator result,
754                 const T& old_value, const T& new_value);
755
756template <class InputIterator, class OutputIterator, class Predicate, class T>
757    constexpr OutputIterator      // constexpr in C++20
758    replace_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred, const T& new_value);
759
760template <class ForwardIterator, class T>
761    constexpr void      // constexpr in C++20
762    fill(ForwardIterator first, ForwardIterator last, const T& value);
763
764template <class OutputIterator, class Size, class T>
765    constexpr OutputIterator      // constexpr in C++20
766    fill_n(OutputIterator first, Size n, const T& value);
767
768template <class ForwardIterator, class Generator>
769    constexpr void      // constexpr in C++20
770    generate(ForwardIterator first, ForwardIterator last, Generator gen);
771
772template <class OutputIterator, class Size, class Generator>
773    constexpr OutputIterator      // constexpr in C++20
774    generate_n(OutputIterator first, Size n, Generator gen);
775
776template <class ForwardIterator, class T>
777    constexpr ForwardIterator     // constexpr in C++20
778    remove(ForwardIterator first, ForwardIterator last, const T& value);
779
780template <class ForwardIterator, class Predicate>
781    constexpr ForwardIterator     // constexpr in C++20
782    remove_if(ForwardIterator first, ForwardIterator last, Predicate pred);
783
784template <class InputIterator, class OutputIterator, class T>
785    constexpr OutputIterator     // constexpr in C++20
786    remove_copy(InputIterator first, InputIterator last, OutputIterator result, const T& value);
787
788template <class InputIterator, class OutputIterator, class Predicate>
789    constexpr OutputIterator     // constexpr in C++20
790    remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred);
791
792template <class ForwardIterator>
793    constexpr ForwardIterator    // constexpr in C++20
794    unique(ForwardIterator first, ForwardIterator last);
795
796template <class ForwardIterator, class BinaryPredicate>
797    constexpr ForwardIterator    // constexpr in C++20
798    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
799
800template <class InputIterator, class OutputIterator>
801    constexpr OutputIterator     // constexpr in C++20
802    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
803
804template <class InputIterator, class OutputIterator, class BinaryPredicate>
805    constexpr OutputIterator     // constexpr in C++20
806    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
807
808template <class BidirectionalIterator>
809    constexpr void               // constexpr in C++20
810    reverse(BidirectionalIterator first, BidirectionalIterator last);
811
812template <class BidirectionalIterator, class OutputIterator>
813    constexpr OutputIterator       // constexpr in C++20
814    reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result);
815
816template <class ForwardIterator>
817    constexpr ForwardIterator      // constexpr in C++20
818    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
819
820template <class ForwardIterator, class OutputIterator>
821    constexpr OutputIterator       // constexpr in C++20
822    rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result);
823
824template <class RandomAccessIterator>
825    void
826    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14, removed in C++17
827
828template <class RandomAccessIterator, class RandomNumberGenerator>
829    void
830    random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
831                   RandomNumberGenerator& rand);  // deprecated in C++14, removed in C++17
832
833template<class PopulationIterator, class SampleIterator,
834         class Distance, class UniformRandomBitGenerator>
835    SampleIterator sample(PopulationIterator first, PopulationIterator last,
836                          SampleIterator out, Distance n,
837                          UniformRandomBitGenerator&& g); // C++17
838
839template<class RandomAccessIterator, class UniformRandomNumberGenerator>
840    void shuffle(RandomAccessIterator first, RandomAccessIterator last,
841                 UniformRandomNumberGenerator&& g);
842
843template<class ForwardIterator>
844  constexpr ForwardIterator
845    shift_left(ForwardIterator first, ForwardIterator last,
846               typename iterator_traits<ForwardIterator>::difference_type n); // C++20
847
848template<class ForwardIterator>
849  constexpr ForwardIterator
850    shift_right(ForwardIterator first, ForwardIterator last,
851                typename iterator_traits<ForwardIterator>::difference_type n); // C++20
852
853template <class InputIterator, class Predicate>
854    constexpr bool  // constexpr in C++20
855    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
856
857template <class ForwardIterator, class Predicate>
858    constexpr ForwardIterator  // constexpr in C++20
859    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
860
861template <class InputIterator, class OutputIterator1,
862          class OutputIterator2, class Predicate>
863    constexpr pair<OutputIterator1, OutputIterator2>   // constexpr in C++20
864    partition_copy(InputIterator first, InputIterator last,
865                   OutputIterator1 out_true, OutputIterator2 out_false,
866                   Predicate pred);
867
868template <class ForwardIterator, class Predicate>
869    ForwardIterator
870    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
871
872template<class ForwardIterator, class Predicate>
873    constexpr ForwardIterator  // constexpr in C++20
874    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
875
876template <class ForwardIterator>
877    constexpr bool  // constexpr in C++20
878    is_sorted(ForwardIterator first, ForwardIterator last);
879
880template <class ForwardIterator, class Compare>
881    constexpr bool  // constexpr in C++20
882    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
883
884template<class ForwardIterator>
885    constexpr ForwardIterator    // constexpr in C++20
886    is_sorted_until(ForwardIterator first, ForwardIterator last);
887
888template <class ForwardIterator, class Compare>
889    constexpr ForwardIterator    // constexpr in C++20
890    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
891
892template <class RandomAccessIterator>
893    constexpr void               // constexpr in C++20
894    sort(RandomAccessIterator first, RandomAccessIterator last);
895
896template <class RandomAccessIterator, class Compare>
897    constexpr void               // constexpr in C++20
898    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
899
900template <class RandomAccessIterator>
901    void
902    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
903
904template <class RandomAccessIterator, class Compare>
905    void
906    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
907
908template <class RandomAccessIterator>
909    constexpr void                    // constexpr in C++20
910    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
911
912template <class RandomAccessIterator, class Compare>
913    constexpr void                    // constexpr in C++20
914    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
915
916template <class InputIterator, class RandomAccessIterator>
917    constexpr RandomAccessIterator    // constexpr in C++20
918    partial_sort_copy(InputIterator first, InputIterator last,
919                      RandomAccessIterator result_first, RandomAccessIterator result_last);
920
921template <class InputIterator, class RandomAccessIterator, class Compare>
922    constexpr RandomAccessIterator    // constexpr in C++20
923    partial_sort_copy(InputIterator first, InputIterator last,
924                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
925
926template <class RandomAccessIterator>
927    constexpr void                    // constexpr in C++20
928    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
929
930template <class RandomAccessIterator, class Compare>
931    constexpr void                    // constexpr in C++20
932    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
933
934template <class ForwardIterator, class T>
935    constexpr ForwardIterator                         // constexpr in C++20
936    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
937
938template <class ForwardIterator, class T, class Compare>
939    constexpr ForwardIterator                         // constexpr in C++20
940    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
941
942template <class ForwardIterator, class T>
943    constexpr ForwardIterator                         // constexpr in C++20
944    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
945
946template <class ForwardIterator, class T, class Compare>
947    constexpr ForwardIterator                         // constexpr in C++20
948    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
949
950template <class ForwardIterator, class T>
951    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
952    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
953
954template <class ForwardIterator, class T, class Compare>
955    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
956    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
957
958template <class ForwardIterator, class T>
959    constexpr bool                                    // constexpr in C++20
960    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
961
962template <class ForwardIterator, class T, class Compare>
963    constexpr bool                                    // constexpr in C++20
964    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
965
966template <class InputIterator1, class InputIterator2, class OutputIterator>
967    constexpr OutputIterator                          // constexpr in C++20
968    merge(InputIterator1 first1, InputIterator1 last1,
969          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
970
971template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
972    constexpr OutputIterator                          // constexpr in C++20
973    merge(InputIterator1 first1, InputIterator1 last1,
974          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
975
976template <class BidirectionalIterator>
977    void
978    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
979
980template <class BidirectionalIterator, class Compare>
981    void
982    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
983
984template <class InputIterator1, class InputIterator2>
985    constexpr bool                                    // constexpr in C++20
986    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
987
988template <class InputIterator1, class InputIterator2, class Compare>
989    constexpr bool                                    // constexpr in C++20
990    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
991
992template <class InputIterator1, class InputIterator2, class OutputIterator>
993    constexpr OutputIterator                          // constexpr in C++20
994    set_union(InputIterator1 first1, InputIterator1 last1,
995              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
996
997template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
998    constexpr OutputIterator                          // constexpr in C++20
999    set_union(InputIterator1 first1, InputIterator1 last1,
1000              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1001
1002template <class InputIterator1, class InputIterator2, class OutputIterator>
1003    constexpr OutputIterator                         // constexpr in C++20
1004    set_intersection(InputIterator1 first1, InputIterator1 last1,
1005                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1006
1007template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1008    constexpr OutputIterator                         // constexpr in C++20
1009    set_intersection(InputIterator1 first1, InputIterator1 last1,
1010                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1011
1012template <class InputIterator1, class InputIterator2, class OutputIterator>
1013    constexpr OutputIterator                         // constexpr in C++20
1014    set_difference(InputIterator1 first1, InputIterator1 last1,
1015                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1016
1017template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1018    constexpr OutputIterator                         // constexpr in C++20
1019    set_difference(InputIterator1 first1, InputIterator1 last1,
1020                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1021
1022template <class InputIterator1, class InputIterator2, class OutputIterator>
1023    constexpr OutputIterator                         // constexpr in C++20
1024    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
1025                             InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1026
1027template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1028    constexpr OutputIterator                         // constexpr in C++20
1029    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
1030                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1031
1032template <class RandomAccessIterator>
1033    constexpr void                                   // constexpr in C++20
1034    push_heap(RandomAccessIterator first, RandomAccessIterator last);
1035
1036template <class RandomAccessIterator, class Compare>
1037    constexpr void                                   // constexpr in C++20
1038    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1039
1040template <class RandomAccessIterator>
1041    constexpr void                                   // constexpr in C++20
1042    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
1043
1044template <class RandomAccessIterator, class Compare>
1045    constexpr void                                   // constexpr in C++20
1046    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1047
1048template <class RandomAccessIterator>
1049    constexpr void                                   // constexpr in C++20
1050    make_heap(RandomAccessIterator first, RandomAccessIterator last);
1051
1052template <class RandomAccessIterator, class Compare>
1053    constexpr void                                   // constexpr in C++20
1054    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1055
1056template <class RandomAccessIterator>
1057    constexpr void                                   // constexpr in C++20
1058    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
1059
1060template <class RandomAccessIterator, class Compare>
1061    constexpr void                                   // constexpr in C++20
1062    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1063
1064template <class RandomAccessIterator>
1065    constexpr bool   // constexpr in C++20
1066    is_heap(RandomAccessIterator first, RandomAccessiterator last);
1067
1068template <class RandomAccessIterator, class Compare>
1069    constexpr bool   // constexpr in C++20
1070    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
1071
1072template <class RandomAccessIterator>
1073    constexpr RandomAccessIterator   // constexpr in C++20
1074    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
1075
1076template <class RandomAccessIterator, class Compare>
1077    constexpr RandomAccessIterator   // constexpr in C++20
1078    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
1079
1080template <class ForwardIterator>
1081    constexpr ForwardIterator        // constexpr in C++14
1082    min_element(ForwardIterator first, ForwardIterator last);
1083
1084template <class ForwardIterator, class Compare>
1085    constexpr ForwardIterator        // constexpr in C++14
1086    min_element(ForwardIterator first, ForwardIterator last, Compare comp);
1087
1088template <class T>
1089    constexpr const T&               // constexpr in C++14
1090    min(const T& a, const T& b);
1091
1092template <class T, class Compare>
1093    constexpr const T&               // constexpr in C++14
1094    min(const T& a, const T& b, Compare comp);
1095
1096template<class T>
1097    constexpr T                      // constexpr in C++14
1098    min(initializer_list<T> t);
1099
1100template<class T, class Compare>
1101    constexpr T                      // constexpr in C++14
1102    min(initializer_list<T> t, Compare comp);
1103
1104template<class T>
1105    constexpr const T& clamp(const T& v, const T& lo, const T& hi);               // C++17
1106
1107template<class T, class Compare>
1108    constexpr const T& clamp(const T& v, const T& lo, const T& hi, Compare comp); // C++17
1109
1110template <class ForwardIterator>
1111    constexpr ForwardIterator        // constexpr in C++14
1112    max_element(ForwardIterator first, ForwardIterator last);
1113
1114template <class ForwardIterator, class Compare>
1115    constexpr ForwardIterator        // constexpr in C++14
1116    max_element(ForwardIterator first, ForwardIterator last, Compare comp);
1117
1118template <class T>
1119    constexpr const T&               // constexpr in C++14
1120    max(const T& a, const T& b);
1121
1122template <class T, class Compare>
1123    constexpr const T&               // constexpr in C++14
1124    max(const T& a, const T& b, Compare comp);
1125
1126template<class T>
1127    constexpr T                      // constexpr in C++14
1128    max(initializer_list<T> t);
1129
1130template<class T, class Compare>
1131    constexpr T                      // constexpr in C++14
1132    max(initializer_list<T> t, Compare comp);
1133
1134template<class ForwardIterator>
1135    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++14
1136    minmax_element(ForwardIterator first, ForwardIterator last);
1137
1138template<class ForwardIterator, class Compare>
1139    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++14
1140    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);
1141
1142template<class T>
1143    constexpr pair<const T&, const T&>  // constexpr in C++14
1144    minmax(const T& a, const T& b);
1145
1146template<class T, class Compare>
1147    constexpr pair<const T&, const T&>  // constexpr in C++14
1148    minmax(const T& a, const T& b, Compare comp);
1149
1150template<class T>
1151    constexpr pair<T, T>                // constexpr in C++14
1152    minmax(initializer_list<T> t);
1153
1154template<class T, class Compare>
1155    constexpr pair<T, T>                // constexpr in C++14
1156    minmax(initializer_list<T> t, Compare comp);
1157
1158template <class InputIterator1, class InputIterator2>
1159    constexpr bool     // constexpr in C++20
1160    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
1161
1162template <class InputIterator1, class InputIterator2, class Compare>
1163    constexpr bool     // constexpr in C++20
1164    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
1165                            InputIterator2 first2, InputIterator2 last2, Compare comp);
1166
1167template <class BidirectionalIterator>
1168    constexpr bool     // constexpr in C++20
1169    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
1170
1171template <class BidirectionalIterator, class Compare>
1172    constexpr bool     // constexpr in C++20
1173    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
1174
1175template <class BidirectionalIterator>
1176    constexpr bool     // constexpr in C++20
1177    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
1178
1179template <class BidirectionalIterator, class Compare>
1180    constexpr bool     // constexpr in C++20
1181    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
1182}  // std
1183
1184*/
1185
1186#include <__assert> // all public C++ headers provide the assertion handler
1187#include <__bits>
1188#include <__config>
1189#include <__debug>
1190#include <cstddef>
1191#include <cstring>
1192#include <memory>
1193#include <type_traits>
1194#include <version>
1195
1196#include <__algorithm/adjacent_find.h>
1197#include <__algorithm/all_of.h>
1198#include <__algorithm/any_of.h>
1199#include <__algorithm/binary_search.h>
1200#include <__algorithm/clamp.h>
1201#include <__algorithm/comp.h>
1202#include <__algorithm/comp_ref_type.h>
1203#include <__algorithm/copy.h>
1204#include <__algorithm/copy_backward.h>
1205#include <__algorithm/copy_if.h>
1206#include <__algorithm/copy_n.h>
1207#include <__algorithm/count.h>
1208#include <__algorithm/count_if.h>
1209#include <__algorithm/equal.h>
1210#include <__algorithm/equal_range.h>
1211#include <__algorithm/fill.h>
1212#include <__algorithm/fill_n.h>
1213#include <__algorithm/find.h>
1214#include <__algorithm/find_end.h>
1215#include <__algorithm/find_first_of.h>
1216#include <__algorithm/find_if.h>
1217#include <__algorithm/find_if_not.h>
1218#include <__algorithm/for_each.h>
1219#include <__algorithm/for_each_n.h>
1220#include <__algorithm/generate.h>
1221#include <__algorithm/generate_n.h>
1222#include <__algorithm/half_positive.h>
1223#include <__algorithm/in_found_result.h>
1224#include <__algorithm/in_fun_result.h>
1225#include <__algorithm/in_in_out_result.h>
1226#include <__algorithm/in_in_result.h>
1227#include <__algorithm/in_out_out_result.h>
1228#include <__algorithm/in_out_result.h>
1229#include <__algorithm/includes.h>
1230#include <__algorithm/inplace_merge.h>
1231#include <__algorithm/is_heap.h>
1232#include <__algorithm/is_heap_until.h>
1233#include <__algorithm/is_partitioned.h>
1234#include <__algorithm/is_permutation.h>
1235#include <__algorithm/is_sorted.h>
1236#include <__algorithm/is_sorted_until.h>
1237#include <__algorithm/iter_swap.h>
1238#include <__algorithm/lexicographical_compare.h>
1239#include <__algorithm/lower_bound.h>
1240#include <__algorithm/make_heap.h>
1241#include <__algorithm/max.h>
1242#include <__algorithm/max_element.h>
1243#include <__algorithm/merge.h>
1244#include <__algorithm/min.h>
1245#include <__algorithm/min_element.h>
1246#include <__algorithm/min_max_result.h>
1247#include <__algorithm/minmax.h>
1248#include <__algorithm/minmax_element.h>
1249#include <__algorithm/mismatch.h>
1250#include <__algorithm/move.h>
1251#include <__algorithm/move_backward.h>
1252#include <__algorithm/next_permutation.h>
1253#include <__algorithm/none_of.h>
1254#include <__algorithm/nth_element.h>
1255#include <__algorithm/partial_sort.h>
1256#include <__algorithm/partial_sort_copy.h>
1257#include <__algorithm/partition.h>
1258#include <__algorithm/partition_copy.h>
1259#include <__algorithm/partition_point.h>
1260#include <__algorithm/pop_heap.h>
1261#include <__algorithm/prev_permutation.h>
1262#include <__algorithm/push_heap.h>
1263#include <__algorithm/ranges_adjacent_find.h>
1264#include <__algorithm/ranges_all_of.h>
1265#include <__algorithm/ranges_any_of.h>
1266#include <__algorithm/ranges_binary_search.h>
1267#include <__algorithm/ranges_copy.h>
1268#include <__algorithm/ranges_copy_backward.h>
1269#include <__algorithm/ranges_copy_if.h>
1270#include <__algorithm/ranges_copy_n.h>
1271#include <__algorithm/ranges_count.h>
1272#include <__algorithm/ranges_count_if.h>
1273#include <__algorithm/ranges_equal.h>
1274#include <__algorithm/ranges_fill.h>
1275#include <__algorithm/ranges_fill_n.h>
1276#include <__algorithm/ranges_find.h>
1277#include <__algorithm/ranges_find_first_of.h>
1278#include <__algorithm/ranges_find_if.h>
1279#include <__algorithm/ranges_find_if_not.h>
1280#include <__algorithm/ranges_for_each.h>
1281#include <__algorithm/ranges_for_each_n.h>
1282#include <__algorithm/ranges_is_partitioned.h>
1283#include <__algorithm/ranges_is_sorted.h>
1284#include <__algorithm/ranges_is_sorted_until.h>
1285#include <__algorithm/ranges_lexicographical_compare.h>
1286#include <__algorithm/ranges_lower_bound.h>
1287#include <__algorithm/ranges_max.h>
1288#include <__algorithm/ranges_max_element.h>
1289#include <__algorithm/ranges_merge.h>
1290#include <__algorithm/ranges_min.h>
1291#include <__algorithm/ranges_min_element.h>
1292#include <__algorithm/ranges_minmax.h>
1293#include <__algorithm/ranges_minmax_element.h>
1294#include <__algorithm/ranges_mismatch.h>
1295#include <__algorithm/ranges_move.h>
1296#include <__algorithm/ranges_move_backward.h>
1297#include <__algorithm/ranges_none_of.h>
1298#include <__algorithm/ranges_remove.h>
1299#include <__algorithm/ranges_remove_if.h>
1300#include <__algorithm/ranges_replace.h>
1301#include <__algorithm/ranges_replace_if.h>
1302#include <__algorithm/ranges_reverse.h>
1303#include <__algorithm/ranges_sort.h>
1304#include <__algorithm/ranges_stable_sort.h>
1305#include <__algorithm/ranges_swap_ranges.h>
1306#include <__algorithm/ranges_transform.h>
1307#include <__algorithm/ranges_upper_bound.h>
1308#include <__algorithm/remove.h>
1309#include <__algorithm/remove_copy.h>
1310#include <__algorithm/remove_copy_if.h>
1311#include <__algorithm/remove_if.h>
1312#include <__algorithm/replace.h>
1313#include <__algorithm/replace_copy.h>
1314#include <__algorithm/replace_copy_if.h>
1315#include <__algorithm/replace_if.h>
1316#include <__algorithm/reverse.h>
1317#include <__algorithm/reverse_copy.h>
1318#include <__algorithm/rotate.h>
1319#include <__algorithm/rotate_copy.h>
1320#include <__algorithm/sample.h>
1321#include <__algorithm/search.h>
1322#include <__algorithm/search_n.h>
1323#include <__algorithm/set_difference.h>
1324#include <__algorithm/set_intersection.h>
1325#include <__algorithm/set_symmetric_difference.h>
1326#include <__algorithm/set_union.h>
1327#include <__algorithm/shift_left.h>
1328#include <__algorithm/shift_right.h>
1329#include <__algorithm/shuffle.h>
1330#include <__algorithm/sift_down.h>
1331#include <__algorithm/sort.h>
1332#include <__algorithm/sort_heap.h>
1333#include <__algorithm/stable_partition.h>
1334#include <__algorithm/stable_sort.h>
1335#include <__algorithm/swap_ranges.h>
1336#include <__algorithm/transform.h>
1337#include <__algorithm/unique.h>
1338#include <__algorithm/unique_copy.h>
1339#include <__algorithm/unwrap_iter.h>
1340#include <__algorithm/upper_bound.h>
1341
1342#ifndef _LIBCPP_REMOVE_TRANSITIVE_INCLUDES
1343#  include <chrono>
1344#  include <iterator>
1345#  include <utility>
1346#endif
1347
1348// standard-mandated includes
1349#include <initializer_list>
1350
1351#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1352#  pragma GCC system_header
1353#endif
1354
1355#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
1356#   include <__pstl_algorithm>
1357#endif
1358
1359#endif // _LIBCPP_ALGORITHM
1360