xref: /llvm-project/libcxx/include/algorithm (revision 760d2b462c04537d119d76d3cc37d2cb53774a05)
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<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
291          class Proj = identity>
292    requires sortable<I, Comp, Proj>
293    constexpr I
294      ranges::push_heap(I first, S last, Comp comp = {}, Proj proj = {});                   // since C++20
295
296  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
297    requires sortable<iterator_t<R>, Comp, Proj>
298    constexpr borrowed_iterator_t<R>
299      ranges::push_heap(R&& r, Comp comp = {}, Proj proj = {});                             // since C++20
300
301  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
302          class Proj = identity>
303    requires sortable<I, Comp, Proj>
304    constexpr I
305      ranges::pop_heap(I first, S last, Comp comp = {}, Proj proj = {});                    // since C++20
306
307  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
308    requires sortable<iterator_t<R>, Comp, Proj>
309    constexpr borrowed_iterator_t<R>
310      ranges::pop_heap(R&& r, Comp comp = {}, Proj proj = {});                              // since C++20
311
312  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
313          class Proj = identity>
314    requires sortable<I, Comp, Proj>
315    constexpr I
316      ranges::make_heap(I first, S last, Comp comp = {}, Proj proj = {});                   // since C++20
317
318  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
319    requires sortable<iterator_t<R>, Comp, Proj>
320    constexpr borrowed_iterator_t<R>
321      ranges::make_heap(R&& r, Comp comp = {}, Proj proj = {});                             // since C++20
322
323  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
324          class Proj = identity>
325    requires sortable<I, Comp, Proj>
326    constexpr I
327      ranges::sort_heap(I first, S last, Comp comp = {}, Proj proj = {});                   // since C++20
328
329  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
330    requires sortable<iterator_t<R>, Comp, Proj>
331    constexpr borrowed_iterator_t<R>
332      ranges::sort_heap(R&& r, Comp comp = {}, Proj proj = {});                             // since C++20
333
334  template<random_access_iterator I, sentinel_for<I> S, class Proj = identity,
335            indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
336    constexpr bool is_heap(I first, S last, Comp comp = {}, Proj proj = {});                // Since C++20
337
338  template<random_access_range R, class Proj = identity,
339            indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
340    constexpr bool is_heap(R&& r, Comp comp = {}, Proj proj = {});                          // Since C++20
341
342  template<random_access_iterator I, sentinel_for<I> S, class Proj = identity,
343           indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
344    constexpr I is_heap_until(I first, S last, Comp comp = {}, Proj proj = {});             // Since C++20
345
346  template<random_access_range R, class Proj = identity,
347           indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
348    constexpr borrowed_iterator_t<R>
349      is_heap_until(R&& r, Comp comp = {}, Proj proj = {});                                 // Since C++20
350
351  template<bidirectional_iterator I, sentinel_for<I> S>
352    requires permutable<I>
353    constexpr I ranges::reverse(I first, S last);                                           // since C++20
354
355  template<bidirectional_range R>
356    requires permutable<iterator_t<R>>
357    constexpr borrowed_iterator_t<R> ranges::reverse(R&& r);                                // since C++20
358
359  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
360            class Proj = identity>
361    requires sortable<I, Comp, Proj>
362    constexpr I
363      ranges::sort(I first, S last, Comp comp = {}, Proj proj = {});                        // since C++20
364
365  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
366    requires sortable<iterator_t<R>, Comp, Proj>
367    constexpr borrowed_iterator_t<R>
368      ranges::sort(R&& r, Comp comp = {}, Proj proj = {});                                  // since C++20
369
370  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
371          class Proj = identity>
372    requires sortable<I, Comp, Proj>
373    I ranges::stable_sort(I first, S last, Comp comp = {}, Proj proj = {});                 // since C++20
374
375  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
376    requires sortable<iterator_t<R>, Comp, Proj>
377    borrowed_iterator_t<R>
378      ranges::stable_sort(R&& r, Comp comp = {}, Proj proj = {});                           // since C++20
379
380  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
381           class Proj = identity>
382    requires sortable<I, Comp, Proj>
383    constexpr I
384      ranges::partial_sort(I first, I middle, S last, Comp comp = {}, Proj proj = {});      // since C++20
385
386  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
387    requires sortable<iterator_t<R>, Comp, Proj>
388    constexpr borrowed_iterator_t<R>
389      ranges::partial_sort(R&& r, iterator_t<R> middle, Comp comp = {}, Proj proj = {});    // since C++20
390
391  template<class T, output_iterator<const T&> O, sentinel_for<O> S>
392    constexpr O ranges::fill(O first, S last, const T& value);                              // since C++20
393
394  template<class T, output_range<const T&> R>
395    constexpr borrowed_iterator_t<R> ranges::fill(R&& r, const T& value);                   // since C++20
396
397  template<class T, output_iterator<const T&> O>
398    constexpr O ranges::fill_n(O first, iter_difference_t<O> n, const T& value);            // since C++20
399
400  template<input_or_output_iterator O, sentinel_for<O> S, copy_constructible F>
401    requires invocable<F&> && indirectly_writable<O, invoke_result_t<F&>>
402    constexpr O generate(O first, S last, F gen);                                           // Since C++20
403
404  template<class R, copy_constructible F>
405    requires invocable<F&> && output_range<R, invoke_result_t<F&>>
406    constexpr borrowed_iterator_t<R> generate(R&& r, F gen);                                // Since C++20
407
408  template<input_or_output_iterator O, copy_constructible F>
409    requires invocable<F&> && indirectly_writable<O, invoke_result_t<F&>>
410    constexpr O generate_n(O first, iter_difference_t<O> n, F gen);                         // Since C++20
411
412 template<input_iterator I1, sentinel_for<I1> S1, input_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 bool ranges::equal(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, input_range R2, class Pred = ranges::equal_to,
420          class Proj1 = identity, class Proj2 = identity>
421   requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
422   constexpr bool ranges::equal(R1&& r1, R2&& r2, Pred pred = {},
423                                Proj1 proj1 = {}, Proj2 proj2 = {});                        // since C++20
424
425  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
426           indirect_unary_predicate<projected<I, Proj>> Pred>
427    constexpr bool ranges::all_of(I first, S last, Pred pred, Proj proj = {});      // since C++20
428
429  template<input_range R, class Proj = identity,
430           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
431    constexpr bool ranges::all_of(R&& r, Pred pred, Proj proj = {});                // since C++20
432
433  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
434           indirect_unary_predicate<projected<I, Proj>> Pred>
435    constexpr bool ranges::any_of(I first, S last, Pred pred, Proj proj = {});      // since C++20
436
437  template<input_range R, class Proj = identity,
438           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
439    constexpr bool ranges::any_of(R&& r, Pred pred, Proj proj = {});                // since C++20
440
441  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
442           indirect_unary_predicate<projected<I, Proj>> Pred>
443    constexpr bool ranges::none_of(I first, S last, Pred pred, Proj proj = {});     // since C++20
444
445  template<input_range R, class Proj = identity,
446           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
447    constexpr bool ranges::none_of(R&& r, Pred pred, Proj proj = {});               // since C++20
448
449  template<input_iterator I1, sentinel_for<I1> S1,
450          random_access_iterator I2, sentinel_for<I2> S2,
451          class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
452    requires indirectly_copyable<I1, I2> && sortable<I2, Comp, Proj2> &&
453            indirect_strict_weak_order<Comp, projected<I1, Proj1>, projected<I2, Proj2>>
454    constexpr partial_sort_copy_result<I1, I2>
455      partial_sort_copy(I1 first, S1 last, I2 result_first, S2 result_last,
456                        Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});        // Since C++20
457
458  template<input_range R1, random_access_range R2, class Comp = ranges::less,
459          class Proj1 = identity, class Proj2 = identity>
460    requires indirectly_copyable<iterator_t<R1>, iterator_t<R2>> &&
461            sortable<iterator_t<R2>, Comp, Proj2> &&
462            indirect_strict_weak_order<Comp, projected<iterator_t<R1>, Proj1>,
463                                        projected<iterator_t<R2>, Proj2>>
464    constexpr partial_sort_copy_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
465      partial_sort_copy(R1&& r, R2&& result_r, Comp comp = {},
466                        Proj1 proj1 = {}, Proj2 proj2 = {});                        // Since C++20
467
468  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
469           indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
470    constexpr bool ranges::is_sorted(I first, S last, Comp comp = {}, Proj proj = {});      // since C++20
471
472  template<forward_range R, class Proj = identity,
473           indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
474    constexpr bool ranges::is_sorted(R&& r, Comp comp = {}, Proj proj = {});                // since C++20
475
476  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
477           indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
478    constexpr I ranges::is_sorted_until(I first, S last, Comp comp = {}, Proj proj = {});   // since C++20
479
480  template<forward_range R, class Proj = identity,
481           indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
482    constexpr borrowed_iterator_t<R>
483      ranges::is_sorted_until(R&& r, Comp comp = {}, Proj proj = {});                       // since C++20
484
485  template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
486          class Proj = identity>
487    requires sortable<I, Comp, Proj>
488    constexpr I
489      ranges::nth_element(I first, I nth, S last, Comp comp = {}, Proj proj = {});            // since C++20
490
491  template<random_access_range R, class Comp = ranges::less, class Proj = identity>
492    requires sortable<iterator_t<R>, Comp, Proj>
493    constexpr borrowed_iterator_t<R>
494      ranges::nth_element(R&& r, iterator_t<R> nth, Comp comp = {}, Proj proj = {});          // since C++20
495
496  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
497           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
498    constexpr I upper_bound(I first, S last, const T& value, Comp comp = {}, Proj proj = {}); // since C++20
499
500  template<forward_range R, class T, class Proj = identity,
501           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
502             ranges::less>
503    constexpr borrowed_iterator_t<R>
504      upper_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});                     // since C++20
505
506  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
507           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
508    constexpr I lower_bound(I first, S last, const T& value, Comp comp = {},
509                                    Proj proj = {});                                          // since C++20
510  template<forward_range R, class T, class Proj = identity,
511           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
512             ranges::less>
513    constexpr borrowed_iterator_t<R>
514      lower_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});                     // since C++20
515
516  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
517           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
518    constexpr bool binary_search(I first, S last, const T& value, Comp comp = {},
519                                         Proj proj = {});                                     // since C++20
520
521  template<forward_range R, class T, class Proj = identity,
522           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
523             ranges::less>
524    constexpr bool binary_search(R&& r, const T& value, Comp comp = {},
525                                         Proj proj = {});                                     // since C++20
526
527  template<permutable I, sentinel_for<I> S, class Proj = identity,
528           indirect_unary_predicate<projected<I, Proj>> Pred>
529    constexpr subrange<I>
530      partition(I first, S last, Pred pred, Proj proj = {});                                  // Since C++20
531
532  template<forward_range R, class Proj = identity,
533           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
534    requires permutable<iterator_t<R>>
535    constexpr borrowed_subrange_t<R>
536      partition(R&& r, Pred pred, Proj proj = {});                                            // Since C++20
537
538  template<bidirectional_iterator I, sentinel_for<I> S, class Proj = identity,
539           indirect_unary_predicate<projected<I, Proj>> Pred>
540    requires permutable<I>
541    subrange<I> stable_partition(I first, S last, Pred pred, Proj proj = {});                 // Since C++20
542
543  template<bidirectional_range R, class Proj = identity,
544           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
545    requires permutable<iterator_t<R>>
546    borrowed_subrange_t<R> stable_partition(R&& r, Pred pred, Proj proj = {});                // Since C++20
547
548  template<input_iterator I1, sentinel_for<I1> S1, forward_iterator I2, sentinel_for<I2> S2,
549           class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
550    requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
551    constexpr I1 ranges::find_first_of(I1 first1, S1 last1, I2 first2, S2 last2,
552                                       Pred pred = {},
553                                       Proj1 proj1 = {}, Proj2 proj2 = {});                 // since C++20
554
555  template<input_range R1, forward_range R2,
556           class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
557    requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
558    constexpr borrowed_iterator_t<R1>
559      ranges::find_first_of(R1&& r1, R2&& r2,
560                            Pred pred = {},
561                            Proj1 proj1 = {}, Proj2 proj2 = {});                            // since C++20
562
563  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
564           indirect_binary_predicate<projected<I, Proj>,
565                                     projected<I, Proj>> Pred = ranges::equal_to>
566    constexpr I ranges::adjacent_find(I first, S last, Pred pred = {}, Proj proj = {});     // since C+20
567
568  template<forward_range R, class Proj = identity,
569           indirect_binary_predicate<projected<iterator_t<R>, Proj>,
570                                     projected<iterator_t<R>, Proj>> Pred = ranges::equal_to>
571    constexpr borrowed_iterator_t<R> ranges::adjacent_find(R&& r, Pred pred = {}, Proj proj = {});  // since C++20
572
573  template<input_iterator I, sentinel_for<I> S, class T1, class T2, class Proj = identity>
574    requires indirectly_writable<I, const T2&> &&
575             indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T1*>
576    constexpr I
577      ranges::replace(I first, S last, const T1& old_value, const T2& new_value, Proj proj = {});   // since C++20
578
579  template<input_range R, class T1, class T2, class Proj = identity>
580    requires indirectly_writable<iterator_t<R>, const T2&> &&
581             indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T1*>
582    constexpr borrowed_iterator_t<R>
583      ranges::replace(R&& r, const T1& old_value, const T2& new_value, Proj proj = {});             // since C++20
584
585  template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity,
586           indirect_unary_predicate<projected<I, Proj>> Pred>
587    requires indirectly_writable<I, const T&>
588    constexpr I ranges::replace_if(I first, S last, Pred pred, const T& new_value, Proj proj = {}); // since C++20
589
590  template<input_range R, class T, class Proj = identity,
591           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
592    requires indirectly_writable<iterator_t<R>, const T&>
593    constexpr borrowed_iterator_t<R>
594      ranges::replace_if(R&& r, Pred pred, const T& new_value, Proj proj = {});                     // since C++20
595
596  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
597           class Proj1 = identity, class Proj2 = identity,
598           indirect_strict_weak_order<projected<I1, Proj1>,
599                                      projected<I2, Proj2>> Comp = ranges::less>
600    constexpr bool
601      ranges::lexicographical_compare(I1 first1, S1 last1, I2 first2, S2 last2,
602                                      Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});    // since C++20
603
604  template<input_range R1, input_range R2, class Proj1 = identity,
605           class Proj2 = identity,
606           indirect_strict_weak_order<projected<iterator_t<R1>, Proj1>,
607                                      projected<iterator_t<R2>, Proj2>> Comp = ranges::less>
608    constexpr bool
609      ranges::lexicographical_compare(R1&& r1, R2&& r2, Comp comp = {},
610                                      Proj1 proj1 = {}, Proj2 proj2 = {});                    // since C++20
611
612  template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2>
613    requires indirectly_movable<I1, I2>
614    constexpr ranges::move_backward_result<I1, I2>
615      ranges::move_backward(I1 first, S1 last, I2 result);                                          // since C++20
616
617  template<bidirectional_range R, bidirectional_iterator I>
618    requires indirectly_movable<iterator_t<R>, I>
619    constexpr ranges::move_backward_result<borrowed_iterator_t<R>, I>
620      ranges::move_backward(R&& r, I result);                                                       // since C++20
621
622  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O>
623    requires indirectly_movable<I, O>
624    constexpr ranges::move_result<I, O>
625      ranges::move(I first, S last, O result);                                                      // since C++20
626
627  template<input_range R, weakly_incrementable O>
628    requires indirectly_movable<iterator_t<R>, O>
629    constexpr ranges::move_result<borrowed_iterator_t<R>, O>
630      ranges::move(R&& r, O result);                                                                // since C++20
631
632  template<class I, class O1, class O2>
633      using partition_copy_result = in_out_out_result<I, O1, O2>;                                   // since C++20
634
635  template<input_iterator I, sentinel_for<I> S,
636          weakly_incrementable O1, weakly_incrementable O2,
637          class Proj = identity, indirect_unary_predicate<projected<I, Proj>> Pred>
638    requires indirectly_copyable<I, O1> && indirectly_copyable<I, O2>
639    constexpr partition_copy_result<I, O1, O2>
640      partition_copy(I first, S last, O1 out_true, O2 out_false, Pred pred,
641                    Proj proj = {});                                                                // Since C++20
642
643  template<input_range R, weakly_incrementable O1, weakly_incrementable O2,
644          class Proj = identity,
645          indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
646    requires indirectly_copyable<iterator_t<R>, O1> &&
647            indirectly_copyable<iterator_t<R>, O2>
648    constexpr partition_copy_result<borrowed_iterator_t<R>, O1, O2>
649      partition_copy(R&& r, O1 out_true, O2 out_false, Pred pred, Proj proj = {});                  // Since C++20
650
651  template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
652           indirect_unary_predicate<projected<I, Proj>> Pred>
653    constexpr I partition_point(I first, S last, Pred pred, Proj proj = {});                        // Since C++20
654
655  template<forward_range R, class Proj = identity,
656           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
657    constexpr borrowed_iterator_t<R>
658      partition_point(R&& r, Pred pred, Proj proj = {});                                            // Since C++20
659
660  template<class I1, class I2, class O>
661    using merge_result = in_in_out_result<I1, I2, O>;                                               // since C++20
662
663  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
664           weakly_incrementable O, class Comp = ranges::less, class Proj1 = identity,
665           class Proj2 = identity>
666    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
667    constexpr merge_result<I1, I2, O>
668      merge(I1 first1, S1 last1, I2 first2, S2 last2, O result,
669            Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                                    // since C++20
670
671  template<input_range R1, input_range R2, weakly_incrementable O, class Comp = ranges::less,
672           class Proj1 = identity, class Proj2 = identity>
673    requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
674    constexpr merge_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
675      merge(R1&& r1, R2&& r2, O result,
676            Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                                    // since C++20
677
678  template<permutable I, sentinel_for<I> S, class T, class Proj = identity>
679    requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
680    constexpr subrange<I> ranges::remove(I first, S last, const T& value, Proj proj = {});          // since C++20
681
682  template<forward_range R, class T, class Proj = identity>
683    requires permutable<iterator_t<R>> &&
684             indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
685    constexpr borrowed_subrange_t<R>
686      ranges::remove(R&& r, const T& value, Proj proj = {});                                        // since C++20
687
688  template<permutable I, sentinel_for<I> S, class Proj = identity,
689           indirect_unary_predicate<projected<I, Proj>> Pred>
690    constexpr subrange<I> ranges::remove_if(I first, S last, Pred pred, Proj proj = {});            // since C++20
691
692  template<forward_range R, class Proj = identity,
693           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
694    requires permutable<iterator_t<R>>
695    constexpr borrowed_subrange_t<R>
696      ranges::remove_if(R&& r, Pred pred, Proj proj = {});                                          // since C++20
697
698  template<class I, class O>
699    using set_difference_result = in_out_result<I, O>;                                              // since C++20
700
701  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
702           weakly_incrementable O, class Comp = ranges::less,
703           class Proj1 = identity, class Proj2 = identity>
704    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
705    constexpr set_difference_result<I1, O>
706      set_difference(I1 first1, S1 last1, I2 first2, S2 last2, O result,
707                     Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                           // since C++20
708
709  template<input_range R1, input_range R2, weakly_incrementable O,
710           class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
711    requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
712    constexpr set_difference_result<borrowed_iterator_t<R1>, O>
713      set_difference(R1&& r1, R2&& r2, O result,
714                     Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                           // since C++20
715
716  template<class I1, class I2, class O>
717    using set_intersection_result = in_in_out_result<I1, I2, O>;                                    // since C++20
718
719  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
720           weakly_incrementable O, class Comp = ranges::less,
721           class Proj1 = identity, class Proj2 = identity>
722    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
723    constexpr set_intersection_result<I1, I2, O>
724      set_intersection(I1 first1, S1 last1, I2 first2, S2 last2, O result,
725                       Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                         // since C++20
726
727  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
728           weakly_incrementable O, class Comp = ranges::less,
729           class Proj1 = identity, class Proj2 = identity>
730    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
731    constexpr set_intersection_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
732      set_intersection(R1&& r1, R2&& r2, O result,
733                       Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});                         // since C++20
734
735  template <class _InIter, class _OutIter>
736  using reverse_copy_result = in_out_result<_InIter, _OutIter>;                                     // since C++20
737
738  template<bidirectional_iterator I, sentinel_for<I> S, weakly_incrementable O>
739    requires indirectly_copyable<I, O>
740    constexpr ranges::reverse_copy_result<I, O>
741      ranges::reverse_copy(I first, S last, O result);                                              // since C++20
742
743  template<bidirectional_range R, weakly_incrementable O>
744    requires indirectly_copyable<iterator_t<R>, O>
745    constexpr ranges::reverse_copy_result<borrowed_iterator_t<R>, O>
746      ranges::reverse_copy(R&& r, O result);                                                        // since C++20
747
748  template <class _InIter, class _OutIter>
749  using rotate_copy_result = in_out_result<_InIter, _OutIter>;                                      // since C++20
750
751  template<forward_iterator I, sentinel_for<I> S, weakly_incrementable O>
752    requires indirectly_copyable<I, O>
753    constexpr ranges::rotate_copy_result<I, O>
754      ranges::rotate_copy(I first, I middle, S last, O result);                                     // since C++20
755
756  template<forward_range R, weakly_incrementable O>
757    requires indirectly_copyable<iterator_t<R>, O>
758    constexpr ranges::rotate_copy_result<borrowed_iterator_t<R>, O>
759      ranges::rotate_copy(R&& r, iterator_t<R> middle, O result);                                   // since C++20
760
761  template<random_access_iterator I, sentinel_for<I> S, class Gen>
762    requires permutable<I> &&
763            uniform_random_bit_generator<remove_reference_t<Gen>>
764    I shuffle(I first, S last, Gen&& g);                                                           // Since C++20
765
766  template<random_access_range R, class Gen>
767    requires permutable<iterator_t<R>> &&
768            uniform_random_bit_generator<remove_reference_t<Gen>>
769    borrowed_iterator_t<R> shuffle(R&& r, Gen&& g);                                                // Since C++20
770
771  template<forward_iterator I1, sentinel_for<I1> S1, forward_iterator I2,
772           sentinel_for<I2> S2, class Pred = ranges::equal_to,
773           class Proj1 = identity, class Proj2 = identity>
774    requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
775    constexpr subrange<I1>
776      ranges::search(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {},
777                     Proj1 proj1 = {}, Proj2 proj2 = {});                                           // since C++20
778
779  template<forward_range R1, forward_range R2, class Pred = ranges::equal_to,
780           class Proj1 = identity, class Proj2 = identity>
781    requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
782    constexpr borrowed_subrange_t<R1>
783      ranges::search(R1&& r1, R2&& r2, Pred pred = {},
784                     Proj1 proj1 = {}, Proj2 proj2 = {});                                           // since C++20
785
786  template<forward_iterator I, sentinel_for<I> S, class T,
787           class Pred = ranges::equal_to, class Proj = identity>
788    requires indirectly_comparable<I, const T*, Pred, Proj>
789    constexpr subrange<I>
790      ranges::search_n(I first, S last, iter_difference_t<I> count,
791                       const T& value, Pred pred = {}, Proj proj = {});                             // since C++20
792
793  template<forward_range R, class T, class Pred = ranges::equal_to,
794           class Proj = identity>
795    requires indirectly_comparable<iterator_t<R>, const T*, Pred, Proj>
796    constexpr borrowed_subrange_t<R>
797      ranges::search_n(R&& r, range_difference_t<R> count,
798                       const T& value, Pred pred = {}, Proj proj = {});                             // since C++20
799
800  template<forward_iterator I1, sentinel_for<I1> S1, forward_iterator I2, sentinel_for<I2> S2,
801           class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
802    requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
803    constexpr subrange<I1>
804      ranges::find_end(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {},
805                       Proj1 proj1 = {}, Proj2 proj2 = {});                                         // since C++20
806
807  template<forward_range R1, forward_range R2,
808           class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
809    requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
810    constexpr borrowed_subrange_t<R1>
811      ranges::find_end(R1&& r1, R2&& r2, Pred pred = {},
812                       Proj1 proj1 = {}, Proj2 proj2 = {});                                         // since C++20
813
814  template<class I1, class I2, class O>
815    using set_symmetric_difference_result = in_in_out_result<I1, I2, O>;                            // since C++20
816
817  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
818           weakly_incrementable O, class Comp = ranges::less,
819           class Proj1 = identity, class Proj2 = identity>
820    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
821    constexpr set_symmetric_difference_result<I1, I2, O>
822      set_symmetric_difference(I1 first1, S1 last1, I2 first2, S2 last2, O result,
823                               Comp comp = {}, Proj1 proj1 = {},
824                               Proj2 proj2 = {});                                                   // since C++20
825
826  template<input_range R1, input_range R2, weakly_incrementable O,
827           class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
828    requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
829    constexpr set_symmetric_difference_result<borrowed_iterator_t<R1>,
830                                                      borrowed_iterator_t<R2>, O>
831      set_symmetric_difference(R1&& r1, R2&& r2, O result, Comp comp = {},
832                               Proj1 proj1 = {}, Proj2 proj2 = {});                                 // since C++20
833
834  template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
835           indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
836    constexpr subrange<I>
837      equal_range(I first, S last, const T& value, Comp comp = {}, Proj proj = {});                 // since C++20
838
839  template<forward_range R, class T, class Proj = identity,
840           indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
841             ranges::less>
842    constexpr borrowed_subrange_t<R>
843      equal_range(R&& r, const T& value, Comp comp = {}, Proj proj = {});                           // since C++20
844
845  template<class I1, class I2, class O>
846    using set_union_result = in_in_out_result<I1, I2, O>;                                           // since C++20
847
848  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
849           weakly_incrementable O, class Comp = ranges::less,
850           class Proj1 = identity, class Proj2 = identity>
851    requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
852    constexpr set_union_result<I1, I2, O>
853      set_union(I1 first1, S1 last1, I2 first2, S2 last2, O result, Comp comp = {},
854                Proj1 proj1 = {}, Proj2 proj2 = {});                                                // since C++20
855
856  template<input_range R1, input_range R2, weakly_incrementable O,
857           class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
858    requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
859    constexpr set_union_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
860      set_union(R1&& r1, R2&& r2, O result, Comp comp = {},
861                Proj1 proj1 = {}, Proj2 proj2 = {});                                                // since C++20
862
863  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
864           class Proj1 = identity, class Proj2 = identity,
865           indirect_strict_weak_order<projected<I1, Proj1>, projected<I2, Proj2>> Comp =
866             ranges::less>
867    constexpr bool includes(I1 first1, S1 last1, I2 first2, S2 last2, Comp comp = {},
868                            Proj1 proj1 = {}, Proj2 proj2 = {});                                   // Since C++20
869
870  template<input_range R1, input_range R2, class Proj1 = identity,
871           class Proj2 = identity,
872           indirect_strict_weak_order<projected<iterator_t<R1>, Proj1>,
873                                      projected<iterator_t<R2>, Proj2>> Comp = ranges::less>
874    constexpr bool includes(R1&& r1, R2&& r2, Comp comp = {},
875                            Proj1 proj1 = {}, Proj2 proj2 = {});                                   // Since C++20
876
877  template<bidirectional_iterator I, sentinel_for<I> S, class Comp = ranges::less,
878           class Proj = identity>
879    requires sortable<I, Comp, Proj>
880    I inplace_merge(I first, I middle, S last, Comp comp = {}, Proj proj = {});                    // Since C++20
881
882  template<bidirectional_range R, class Comp = ranges::less, class Proj = identity>
883    requires sortable<iterator_t<R>, Comp, Proj>
884    borrowed_iterator_t<R>
885      inplace_merge(R&& r, iterator_t<R> middle, Comp comp = {},
886                    Proj proj = {});                                                               // Since C++20
887
888  template<permutable I, sentinel_for<I> S, class Proj = identity,
889           indirect_equivalence_relation<projected<I, Proj>> C = ranges::equal_to>
890    constexpr subrange<I> unique(I first, S last, C comp = {}, Proj proj = {});                    // Since C++20
891
892  template<forward_range R, class Proj = identity,
893           indirect_equivalence_relation<projected<iterator_t<R>, Proj>> C = ranges::equal_to>
894    requires permutable<iterator_t<R>>
895    constexpr borrowed_subrange_t<R>
896      unique(R&& r, C comp = {}, Proj proj = {});                                                  // Since C++20
897
898  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O, class Proj = identity,
899           indirect_equivalence_relation<projected<I, Proj>> C = ranges::equal_to>
900    requires indirectly_copyable<I, O> &&
901             (forward_iterator<I> ||
902              (input_iterator<O> && same_as<iter_value_t<I>, iter_value_t<O>>) ||
903              indirectly_copyable_storable<I, O>)
904    constexpr unique_copy_result<I, O>
905      unique_copy(I first, S last, O result, C comp = {}, Proj proj = {});                         // Since C++20
906
907  template<input_range R, weakly_incrementable O, class Proj = identity,
908           indirect_equivalence_relation<projected<iterator_t<R>, Proj>> C = ranges::equal_to>
909    requires indirectly_copyable<iterator_t<R>, O> &&
910             (forward_iterator<iterator_t<R>> ||
911              (input_iterator<O> && same_as<range_value_t<R>, iter_value_t<O>>) ||
912              indirectly_copyable_storable<iterator_t<R>, O>)
913    constexpr unique_copy_result<borrowed_iterator_t<R>, O>
914      unique_copy(R&& r, O result, C comp = {}, Proj proj = {});                                   // Since C++20
915
916  template<class I, class O>
917      using remove_copy_result = in_out_result<I, O>;                                              // Since C++20
918
919  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O, class T,
920           class Proj = identity>
921             indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
922    constexpr remove_copy_result<I, O>
923      remove_copy(I first, S last, O result, const T& value, Proj proj = {});                      // Since C++20
924
925  template<input_range R, weakly_incrementable O, class T, class Proj = identity>
926    requires indirectly_copyable<iterator_t<R>, O> &&
927             indirect_binary_predicate<ranges::equal_to,
928                                       projected<iterator_t<R>, Proj>, const T*>
929    constexpr remove_copy_result<borrowed_iterator_t<R>, O>
930      remove_copy(R&& r, O result, const T& value, Proj proj = {});                                // Since C++20
931
932  template<class I, class O>
933      using remove_copy_if_result = in_out_result<I, O>;                                           // Since C++20
934
935  template<input_iterator I, sentinel_for<I> S, weakly_incrementable O,
936           class Proj = identity, indirect_unary_predicate<projected<I, Proj>> Pred>
937    requires indirectly_copyable<I, O>
938    constexpr remove_copy_if_result<I, O>
939      remove_copy_if(I first, S last, O result, Pred pred, Proj proj = {});                        // Since C++20
940
941  template<input_range R, weakly_incrementable O, class Proj = identity,
942           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
943    requires indirectly_copyable<iterator_t<R>, O>
944    constexpr remove_copy_if_result<borrowed_iterator_t<R>, O>
945      remove_copy_if(R&& r, O result, Pred pred, Proj proj = {});                                  // Since C++20
946
947}
948
949    constexpr bool     // constexpr in C++20
950    all_of(InputIterator first, InputIterator last, Predicate pred);
951
952template <class InputIterator, class Predicate>
953    constexpr bool     // constexpr in C++20
954    any_of(InputIterator first, InputIterator last, Predicate pred);
955
956template <class InputIterator, class Predicate>
957    constexpr bool     // constexpr in C++20
958    none_of(InputIterator first, InputIterator last, Predicate pred);
959
960template <class InputIterator, class Function>
961    constexpr Function          // constexpr in C++20
962    for_each(InputIterator first, InputIterator last, Function f);
963
964template<class InputIterator, class Size, class Function>
965    constexpr InputIterator     // constexpr in C++20
966    for_each_n(InputIterator first, Size n, Function f); // C++17
967
968template <class InputIterator, class T>
969    constexpr InputIterator     // constexpr in C++20
970    find(InputIterator first, InputIterator last, const T& value);
971
972template <class InputIterator, class Predicate>
973    constexpr InputIterator     // constexpr in C++20
974    find_if(InputIterator first, InputIterator last, Predicate pred);
975
976template<class InputIterator, class Predicate>
977    constexpr InputIterator     // constexpr in C++20
978    find_if_not(InputIterator first, InputIterator last, Predicate pred);
979
980template <class ForwardIterator1, class ForwardIterator2>
981    constexpr ForwardIterator1  // constexpr in C++20
982    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
983             ForwardIterator2 first2, ForwardIterator2 last2);
984
985template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
986    constexpr ForwardIterator1  // constexpr in C++20
987    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
988             ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
989
990template <class ForwardIterator1, class ForwardIterator2>
991    constexpr ForwardIterator1  // constexpr in C++20
992    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
993                  ForwardIterator2 first2, ForwardIterator2 last2);
994
995template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
996    constexpr ForwardIterator1  // constexpr in C++20
997    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
998                  ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
999
1000template <class ForwardIterator>
1001    constexpr ForwardIterator   // constexpr in C++20
1002    adjacent_find(ForwardIterator first, ForwardIterator last);
1003
1004template <class ForwardIterator, class BinaryPredicate>
1005    constexpr ForwardIterator   // constexpr in C++20
1006    adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
1007
1008template <class InputIterator, class T>
1009    constexpr typename iterator_traits<InputIterator>::difference_type  // constexpr in C++20
1010    count(InputIterator first, InputIterator last, const T& value);
1011
1012template <class InputIterator, class Predicate>
1013    constexpr typename iterator_traits<InputIterator>::difference_type // constexpr in C++20
1014    count_if(InputIterator first, InputIterator last, Predicate pred);
1015
1016template <class InputIterator1, class InputIterator2>
1017    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
1018    mismatch(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
1019
1020template <class InputIterator1, class InputIterator2>
1021    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
1022    mismatch(InputIterator1 first1, InputIterator1 last1,
1023             InputIterator2 first2, InputIterator2 last2); // **C++14**
1024
1025template <class InputIterator1, class InputIterator2, class BinaryPredicate>
1026    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
1027    mismatch(InputIterator1 first1, InputIterator1 last1,
1028             InputIterator2 first2, BinaryPredicate pred);
1029
1030template <class InputIterator1, class InputIterator2, class BinaryPredicate>
1031    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
1032    mismatch(InputIterator1 first1, InputIterator1 last1,
1033             InputIterator2 first2, InputIterator2 last2,
1034             BinaryPredicate pred); // **C++14**
1035
1036template <class InputIterator1, class InputIterator2>
1037    constexpr bool      // constexpr in C++20
1038    equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
1039
1040template <class InputIterator1, class InputIterator2>
1041    constexpr bool      // constexpr in C++20
1042    equal(InputIterator1 first1, InputIterator1 last1,
1043          InputIterator2 first2, InputIterator2 last2); // **C++14**
1044
1045template <class InputIterator1, class InputIterator2, class BinaryPredicate>
1046    constexpr bool      // constexpr in C++20
1047    equal(InputIterator1 first1, InputIterator1 last1,
1048          InputIterator2 first2, BinaryPredicate pred);
1049
1050template <class InputIterator1, class InputIterator2, class BinaryPredicate>
1051    constexpr bool      // constexpr in C++20
1052    equal(InputIterator1 first1, InputIterator1 last1,
1053          InputIterator2 first2, InputIterator2 last2,
1054          BinaryPredicate pred); // **C++14**
1055
1056template<class ForwardIterator1, class ForwardIterator2>
1057    constexpr bool      // constexpr in C++20
1058    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1059                   ForwardIterator2 first2);
1060
1061template<class ForwardIterator1, class ForwardIterator2>
1062    constexpr bool      // constexpr in C++20
1063    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1064                   ForwardIterator2 first2, ForwardIterator2 last2); // **C++14**
1065
1066template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
1067    constexpr bool      // constexpr in C++20
1068    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1069                   ForwardIterator2 first2, BinaryPredicate pred);
1070
1071template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
1072    constexpr bool      // constexpr in C++20
1073    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
1074                   ForwardIterator2 first2, ForwardIterator2 last2,
1075                   BinaryPredicate pred);  // **C++14**
1076
1077template <class ForwardIterator1, class ForwardIterator2>
1078    constexpr ForwardIterator1      // constexpr in C++20
1079    search(ForwardIterator1 first1, ForwardIterator1 last1,
1080           ForwardIterator2 first2, ForwardIterator2 last2);
1081
1082template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
1083    constexpr ForwardIterator1      // constexpr in C++20
1084    search(ForwardIterator1 first1, ForwardIterator1 last1,
1085           ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
1086
1087template <class ForwardIterator, class Size, class T>
1088    constexpr ForwardIterator       // constexpr in C++20
1089    search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value);
1090
1091template <class ForwardIterator, class Size, class T, class BinaryPredicate>
1092    constexpr ForwardIterator       // constexpr in C++20
1093    search_n(ForwardIterator first, ForwardIterator last,
1094             Size count, const T& value, BinaryPredicate pred);
1095
1096template <class InputIterator, class OutputIterator>
1097    constexpr OutputIterator      // constexpr in C++20
1098    copy(InputIterator first, InputIterator last, OutputIterator result);
1099
1100template<class InputIterator, class OutputIterator, class Predicate>
1101    constexpr OutputIterator      // constexpr in C++20
1102    copy_if(InputIterator first, InputIterator last,
1103            OutputIterator result, Predicate pred);
1104
1105template<class InputIterator, class Size, class OutputIterator>
1106    constexpr OutputIterator      // constexpr in C++20
1107    copy_n(InputIterator first, Size n, OutputIterator result);
1108
1109template <class BidirectionalIterator1, class BidirectionalIterator2>
1110    constexpr BidirectionalIterator2      // constexpr in C++20
1111    copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
1112                  BidirectionalIterator2 result);
1113
1114// [alg.move], move
1115template<class InputIterator, class OutputIterator>
1116    constexpr OutputIterator move(InputIterator first, InputIterator last,
1117                                OutputIterator result);
1118
1119template<class BidirectionalIterator1, class BidirectionalIterator2>
1120    constexpr BidirectionalIterator2
1121    move_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
1122                  BidirectionalIterator2 result);
1123
1124template <class ForwardIterator1, class ForwardIterator2>
1125    constexpr ForwardIterator2    // constexpr in C++20
1126    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
1127
1128namespace ranges {
1129    template<class I1, class I2>
1130    using swap_ranges_result = in_in_result<I1, I2>;
1131
1132template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2>
1133        requires indirectly_swappable<I1, I2>
1134    constexpr ranges::swap_ranges_result<I1, I2>
1135        swap_ranges(I1 first1, S1 last1, I2 first2, S2 last2);
1136
1137template<input_range R1, input_range R2>
1138        requires indirectly_swappable<iterator_t<R1>, iterator_t<R2>>
1139    constexpr ranges::swap_ranges_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
1140        swap_ranges(R1&& r1, R2&& r2);
1141}
1142
1143template <class ForwardIterator1, class ForwardIterator2>
1144    constexpr void                // constexpr in C++20
1145    iter_swap(ForwardIterator1 a, ForwardIterator2 b);
1146
1147template <class InputIterator, class OutputIterator, class UnaryOperation>
1148    constexpr OutputIterator      // constexpr in C++20
1149    transform(InputIterator first, InputIterator last, OutputIterator result, UnaryOperation op);
1150
1151template <class InputIterator1, class InputIterator2, class OutputIterator, class BinaryOperation>
1152    constexpr OutputIterator      // constexpr in C++20
1153    transform(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
1154              OutputIterator result, BinaryOperation binary_op);
1155
1156template <class ForwardIterator, class T>
1157    constexpr void      // constexpr in C++20
1158    replace(ForwardIterator first, ForwardIterator last, const T& old_value, const T& new_value);
1159
1160template <class ForwardIterator, class Predicate, class T>
1161    constexpr void      // constexpr in C++20
1162    replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, const T& new_value);
1163
1164template <class InputIterator, class OutputIterator, class T>
1165    constexpr OutputIterator      // constexpr in C++20
1166    replace_copy(InputIterator first, InputIterator last, OutputIterator result,
1167                 const T& old_value, const T& new_value);
1168
1169template <class InputIterator, class OutputIterator, class Predicate, class T>
1170    constexpr OutputIterator      // constexpr in C++20
1171    replace_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred, const T& new_value);
1172
1173template <class ForwardIterator, class T>
1174    constexpr void      // constexpr in C++20
1175    fill(ForwardIterator first, ForwardIterator last, const T& value);
1176
1177template <class OutputIterator, class Size, class T>
1178    constexpr OutputIterator      // constexpr in C++20
1179    fill_n(OutputIterator first, Size n, const T& value);
1180
1181template <class ForwardIterator, class Generator>
1182    constexpr void      // constexpr in C++20
1183    generate(ForwardIterator first, ForwardIterator last, Generator gen);
1184
1185template <class OutputIterator, class Size, class Generator>
1186    constexpr OutputIterator      // constexpr in C++20
1187    generate_n(OutputIterator first, Size n, Generator gen);
1188
1189template <class ForwardIterator, class T>
1190    constexpr ForwardIterator     // constexpr in C++20
1191    remove(ForwardIterator first, ForwardIterator last, const T& value);
1192
1193template <class ForwardIterator, class Predicate>
1194    constexpr ForwardIterator     // constexpr in C++20
1195    remove_if(ForwardIterator first, ForwardIterator last, Predicate pred);
1196
1197template <class InputIterator, class OutputIterator, class T>
1198    constexpr OutputIterator     // constexpr in C++20
1199    remove_copy(InputIterator first, InputIterator last, OutputIterator result, const T& value);
1200
1201template <class InputIterator, class OutputIterator, class Predicate>
1202    constexpr OutputIterator     // constexpr in C++20
1203    remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred);
1204
1205template <class ForwardIterator>
1206    constexpr ForwardIterator    // constexpr in C++20
1207    unique(ForwardIterator first, ForwardIterator last);
1208
1209template <class ForwardIterator, class BinaryPredicate>
1210    constexpr ForwardIterator    // constexpr in C++20
1211    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
1212
1213template <class InputIterator, class OutputIterator>
1214    constexpr OutputIterator     // constexpr in C++20
1215    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
1216
1217template <class InputIterator, class OutputIterator, class BinaryPredicate>
1218    constexpr OutputIterator     // constexpr in C++20
1219    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
1220
1221template <class BidirectionalIterator>
1222    constexpr void               // constexpr in C++20
1223    reverse(BidirectionalIterator first, BidirectionalIterator last);
1224
1225template <class BidirectionalIterator, class OutputIterator>
1226    constexpr OutputIterator       // constexpr in C++20
1227    reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result);
1228
1229template <class ForwardIterator>
1230    constexpr ForwardIterator      // constexpr in C++20
1231    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
1232
1233template <class ForwardIterator, class OutputIterator>
1234    constexpr OutputIterator       // constexpr in C++20
1235    rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result);
1236
1237template <class RandomAccessIterator>
1238    void
1239    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14, removed in C++17
1240
1241template <class RandomAccessIterator, class RandomNumberGenerator>
1242    void
1243    random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
1244                   RandomNumberGenerator& rand);  // deprecated in C++14, removed in C++17
1245
1246template<class PopulationIterator, class SampleIterator,
1247         class Distance, class UniformRandomBitGenerator>
1248    SampleIterator sample(PopulationIterator first, PopulationIterator last,
1249                          SampleIterator out, Distance n,
1250                          UniformRandomBitGenerator&& g); // C++17
1251
1252template<class RandomAccessIterator, class UniformRandomNumberGenerator>
1253    void shuffle(RandomAccessIterator first, RandomAccessIterator last,
1254                 UniformRandomNumberGenerator&& g);
1255
1256template<class ForwardIterator>
1257  constexpr ForwardIterator
1258    shift_left(ForwardIterator first, ForwardIterator last,
1259               typename iterator_traits<ForwardIterator>::difference_type n); // C++20
1260
1261template<class ForwardIterator>
1262  constexpr ForwardIterator
1263    shift_right(ForwardIterator first, ForwardIterator last,
1264                typename iterator_traits<ForwardIterator>::difference_type n); // C++20
1265
1266template <class InputIterator, class Predicate>
1267    constexpr bool  // constexpr in C++20
1268    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
1269
1270template <class ForwardIterator, class Predicate>
1271    constexpr ForwardIterator  // constexpr in C++20
1272    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
1273
1274template <class InputIterator, class OutputIterator1,
1275          class OutputIterator2, class Predicate>
1276    constexpr pair<OutputIterator1, OutputIterator2>   // constexpr in C++20
1277    partition_copy(InputIterator first, InputIterator last,
1278                   OutputIterator1 out_true, OutputIterator2 out_false,
1279                   Predicate pred);
1280
1281template <class ForwardIterator, class Predicate>
1282    ForwardIterator
1283    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
1284
1285template<class ForwardIterator, class Predicate>
1286    constexpr ForwardIterator  // constexpr in C++20
1287    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
1288
1289template <class ForwardIterator>
1290    constexpr bool  // constexpr in C++20
1291    is_sorted(ForwardIterator first, ForwardIterator last);
1292
1293template <class ForwardIterator, class Compare>
1294    constexpr bool  // constexpr in C++20
1295    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
1296
1297template<class ForwardIterator>
1298    constexpr ForwardIterator    // constexpr in C++20
1299    is_sorted_until(ForwardIterator first, ForwardIterator last);
1300
1301template <class ForwardIterator, class Compare>
1302    constexpr ForwardIterator    // constexpr in C++20
1303    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
1304
1305template <class RandomAccessIterator>
1306    constexpr void               // constexpr in C++20
1307    sort(RandomAccessIterator first, RandomAccessIterator last);
1308
1309template <class RandomAccessIterator, class Compare>
1310    constexpr void               // constexpr in C++20
1311    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1312
1313template <class RandomAccessIterator>
1314    void
1315    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
1316
1317template <class RandomAccessIterator, class Compare>
1318    void
1319    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1320
1321template <class RandomAccessIterator>
1322    constexpr void                    // constexpr in C++20
1323    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
1324
1325template <class RandomAccessIterator, class Compare>
1326    constexpr void                    // constexpr in C++20
1327    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
1328
1329template <class InputIterator, class RandomAccessIterator>
1330    constexpr RandomAccessIterator    // constexpr in C++20
1331    partial_sort_copy(InputIterator first, InputIterator last,
1332                      RandomAccessIterator result_first, RandomAccessIterator result_last);
1333
1334template <class InputIterator, class RandomAccessIterator, class Compare>
1335    constexpr RandomAccessIterator    // constexpr in C++20
1336    partial_sort_copy(InputIterator first, InputIterator last,
1337                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
1338
1339template <class RandomAccessIterator>
1340    constexpr void                    // constexpr in C++20
1341    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
1342
1343template <class RandomAccessIterator, class Compare>
1344    constexpr void                    // constexpr in C++20
1345    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
1346
1347template <class ForwardIterator, class T>
1348    constexpr ForwardIterator                         // constexpr in C++20
1349    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
1350
1351template <class ForwardIterator, class T, class Compare>
1352    constexpr ForwardIterator                         // constexpr in C++20
1353    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
1354
1355template <class ForwardIterator, class T>
1356    constexpr ForwardIterator                         // constexpr in C++20
1357    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
1358
1359template <class ForwardIterator, class T, class Compare>
1360    constexpr ForwardIterator                         // constexpr in C++20
1361    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
1362
1363template <class ForwardIterator, class T>
1364    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
1365    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
1366
1367template <class ForwardIterator, class T, class Compare>
1368    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
1369    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
1370
1371template <class ForwardIterator, class T>
1372    constexpr bool                                    // constexpr in C++20
1373    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
1374
1375template <class ForwardIterator, class T, class Compare>
1376    constexpr bool                                    // constexpr in C++20
1377    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
1378
1379template <class InputIterator1, class InputIterator2, class OutputIterator>
1380    constexpr OutputIterator                          // constexpr in C++20
1381    merge(InputIterator1 first1, InputIterator1 last1,
1382          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1383
1384template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1385    constexpr OutputIterator                          // constexpr in C++20
1386    merge(InputIterator1 first1, InputIterator1 last1,
1387          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1388
1389template <class BidirectionalIterator>
1390    void
1391    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
1392
1393template <class BidirectionalIterator, class Compare>
1394    void
1395    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
1396
1397template <class InputIterator1, class InputIterator2>
1398    constexpr bool                                    // constexpr in C++20
1399    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
1400
1401template <class InputIterator1, class InputIterator2, class Compare>
1402    constexpr bool                                    // constexpr in C++20
1403    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
1404
1405template <class InputIterator1, class InputIterator2, class OutputIterator>
1406    constexpr OutputIterator                          // constexpr in C++20
1407    set_union(InputIterator1 first1, InputIterator1 last1,
1408              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1409
1410template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1411    constexpr OutputIterator                          // constexpr in C++20
1412    set_union(InputIterator1 first1, InputIterator1 last1,
1413              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1414
1415template <class InputIterator1, class InputIterator2, class OutputIterator>
1416    constexpr OutputIterator                         // constexpr in C++20
1417    set_intersection(InputIterator1 first1, InputIterator1 last1,
1418                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1419
1420template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1421    constexpr OutputIterator                         // constexpr in C++20
1422    set_intersection(InputIterator1 first1, InputIterator1 last1,
1423                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1424
1425template <class InputIterator1, class InputIterator2, class OutputIterator>
1426    constexpr OutputIterator                         // constexpr in C++20
1427    set_difference(InputIterator1 first1, InputIterator1 last1,
1428                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1429
1430template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1431    constexpr OutputIterator                         // constexpr in C++20
1432    set_difference(InputIterator1 first1, InputIterator1 last1,
1433                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1434
1435template <class InputIterator1, class InputIterator2, class OutputIterator>
1436    constexpr OutputIterator                         // constexpr in C++20
1437    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
1438                             InputIterator2 first2, InputIterator2 last2, OutputIterator result);
1439
1440template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
1441    constexpr OutputIterator                         // constexpr in C++20
1442    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
1443                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
1444
1445template <class RandomAccessIterator>
1446    constexpr void                                   // constexpr in C++20
1447    push_heap(RandomAccessIterator first, RandomAccessIterator last);
1448
1449template <class RandomAccessIterator, class Compare>
1450    constexpr void                                   // constexpr in C++20
1451    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1452
1453template <class RandomAccessIterator>
1454    constexpr void                                   // constexpr in C++20
1455    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
1456
1457template <class RandomAccessIterator, class Compare>
1458    constexpr void                                   // constexpr in C++20
1459    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1460
1461template <class RandomAccessIterator>
1462    constexpr void                                   // constexpr in C++20
1463    make_heap(RandomAccessIterator first, RandomAccessIterator last);
1464
1465template <class RandomAccessIterator, class Compare>
1466    constexpr void                                   // constexpr in C++20
1467    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1468
1469template <class RandomAccessIterator>
1470    constexpr void                                   // constexpr in C++20
1471    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
1472
1473template <class RandomAccessIterator, class Compare>
1474    constexpr void                                   // constexpr in C++20
1475    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
1476
1477template <class RandomAccessIterator>
1478    constexpr bool   // constexpr in C++20
1479    is_heap(RandomAccessIterator first, RandomAccessiterator last);
1480
1481template <class RandomAccessIterator, class Compare>
1482    constexpr bool   // constexpr in C++20
1483    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
1484
1485template <class RandomAccessIterator>
1486    constexpr RandomAccessIterator   // constexpr in C++20
1487    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
1488
1489template <class RandomAccessIterator, class Compare>
1490    constexpr RandomAccessIterator   // constexpr in C++20
1491    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
1492
1493template <class ForwardIterator>
1494    constexpr ForwardIterator        // constexpr in C++14
1495    min_element(ForwardIterator first, ForwardIterator last);
1496
1497template <class ForwardIterator, class Compare>
1498    constexpr ForwardIterator        // constexpr in C++14
1499    min_element(ForwardIterator first, ForwardIterator last, Compare comp);
1500
1501template <class T>
1502    constexpr const T&               // constexpr in C++14
1503    min(const T& a, const T& b);
1504
1505template <class T, class Compare>
1506    constexpr const T&               // constexpr in C++14
1507    min(const T& a, const T& b, Compare comp);
1508
1509template<class T>
1510    constexpr T                      // constexpr in C++14
1511    min(initializer_list<T> t);
1512
1513template<class T, class Compare>
1514    constexpr T                      // constexpr in C++14
1515    min(initializer_list<T> t, Compare comp);
1516
1517template<class T>
1518    constexpr const T& clamp(const T& v, const T& lo, const T& hi);               // C++17
1519
1520template<class T, class Compare>
1521    constexpr const T& clamp(const T& v, const T& lo, const T& hi, Compare comp); // C++17
1522
1523template <class ForwardIterator>
1524    constexpr ForwardIterator        // constexpr in C++14
1525    max_element(ForwardIterator first, ForwardIterator last);
1526
1527template <class ForwardIterator, class Compare>
1528    constexpr ForwardIterator        // constexpr in C++14
1529    max_element(ForwardIterator first, ForwardIterator last, Compare comp);
1530
1531template <class T>
1532    constexpr const T&               // constexpr in C++14
1533    max(const T& a, const T& b);
1534
1535template <class T, class Compare>
1536    constexpr const T&               // constexpr in C++14
1537    max(const T& a, const T& b, Compare comp);
1538
1539template<class T>
1540    constexpr T                      // constexpr in C++14
1541    max(initializer_list<T> t);
1542
1543template<class T, class Compare>
1544    constexpr T                      // constexpr in C++14
1545    max(initializer_list<T> t, Compare comp);
1546
1547template<class ForwardIterator>
1548    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++14
1549    minmax_element(ForwardIterator first, ForwardIterator last);
1550
1551template<class ForwardIterator, class Compare>
1552    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++14
1553    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);
1554
1555template<class T>
1556    constexpr pair<const T&, const T&>  // constexpr in C++14
1557    minmax(const T& a, const T& b);
1558
1559template<class T, class Compare>
1560    constexpr pair<const T&, const T&>  // constexpr in C++14
1561    minmax(const T& a, const T& b, Compare comp);
1562
1563template<class T>
1564    constexpr pair<T, T>                // constexpr in C++14
1565    minmax(initializer_list<T> t);
1566
1567template<class T, class Compare>
1568    constexpr pair<T, T>                // constexpr in C++14
1569    minmax(initializer_list<T> t, Compare comp);
1570
1571template <class InputIterator1, class InputIterator2>
1572    constexpr bool     // constexpr in C++20
1573    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
1574
1575template <class InputIterator1, class InputIterator2, class Compare>
1576    constexpr bool     // constexpr in C++20
1577    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
1578                            InputIterator2 first2, InputIterator2 last2, Compare comp);
1579
1580template <class BidirectionalIterator>
1581    constexpr bool     // constexpr in C++20
1582    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
1583
1584template <class BidirectionalIterator, class Compare>
1585    constexpr bool     // constexpr in C++20
1586    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
1587
1588template <class BidirectionalIterator>
1589    constexpr bool     // constexpr in C++20
1590    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
1591
1592template <class BidirectionalIterator, class Compare>
1593    constexpr bool     // constexpr in C++20
1594    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
1595}  // std
1596
1597*/
1598
1599#include <__assert> // all public C++ headers provide the assertion handler
1600#include <__bits>
1601#include <__config>
1602#include <__debug>
1603#include <cstddef>
1604#include <cstring>
1605#include <memory>
1606#include <type_traits>
1607#include <version>
1608
1609#include <__algorithm/adjacent_find.h>
1610#include <__algorithm/all_of.h>
1611#include <__algorithm/any_of.h>
1612#include <__algorithm/binary_search.h>
1613#include <__algorithm/clamp.h>
1614#include <__algorithm/comp.h>
1615#include <__algorithm/comp_ref_type.h>
1616#include <__algorithm/copy.h>
1617#include <__algorithm/copy_backward.h>
1618#include <__algorithm/copy_if.h>
1619#include <__algorithm/copy_n.h>
1620#include <__algorithm/count.h>
1621#include <__algorithm/count_if.h>
1622#include <__algorithm/equal.h>
1623#include <__algorithm/equal_range.h>
1624#include <__algorithm/fill.h>
1625#include <__algorithm/fill_n.h>
1626#include <__algorithm/find.h>
1627#include <__algorithm/find_end.h>
1628#include <__algorithm/find_first_of.h>
1629#include <__algorithm/find_if.h>
1630#include <__algorithm/find_if_not.h>
1631#include <__algorithm/for_each.h>
1632#include <__algorithm/for_each_n.h>
1633#include <__algorithm/generate.h>
1634#include <__algorithm/generate_n.h>
1635#include <__algorithm/half_positive.h>
1636#include <__algorithm/in_found_result.h>
1637#include <__algorithm/in_fun_result.h>
1638#include <__algorithm/in_in_out_result.h>
1639#include <__algorithm/in_in_result.h>
1640#include <__algorithm/in_out_out_result.h>
1641#include <__algorithm/in_out_result.h>
1642#include <__algorithm/includes.h>
1643#include <__algorithm/inplace_merge.h>
1644#include <__algorithm/is_heap.h>
1645#include <__algorithm/is_heap_until.h>
1646#include <__algorithm/is_partitioned.h>
1647#include <__algorithm/is_permutation.h>
1648#include <__algorithm/is_sorted.h>
1649#include <__algorithm/is_sorted_until.h>
1650#include <__algorithm/iter_swap.h>
1651#include <__algorithm/lexicographical_compare.h>
1652#include <__algorithm/lower_bound.h>
1653#include <__algorithm/make_heap.h>
1654#include <__algorithm/max.h>
1655#include <__algorithm/max_element.h>
1656#include <__algorithm/merge.h>
1657#include <__algorithm/min.h>
1658#include <__algorithm/min_element.h>
1659#include <__algorithm/min_max_result.h>
1660#include <__algorithm/minmax.h>
1661#include <__algorithm/minmax_element.h>
1662#include <__algorithm/mismatch.h>
1663#include <__algorithm/move.h>
1664#include <__algorithm/move_backward.h>
1665#include <__algorithm/next_permutation.h>
1666#include <__algorithm/none_of.h>
1667#include <__algorithm/nth_element.h>
1668#include <__algorithm/partial_sort.h>
1669#include <__algorithm/partial_sort_copy.h>
1670#include <__algorithm/partition.h>
1671#include <__algorithm/partition_copy.h>
1672#include <__algorithm/partition_point.h>
1673#include <__algorithm/pop_heap.h>
1674#include <__algorithm/prev_permutation.h>
1675#include <__algorithm/push_heap.h>
1676#include <__algorithm/ranges_adjacent_find.h>
1677#include <__algorithm/ranges_all_of.h>
1678#include <__algorithm/ranges_any_of.h>
1679#include <__algorithm/ranges_binary_search.h>
1680#include <__algorithm/ranges_copy.h>
1681#include <__algorithm/ranges_copy_backward.h>
1682#include <__algorithm/ranges_copy_if.h>
1683#include <__algorithm/ranges_copy_n.h>
1684#include <__algorithm/ranges_count.h>
1685#include <__algorithm/ranges_count_if.h>
1686#include <__algorithm/ranges_equal.h>
1687#include <__algorithm/ranges_equal_range.h>
1688#include <__algorithm/ranges_fill.h>
1689#include <__algorithm/ranges_fill_n.h>
1690#include <__algorithm/ranges_find.h>
1691#include <__algorithm/ranges_find_end.h>
1692#include <__algorithm/ranges_find_first_of.h>
1693#include <__algorithm/ranges_find_if.h>
1694#include <__algorithm/ranges_find_if_not.h>
1695#include <__algorithm/ranges_for_each.h>
1696#include <__algorithm/ranges_for_each_n.h>
1697#include <__algorithm/ranges_generate.h>
1698#include <__algorithm/ranges_generate_n.h>
1699#include <__algorithm/ranges_includes.h>
1700#include <__algorithm/ranges_inplace_merge.h>
1701#include <__algorithm/ranges_is_heap.h>
1702#include <__algorithm/ranges_is_heap_until.h>
1703#include <__algorithm/ranges_is_partitioned.h>
1704#include <__algorithm/ranges_is_sorted.h>
1705#include <__algorithm/ranges_is_sorted_until.h>
1706#include <__algorithm/ranges_lexicographical_compare.h>
1707#include <__algorithm/ranges_lower_bound.h>
1708#include <__algorithm/ranges_make_heap.h>
1709#include <__algorithm/ranges_max.h>
1710#include <__algorithm/ranges_max_element.h>
1711#include <__algorithm/ranges_merge.h>
1712#include <__algorithm/ranges_min.h>
1713#include <__algorithm/ranges_min_element.h>
1714#include <__algorithm/ranges_minmax.h>
1715#include <__algorithm/ranges_minmax_element.h>
1716#include <__algorithm/ranges_mismatch.h>
1717#include <__algorithm/ranges_move.h>
1718#include <__algorithm/ranges_move_backward.h>
1719#include <__algorithm/ranges_none_of.h>
1720#include <__algorithm/ranges_nth_element.h>
1721#include <__algorithm/ranges_partial_sort.h>
1722#include <__algorithm/ranges_partial_sort_copy.h>
1723#include <__algorithm/ranges_partition.h>
1724#include <__algorithm/ranges_partition_copy.h>
1725#include <__algorithm/ranges_partition_point.h>
1726#include <__algorithm/ranges_pop_heap.h>
1727#include <__algorithm/ranges_push_heap.h>
1728#include <__algorithm/ranges_remove.h>
1729#include <__algorithm/ranges_remove_copy.h>
1730#include <__algorithm/ranges_remove_copy_if.h>
1731#include <__algorithm/ranges_remove_if.h>
1732#include <__algorithm/ranges_replace.h>
1733#include <__algorithm/ranges_replace_if.h>
1734#include <__algorithm/ranges_reverse.h>
1735#include <__algorithm/ranges_reverse_copy.h>
1736#include <__algorithm/ranges_rotate_copy.h>
1737#include <__algorithm/ranges_search.h>
1738#include <__algorithm/ranges_search_n.h>
1739#include <__algorithm/ranges_set_difference.h>
1740#include <__algorithm/ranges_set_intersection.h>
1741#include <__algorithm/ranges_set_symmetric_difference.h>
1742#include <__algorithm/ranges_set_union.h>
1743#include <__algorithm/ranges_shuffle.h>
1744#include <__algorithm/ranges_sort.h>
1745#include <__algorithm/ranges_sort_heap.h>
1746#include <__algorithm/ranges_stable_partition.h>
1747#include <__algorithm/ranges_stable_sort.h>
1748#include <__algorithm/ranges_swap_ranges.h>
1749#include <__algorithm/ranges_transform.h>
1750#include <__algorithm/ranges_unique.h>
1751#include <__algorithm/ranges_unique_copy.h>
1752#include <__algorithm/ranges_upper_bound.h>
1753#include <__algorithm/remove.h>
1754#include <__algorithm/remove_copy.h>
1755#include <__algorithm/remove_copy_if.h>
1756#include <__algorithm/remove_if.h>
1757#include <__algorithm/replace.h>
1758#include <__algorithm/replace_copy.h>
1759#include <__algorithm/replace_copy_if.h>
1760#include <__algorithm/replace_if.h>
1761#include <__algorithm/reverse.h>
1762#include <__algorithm/reverse_copy.h>
1763#include <__algorithm/rotate.h>
1764#include <__algorithm/rotate_copy.h>
1765#include <__algorithm/sample.h>
1766#include <__algorithm/search.h>
1767#include <__algorithm/search_n.h>
1768#include <__algorithm/set_difference.h>
1769#include <__algorithm/set_intersection.h>
1770#include <__algorithm/set_symmetric_difference.h>
1771#include <__algorithm/set_union.h>
1772#include <__algorithm/shift_left.h>
1773#include <__algorithm/shift_right.h>
1774#include <__algorithm/shuffle.h>
1775#include <__algorithm/sift_down.h>
1776#include <__algorithm/sort.h>
1777#include <__algorithm/sort_heap.h>
1778#include <__algorithm/stable_partition.h>
1779#include <__algorithm/stable_sort.h>
1780#include <__algorithm/swap_ranges.h>
1781#include <__algorithm/transform.h>
1782#include <__algorithm/unique.h>
1783#include <__algorithm/unique_copy.h>
1784#include <__algorithm/unwrap_iter.h>
1785#include <__algorithm/upper_bound.h>
1786
1787#ifndef _LIBCPP_REMOVE_TRANSITIVE_INCLUDES
1788#  include <chrono>
1789#  include <iterator>
1790#  include <utility>
1791#endif
1792
1793// standard-mandated includes
1794#include <initializer_list>
1795
1796#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1797#  pragma GCC system_header
1798#endif
1799
1800#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
1801#   include <__pstl_algorithm>
1802#endif
1803
1804#endif // _LIBCPP_ALGORITHM
1805