1// Algorithm implementation -*- C++ -*-
2
3// Copyright (C) 2001-2017 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_algo.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{algorithm}
54 */
55
56#ifndef _STL_ALGO_H
57#define _STL_ALGO_H 1
58
59#include <cstdlib> // for rand
60#include <bits/algorithmfwd.h>
61#include <bits/stl_heap.h>
62#include <bits/stl_tempbuf.h> // for _Temporary_buffer
63#include <bits/predefined_ops.h>
64
65#if __cplusplus >= 201103L
66#include <bits/uniform_int_dist.h>
67#endif
68
69// See concept_check.h for the __glibcxx_*_requires macros.
70
71namespace std _GLIBCXX_VISIBILITY(default)
72{
73_GLIBCXX_BEGIN_NAMESPACE_VERSION
74
75 /// Swaps the median value of *__a, *__b and *__c under __comp to *__result
76 template<typename _Iterator, typename _Compare>
77 void
78 __move_median_to_first(_Iterator __result,_Iterator __a, _Iterator __b,
79 _Iterator __c, _Compare __comp)
80 {
81 if (__comp(__a, __b))
82 {
83 if (__comp(__b, __c))
84 std::iter_swap(__result, __b);
85 else if (__comp(__a, __c))
86 std::iter_swap(__result, __c);
87 else
88 std::iter_swap(__result, __a);
89 }
90 else if (__comp(__a, __c))
91 std::iter_swap(__result, __a);
92 else if (__comp(__b, __c))
93 std::iter_swap(__result, __c);
94 else
95 std::iter_swap(__result, __b);
96 }
97
98 /// This is an overload used by find algos for the Input Iterator case.
99 template<typename _InputIterator, typename _Predicate>
100 inline _InputIterator
101 __find_if(_InputIterator __first, _InputIterator __last,
102 _Predicate __pred, input_iterator_tag)
103 {
104 while (__first != __last && !__pred(__first))
105 ++__first;
106 return __first;
107 }
108
109 /// This is an overload used by find algos for the RAI case.
110 template<typename _RandomAccessIterator, typename _Predicate>
111 _RandomAccessIterator
112 __find_if(_RandomAccessIterator __first, _RandomAccessIterator __last,
113 _Predicate __pred, random_access_iterator_tag)
114 {
115 typename iterator_traits<_RandomAccessIterator>::difference_type
116 __trip_count = (__last - __first) >> 2;
117
118 for (; __trip_count > 0; --__trip_count)
119 {
120 if (__pred(__first))
121 return __first;
122 ++__first;
123
124 if (__pred(__first))
125 return __first;
126 ++__first;
127
128 if (__pred(__first))
129 return __first;
130 ++__first;
131
132 if (__pred(__first))
133 return __first;
134 ++__first;
135 }
136
137 switch (__last - __first)
138 {
139 case 3:
140 if (__pred(__first))
141 return __first;
142 ++__first;
143 case 2:
144 if (__pred(__first))
145 return __first;
146 ++__first;
147 case 1:
148 if (__pred(__first))
149 return __first;
150 ++__first;
151 case 0:
152 default:
153 return __last;
154 }
155 }
156
157 template<typename _Iterator, typename _Predicate>
158 inline _Iterator
159 __find_if(_Iterator __first, _Iterator __last, _Predicate __pred)
160 {
161 return __find_if(__first, __last, __pred,
162 std::__iterator_category(__first));
163 }
164
165 /// Provided for stable_partition to use.
166 template<typename _InputIterator, typename _Predicate>
167 inline _InputIterator
168 __find_if_not(_InputIterator __first, _InputIterator __last,
169 _Predicate __pred)
170 {
171 return std::__find_if(__first, __last,
172 __gnu_cxx::__ops::__negate(__pred),
173 std::__iterator_category(__first));
174 }
175
176 /// Like find_if_not(), but uses and updates a count of the
177 /// remaining range length instead of comparing against an end
178 /// iterator.
179 template<typename _InputIterator, typename _Predicate, typename _Distance>
180 _InputIterator
181 __find_if_not_n(_InputIterator __first, _Distance& __len, _Predicate __pred)
182 {
183 for (; __len; --__len, ++__first)
184 if (!__pred(__first))
185 break;
186 return __first;
187 }
188
189 // set_difference
190 // set_intersection
191 // set_symmetric_difference
192 // set_union
193 // for_each
194 // find
195 // find_if
196 // find_first_of
197 // adjacent_find
198 // count
199 // count_if
200 // search
201
202 template<typename _ForwardIterator1, typename _ForwardIterator2,
203 typename _BinaryPredicate>
204 _ForwardIterator1
205 __search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
206 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
207 _BinaryPredicate __predicate)
208 {
209 // Test for empty ranges
210 if (__first1 == __last1 || __first2 == __last2)
211 return __first1;
212
213 // Test for a pattern of length 1.
214 _ForwardIterator2 __p1(__first2);
215 if (++__p1 == __last2)
216 return std::__find_if(__first1, __last1,
217 __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2));
218
219 // General case.
220 _ForwardIterator2 __p;
221 _ForwardIterator1 __current = __first1;
222
223 for (;;)
224 {
225 __first1 =
226 std::__find_if(__first1, __last1,
227 __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2));
228
229 if (__first1 == __last1)
230 return __last1;
231
232 __p = __p1;
233 __current = __first1;
234 if (++__current == __last1)
235 return __last1;
236
237 while (__predicate(__current, __p))
238 {
239 if (++__p == __last2)
240 return __first1;
241 if (++__current == __last1)
242 return __last1;
243 }
244 ++__first1;
245 }
246 return __first1;
247 }
248
249 // search_n
250
251 /**
252 * This is an helper function for search_n overloaded for forward iterators.
253 */
254 template<typename _ForwardIterator, typename _Integer,
255 typename _UnaryPredicate>
256 _ForwardIterator
257 __search_n_aux(_ForwardIterator __first, _ForwardIterator __last,
258 _Integer __count, _UnaryPredicate __unary_pred,
259 std::forward_iterator_tag)
260 {
261 __first = std::__find_if(__first, __last, __unary_pred);
262 while (__first != __last)
263 {
264 typename iterator_traits<_ForwardIterator>::difference_type
265 __n = __count;
266 _ForwardIterator __i = __first;
267 ++__i;
268 while (__i != __last && __n != 1 && __unary_pred(__i))
269 {
270 ++__i;
271 --__n;
272 }
273 if (__n == 1)
274 return __first;
275 if (__i == __last)
276 return __last;
277 __first = std::__find_if(++__i, __last, __unary_pred);
278 }
279 return __last;
280 }
281
282 /**
283 * This is an helper function for search_n overloaded for random access
284 * iterators.
285 */
286 template<typename _RandomAccessIter, typename _Integer,
287 typename _UnaryPredicate>
288 _RandomAccessIter
289 __search_n_aux(_RandomAccessIter __first, _RandomAccessIter __last,
290 _Integer __count, _UnaryPredicate __unary_pred,
291 std::random_access_iterator_tag)
292 {
293 typedef typename std::iterator_traits<_RandomAccessIter>::difference_type
294 _DistanceType;
295
296 _DistanceType __tailSize = __last - __first;
297 _DistanceType __remainder = __count;
298
299 while (__remainder <= __tailSize) // the main loop...
300 {
301 __first += __remainder;
302 __tailSize -= __remainder;
303 // __first here is always pointing to one past the last element of
304 // next possible match.
305 _RandomAccessIter __backTrack = __first;
306 while (__unary_pred(--__backTrack))
307 {
308 if (--__remainder == 0)
309 return (__first - __count); // Success
310 }
311 __remainder = __count + 1 - (__first - __backTrack);
312 }
313 return __last; // Failure
314 }
315
316 template<typename _ForwardIterator, typename _Integer,
317 typename _UnaryPredicate>
318 _ForwardIterator
319 __search_n(_ForwardIterator __first, _ForwardIterator __last,
320 _Integer __count,
321 _UnaryPredicate __unary_pred)
322 {
323 if (__count <= 0)
324 return __first;
325
326 if (__count == 1)
327 return std::__find_if(__first, __last, __unary_pred);
328
329 return std::__search_n_aux(__first, __last, __count, __unary_pred,
330 std::__iterator_category(__first));
331 }
332
333 // find_end for forward iterators.
334 template<typename _ForwardIterator1, typename _ForwardIterator2,
335 typename _BinaryPredicate>
336 _ForwardIterator1
337 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
338 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
339 forward_iterator_tag, forward_iterator_tag,
340 _BinaryPredicate __comp)
341 {
342 if (__first2 == __last2)
343 return __last1;
344
345 _ForwardIterator1 __result = __last1;
346 while (1)
347 {
348 _ForwardIterator1 __new_result
349 = std::__search(__first1, __last1, __first2, __last2, __comp);
350 if (__new_result == __last1)
351 return __result;
352 else
353 {
354 __result = __new_result;
355 __first1 = __new_result;
356 ++__first1;
357 }
358 }
359 }
360
361 // find_end for bidirectional iterators (much faster).
362 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
363 typename _BinaryPredicate>
364 _BidirectionalIterator1
365 __find_end(_BidirectionalIterator1 __first1,
366 _BidirectionalIterator1 __last1,
367 _BidirectionalIterator2 __first2,
368 _BidirectionalIterator2 __last2,
369 bidirectional_iterator_tag, bidirectional_iterator_tag,
370 _BinaryPredicate __comp)
371 {
372 // concept requirements
373 __glibcxx_function_requires(_BidirectionalIteratorConcept<
374 _BidirectionalIterator1>)
375 __glibcxx_function_requires(_BidirectionalIteratorConcept<
376 _BidirectionalIterator2>)
377
378 typedef reverse_iterator<_BidirectionalIterator1> _RevIterator1;
379 typedef reverse_iterator<_BidirectionalIterator2> _RevIterator2;
380
381 _RevIterator1 __rlast1(__first1);
382 _RevIterator2 __rlast2(__first2);
383 _RevIterator1 __rresult = std::__search(_RevIterator1(__last1), __rlast1,
384 _RevIterator2(__last2), __rlast2,
385 __comp);
386
387 if (__rresult == __rlast1)
388 return __last1;
389 else
390 {
391 _BidirectionalIterator1 __result = __rresult.base();
392 std::advance(__result, -std::distance(__first2, __last2));
393 return __result;
394 }
395 }
396
397 /**
398 * @brief Find last matching subsequence in a sequence.
399 * @ingroup non_mutating_algorithms
400 * @param __first1 Start of range to search.
401 * @param __last1 End of range to search.
402 * @param __first2 Start of sequence to match.
403 * @param __last2 End of sequence to match.
404 * @return The last iterator @c i in the range
405 * @p [__first1,__last1-(__last2-__first2)) such that @c *(i+N) ==
406 * @p *(__first2+N) for each @c N in the range @p
407 * [0,__last2-__first2), or @p __last1 if no such iterator exists.
408 *
409 * Searches the range @p [__first1,__last1) for a sub-sequence that
410 * compares equal value-by-value with the sequence given by @p
411 * [__first2,__last2) and returns an iterator to the __first
412 * element of the sub-sequence, or @p __last1 if the sub-sequence
413 * is not found. The sub-sequence will be the last such
414 * subsequence contained in [__first1,__last1).
415 *
416 * Because the sub-sequence must lie completely within the range @p
417 * [__first1,__last1) it must start at a position less than @p
418 * __last1-(__last2-__first2) where @p __last2-__first2 is the
419 * length of the sub-sequence. This means that the returned
420 * iterator @c i will be in the range @p
421 * [__first1,__last1-(__last2-__first2))
422 */
423 template<typename _ForwardIterator1, typename _ForwardIterator2>
424 inline _ForwardIterator1
425 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
426 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
427 {
428 // concept requirements
429 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
430 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
431 __glibcxx_function_requires(_EqualOpConcept<
432 typename iterator_traits<_ForwardIterator1>::value_type,
433 typename iterator_traits<_ForwardIterator2>::value_type>)
434 __glibcxx_requires_valid_range(__first1, __last1);
435 __glibcxx_requires_valid_range(__first2, __last2);
436
437 return std::__find_end(__first1, __last1, __first2, __last2,
438 std::__iterator_category(__first1),
439 std::__iterator_category(__first2),
440 __gnu_cxx::__ops::__iter_equal_to_iter());
441 }
442
443 /**
444 * @brief Find last matching subsequence in a sequence using a predicate.
445 * @ingroup non_mutating_algorithms
446 * @param __first1 Start of range to search.
447 * @param __last1 End of range to search.
448 * @param __first2 Start of sequence to match.
449 * @param __last2 End of sequence to match.
450 * @param __comp The predicate to use.
451 * @return The last iterator @c i in the range @p
452 * [__first1,__last1-(__last2-__first2)) such that @c
453 * predicate(*(i+N), @p (__first2+N)) is true for each @c N in the
454 * range @p [0,__last2-__first2), or @p __last1 if no such iterator
455 * exists.
456 *
457 * Searches the range @p [__first1,__last1) for a sub-sequence that
458 * compares equal value-by-value with the sequence given by @p
459 * [__first2,__last2) using comp as a predicate and returns an
460 * iterator to the first element of the sub-sequence, or @p __last1
461 * if the sub-sequence is not found. The sub-sequence will be the
462 * last such subsequence contained in [__first,__last1).
463 *
464 * Because the sub-sequence must lie completely within the range @p
465 * [__first1,__last1) it must start at a position less than @p
466 * __last1-(__last2-__first2) where @p __last2-__first2 is the
467 * length of the sub-sequence. This means that the returned
468 * iterator @c i will be in the range @p
469 * [__first1,__last1-(__last2-__first2))
470 */
471 template<typename _ForwardIterator1, typename _ForwardIterator2,
472 typename _BinaryPredicate>
473 inline _ForwardIterator1
474 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
475 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
476 _BinaryPredicate __comp)
477 {
478 // concept requirements
479 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
480 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
481 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
482 typename iterator_traits<_ForwardIterator1>::value_type,
483 typename iterator_traits<_ForwardIterator2>::value_type>)
484 __glibcxx_requires_valid_range(__first1, __last1);
485 __glibcxx_requires_valid_range(__first2, __last2);
486
487 return std::__find_end(__first1, __last1, __first2, __last2,
488 std::__iterator_category(__first1),
489 std::__iterator_category(__first2),
490 __gnu_cxx::__ops::__iter_comp_iter(__comp));
491 }
492
493#if __cplusplus >= 201103L
494 /**
495 * @brief Checks that a predicate is true for all the elements
496 * of a sequence.
497 * @ingroup non_mutating_algorithms
498 * @param __first An input iterator.
499 * @param __last An input iterator.
500 * @param __pred A predicate.
501 * @return True if the check is true, false otherwise.
502 *
503 * Returns true if @p __pred is true for each element in the range
504 * @p [__first,__last), and false otherwise.
505 */
506 template<typename _InputIterator, typename _Predicate>
507 inline bool
508 all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
509 { return __last == std::find_if_not(__first, __last, __pred); }
510
511 /**
512 * @brief Checks that a predicate is false for all the elements
513 * of a sequence.
514 * @ingroup non_mutating_algorithms
515 * @param __first An input iterator.
516 * @param __last An input iterator.
517 * @param __pred A predicate.
518 * @return True if the check is true, false otherwise.
519 *
520 * Returns true if @p __pred is false for each element in the range
521 * @p [__first,__last), and false otherwise.
522 */
523 template<typename _InputIterator, typename _Predicate>
524 inline bool
525 none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
526 { return __last == _GLIBCXX_STD_A::find_if(__first, __last, __pred); }
527
528 /**
529 * @brief Checks that a predicate is false for at least an element
530 * of a sequence.
531 * @ingroup non_mutating_algorithms
532 * @param __first An input iterator.
533 * @param __last An input iterator.
534 * @param __pred A predicate.
535 * @return True if the check is true, false otherwise.
536 *
537 * Returns true if an element exists in the range @p
538 * [__first,__last) such that @p __pred is true, and false
539 * otherwise.
540 */
541 template<typename _InputIterator, typename _Predicate>
542 inline bool
543 any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
544 { return !std::none_of(__first, __last, __pred); }
545
546 /**
547 * @brief Find the first element in a sequence for which a
548 * predicate is false.
549 * @ingroup non_mutating_algorithms
550 * @param __first An input iterator.
551 * @param __last An input iterator.
552 * @param __pred A predicate.
553 * @return The first iterator @c i in the range @p [__first,__last)
554 * such that @p __pred(*i) is false, or @p __last if no such iterator exists.
555 */
556 template<typename _InputIterator, typename _Predicate>
557 inline _InputIterator
558 find_if_not(_InputIterator __first, _InputIterator __last,
559 _Predicate __pred)
560 {
561 // concept requirements
562 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
563 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
564 typename iterator_traits<_InputIterator>::value_type>)
565 __glibcxx_requires_valid_range(__first, __last);
566 return std::__find_if_not(__first, __last,
567 __gnu_cxx::__ops::__pred_iter(__pred));
568 }
569
570 /**
571 * @brief Checks whether the sequence is partitioned.
572 * @ingroup mutating_algorithms
573 * @param __first An input iterator.
574 * @param __last An input iterator.
575 * @param __pred A predicate.
576 * @return True if the range @p [__first,__last) is partioned by @p __pred,
577 * i.e. if all elements that satisfy @p __pred appear before those that
578 * do not.
579 */
580 template<typename _InputIterator, typename _Predicate>
581 inline bool
582 is_partitioned(_InputIterator __first, _InputIterator __last,
583 _Predicate __pred)
584 {
585 __first = std::find_if_not(__first, __last, __pred);
586 if (__first == __last)
587 return true;
588 ++__first;
589 return std::none_of(__first, __last, __pred);
590 }
591
592 /**
593 * @brief Find the partition point of a partitioned range.
594 * @ingroup mutating_algorithms
595 * @param __first An iterator.
596 * @param __last Another iterator.
597 * @param __pred A predicate.
598 * @return An iterator @p mid such that @p all_of(__first, mid, __pred)
599 * and @p none_of(mid, __last, __pred) are both true.
600 */
601 template<typename _ForwardIterator, typename _Predicate>
602 _ForwardIterator
603 partition_point(_ForwardIterator __first, _ForwardIterator __last,
604 _Predicate __pred)
605 {
606 // concept requirements
607 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
608 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
609 typename iterator_traits<_ForwardIterator>::value_type>)
610
611 // A specific debug-mode test will be necessary...
612 __glibcxx_requires_valid_range(__first, __last);
613
614 typedef typename iterator_traits<_ForwardIterator>::difference_type
615 _DistanceType;
616
617 _DistanceType __len = std::distance(__first, __last);
618 _DistanceType __half;
619 _ForwardIterator __middle;
620
621 while (__len > 0)
622 {
623 __half = __len >> 1;
624 __middle = __first;
625 std::advance(__middle, __half);
626 if (__pred(*__middle))
627 {
628 __first = __middle;
629 ++__first;
630 __len = __len - __half - 1;
631 }
632 else
633 __len = __half;
634 }
635 return __first;
636 }
637#endif
638
639 template<typename _InputIterator, typename _OutputIterator,
640 typename _Predicate>
641 _OutputIterator
642 __remove_copy_if(_InputIterator __first, _InputIterator __last,
643 _OutputIterator __result, _Predicate __pred)
644 {
645 for (; __first != __last; ++__first)
646 if (!__pred(__first))
647 {
648 *__result = *__first;
649 ++__result;
650 }
651 return __result;
652 }
653
654 /**
655 * @brief Copy a sequence, removing elements of a given value.
656 * @ingroup mutating_algorithms
657 * @param __first An input iterator.
658 * @param __last An input iterator.
659 * @param __result An output iterator.
660 * @param __value The value to be removed.
661 * @return An iterator designating the end of the resulting sequence.
662 *
663 * Copies each element in the range @p [__first,__last) not equal
664 * to @p __value to the range beginning at @p __result.
665 * remove_copy() is stable, so the relative order of elements that
666 * are copied is unchanged.
667 */
668 template<typename _InputIterator, typename _OutputIterator, typename _Tp>
669 inline _OutputIterator
670 remove_copy(_InputIterator __first, _InputIterator __last,
671 _OutputIterator __result, const _Tp& __value)
672 {
673 // concept requirements
674 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
675 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
676 typename iterator_traits<_InputIterator>::value_type>)
677 __glibcxx_function_requires(_EqualOpConcept<
678 typename iterator_traits<_InputIterator>::value_type, _Tp>)
679 __glibcxx_requires_valid_range(__first, __last);
680
681 return std::__remove_copy_if(__first, __last, __result,
682 __gnu_cxx::__ops::__iter_equals_val(__value));
683 }
684
685 /**
686 * @brief Copy a sequence, removing elements for which a predicate is true.
687 * @ingroup mutating_algorithms
688 * @param __first An input iterator.
689 * @param __last An input iterator.
690 * @param __result An output iterator.
691 * @param __pred A predicate.
692 * @return An iterator designating the end of the resulting sequence.
693 *
694 * Copies each element in the range @p [__first,__last) for which
695 * @p __pred returns false to the range beginning at @p __result.
696 *
697 * remove_copy_if() is stable, so the relative order of elements that are
698 * copied is unchanged.
699 */
700 template<typename _InputIterator, typename _OutputIterator,
701 typename _Predicate>
702 inline _OutputIterator
703 remove_copy_if(_InputIterator __first, _InputIterator __last,
704 _OutputIterator __result, _Predicate __pred)
705 {
706 // concept requirements
707 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
708 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
709 typename iterator_traits<_InputIterator>::value_type>)
710 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
711 typename iterator_traits<_InputIterator>::value_type>)
712 __glibcxx_requires_valid_range(__first, __last);
713
714 return std::__remove_copy_if(__first, __last, __result,
715 __gnu_cxx::__ops::__pred_iter(__pred));
716 }
717
718#if __cplusplus >= 201103L
719 /**
720 * @brief Copy the elements of a sequence for which a predicate is true.
721 * @ingroup mutating_algorithms
722 * @param __first An input iterator.
723 * @param __last An input iterator.
724 * @param __result An output iterator.
725 * @param __pred A predicate.
726 * @return An iterator designating the end of the resulting sequence.
727 *
728 * Copies each element in the range @p [__first,__last) for which
729 * @p __pred returns true to the range beginning at @p __result.
730 *
731 * copy_if() is stable, so the relative order of elements that are
732 * copied is unchanged.
733 */
734 template<typename _InputIterator, typename _OutputIterator,
735 typename _Predicate>
736 _OutputIterator
737 copy_if(_InputIterator __first, _InputIterator __last,
738 _OutputIterator __result, _Predicate __pred)
739 {
740 // concept requirements
741 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
742 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
743 typename iterator_traits<_InputIterator>::value_type>)
744 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
745 typename iterator_traits<_InputIterator>::value_type>)
746 __glibcxx_requires_valid_range(__first, __last);
747
748 for (; __first != __last; ++__first)
749 if (__pred(*__first))
750 {
751 *__result = *__first;
752 ++__result;
753 }
754 return __result;
755 }
756
757 template<typename _InputIterator, typename _Size, typename _OutputIterator>
758 _OutputIterator
759 __copy_n(_InputIterator __first, _Size __n,
760 _OutputIterator __result, input_iterator_tag)
761 {
762 if (__n > 0)
763 {
764 while (true)
765 {
766 *__result = *__first;
767 ++__result;
768 if (--__n > 0)
769 ++__first;
770 else
771 break;
772 }
773 }
774 return __result;
775 }
776
777 template<typename _RandomAccessIterator, typename _Size,
778 typename _OutputIterator>
779 inline _OutputIterator
780 __copy_n(_RandomAccessIterator __first, _Size __n,
781 _OutputIterator __result, random_access_iterator_tag)
782 { return std::copy(__first, __first + __n, __result); }
783
784 /**
785 * @brief Copies the range [first,first+n) into [result,result+n).
786 * @ingroup mutating_algorithms
787 * @param __first An input iterator.
788 * @param __n The number of elements to copy.
789 * @param __result An output iterator.
790 * @return result+n.
791 *
792 * This inline function will boil down to a call to @c memmove whenever
793 * possible. Failing that, if random access iterators are passed, then the
794 * loop count will be known (and therefore a candidate for compiler
795 * optimizations such as unrolling).
796 */
797 template<typename _InputIterator, typename _Size, typename _OutputIterator>
798 inline _OutputIterator
799 copy_n(_InputIterator __first, _Size __n, _OutputIterator __result)
800 {
801 // concept requirements
802 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
803 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
804 typename iterator_traits<_InputIterator>::value_type>)
805
806 return std::__copy_n(__first, __n, __result,
807 std::__iterator_category(__first));
808 }
809
810 /**
811 * @brief Copy the elements of a sequence to separate output sequences
812 * depending on the truth value of a predicate.
813 * @ingroup mutating_algorithms
814 * @param __first An input iterator.
815 * @param __last An input iterator.
816 * @param __out_true An output iterator.
817 * @param __out_false An output iterator.
818 * @param __pred A predicate.
819 * @return A pair designating the ends of the resulting sequences.
820 *
821 * Copies each element in the range @p [__first,__last) for which
822 * @p __pred returns true to the range beginning at @p out_true
823 * and each element for which @p __pred returns false to @p __out_false.
824 */
825 template<typename _InputIterator, typename _OutputIterator1,
826 typename _OutputIterator2, typename _Predicate>
827 pair<_OutputIterator1, _OutputIterator2>
828 partition_copy(_InputIterator __first, _InputIterator __last,
829 _OutputIterator1 __out_true, _OutputIterator2 __out_false,
830 _Predicate __pred)
831 {
832 // concept requirements
833 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
834 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator1,
835 typename iterator_traits<_InputIterator>::value_type>)
836 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator2,
837 typename iterator_traits<_InputIterator>::value_type>)
838 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
839 typename iterator_traits<_InputIterator>::value_type>)
840 __glibcxx_requires_valid_range(__first, __last);
841
842 for (; __first != __last; ++__first)
843 if (__pred(*__first))
844 {
845 *__out_true = *__first;
846 ++__out_true;
847 }
848 else
849 {
850 *__out_false = *__first;
851 ++__out_false;
852 }
853
854 return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
855 }
856#endif
857
858 template<typename _ForwardIterator, typename _Predicate>
859 _ForwardIterator
860 __remove_if(_ForwardIterator __first, _ForwardIterator __last,
861 _Predicate __pred)
862 {
863 __first = std::__find_if(__first, __last, __pred);
864 if (__first == __last)
865 return __first;
866 _ForwardIterator __result = __first;
867 ++__first;
868 for (; __first != __last; ++__first)
869 if (!__pred(__first))
870 {
871 *__result = _GLIBCXX_MOVE(*__first);
872 ++__result;
873 }
874 return __result;
875 }
876
877 /**
878 * @brief Remove elements from a sequence.
879 * @ingroup mutating_algorithms
880 * @param __first An input iterator.
881 * @param __last An input iterator.
882 * @param __value The value to be removed.
883 * @return An iterator designating the end of the resulting sequence.
884 *
885 * All elements equal to @p __value are removed from the range
886 * @p [__first,__last).
887 *
888 * remove() is stable, so the relative order of elements that are
889 * not removed is unchanged.
890 *
891 * Elements between the end of the resulting sequence and @p __last
892 * are still present, but their value is unspecified.
893 */
894 template<typename _ForwardIterator, typename _Tp>
895 inline _ForwardIterator
896 remove(_ForwardIterator __first, _ForwardIterator __last,
897 const _Tp& __value)
898 {
899 // concept requirements
900 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
901 _ForwardIterator>)
902 __glibcxx_function_requires(_EqualOpConcept<
903 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
904 __glibcxx_requires_valid_range(__first, __last);
905
906 return std::__remove_if(__first, __last,
907 __gnu_cxx::__ops::__iter_equals_val(__value));
908 }
909
910 /**
911 * @brief Remove elements from a sequence using a predicate.
912 * @ingroup mutating_algorithms
913 * @param __first A forward iterator.
914 * @param __last A forward iterator.
915 * @param __pred A predicate.
916 * @return An iterator designating the end of the resulting sequence.
917 *
918 * All elements for which @p __pred returns true are removed from the range
919 * @p [__first,__last).
920 *
921 * remove_if() is stable, so the relative order of elements that are
922 * not removed is unchanged.
923 *
924 * Elements between the end of the resulting sequence and @p __last
925 * are still present, but their value is unspecified.
926 */
927 template<typename _ForwardIterator, typename _Predicate>
928 inline _ForwardIterator
929 remove_if(_ForwardIterator __first, _ForwardIterator __last,
930 _Predicate __pred)
931 {
932 // concept requirements
933 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
934 _ForwardIterator>)
935 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
936 typename iterator_traits<_ForwardIterator>::value_type>)
937 __glibcxx_requires_valid_range(__first, __last);
938
939 return std::__remove_if(__first, __last,
940 __gnu_cxx::__ops::__pred_iter(__pred));
941 }
942
943 template<typename _ForwardIterator, typename _BinaryPredicate>
944 _ForwardIterator
945 __adjacent_find(_ForwardIterator __first, _ForwardIterator __last,
946 _BinaryPredicate __binary_pred)
947 {
948 if (__first == __last)
949 return __last;
950 _ForwardIterator __next = __first;
951 while (++__next != __last)
952 {
953 if (__binary_pred(__first, __next))
954 return __first;
955 __first = __next;
956 }
957 return __last;
958 }
959
960 template<typename _ForwardIterator, typename _BinaryPredicate>
961 _ForwardIterator
962 __unique(_ForwardIterator __first, _ForwardIterator __last,
963 _BinaryPredicate __binary_pred)
964 {
965 // Skip the beginning, if already unique.
966 __first = std::__adjacent_find(__first, __last, __binary_pred);
967 if (__first == __last)
968 return __last;
969
970 // Do the real copy work.
971 _ForwardIterator __dest = __first;
972 ++__first;
973 while (++__first != __last)
974 if (!__binary_pred(__dest, __first))
975 *++__dest = _GLIBCXX_MOVE(*__first);
976 return ++__dest;
977 }
978
979 /**
980 * @brief Remove consecutive duplicate values from a sequence.
981 * @ingroup mutating_algorithms
982 * @param __first A forward iterator.
983 * @param __last A forward iterator.
984 * @return An iterator designating the end of the resulting sequence.
985 *
986 * Removes all but the first element from each group of consecutive
987 * values that compare equal.
988 * unique() is stable, so the relative order of elements that are
989 * not removed is unchanged.
990 * Elements between the end of the resulting sequence and @p __last
991 * are still present, but their value is unspecified.
992 */
993 template<typename _ForwardIterator>
994 inline _ForwardIterator
995 unique(_ForwardIterator __first, _ForwardIterator __last)
996 {
997 // concept requirements
998 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
999 _ForwardIterator>)
1000 __glibcxx_function_requires(_EqualityComparableConcept<
1001 typename iterator_traits<_ForwardIterator>::value_type>)
1002 __glibcxx_requires_valid_range(__first, __last);
1003
1004 return std::__unique(__first, __last,
1005 __gnu_cxx::__ops::__iter_equal_to_iter());
1006 }
1007
1008 /**
1009 * @brief Remove consecutive values from a sequence using a predicate.
1010 * @ingroup mutating_algorithms
1011 * @param __first A forward iterator.
1012 * @param __last A forward iterator.
1013 * @param __binary_pred A binary predicate.
1014 * @return An iterator designating the end of the resulting sequence.
1015 *
1016 * Removes all but the first element from each group of consecutive
1017 * values for which @p __binary_pred returns true.
1018 * unique() is stable, so the relative order of elements that are
1019 * not removed is unchanged.
1020 * Elements between the end of the resulting sequence and @p __last
1021 * are still present, but their value is unspecified.
1022 */
1023 template<typename _ForwardIterator, typename _BinaryPredicate>
1024 inline _ForwardIterator
1025 unique(_ForwardIterator __first, _ForwardIterator __last,
1026 _BinaryPredicate __binary_pred)
1027 {
1028 // concept requirements
1029 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1030 _ForwardIterator>)
1031 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1032 typename iterator_traits<_ForwardIterator>::value_type,
1033 typename iterator_traits<_ForwardIterator>::value_type>)
1034 __glibcxx_requires_valid_range(__first, __last);
1035
1036 return std::__unique(__first, __last,
1037 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
1038 }
1039
1040 /**
1041 * This is an uglified
1042 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1043 * _BinaryPredicate)
1044 * overloaded for forward iterators and output iterator as result.
1045 */
1046 template<typename _ForwardIterator, typename _OutputIterator,
1047 typename _BinaryPredicate>
1048 _OutputIterator
1049 __unique_copy(_ForwardIterator __first, _ForwardIterator __last,
1050 _OutputIterator __result, _BinaryPredicate __binary_pred,
1051 forward_iterator_tag, output_iterator_tag)
1052 {
1053 // concept requirements -- iterators already checked
1054 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1055 typename iterator_traits<_ForwardIterator>::value_type,
1056 typename iterator_traits<_ForwardIterator>::value_type>)
1057
1058 _ForwardIterator __next = __first;
1059 *__result = *__first;
1060 while (++__next != __last)
1061 if (!__binary_pred(__first, __next))
1062 {
1063 __first = __next;
1064 *++__result = *__first;
1065 }
1066 return ++__result;
1067 }
1068
1069 /**
1070 * This is an uglified
1071 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1072 * _BinaryPredicate)
1073 * overloaded for input iterators and output iterator as result.
1074 */
1075 template<typename _InputIterator, typename _OutputIterator,
1076 typename _BinaryPredicate>
1077 _OutputIterator
1078 __unique_copy(_InputIterator __first, _InputIterator __last,
1079 _OutputIterator __result, _BinaryPredicate __binary_pred,
1080 input_iterator_tag, output_iterator_tag)
1081 {
1082 // concept requirements -- iterators already checked
1083 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1084 typename iterator_traits<_InputIterator>::value_type,
1085 typename iterator_traits<_InputIterator>::value_type>)
1086
1087 typename iterator_traits<_InputIterator>::value_type __value = *__first;
1088 __decltype(__gnu_cxx::__ops::__iter_comp_val(__binary_pred))
1089 __rebound_pred
1090 = __gnu_cxx::__ops::__iter_comp_val(__binary_pred);
1091 *__result = __value;
1092 while (++__first != __last)
1093 if (!__rebound_pred(__first, __value))
1094 {
1095 __value = *__first;
1096 *++__result = __value;
1097 }
1098 return ++__result;
1099 }
1100
1101 /**
1102 * This is an uglified
1103 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1104 * _BinaryPredicate)
1105 * overloaded for input iterators and forward iterator as result.
1106 */
1107 template<typename _InputIterator, typename _ForwardIterator,
1108 typename _BinaryPredicate>
1109 _ForwardIterator
1110 __unique_copy(_InputIterator __first, _InputIterator __last,
1111 _ForwardIterator __result, _BinaryPredicate __binary_pred,
1112 input_iterator_tag, forward_iterator_tag)
1113 {
1114 // concept requirements -- iterators already checked
1115 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1116 typename iterator_traits<_ForwardIterator>::value_type,
1117 typename iterator_traits<_InputIterator>::value_type>)
1118 *__result = *__first;
1119 while (++__first != __last)
1120 if (!__binary_pred(__result, __first))
1121 *++__result = *__first;
1122 return ++__result;
1123 }
1124
1125 /**
1126 * This is an uglified reverse(_BidirectionalIterator,
1127 * _BidirectionalIterator)
1128 * overloaded for bidirectional iterators.
1129 */
1130 template<typename _BidirectionalIterator>
1131 void
1132 __reverse(_BidirectionalIterator __first, _BidirectionalIterator __last,
1133 bidirectional_iterator_tag)
1134 {
1135 while (true)
1136 if (__first == __last || __first == --__last)
1137 return;
1138 else
1139 {
1140 std::iter_swap(__first, __last);
1141 ++__first;
1142 }
1143 }
1144
1145 /**
1146 * This is an uglified reverse(_BidirectionalIterator,
1147 * _BidirectionalIterator)
1148 * overloaded for random access iterators.
1149 */
1150 template<typename _RandomAccessIterator>
1151 void
1152 __reverse(_RandomAccessIterator __first, _RandomAccessIterator __last,
1153 random_access_iterator_tag)
1154 {
1155 if (__first == __last)
1156 return;
1157 --__last;
1158 while (__first < __last)
1159 {
1160 std::iter_swap(__first, __last);
1161 ++__first;
1162 --__last;
1163 }
1164 }
1165
1166 /**
1167 * @brief Reverse a sequence.
1168 * @ingroup mutating_algorithms
1169 * @param __first A bidirectional iterator.
1170 * @param __last A bidirectional iterator.
1171 * @return reverse() returns no value.
1172 *
1173 * Reverses the order of the elements in the range @p [__first,__last),
1174 * so that the first element becomes the last etc.
1175 * For every @c i such that @p 0<=i<=(__last-__first)/2), @p reverse()
1176 * swaps @p *(__first+i) and @p *(__last-(i+1))
1177 */
1178 template<typename _BidirectionalIterator>
1179 inline void
1180 reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
1181 {
1182 // concept requirements
1183 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
1184 _BidirectionalIterator>)
1185 __glibcxx_requires_valid_range(__first, __last);
1186 std::__reverse(__first, __last, std::__iterator_category(__first));
1187 }
1188
1189 /**
1190 * @brief Copy a sequence, reversing its elements.
1191 * @ingroup mutating_algorithms
1192 * @param __first A bidirectional iterator.
1193 * @param __last A bidirectional iterator.
1194 * @param __result An output iterator.
1195 * @return An iterator designating the end of the resulting sequence.
1196 *
1197 * Copies the elements in the range @p [__first,__last) to the
1198 * range @p [__result,__result+(__last-__first)) such that the
1199 * order of the elements is reversed. For every @c i such that @p
1200 * 0<=i<=(__last-__first), @p reverse_copy() performs the
1201 * assignment @p *(__result+(__last-__first)-1-i) = *(__first+i).
1202 * The ranges @p [__first,__last) and @p
1203 * [__result,__result+(__last-__first)) must not overlap.
1204 */
1205 template<typename _BidirectionalIterator, typename _OutputIterator>
1206 _OutputIterator
1207 reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last,
1208 _OutputIterator __result)
1209 {
1210 // concept requirements
1211 __glibcxx_function_requires(_BidirectionalIteratorConcept<
1212 _BidirectionalIterator>)
1213 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1214 typename iterator_traits<_BidirectionalIterator>::value_type>)
1215 __glibcxx_requires_valid_range(__first, __last);
1216
1217 while (__first != __last)
1218 {
1219 --__last;
1220 *__result = *__last;
1221 ++__result;
1222 }
1223 return __result;
1224 }
1225
1226 /**
1227 * This is a helper function for the rotate algorithm specialized on RAIs.
1228 * It returns the greatest common divisor of two integer values.
1229 */
1230 template<typename _EuclideanRingElement>
1231 _EuclideanRingElement
1232 __gcd(_EuclideanRingElement __m, _EuclideanRingElement __n)
1233 {
1234 while (__n != 0)
1235 {
1236 _EuclideanRingElement __t = __m % __n;
1237 __m = __n;
1238 __n = __t;
1239 }
1240 return __m;
1241 }
1242
1243 inline namespace _V2
1244 {
1245
1246 /// This is a helper function for the rotate algorithm.
1247 template<typename _ForwardIterator>
1248 _ForwardIterator
1249 __rotate(_ForwardIterator __first,
1250 _ForwardIterator __middle,
1251 _ForwardIterator __last,
1252 forward_iterator_tag)
1253 {
1254 if (__first == __middle)
1255 return __last;
1256 else if (__last == __middle)
1257 return __first;
1258
1259 _ForwardIterator __first2 = __middle;
1260 do
1261 {
1262 std::iter_swap(__first, __first2);
1263 ++__first;
1264 ++__first2;
1265 if (__first == __middle)
1266 __middle = __first2;
1267 }
1268 while (__first2 != __last);
1269
1270 _ForwardIterator __ret = __first;
1271
1272 __first2 = __middle;
1273
1274 while (__first2 != __last)
1275 {
1276 std::iter_swap(__first, __first2);
1277 ++__first;
1278 ++__first2;
1279 if (__first == __middle)
1280 __middle = __first2;
1281 else if (__first2 == __last)
1282 __first2 = __middle;
1283 }
1284 return __ret;
1285 }
1286
1287 /// This is a helper function for the rotate algorithm.
1288 template<typename _BidirectionalIterator>
1289 _BidirectionalIterator
1290 __rotate(_BidirectionalIterator __first,
1291 _BidirectionalIterator __middle,
1292 _BidirectionalIterator __last,
1293 bidirectional_iterator_tag)
1294 {
1295 // concept requirements
1296 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
1297 _BidirectionalIterator>)
1298
1299 if (__first == __middle)
1300 return __last;
1301 else if (__last == __middle)
1302 return __first;
1303
1304 std::__reverse(__first, __middle, bidirectional_iterator_tag());
1305 std::__reverse(__middle, __last, bidirectional_iterator_tag());
1306
1307 while (__first != __middle && __middle != __last)
1308 {
1309 std::iter_swap(__first, --__last);
1310 ++__first;
1311 }
1312
1313 if (__first == __middle)
1314 {
1315 std::__reverse(__middle, __last, bidirectional_iterator_tag());
1316 return __last;
1317 }
1318 else
1319 {
1320 std::__reverse(__first, __middle, bidirectional_iterator_tag());
1321 return __first;
1322 }
1323 }
1324
1325 /// This is a helper function for the rotate algorithm.
1326 template<typename _RandomAccessIterator>
1327 _RandomAccessIterator
1328 __rotate(_RandomAccessIterator __first,
1329 _RandomAccessIterator __middle,
1330 _RandomAccessIterator __last,
1331 random_access_iterator_tag)
1332 {
1333 // concept requirements
1334 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1335 _RandomAccessIterator>)
1336
1337 if (__first == __middle)
1338 return __last;
1339 else if (__last == __middle)
1340 return __first;
1341
1342 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
1343 _Distance;
1344 typedef typename iterator_traits<_RandomAccessIterator>::value_type
1345 _ValueType;
1346
1347 _Distance __n = __last - __first;
1348 _Distance __k = __middle - __first;
1349
1350 if (__k == __n - __k)
1351 {
1352 std::swap_ranges(__first, __middle, __middle);
1353 return __middle;
1354 }
1355
1356 _RandomAccessIterator __p = __first;
1357 _RandomAccessIterator __ret = __first + (__last - __middle);
1358
1359 for (;;)
1360 {
1361 if (__k < __n - __k)
1362 {
1363 if (__is_pod(_ValueType) && __k == 1)
1364 {
1365 _ValueType __t = _GLIBCXX_MOVE(*__p);
1366 _GLIBCXX_MOVE3(__p + 1, __p + __n, __p);
1367 *(__p + __n - 1) = _GLIBCXX_MOVE(__t);
1368 return __ret;
1369 }
1370 _RandomAccessIterator __q = __p + __k;
1371 for (_Distance __i = 0; __i < __n - __k; ++ __i)
1372 {
1373 std::iter_swap(__p, __q);
1374 ++__p;
1375 ++__q;
1376 }
1377 __n %= __k;
1378 if (__n == 0)
1379 return __ret;
1380 std::swap(__n, __k);
1381 __k = __n - __k;
1382 }
1383 else
1384 {
1385 __k = __n - __k;
1386 if (__is_pod(_ValueType) && __k == 1)
1387 {
1388 _ValueType __t = _GLIBCXX_MOVE(*(__p + __n - 1));
1389 _GLIBCXX_MOVE_BACKWARD3(__p, __p + __n - 1, __p + __n);
1390 *__p = _GLIBCXX_MOVE(__t);
1391 return __ret;
1392 }
1393 _RandomAccessIterator __q = __p + __n;
1394 __p = __q - __k;
1395 for (_Distance __i = 0; __i < __n - __k; ++ __i)
1396 {
1397 --__p;
1398 --__q;
1399 std::iter_swap(__p, __q);
1400 }
1401 __n %= __k;
1402 if (__n == 0)
1403 return __ret;
1404 std::swap(__n, __k);
1405 }
1406 }
1407 }
1408
1409 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1410 // DR 488. rotate throws away useful information
1411 /**
1412 * @brief Rotate the elements of a sequence.
1413 * @ingroup mutating_algorithms
1414 * @param __first A forward iterator.
1415 * @param __middle A forward iterator.
1416 * @param __last A forward iterator.
1417 * @return first + (last - middle).
1418 *
1419 * Rotates the elements of the range @p [__first,__last) by
1420 * @p (__middle - __first) positions so that the element at @p __middle
1421 * is moved to @p __first, the element at @p __middle+1 is moved to
1422 * @p __first+1 and so on for each element in the range
1423 * @p [__first,__last).
1424 *
1425 * This effectively swaps the ranges @p [__first,__middle) and
1426 * @p [__middle,__last).
1427 *
1428 * Performs
1429 * @p *(__first+(n+(__last-__middle))%(__last-__first))=*(__first+n)
1430 * for each @p n in the range @p [0,__last-__first).
1431 */
1432 template<typename _ForwardIterator>
1433 inline _ForwardIterator
1434 rotate(_ForwardIterator __first, _ForwardIterator __middle,
1435 _ForwardIterator __last)
1436 {
1437 // concept requirements
1438 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1439 _ForwardIterator>)
1440 __glibcxx_requires_valid_range(__first, __middle);
1441 __glibcxx_requires_valid_range(__middle, __last);
1442
1443 return std::__rotate(__first, __middle, __last,
1444 std::__iterator_category(__first));
1445 }
1446
1447 } // namespace _V2
1448
1449 /**
1450 * @brief Copy a sequence, rotating its elements.
1451 * @ingroup mutating_algorithms
1452 * @param __first A forward iterator.
1453 * @param __middle A forward iterator.
1454 * @param __last A forward iterator.
1455 * @param __result An output iterator.
1456 * @return An iterator designating the end of the resulting sequence.
1457 *
1458 * Copies the elements of the range @p [__first,__last) to the
1459 * range beginning at @result, rotating the copied elements by
1460 * @p (__middle-__first) positions so that the element at @p __middle
1461 * is moved to @p __result, the element at @p __middle+1 is moved
1462 * to @p __result+1 and so on for each element in the range @p
1463 * [__first,__last).
1464 *
1465 * Performs
1466 * @p *(__result+(n+(__last-__middle))%(__last-__first))=*(__first+n)
1467 * for each @p n in the range @p [0,__last-__first).
1468 */
1469 template<typename _ForwardIterator, typename _OutputIterator>
1470 inline _OutputIterator
1471 rotate_copy(_ForwardIterator __first, _ForwardIterator __middle,
1472 _ForwardIterator __last, _OutputIterator __result)
1473 {
1474 // concept requirements
1475 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1476 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1477 typename iterator_traits<_ForwardIterator>::value_type>)
1478 __glibcxx_requires_valid_range(__first, __middle);
1479 __glibcxx_requires_valid_range(__middle, __last);
1480
1481 return std::copy(__first, __middle,
1482 std::copy(__middle, __last, __result));
1483 }
1484
1485 /// This is a helper function...
1486 template<typename _ForwardIterator, typename _Predicate>
1487 _ForwardIterator
1488 __partition(_ForwardIterator __first, _ForwardIterator __last,
1489 _Predicate __pred, forward_iterator_tag)
1490 {
1491 if (__first == __last)
1492 return __first;
1493
1494 while (__pred(*__first))
1495 if (++__first == __last)
1496 return __first;
1497
1498 _ForwardIterator __next = __first;
1499
1500 while (++__next != __last)
1501 if (__pred(*__next))
1502 {
1503 std::iter_swap(__first, __next);
1504 ++__first;
1505 }
1506
1507 return __first;
1508 }
1509
1510 /// This is a helper function...
1511 template<typename _BidirectionalIterator, typename _Predicate>
1512 _BidirectionalIterator
1513 __partition(_BidirectionalIterator __first, _BidirectionalIterator __last,
1514 _Predicate __pred, bidirectional_iterator_tag)
1515 {
1516 while (true)
1517 {
1518 while (true)
1519 if (__first == __last)
1520 return __first;
1521 else if (__pred(*__first))
1522 ++__first;
1523 else
1524 break;
1525 --__last;
1526 while (true)
1527 if (__first == __last)
1528 return __first;
1529 else if (!bool(__pred(*__last)))
1530 --__last;
1531 else
1532 break;
1533 std::iter_swap(__first, __last);
1534 ++__first;
1535 }
1536 }
1537
1538 // partition
1539
1540 /// This is a helper function...
1541 /// Requires __first != __last and !__pred(__first)
1542 /// and __len == distance(__first, __last).
1543 ///
1544 /// !__pred(__first) allows us to guarantee that we don't
1545 /// move-assign an element onto itself.
1546 template<typename _ForwardIterator, typename _Pointer, typename _Predicate,
1547 typename _Distance>
1548 _ForwardIterator
1549 __stable_partition_adaptive(_ForwardIterator __first,
1550 _ForwardIterator __last,
1551 _Predicate __pred, _Distance __len,
1552 _Pointer __buffer,
1553 _Distance __buffer_size)
1554 {
1555 if (__len == 1)
1556 return __first;
1557
1558 if (__len <= __buffer_size)
1559 {
1560 _ForwardIterator __result1 = __first;
1561 _Pointer __result2 = __buffer;
1562
1563 // The precondition guarantees that !__pred(__first), so
1564 // move that element to the buffer before starting the loop.
1565 // This ensures that we only call __pred once per element.
1566 *__result2 = _GLIBCXX_MOVE(*__first);
1567 ++__result2;
1568 ++__first;
1569 for (; __first != __last; ++__first)
1570 if (__pred(__first))
1571 {
1572 *__result1 = _GLIBCXX_MOVE(*__first);
1573 ++__result1;
1574 }
1575 else
1576 {
1577 *__result2 = _GLIBCXX_MOVE(*__first);
1578 ++__result2;
1579 }
1580
1581 _GLIBCXX_MOVE3(__buffer, __result2, __result1);
1582 return __result1;
1583 }
1584
1585 _ForwardIterator __middle = __first;
1586 std::advance(__middle, __len / 2);
1587 _ForwardIterator __left_split =
1588 std::__stable_partition_adaptive(__first, __middle, __pred,
1589 __len / 2, __buffer,
1590 __buffer_size);
1591
1592 // Advance past true-predicate values to satisfy this
1593 // function's preconditions.
1594 _Distance __right_len = __len - __len / 2;
1595 _ForwardIterator __right_split =
1596 std::__find_if_not_n(__middle, __right_len, __pred);
1597
1598 if (__right_len)
1599 __right_split =
1600 std::__stable_partition_adaptive(__right_split, __last, __pred,
1601 __right_len,
1602 __buffer, __buffer_size);
1603
1604 std::rotate(__left_split, __middle, __right_split);
1605 std::advance(__left_split, std::distance(__middle, __right_split));
1606 return __left_split;
1607 }
1608
1609 template<typename _ForwardIterator, typename _Predicate>
1610 _ForwardIterator
1611 __stable_partition(_ForwardIterator __first, _ForwardIterator __last,
1612 _Predicate __pred)
1613 {
1614 __first = std::__find_if_not(__first, __last, __pred);
1615
1616 if (__first == __last)
1617 return __first;
1618
1619 typedef typename iterator_traits<_ForwardIterator>::value_type
1620 _ValueType;
1621 typedef typename iterator_traits<_ForwardIterator>::difference_type
1622 _DistanceType;
1623
1624 _Temporary_buffer<_ForwardIterator, _ValueType> __buf(__first, __last);
1625 return
1626 std::__stable_partition_adaptive(__first, __last, __pred,
1627 _DistanceType(__buf.requested_size()),
1628 __buf.begin(),
1629 _DistanceType(__buf.size()));
1630 }
1631
1632 /**
1633 * @brief Move elements for which a predicate is true to the beginning
1634 * of a sequence, preserving relative ordering.
1635 * @ingroup mutating_algorithms
1636 * @param __first A forward iterator.
1637 * @param __last A forward iterator.
1638 * @param __pred A predicate functor.
1639 * @return An iterator @p middle such that @p __pred(i) is true for each
1640 * iterator @p i in the range @p [first,middle) and false for each @p i
1641 * in the range @p [middle,last).
1642 *
1643 * Performs the same function as @p partition() with the additional
1644 * guarantee that the relative ordering of elements in each group is
1645 * preserved, so any two elements @p x and @p y in the range
1646 * @p [__first,__last) such that @p __pred(x)==__pred(y) will have the same
1647 * relative ordering after calling @p stable_partition().
1648 */
1649 template<typename _ForwardIterator, typename _Predicate>
1650 inline _ForwardIterator
1651 stable_partition(_ForwardIterator __first, _ForwardIterator __last,
1652 _Predicate __pred)
1653 {
1654 // concept requirements
1655 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1656 _ForwardIterator>)
1657 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1658 typename iterator_traits<_ForwardIterator>::value_type>)
1659 __glibcxx_requires_valid_range(__first, __last);
1660
1661 return std::__stable_partition(__first, __last,
1662 __gnu_cxx::__ops::__pred_iter(__pred));
1663 }
1664
1665 /// This is a helper function for the sort routines.
1666 template<typename _RandomAccessIterator, typename _Compare>
1667 void
1668 __heap_select(_RandomAccessIterator __first,
1669 _RandomAccessIterator __middle,
1670 _RandomAccessIterator __last, _Compare __comp)
1671 {
1672 std::__make_heap(__first, __middle, __comp);
1673 for (_RandomAccessIterator __i = __middle; __i < __last; ++__i)
1674 if (__comp(__i, __first))
1675 std::__pop_heap(__first, __middle, __i, __comp);
1676 }
1677
1678 // partial_sort
1679
1680 template<typename _InputIterator, typename _RandomAccessIterator,
1681 typename _Compare>
1682 _RandomAccessIterator
1683 __partial_sort_copy(_InputIterator __first, _InputIterator __last,
1684 _RandomAccessIterator __result_first,
1685 _RandomAccessIterator __result_last,
1686 _Compare __comp)
1687 {
1688 typedef typename iterator_traits<_InputIterator>::value_type
1689 _InputValueType;
1690 typedef iterator_traits<_RandomAccessIterator> _RItTraits;
1691 typedef typename _RItTraits::difference_type _DistanceType;
1692
1693 if (__result_first == __result_last)
1694 return __result_last;
1695 _RandomAccessIterator __result_real_last = __result_first;
1696 while (__first != __last && __result_real_last != __result_last)
1697 {
1698 *__result_real_last = *__first;
1699 ++__result_real_last;
1700 ++__first;
1701 }
1702
1703 std::__make_heap(__result_first, __result_real_last, __comp);
1704 while (__first != __last)
1705 {
1706 if (__comp(__first, __result_first))
1707 std::__adjust_heap(__result_first, _DistanceType(0),
1708 _DistanceType(__result_real_last
1709 - __result_first),
1710 _InputValueType(*__first), __comp);
1711 ++__first;
1712 }
1713 std::__sort_heap(__result_first, __result_real_last, __comp);
1714 return __result_real_last;
1715 }
1716
1717 /**
1718 * @brief Copy the smallest elements of a sequence.
1719 * @ingroup sorting_algorithms
1720 * @param __first An iterator.
1721 * @param __last Another iterator.
1722 * @param __result_first A random-access iterator.
1723 * @param __result_last Another random-access iterator.
1724 * @return An iterator indicating the end of the resulting sequence.
1725 *
1726 * Copies and sorts the smallest N values from the range @p [__first,__last)
1727 * to the range beginning at @p __result_first, where the number of
1728 * elements to be copied, @p N, is the smaller of @p (__last-__first) and
1729 * @p (__result_last-__result_first).
1730 * After the sort if @e i and @e j are iterators in the range
1731 * @p [__result_first,__result_first+N) such that i precedes j then
1732 * *j<*i is false.
1733 * The value returned is @p __result_first+N.
1734 */
1735 template<typename _InputIterator, typename _RandomAccessIterator>
1736 inline _RandomAccessIterator
1737 partial_sort_copy(_InputIterator __first, _InputIterator __last,
1738 _RandomAccessIterator __result_first,
1739 _RandomAccessIterator __result_last)
1740 {
1741#ifdef _GLIBCXX_CONCEPT_CHECKS
1742 typedef typename iterator_traits<_InputIterator>::value_type
1743 _InputValueType;
1744 typedef typename iterator_traits<_RandomAccessIterator>::value_type
1745 _OutputValueType;
1746#endif
1747
1748 // concept requirements
1749 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1750 __glibcxx_function_requires(_ConvertibleConcept<_InputValueType,
1751 _OutputValueType>)
1752 __glibcxx_function_requires(_LessThanOpConcept<_InputValueType,
1753 _OutputValueType>)
1754 __glibcxx_function_requires(_LessThanComparableConcept<_OutputValueType>)
1755 __glibcxx_requires_valid_range(__first, __last);
1756 __glibcxx_requires_irreflexive(__first, __last);
1757 __glibcxx_requires_valid_range(__result_first, __result_last);
1758
1759 return std::__partial_sort_copy(__first, __last,
1760 __result_first, __result_last,
1761 __gnu_cxx::__ops::__iter_less_iter());
1762 }
1763
1764 /**
1765 * @brief Copy the smallest elements of a sequence using a predicate for
1766 * comparison.
1767 * @ingroup sorting_algorithms
1768 * @param __first An input iterator.
1769 * @param __last Another input iterator.
1770 * @param __result_first A random-access iterator.
1771 * @param __result_last Another random-access iterator.
1772 * @param __comp A comparison functor.
1773 * @return An iterator indicating the end of the resulting sequence.
1774 *
1775 * Copies and sorts the smallest N values from the range @p [__first,__last)
1776 * to the range beginning at @p result_first, where the number of
1777 * elements to be copied, @p N, is the smaller of @p (__last-__first) and
1778 * @p (__result_last-__result_first).
1779 * After the sort if @e i and @e j are iterators in the range
1780 * @p [__result_first,__result_first+N) such that i precedes j then
1781 * @p __comp(*j,*i) is false.
1782 * The value returned is @p __result_first+N.
1783 */
1784 template<typename _InputIterator, typename _RandomAccessIterator,
1785 typename _Compare>
1786 inline _RandomAccessIterator
1787 partial_sort_copy(_InputIterator __first, _InputIterator __last,
1788 _RandomAccessIterator __result_first,
1789 _RandomAccessIterator __result_last,
1790 _Compare __comp)
1791 {
1792#ifdef _GLIBCXX_CONCEPT_CHECKS
1793 typedef typename iterator_traits<_InputIterator>::value_type
1794 _InputValueType;
1795 typedef typename iterator_traits<_RandomAccessIterator>::value_type
1796 _OutputValueType;
1797#endif
1798
1799 // concept requirements
1800 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1801 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1802 _RandomAccessIterator>)
1803 __glibcxx_function_requires(_ConvertibleConcept<_InputValueType,
1804 _OutputValueType>)
1805 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
1806 _InputValueType, _OutputValueType>)
1807 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
1808 _OutputValueType, _OutputValueType>)
1809 __glibcxx_requires_valid_range(__first, __last);
1810 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
1811 __glibcxx_requires_valid_range(__result_first, __result_last);
1812
1813 return std::__partial_sort_copy(__first, __last,
1814 __result_first, __result_last,
1815 __gnu_cxx::__ops::__iter_comp_iter(__comp));
1816 }
1817
1818 /// This is a helper function for the sort routine.
1819 template<typename _RandomAccessIterator, typename _Compare>
1820 void
1821 __unguarded_linear_insert(_RandomAccessIterator __last,
1822 _Compare __comp)
1823 {
1824 typename iterator_traits<_RandomAccessIterator>::value_type
1825 __val = _GLIBCXX_MOVE(*__last);
1826 _RandomAccessIterator __next = __last;
1827 --__next;
1828 while (__comp(__val, __next))
1829 {
1830 *__last = _GLIBCXX_MOVE(*__next);
1831 __last = __next;
1832 --__next;
1833 }
1834 *__last = _GLIBCXX_MOVE(__val);
1835 }
1836
1837 /// This is a helper function for the sort routine.
1838 template<typename _RandomAccessIterator, typename _Compare>
1839 void
1840 __insertion_sort(_RandomAccessIterator __first,
1841 _RandomAccessIterator __last, _Compare __comp)
1842 {
1843 if (__first == __last) return;
1844
1845 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
1846 {
1847 if (__comp(__i, __first))
1848 {
1849 typename iterator_traits<_RandomAccessIterator>::value_type
1850 __val = _GLIBCXX_MOVE(*__i);
1851 _GLIBCXX_MOVE_BACKWARD3(__first, __i, __i + 1);
1852 *__first = _GLIBCXX_MOVE(__val);
1853 }
1854 else
1855 std::__unguarded_linear_insert(__i,
1856 __gnu_cxx::__ops::__val_comp_iter(__comp));
1857 }
1858 }
1859
1860 /// This is a helper function for the sort routine.
1861 template<typename _RandomAccessIterator, typename _Compare>
1862 inline void
1863 __unguarded_insertion_sort(_RandomAccessIterator __first,
1864 _RandomAccessIterator __last, _Compare __comp)
1865 {
1866 for (_RandomAccessIterator __i = __first; __i != __last; ++__i)
1867 std::__unguarded_linear_insert(__i,
1868 __gnu_cxx::__ops::__val_comp_iter(__comp));
1869 }
1870
1871 /**
1872 * @doctodo
1873 * This controls some aspect of the sort routines.
1874 */
1875 enum { _S_threshold = 16 };
1876
1877 /// This is a helper function for the sort routine.
1878 template<typename _RandomAccessIterator, typename _Compare>
1879 void
1880 __final_insertion_sort(_RandomAccessIterator __first,
1881 _RandomAccessIterator __last, _Compare __comp)
1882 {
1883 if (__last - __first > int(_S_threshold))
1884 {
1885 std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
1886 std::__unguarded_insertion_sort(__first + int(_S_threshold), __last,
1887 __comp);
1888 }
1889 else
1890 std::__insertion_sort(__first, __last, __comp);
1891 }
1892
1893 /// This is a helper function...
1894 template<typename _RandomAccessIterator, typename _Compare>
1895 _RandomAccessIterator
1896 __unguarded_partition(_RandomAccessIterator __first,
1897 _RandomAccessIterator __last,
1898 _RandomAccessIterator __pivot, _Compare __comp)
1899 {
1900 while (true)
1901 {
1902 while (__comp(__first, __pivot))
1903 ++__first;
1904 --__last;
1905 while (__comp(__pivot, __last))
1906 --__last;
1907 if (!(__first < __last))
1908 return __first;
1909 std::iter_swap(__first, __last);
1910 ++__first;
1911 }
1912 }
1913
1914 /// This is a helper function...
1915 template<typename _RandomAccessIterator, typename _Compare>
1916 inline _RandomAccessIterator
1917 __unguarded_partition_pivot(_RandomAccessIterator __first,
1918 _RandomAccessIterator __last, _Compare __comp)
1919 {
1920 _RandomAccessIterator __mid = __first + (__last - __first) / 2;
1921 std::__move_median_to_first(__first, __first + 1, __mid, __last - 1,
1922 __comp);
1923 return std::__unguarded_partition(__first + 1, __last, __first, __comp);
1924 }
1925
1926 template<typename _RandomAccessIterator, typename _Compare>
1927 inline void
1928 __partial_sort(_RandomAccessIterator __first,
1929 _RandomAccessIterator __middle,
1930 _RandomAccessIterator __last,
1931 _Compare __comp)
1932 {
1933 std::__heap_select(__first, __middle, __last, __comp);
1934 std::__sort_heap(__first, __middle, __comp);
1935 }
1936
1937 /// This is a helper function for the sort routine.
1938 template<typename _RandomAccessIterator, typename _Size, typename _Compare>
1939 void
1940 __introsort_loop(_RandomAccessIterator __first,
1941 _RandomAccessIterator __last,
1942 _Size __depth_limit, _Compare __comp)
1943 {
1944 while (__last - __first > int(_S_threshold))
1945 {
1946 if (__depth_limit == 0)
1947 {
1948 std::__partial_sort(__first, __last, __last, __comp);
1949 return;
1950 }
1951 --__depth_limit;
1952 _RandomAccessIterator __cut =
1953 std::__unguarded_partition_pivot(__first, __last, __comp);
1954 std::__introsort_loop(__cut, __last, __depth_limit, __comp);
1955 __last = __cut;
1956 }
1957 }
1958
1959 // sort
1960
1961 template<typename _RandomAccessIterator, typename _Compare>
1962 inline void
1963 __sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
1964 _Compare __comp)
1965 {
1966 if (__first != __last)
1967 {
1968 std::__introsort_loop(__first, __last,
1969 std::__lg(__last - __first) * 2,
1970 __comp);
1971 std::__final_insertion_sort(__first, __last, __comp);
1972 }
1973 }
1974
1975 template<typename _RandomAccessIterator, typename _Size, typename _Compare>
1976 void
1977 __introselect(_RandomAccessIterator __first, _RandomAccessIterator __nth,
1978 _RandomAccessIterator __last, _Size __depth_limit,
1979 _Compare __comp)
1980 {
1981 while (__last - __first > 3)
1982 {
1983 if (__depth_limit == 0)
1984 {
1985 std::__heap_select(__first, __nth + 1, __last, __comp);
1986 // Place the nth largest element in its final position.
1987 std::iter_swap(__first, __nth);
1988 return;
1989 }
1990 --__depth_limit;
1991 _RandomAccessIterator __cut =
1992 std::__unguarded_partition_pivot(__first, __last, __comp);
1993 if (__cut <= __nth)
1994 __first = __cut;
1995 else
1996 __last = __cut;
1997 }
1998 std::__insertion_sort(__first, __last, __comp);
1999 }
2000
2001 // nth_element
2002
2003 // lower_bound moved to stl_algobase.h
2004
2005 /**
2006 * @brief Finds the first position in which @p __val could be inserted
2007 * without changing the ordering.
2008 * @ingroup binary_search_algorithms
2009 * @param __first An iterator.
2010 * @param __last Another iterator.
2011 * @param __val The search term.
2012 * @param __comp A functor to use for comparisons.
2013 * @return An iterator pointing to the first element <em>not less
2014 * than</em> @p __val, or end() if every element is less
2015 * than @p __val.
2016 * @ingroup binary_search_algorithms
2017 *
2018 * The comparison function should have the same effects on ordering as
2019 * the function used for the initial sort.
2020 */
2021 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2022 inline _ForwardIterator
2023 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
2024 const _Tp& __val, _Compare __comp)
2025 {
2026 // concept requirements
2027 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2028 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2029 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
2030 __glibcxx_requires_partitioned_lower_pred(__first, __last,
2031 __val, __comp);
2032
2033 return std::__lower_bound(__first, __last, __val,
2034 __gnu_cxx::__ops::__iter_comp_val(__comp));
2035 }
2036
2037 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2038 _ForwardIterator
2039 __upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2040 const _Tp& __val, _Compare __comp)
2041 {
2042 typedef typename iterator_traits<_ForwardIterator>::difference_type
2043 _DistanceType;
2044
2045 _DistanceType __len = std::distance(__first, __last);
2046
2047 while (__len > 0)
2048 {
2049 _DistanceType __half = __len >> 1;
2050 _ForwardIterator __middle = __first;
2051 std::advance(__middle, __half);
2052 if (__comp(__val, __middle))
2053 __len = __half;
2054 else
2055 {
2056 __first = __middle;
2057 ++__first;
2058 __len = __len - __half - 1;
2059 }
2060 }
2061 return __first;
2062 }
2063
2064 /**
2065 * @brief Finds the last position in which @p __val could be inserted
2066 * without changing the ordering.
2067 * @ingroup binary_search_algorithms
2068 * @param __first An iterator.
2069 * @param __last Another iterator.
2070 * @param __val The search term.
2071 * @return An iterator pointing to the first element greater than @p __val,
2072 * or end() if no elements are greater than @p __val.
2073 * @ingroup binary_search_algorithms
2074 */
2075 template<typename _ForwardIterator, typename _Tp>
2076 inline _ForwardIterator
2077 upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2078 const _Tp& __val)
2079 {
2080 // concept requirements
2081 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2082 __glibcxx_function_requires(_LessThanOpConcept<
2083 _Tp, typename iterator_traits<_ForwardIterator>::value_type>)
2084 __glibcxx_requires_partitioned_upper(__first, __last, __val);
2085
2086 return std::__upper_bound(__first, __last, __val,
2087 __gnu_cxx::__ops::__val_less_iter());
2088 }
2089
2090 /**
2091 * @brief Finds the last position in which @p __val could be inserted
2092 * without changing the ordering.
2093 * @ingroup binary_search_algorithms
2094 * @param __first An iterator.
2095 * @param __last Another iterator.
2096 * @param __val The search term.
2097 * @param __comp A functor to use for comparisons.
2098 * @return An iterator pointing to the first element greater than @p __val,
2099 * or end() if no elements are greater than @p __val.
2100 * @ingroup binary_search_algorithms
2101 *
2102 * The comparison function should have the same effects on ordering as
2103 * the function used for the initial sort.
2104 */
2105 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2106 inline _ForwardIterator
2107 upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2108 const _Tp& __val, _Compare __comp)
2109 {
2110 // concept requirements
2111 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2112 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2113 _Tp, typename iterator_traits<_ForwardIterator>::value_type>)
2114 __glibcxx_requires_partitioned_upper_pred(__first, __last,
2115 __val, __comp);
2116
2117 return std::__upper_bound(__first, __last, __val,
2118 __gnu_cxx::__ops::__val_comp_iter(__comp));
2119 }
2120
2121 template<typename _ForwardIterator, typename _Tp,
2122 typename _CompareItTp, typename _CompareTpIt>
2123 pair<_ForwardIterator, _ForwardIterator>
2124 __equal_range(_ForwardIterator __first, _ForwardIterator __last,
2125 const _Tp& __val,
2126 _CompareItTp __comp_it_val, _CompareTpIt __comp_val_it)
2127 {
2128 typedef typename iterator_traits<_ForwardIterator>::difference_type
2129 _DistanceType;
2130
2131 _DistanceType __len = std::distance(__first, __last);
2132
2133 while (__len > 0)
2134 {
2135 _DistanceType __half = __len >> 1;
2136 _ForwardIterator __middle = __first;
2137 std::advance(__middle, __half);
2138 if (__comp_it_val(__middle, __val))
2139 {
2140 __first = __middle;
2141 ++__first;
2142 __len = __len - __half - 1;
2143 }
2144 else if (__comp_val_it(__val, __middle))
2145 __len = __half;
2146 else
2147 {
2148 _ForwardIterator __left
2149 = std::__lower_bound(__first, __middle, __val, __comp_it_val);
2150 std::advance(__first, __len);
2151 _ForwardIterator __right
2152 = std::__upper_bound(++__middle, __first, __val, __comp_val_it);
2153 return pair<_ForwardIterator, _ForwardIterator>(__left, __right);
2154 }
2155 }
2156 return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
2157 }
2158
2159 /**
2160 * @brief Finds the largest subrange in which @p __val could be inserted
2161 * at any place in it without changing the ordering.
2162 * @ingroup binary_search_algorithms
2163 * @param __first An iterator.
2164 * @param __last Another iterator.
2165 * @param __val The search term.
2166 * @return An pair of iterators defining the subrange.
2167 * @ingroup binary_search_algorithms
2168 *
2169 * This is equivalent to
2170 * @code
2171 * std::make_pair(lower_bound(__first, __last, __val),
2172 * upper_bound(__first, __last, __val))
2173 * @endcode
2174 * but does not actually call those functions.
2175 */
2176 template<typename _ForwardIterator, typename _Tp>
2177 inline pair<_ForwardIterator, _ForwardIterator>
2178 equal_range(_ForwardIterator __first, _ForwardIterator __last,
2179 const _Tp& __val)
2180 {
2181 // concept requirements
2182 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2183 __glibcxx_function_requires(_LessThanOpConcept<
2184 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
2185 __glibcxx_function_requires(_LessThanOpConcept<
2186 _Tp, typename iterator_traits<_ForwardIterator>::value_type>)
2187 __glibcxx_requires_partitioned_lower(__first, __last, __val);
2188 __glibcxx_requires_partitioned_upper(__first, __last, __val);
2189
2190 return std::__equal_range(__first, __last, __val,
2191 __gnu_cxx::__ops::__iter_less_val(),
2192 __gnu_cxx::__ops::__val_less_iter());
2193 }
2194
2195 /**
2196 * @brief Finds the largest subrange in which @p __val could be inserted
2197 * at any place in it without changing the ordering.
2198 * @param __first An iterator.
2199 * @param __last Another iterator.
2200 * @param __val The search term.
2201 * @param __comp A functor to use for comparisons.
2202 * @return An pair of iterators defining the subrange.
2203 * @ingroup binary_search_algorithms
2204 *
2205 * This is equivalent to
2206 * @code
2207 * std::make_pair(lower_bound(__first, __last, __val, __comp),
2208 * upper_bound(__first, __last, __val, __comp))
2209 * @endcode
2210 * but does not actually call those functions.
2211 */
2212 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2213 inline pair<_ForwardIterator, _ForwardIterator>
2214 equal_range(_ForwardIterator __first, _ForwardIterator __last,
2215 const _Tp& __val, _Compare __comp)
2216 {
2217 // concept requirements
2218 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2219 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2220 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
2221 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2222 _Tp, typename iterator_traits<_ForwardIterator>::value_type>)
2223 __glibcxx_requires_partitioned_lower_pred(__first, __last,
2224 __val, __comp);
2225 __glibcxx_requires_partitioned_upper_pred(__first, __last,
2226 __val, __comp);
2227
2228 return std::__equal_range(__first, __last, __val,
2229 __gnu_cxx::__ops::__iter_comp_val(__comp),
2230 __gnu_cxx::__ops::__val_comp_iter(__comp));
2231 }
2232
2233 /**
2234 * @brief Determines whether an element exists in a range.
2235 * @ingroup binary_search_algorithms
2236 * @param __first An iterator.
2237 * @param __last Another iterator.
2238 * @param __val The search term.
2239 * @return True if @p __val (or its equivalent) is in [@p
2240 * __first,@p __last ].
2241 *
2242 * Note that this does not actually return an iterator to @p __val. For
2243 * that, use std::find or a container's specialized find member functions.
2244 */
2245 template<typename _ForwardIterator, typename _Tp>
2246 bool
2247 binary_search(_ForwardIterator __first, _ForwardIterator __last,
2248 const _Tp& __val)
2249 {
2250 // concept requirements
2251 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2252 __glibcxx_function_requires(_LessThanOpConcept<
2253 _Tp, typename iterator_traits<_ForwardIterator>::value_type>)
2254 __glibcxx_requires_partitioned_lower(__first, __last, __val);
2255 __glibcxx_requires_partitioned_upper(__first, __last, __val);
2256
2257 _ForwardIterator __i
2258 = std::__lower_bound(__first, __last, __val,
2259 __gnu_cxx::__ops::__iter_less_val());
2260 return __i != __last && !(__val < *__i);
2261 }
2262
2263 /**
2264 * @brief Determines whether an element exists in a range.
2265 * @ingroup binary_search_algorithms
2266 * @param __first An iterator.
2267 * @param __last Another iterator.
2268 * @param __val The search term.
2269 * @param __comp A functor to use for comparisons.
2270 * @return True if @p __val (or its equivalent) is in @p [__first,__last].
2271 *
2272 * Note that this does not actually return an iterator to @p __val. For
2273 * that, use std::find or a container's specialized find member functions.
2274 *
2275 * The comparison function should have the same effects on ordering as
2276 * the function used for the initial sort.
2277 */
2278 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2279 bool
2280 binary_search(_ForwardIterator __first, _ForwardIterator __last,
2281 const _Tp& __val, _Compare __comp)
2282 {
2283 // concept requirements
2284 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2285 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2286 _Tp, typename iterator_traits<_ForwardIterator>::value_type>)
2287 __glibcxx_requires_partitioned_lower_pred(__first, __last,
2288 __val, __comp);
2289 __glibcxx_requires_partitioned_upper_pred(__first, __last,
2290 __val, __comp);
2291
2292 _ForwardIterator __i
2293 = std::__lower_bound(__first, __last, __val,
2294 __gnu_cxx::__ops::__iter_comp_val(__comp));
2295 return __i != __last && !bool(__comp(__val, *__i));
2296 }
2297
2298 // merge
2299
2300 /// This is a helper function for the __merge_adaptive routines.
2301 template<typename _InputIterator1, typename _InputIterator2,
2302 typename _OutputIterator, typename _Compare>
2303 void
2304 __move_merge_adaptive(_InputIterator1 __first1, _InputIterator1 __last1,
2305 _InputIterator2 __first2, _InputIterator2 __last2,
2306 _OutputIterator __result, _Compare __comp)
2307 {
2308 while (__first1 != __last1 && __first2 != __last2)
2309 {
2310 if (__comp(__first2, __first1))
2311 {
2312 *__result = _GLIBCXX_MOVE(*__first2);
2313 ++__first2;
2314 }
2315 else
2316 {
2317 *__result = _GLIBCXX_MOVE(*__first1);
2318 ++__first1;
2319 }
2320 ++__result;
2321 }
2322 if (__first1 != __last1)
2323 _GLIBCXX_MOVE3(__first1, __last1, __result);
2324 }
2325
2326 /// This is a helper function for the __merge_adaptive routines.
2327 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
2328 typename _BidirectionalIterator3, typename _Compare>
2329 void
2330 __move_merge_adaptive_backward(_BidirectionalIterator1 __first1,
2331 _BidirectionalIterator1 __last1,
2332 _BidirectionalIterator2 __first2,
2333 _BidirectionalIterator2 __last2,
2334 _BidirectionalIterator3 __result,
2335 _Compare __comp)
2336 {
2337 if (__first1 == __last1)
2338 {
2339 _GLIBCXX_MOVE_BACKWARD3(__first2, __last2, __result);
2340 return;
2341 }
2342 else if (__first2 == __last2)
2343 return;
2344
2345 --__last1;
2346 --__last2;
2347 while (true)
2348 {
2349 if (__comp(__last2, __last1))
2350 {
2351 *--__result = _GLIBCXX_MOVE(*__last1);
2352 if (__first1 == __last1)
2353 {
2354 _GLIBCXX_MOVE_BACKWARD3(__first2, ++__last2, __result);
2355 return;
2356 }
2357 --__last1;
2358 }
2359 else
2360 {
2361 *--__result = _GLIBCXX_MOVE(*__last2);
2362 if (__first2 == __last2)
2363 return;
2364 --__last2;
2365 }
2366 }
2367 }
2368
2369 /// This is a helper function for the merge routines.
2370 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
2371 typename _Distance>
2372 _BidirectionalIterator1
2373 __rotate_adaptive(_BidirectionalIterator1 __first,
2374 _BidirectionalIterator1 __middle,
2375 _BidirectionalIterator1 __last,
2376 _Distance __len1, _Distance __len2,
2377 _BidirectionalIterator2 __buffer,
2378 _Distance __buffer_size)
2379 {
2380 _BidirectionalIterator2 __buffer_end;
2381 if (__len1 > __len2 && __len2 <= __buffer_size)
2382 {
2383 if (__len2)
2384 {
2385 __buffer_end = _GLIBCXX_MOVE3(__middle, __last, __buffer);
2386 _GLIBCXX_MOVE_BACKWARD3(__first, __middle, __last);
2387 return _GLIBCXX_MOVE3(__buffer, __buffer_end, __first);
2388 }
2389 else
2390 return __first;
2391 }
2392 else if (__len1 <= __buffer_size)
2393 {
2394 if (__len1)
2395 {
2396 __buffer_end = _GLIBCXX_MOVE3(__first, __middle, __buffer);
2397 _GLIBCXX_MOVE3(__middle, __last, __first);
2398 return _GLIBCXX_MOVE_BACKWARD3(__buffer, __buffer_end, __last);
2399 }
2400 else
2401 return __last;
2402 }
2403 else
2404 {
2405 std::rotate(__first, __middle, __last);
2406 std::advance(__first, std::distance(__middle, __last));
2407 return __first;
2408 }
2409 }
2410
2411 /// This is a helper function for the merge routines.
2412 template<typename _BidirectionalIterator, typename _Distance,
2413 typename _Pointer, typename _Compare>
2414 void
2415 __merge_adaptive(_BidirectionalIterator __first,
2416 _BidirectionalIterator __middle,
2417 _BidirectionalIterator __last,
2418 _Distance __len1, _Distance __len2,
2419 _Pointer __buffer, _Distance __buffer_size,
2420 _Compare __comp)
2421 {
2422 if (__len1 <= __len2 && __len1 <= __buffer_size)
2423 {
2424 _Pointer __buffer_end = _GLIBCXX_MOVE3(__first, __middle, __buffer);
2425 std::__move_merge_adaptive(__buffer, __buffer_end, __middle, __last,
2426 __first, __comp);
2427 }
2428 else if (__len2 <= __buffer_size)
2429 {
2430 _Pointer __buffer_end = _GLIBCXX_MOVE3(__middle, __last, __buffer);
2431 std::__move_merge_adaptive_backward(__first, __middle, __buffer,
2432 __buffer_end, __last, __comp);
2433 }
2434 else
2435 {
2436 _BidirectionalIterator __first_cut = __first;
2437 _BidirectionalIterator __second_cut = __middle;
2438 _Distance __len11 = 0;
2439 _Distance __len22 = 0;
2440 if (__len1 > __len2)
2441 {
2442 __len11 = __len1 / 2;
2443 std::advance(__first_cut, __len11);
2444 __second_cut
2445 = std::__lower_bound(__middle, __last, *__first_cut,
2446 __gnu_cxx::__ops::__iter_comp_val(__comp));
2447 __len22 = std::distance(__middle, __second_cut);
2448 }
2449 else
2450 {
2451 __len22 = __len2 / 2;
2452 std::advance(__second_cut, __len22);
2453 __first_cut
2454 = std::__upper_bound(__first, __middle, *__second_cut,
2455 __gnu_cxx::__ops::__val_comp_iter(__comp));
2456 __len11 = std::distance(__first, __first_cut);
2457 }
2458
2459 _BidirectionalIterator __new_middle
2460 = std::__rotate_adaptive(__first_cut, __middle, __second_cut,
2461 __len1 - __len11, __len22, __buffer,
2462 __buffer_size);
2463 std::__merge_adaptive(__first, __first_cut, __new_middle, __len11,
2464 __len22, __buffer, __buffer_size, __comp);
2465 std::__merge_adaptive(__new_middle, __second_cut, __last,
2466 __len1 - __len11,
2467 __len2 - __len22, __buffer,
2468 __buffer_size, __comp);
2469 }
2470 }
2471
2472 /// This is a helper function for the merge routines.
2473 template<typename _BidirectionalIterator, typename _Distance,
2474 typename _Compare>
2475 void
2476 __merge_without_buffer(_BidirectionalIterator __first,
2477 _BidirectionalIterator __middle,
2478 _BidirectionalIterator __last,
2479 _Distance __len1, _Distance __len2,
2480 _Compare __comp)
2481 {
2482 if (__len1 == 0 || __len2 == 0)
2483 return;
2484
2485 if (__len1 + __len2 == 2)
2486 {
2487 if (__comp(__middle, __first))
2488 std::iter_swap(__first, __middle);
2489 return;
2490 }
2491
2492 _BidirectionalIterator __first_cut = __first;
2493 _BidirectionalIterator __second_cut = __middle;
2494 _Distance __len11 = 0;
2495 _Distance __len22 = 0;
2496 if (__len1 > __len2)
2497 {
2498 __len11 = __len1 / 2;
2499 std::advance(__first_cut, __len11);
2500 __second_cut
2501 = std::__lower_bound(__middle, __last, *__first_cut,
2502 __gnu_cxx::__ops::__iter_comp_val(__comp));
2503 __len22 = std::distance(__middle, __second_cut);
2504 }
2505 else
2506 {
2507 __len22 = __len2 / 2;
2508 std::advance(__second_cut, __len22);
2509 __first_cut
2510 = std::__upper_bound(__first, __middle, *__second_cut,
2511 __gnu_cxx::__ops::__val_comp_iter(__comp));
2512 __len11 = std::distance(__first, __first_cut);
2513 }
2514
2515 std::rotate(__first_cut, __middle, __second_cut);
2516 _BidirectionalIterator __new_middle = __first_cut;
2517 std::advance(__new_middle, std::distance(__middle, __second_cut));
2518 std::__merge_without_buffer(__first, __first_cut, __new_middle,
2519 __len11, __len22, __comp);
2520 std::__merge_without_buffer(__new_middle, __second_cut, __last,
2521 __len1 - __len11, __len2 - __len22, __comp);
2522 }
2523
2524 template<typename _BidirectionalIterator, typename _Compare>
2525 void
2526 __inplace_merge(_BidirectionalIterator __first,
2527 _BidirectionalIterator __middle,
2528 _BidirectionalIterator __last,
2529 _Compare __comp)
2530 {
2531 typedef typename iterator_traits<_BidirectionalIterator>::value_type
2532 _ValueType;
2533 typedef typename iterator_traits<_BidirectionalIterator>::difference_type
2534 _DistanceType;
2535
2536 if (__first == __middle || __middle == __last)
2537 return;
2538
2539 const _DistanceType __len1 = std::distance(__first, __middle);
2540 const _DistanceType __len2 = std::distance(__middle, __last);
2541
2542 typedef _Temporary_buffer<_BidirectionalIterator, _ValueType> _TmpBuf;
2543 _TmpBuf __buf(__first, __last);
2544
2545 if (__buf.begin() == 0)
2546 std::__merge_without_buffer
2547 (__first, __middle, __last, __len1, __len2, __comp);
2548 else
2549 std::__merge_adaptive
2550 (__first, __middle, __last, __len1, __len2, __buf.begin(),
2551 _DistanceType(__buf.size()), __comp);
2552 }
2553
2554 /**
2555 * @brief Merges two sorted ranges in place.
2556 * @ingroup sorting_algorithms
2557 * @param __first An iterator.
2558 * @param __middle Another iterator.
2559 * @param __last Another iterator.
2560 * @return Nothing.
2561 *
2562 * Merges two sorted and consecutive ranges, [__first,__middle) and
2563 * [__middle,__last), and puts the result in [__first,__last). The
2564 * output will be sorted. The sort is @e stable, that is, for
2565 * equivalent elements in the two ranges, elements from the first
2566 * range will always come before elements from the second.
2567 *
2568 * If enough additional memory is available, this takes (__last-__first)-1
2569 * comparisons. Otherwise an NlogN algorithm is used, where N is
2570 * distance(__first,__last).
2571 */
2572 template<typename _BidirectionalIterator>
2573 inline void
2574 inplace_merge(_BidirectionalIterator __first,
2575 _BidirectionalIterator __middle,
2576 _BidirectionalIterator __last)
2577 {
2578 // concept requirements
2579 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
2580 _BidirectionalIterator>)
2581 __glibcxx_function_requires(_LessThanComparableConcept<
2582 typename iterator_traits<_BidirectionalIterator>::value_type>)
2583 __glibcxx_requires_sorted(__first, __middle);
2584 __glibcxx_requires_sorted(__middle, __last);
2585 __glibcxx_requires_irreflexive(__first, __last);
2586
2587 std::__inplace_merge(__first, __middle, __last,
2588 __gnu_cxx::__ops::__iter_less_iter());
2589 }
2590
2591 /**
2592 * @brief Merges two sorted ranges in place.
2593 * @ingroup sorting_algorithms
2594 * @param __first An iterator.
2595 * @param __middle Another iterator.
2596 * @param __last Another iterator.
2597 * @param __comp A functor to use for comparisons.
2598 * @return Nothing.
2599 *
2600 * Merges two sorted and consecutive ranges, [__first,__middle) and
2601 * [middle,last), and puts the result in [__first,__last). The output will
2602 * be sorted. The sort is @e stable, that is, for equivalent
2603 * elements in the two ranges, elements from the first range will always
2604 * come before elements from the second.
2605 *
2606 * If enough additional memory is available, this takes (__last-__first)-1
2607 * comparisons. Otherwise an NlogN algorithm is used, where N is
2608 * distance(__first,__last).
2609 *
2610 * The comparison function should have the same effects on ordering as
2611 * the function used for the initial sort.
2612 */
2613 template<typename _BidirectionalIterator, typename _Compare>
2614 inline void
2615 inplace_merge(_BidirectionalIterator __first,
2616 _BidirectionalIterator __middle,
2617 _BidirectionalIterator __last,
2618 _Compare __comp)
2619 {
2620 // concept requirements
2621 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
2622 _BidirectionalIterator>)
2623 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2624 typename iterator_traits<_BidirectionalIterator>::value_type,
2625 typename iterator_traits<_BidirectionalIterator>::value_type>)
2626 __glibcxx_requires_sorted_pred(__first, __middle, __comp);
2627 __glibcxx_requires_sorted_pred(__middle, __last, __comp);
2628 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
2629
2630 std::__inplace_merge(__first, __middle, __last,
2631 __gnu_cxx::__ops::__iter_comp_iter(__comp));
2632 }
2633
2634
2635 /// This is a helper function for the __merge_sort_loop routines.
2636 template<typename _InputIterator, typename _OutputIterator,
2637 typename _Compare>
2638 _OutputIterator
2639 __move_merge(_InputIterator __first1, _InputIterator __last1,
2640 _InputIterator __first2, _InputIterator __last2,
2641 _OutputIterator __result, _Compare __comp)
2642 {
2643 while (__first1 != __last1 && __first2 != __last2)
2644 {
2645 if (__comp(__first2, __first1))
2646 {
2647 *__result = _GLIBCXX_MOVE(*__first2);
2648 ++__first2;
2649 }
2650 else
2651 {
2652 *__result = _GLIBCXX_MOVE(*__first1);
2653 ++__first1;
2654 }
2655 ++__result;
2656 }
2657 return _GLIBCXX_MOVE3(__first2, __last2,
2658 _GLIBCXX_MOVE3(__first1, __last1,
2659 __result));
2660 }
2661
2662 template<typename _RandomAccessIterator1, typename _RandomAccessIterator2,
2663 typename _Distance, typename _Compare>
2664 void
2665 __merge_sort_loop(_RandomAccessIterator1 __first,
2666 _RandomAccessIterator1 __last,
2667 _RandomAccessIterator2 __result, _Distance __step_size,
2668 _Compare __comp)
2669 {
2670 const _Distance __two_step = 2 * __step_size;
2671
2672 while (__last - __first >= __two_step)
2673 {
2674 __result = std::__move_merge(__first, __first + __step_size,
2675 __first + __step_size,
2676 __first + __two_step,
2677 __result, __comp);
2678 __first += __two_step;
2679 }
2680 __step_size = std::min(_Distance(__last - __first), __step_size);
2681
2682 std::__move_merge(__first, __first + __step_size,
2683 __first + __step_size, __last, __result, __comp);
2684 }
2685
2686 template<typename _RandomAccessIterator, typename _Distance,
2687 typename _Compare>
2688 void
2689 __chunk_insertion_sort(_RandomAccessIterator __first,
2690 _RandomAccessIterator __last,
2691 _Distance __chunk_size, _Compare __comp)
2692 {
2693 while (__last - __first >= __chunk_size)
2694 {
2695 std::__insertion_sort(__first, __first + __chunk_size, __comp);
2696 __first += __chunk_size;
2697 }
2698 std::__insertion_sort(__first, __last, __comp);
2699 }
2700
2701 enum { _S_chunk_size = 7 };
2702
2703 template<typename _RandomAccessIterator, typename _Pointer, typename _Compare>
2704 void
2705 __merge_sort_with_buffer(_RandomAccessIterator __first,
2706 _RandomAccessIterator __last,
2707 _Pointer __buffer, _Compare __comp)
2708 {
2709 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
2710 _Distance;
2711
2712 const _Distance __len = __last - __first;
2713 const _Pointer __buffer_last = __buffer + __len;
2714
2715 _Distance __step_size = _S_chunk_size;
2716 std::__chunk_insertion_sort(__first, __last, __step_size, __comp);
2717
2718 while (__step_size < __len)
2719 {
2720 std::__merge_sort_loop(__first, __last, __buffer,
2721 __step_size, __comp);
2722 __step_size *= 2;
2723 std::__merge_sort_loop(__buffer, __buffer_last, __first,
2724 __step_size, __comp);
2725 __step_size *= 2;
2726 }
2727 }
2728
2729 template<typename _RandomAccessIterator, typename _Pointer,
2730 typename _Distance, typename _Compare>
2731 void
2732 __stable_sort_adaptive(_RandomAccessIterator __first,
2733 _RandomAccessIterator __last,
2734 _Pointer __buffer, _Distance __buffer_size,
2735 _Compare __comp)
2736 {
2737 const _Distance __len = (__last - __first + 1) / 2;
2738 const _RandomAccessIterator __middle = __first + __len;
2739 if (__len > __buffer_size)
2740 {
2741 std::__stable_sort_adaptive(__first, __middle, __buffer,
2742 __buffer_size, __comp);
2743 std::__stable_sort_adaptive(__middle, __last, __buffer,
2744 __buffer_size, __comp);
2745 }
2746 else
2747 {
2748 std::__merge_sort_with_buffer(__first, __middle, __buffer, __comp);
2749 std::__merge_sort_with_buffer(__middle, __last, __buffer, __comp);
2750 }
2751 std::__merge_adaptive(__first, __middle, __last,
2752 _Distance(__middle - __first),
2753 _Distance(__last - __middle),
2754 __buffer, __buffer_size,
2755 __comp);
2756 }
2757
2758 /// This is a helper function for the stable sorting routines.
2759 template<typename _RandomAccessIterator, typename _Compare>
2760 void
2761 __inplace_stable_sort(_RandomAccessIterator __first,
2762 _RandomAccessIterator __last, _Compare __comp)
2763 {
2764 if (__last - __first < 15)
2765 {
2766 std::__insertion_sort(__first, __last, __comp);
2767 return;
2768 }
2769 _RandomAccessIterator __middle = __first + (__last - __first) / 2;
2770 std::__inplace_stable_sort(__first, __middle, __comp);
2771 std::__inplace_stable_sort(__middle, __last, __comp);
2772 std::__merge_without_buffer(__first, __middle, __last,
2773 __middle - __first,
2774 __last - __middle,
2775 __comp);
2776 }
2777
2778 // stable_sort
2779
2780 // Set algorithms: includes, set_union, set_intersection, set_difference,
2781 // set_symmetric_difference. All of these algorithms have the precondition
2782 // that their input ranges are sorted and the postcondition that their output
2783 // ranges are sorted.
2784
2785 template<typename _InputIterator1, typename _InputIterator2,
2786 typename _Compare>
2787 bool
2788 __includes(_InputIterator1 __first1, _InputIterator1 __last1,
2789 _InputIterator2 __first2, _InputIterator2 __last2,
2790 _Compare __comp)
2791 {
2792 while (__first1 != __last1 && __first2 != __last2)
2793 if (__comp(__first2, __first1))
2794 return false;
2795 else if (__comp(__first1, __first2))
2796 ++__first1;
2797 else
2798 {
2799 ++__first1;
2800 ++__first2;
2801 }
2802
2803 return __first2 == __last2;
2804 }
2805
2806 /**
2807 * @brief Determines whether all elements of a sequence exists in a range.
2808 * @param __first1 Start of search range.
2809 * @param __last1 End of search range.
2810 * @param __first2 Start of sequence
2811 * @param __last2 End of sequence.
2812 * @return True if each element in [__first2,__last2) is contained in order
2813 * within [__first1,__last1). False otherwise.
2814 * @ingroup set_algorithms
2815 *
2816 * This operation expects both [__first1,__last1) and
2817 * [__first2,__last2) to be sorted. Searches for the presence of
2818 * each element in [__first2,__last2) within [__first1,__last1).
2819 * The iterators over each range only move forward, so this is a
2820 * linear algorithm. If an element in [__first2,__last2) is not
2821 * found before the search iterator reaches @p __last2, false is
2822 * returned.
2823 */
2824 template<typename _InputIterator1, typename _InputIterator2>
2825 inline bool
2826 includes(_InputIterator1 __first1, _InputIterator1 __last1,
2827 _InputIterator2 __first2, _InputIterator2 __last2)
2828 {
2829 // concept requirements
2830 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2831 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2832 __glibcxx_function_requires(_LessThanOpConcept<
2833 typename iterator_traits<_InputIterator1>::value_type,
2834 typename iterator_traits<_InputIterator2>::value_type>)
2835 __glibcxx_function_requires(_LessThanOpConcept<
2836 typename iterator_traits<_InputIterator2>::value_type,
2837 typename iterator_traits<_InputIterator1>::value_type>)
2838 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
2839 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
2840 __glibcxx_requires_irreflexive2(__first1, __last1);
2841 __glibcxx_requires_irreflexive2(__first2, __last2);
2842
2843 return std::__includes(__first1, __last1, __first2, __last2,
2844 __gnu_cxx::__ops::__iter_less_iter());
2845 }
2846
2847 /**
2848 * @brief Determines whether all elements of a sequence exists in a range
2849 * using comparison.
2850 * @ingroup set_algorithms
2851 * @param __first1 Start of search range.
2852 * @param __last1 End of search range.
2853 * @param __first2 Start of sequence
2854 * @param __last2 End of sequence.
2855 * @param __comp Comparison function to use.
2856 * @return True if each element in [__first2,__last2) is contained
2857 * in order within [__first1,__last1) according to comp. False
2858 * otherwise. @ingroup set_algorithms
2859 *
2860 * This operation expects both [__first1,__last1) and
2861 * [__first2,__last2) to be sorted. Searches for the presence of
2862 * each element in [__first2,__last2) within [__first1,__last1),
2863 * using comp to decide. The iterators over each range only move
2864 * forward, so this is a linear algorithm. If an element in
2865 * [__first2,__last2) is not found before the search iterator
2866 * reaches @p __last2, false is returned.
2867 */
2868 template<typename _InputIterator1, typename _InputIterator2,
2869 typename _Compare>
2870 inline bool
2871 includes(_InputIterator1 __first1, _InputIterator1 __last1,
2872 _InputIterator2 __first2, _InputIterator2 __last2,
2873 _Compare __comp)
2874 {
2875 // concept requirements
2876 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2877 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2878 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2879 typename iterator_traits<_InputIterator1>::value_type,
2880 typename iterator_traits<_InputIterator2>::value_type>)
2881 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2882 typename iterator_traits<_InputIterator2>::value_type,
2883 typename iterator_traits<_InputIterator1>::value_type>)
2884 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
2885 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
2886 __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp);
2887 __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp);
2888
2889 return std::__includes(__first1, __last1, __first2, __last2,
2890 __gnu_cxx::__ops::__iter_comp_iter(__comp));
2891 }
2892
2893 // nth_element
2894 // merge
2895 // set_difference
2896 // set_intersection
2897 // set_union
2898 // stable_sort
2899 // set_symmetric_difference
2900 // min_element
2901 // max_element
2902
2903 template<typename _BidirectionalIterator, typename _Compare>
2904 bool
2905 __next_permutation(_BidirectionalIterator __first,
2906 _BidirectionalIterator __last, _Compare __comp)
2907 {
2908 if (__first == __last)
2909 return false;
2910 _BidirectionalIterator __i = __first;
2911 ++__i;
2912 if (__i == __last)
2913 return false;
2914 __i = __last;
2915 --__i;
2916
2917 for(;;)
2918 {
2919 _BidirectionalIterator __ii = __i;
2920 --__i;
2921 if (__comp(__i, __ii))
2922 {
2923 _BidirectionalIterator __j = __last;
2924 while (!__comp(__i, --__j))
2925 {}
2926 std::iter_swap(__i, __j);
2927 std::__reverse(__ii, __last,
2928 std::__iterator_category(__first));
2929 return true;
2930 }
2931 if (__i == __first)
2932 {
2933 std::__reverse(__first, __last,
2934 std::__iterator_category(__first));
2935 return false;
2936 }
2937 }
2938 }
2939
2940 /**
2941 * @brief Permute range into the next @e dictionary ordering.
2942 * @ingroup sorting_algorithms
2943 * @param __first Start of range.
2944 * @param __last End of range.
2945 * @return False if wrapped to first permutation, true otherwise.
2946 *
2947 * Treats all permutations of the range as a set of @e dictionary sorted
2948 * sequences. Permutes the current sequence into the next one of this set.
2949 * Returns true if there are more sequences to generate. If the sequence
2950 * is the largest of the set, the smallest is generated and false returned.
2951 */
2952 template<typename _BidirectionalIterator>
2953 inline bool
2954 next_permutation(_BidirectionalIterator __first,
2955 _BidirectionalIterator __last)
2956 {
2957 // concept requirements
2958 __glibcxx_function_requires(_BidirectionalIteratorConcept<
2959 _BidirectionalIterator>)
2960 __glibcxx_function_requires(_LessThanComparableConcept<
2961 typename iterator_traits<_BidirectionalIterator>::value_type>)
2962 __glibcxx_requires_valid_range(__first, __last);
2963 __glibcxx_requires_irreflexive(__first, __last);
2964
2965 return std::__next_permutation
2966 (__first, __last, __gnu_cxx::__ops::__iter_less_iter());
2967 }
2968
2969 /**
2970 * @brief Permute range into the next @e dictionary ordering using
2971 * comparison functor.
2972 * @ingroup sorting_algorithms
2973 * @param __first Start of range.
2974 * @param __last End of range.
2975 * @param __comp A comparison functor.
2976 * @return False if wrapped to first permutation, true otherwise.
2977 *
2978 * Treats all permutations of the range [__first,__last) as a set of
2979 * @e dictionary sorted sequences ordered by @p __comp. Permutes the current
2980 * sequence into the next one of this set. Returns true if there are more
2981 * sequences to generate. If the sequence is the largest of the set, the
2982 * smallest is generated and false returned.
2983 */
2984 template<typename _BidirectionalIterator, typename _Compare>
2985 inline bool
2986 next_permutation(_BidirectionalIterator __first,
2987 _BidirectionalIterator __last, _Compare __comp)
2988 {
2989 // concept requirements
2990 __glibcxx_function_requires(_BidirectionalIteratorConcept<
2991 _BidirectionalIterator>)
2992 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2993 typename iterator_traits<_BidirectionalIterator>::value_type,
2994 typename iterator_traits<_BidirectionalIterator>::value_type>)
2995 __glibcxx_requires_valid_range(__first, __last);
2996 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
2997
2998 return std::__next_permutation
2999 (__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
3000 }
3001
3002 template<typename _BidirectionalIterator, typename _Compare>
3003 bool
3004 __prev_permutation(_BidirectionalIterator __first,
3005 _BidirectionalIterator __last, _Compare __comp)
3006 {
3007 if (__first == __last)
3008 return false;
3009 _BidirectionalIterator __i = __first;
3010 ++__i;
3011 if (__i == __last)
3012 return false;
3013 __i = __last;
3014 --__i;
3015
3016 for(;;)
3017 {
3018 _BidirectionalIterator __ii = __i;
3019 --__i;
3020 if (__comp(__ii, __i))
3021 {
3022 _BidirectionalIterator __j = __last;
3023 while (!__comp(--__j, __i))
3024 {}
3025 std::iter_swap(__i, __j);
3026 std::__reverse(__ii, __last,
3027 std::__iterator_category(__first));
3028 return true;
3029 }
3030 if (__i == __first)
3031 {
3032 std::__reverse(__first, __last,
3033 std::__iterator_category(__first));
3034 return false;
3035 }
3036 }
3037 }
3038
3039 /**
3040 * @brief Permute range into the previous @e dictionary ordering.
3041 * @ingroup sorting_algorithms
3042 * @param __first Start of range.
3043 * @param __last End of range.
3044 * @return False if wrapped to last permutation, true otherwise.
3045 *
3046 * Treats all permutations of the range as a set of @e dictionary sorted
3047 * sequences. Permutes the current sequence into the previous one of this
3048 * set. Returns true if there are more sequences to generate. If the
3049 * sequence is the smallest of the set, the largest is generated and false
3050 * returned.
3051 */
3052 template<typename _BidirectionalIterator>
3053 inline bool
3054 prev_permutation(_BidirectionalIterator __first,
3055 _BidirectionalIterator __last)
3056 {
3057 // concept requirements
3058 __glibcxx_function_requires(_BidirectionalIteratorConcept<
3059 _BidirectionalIterator>)
3060 __glibcxx_function_requires(_LessThanComparableConcept<
3061 typename iterator_traits<_BidirectionalIterator>::value_type>)
3062 __glibcxx_requires_valid_range(__first, __last);
3063 __glibcxx_requires_irreflexive(__first, __last);
3064
3065 return std::__prev_permutation(__first, __last,
3066 __gnu_cxx::__ops::__iter_less_iter());
3067 }
3068
3069 /**
3070 * @brief Permute range into the previous @e dictionary ordering using
3071 * comparison functor.
3072 * @ingroup sorting_algorithms
3073 * @param __first Start of range.
3074 * @param __last End of range.
3075 * @param __comp A comparison functor.
3076 * @return False if wrapped to last permutation, true otherwise.
3077 *
3078 * Treats all permutations of the range [__first,__last) as a set of
3079 * @e dictionary sorted sequences ordered by @p __comp. Permutes the current
3080 * sequence into the previous one of this set. Returns true if there are
3081 * more sequences to generate. If the sequence is the smallest of the set,
3082 * the largest is generated and false returned.
3083 */
3084 template<typename _BidirectionalIterator, typename _Compare>
3085 inline bool
3086 prev_permutation(_BidirectionalIterator __first,
3087 _BidirectionalIterator __last, _Compare __comp)
3088 {
3089 // concept requirements
3090 __glibcxx_function_requires(_BidirectionalIteratorConcept<
3091 _BidirectionalIterator>)
3092 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3093 typename iterator_traits<_BidirectionalIterator>::value_type,
3094 typename iterator_traits<_BidirectionalIterator>::value_type>)
3095 __glibcxx_requires_valid_range(__first, __last);
3096 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
3097
3098 return std::__prev_permutation(__first, __last,
3099 __gnu_cxx::__ops::__iter_comp_iter(__comp));
3100 }
3101
3102 // replace
3103 // replace_if
3104
3105 template<typename _InputIterator, typename _OutputIterator,
3106 typename _Predicate, typename _Tp>
3107 _OutputIterator
3108 __replace_copy_if(_InputIterator __first, _InputIterator __last,
3109 _OutputIterator __result,
3110 _Predicate __pred, const _Tp& __new_value)
3111 {
3112 for (; __first != __last; ++__first, (void)++__result)
3113 if (__pred(__first))
3114 *__result = __new_value;
3115 else
3116 *__result = *__first;
3117 return __result;
3118 }
3119
3120 /**
3121 * @brief Copy a sequence, replacing each element of one value with another
3122 * value.
3123 * @param __first An input iterator.
3124 * @param __last An input iterator.
3125 * @param __result An output iterator.
3126 * @param __old_value The value to be replaced.
3127 * @param __new_value The replacement value.
3128 * @return The end of the output sequence, @p result+(last-first).
3129 *
3130 * Copies each element in the input range @p [__first,__last) to the
3131 * output range @p [__result,__result+(__last-__first)) replacing elements
3132 * equal to @p __old_value with @p __new_value.
3133 */
3134 template<typename _InputIterator, typename _OutputIterator, typename _Tp>
3135 inline _OutputIterator
3136 replace_copy(_InputIterator __first, _InputIterator __last,
3137 _OutputIterator __result,
3138 const _Tp& __old_value, const _Tp& __new_value)
3139 {
3140 // concept requirements
3141 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
3142 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
3143 typename iterator_traits<_InputIterator>::value_type>)
3144 __glibcxx_function_requires(_EqualOpConcept<
3145 typename iterator_traits<_InputIterator>::value_type, _Tp>)
3146 __glibcxx_requires_valid_range(__first, __last);
3147
3148 return std::__replace_copy_if(__first, __last, __result,
3149 __gnu_cxx::__ops::__iter_equals_val(__old_value),
3150 __new_value);
3151 }
3152
3153 /**
3154 * @brief Copy a sequence, replacing each value for which a predicate
3155 * returns true with another value.
3156 * @ingroup mutating_algorithms
3157 * @param __first An input iterator.
3158 * @param __last An input iterator.
3159 * @param __result An output iterator.
3160 * @param __pred A predicate.
3161 * @param __new_value The replacement value.
3162 * @return The end of the output sequence, @p __result+(__last-__first).
3163 *
3164 * Copies each element in the range @p [__first,__last) to the range
3165 * @p [__result,__result+(__last-__first)) replacing elements for which
3166 * @p __pred returns true with @p __new_value.
3167 */
3168 template<typename _InputIterator, typename _OutputIterator,
3169 typename _Predicate, typename _Tp>
3170 inline _OutputIterator
3171 replace_copy_if(_InputIterator __first, _InputIterator __last,
3172 _OutputIterator __result,
3173 _Predicate __pred, const _Tp& __new_value)
3174 {
3175 // concept requirements
3176 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
3177 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
3178 typename iterator_traits<_InputIterator>::value_type>)
3179 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
3180 typename iterator_traits<_InputIterator>::value_type>)
3181 __glibcxx_requires_valid_range(__first, __last);
3182
3183 return std::__replace_copy_if(__first, __last, __result,
3184 __gnu_cxx::__ops::__pred_iter(__pred),
3185 __new_value);
3186 }
3187
3188 template<typename _InputIterator, typename _Predicate>
3189 typename iterator_traits<_InputIterator>::difference_type
3190 __count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
3191 {
3192 typename iterator_traits<_InputIterator>::difference_type __n = 0;
3193 for (; __first != __last; ++__first)
3194 if (__pred(__first))
3195 ++__n;
3196 return __n;
3197 }
3198
3199#if __cplusplus >= 201103L
3200 /**
3201 * @brief Determines whether the elements of a sequence are sorted.
3202 * @ingroup sorting_algorithms
3203 * @param __first An iterator.
3204 * @param __last Another iterator.
3205 * @return True if the elements are sorted, false otherwise.
3206 */
3207 template<typename _ForwardIterator>
3208 inline bool
3209 is_sorted(_ForwardIterator __first, _ForwardIterator __last)
3210 { return std::is_sorted_until(__first, __last) == __last; }
3211
3212 /**
3213 * @brief Determines whether the elements of a sequence are sorted
3214 * according to a comparison functor.
3215 * @ingroup sorting_algorithms
3216 * @param __first An iterator.
3217 * @param __last Another iterator.
3218 * @param __comp A comparison functor.
3219 * @return True if the elements are sorted, false otherwise.
3220 */
3221 template<typename _ForwardIterator, typename _Compare>
3222 inline bool
3223 is_sorted(_ForwardIterator __first, _ForwardIterator __last,
3224 _Compare __comp)
3225 { return std::is_sorted_until(__first, __last, __comp) == __last; }
3226
3227 template<typename _ForwardIterator, typename _Compare>
3228 _ForwardIterator
3229 __is_sorted_until(_ForwardIterator __first, _ForwardIterator __last,
3230 _Compare __comp)
3231 {
3232 if (__first == __last)
3233 return __last;
3234
3235 _ForwardIterator __next = __first;
3236 for (++__next; __next != __last; __first = __next, (void)++__next)
3237 if (__comp(__next, __first))
3238 return __next;
3239 return __next;
3240 }
3241
3242 /**
3243 * @brief Determines the end of a sorted sequence.
3244 * @ingroup sorting_algorithms
3245 * @param __first An iterator.
3246 * @param __last Another iterator.
3247 * @return An iterator pointing to the last iterator i in [__first, __last)
3248 * for which the range [__first, i) is sorted.
3249 */
3250 template<typename _ForwardIterator>
3251 inline _ForwardIterator
3252 is_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
3253 {
3254 // concept requirements
3255 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3256 __glibcxx_function_requires(_LessThanComparableConcept<
3257 typename iterator_traits<_ForwardIterator>::value_type>)
3258 __glibcxx_requires_valid_range(__first, __last);
3259 __glibcxx_requires_irreflexive(__first, __last);
3260
3261 return std::__is_sorted_until(__first, __last,
3262 __gnu_cxx::__ops::__iter_less_iter());
3263 }
3264
3265 /**
3266 * @brief Determines the end of a sorted sequence using comparison functor.
3267 * @ingroup sorting_algorithms
3268 * @param __first An iterator.
3269 * @param __last Another iterator.
3270 * @param __comp A comparison functor.
3271 * @return An iterator pointing to the last iterator i in [__first, __last)
3272 * for which the range [__first, i) is sorted.
3273 */
3274 template<typename _ForwardIterator, typename _Compare>
3275 inline _ForwardIterator
3276 is_sorted_until(_ForwardIterator __first, _ForwardIterator __last,
3277 _Compare __comp)
3278 {
3279 // concept requirements
3280 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3281 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3282 typename iterator_traits<_ForwardIterator>::value_type,
3283 typename iterator_traits<_ForwardIterator>::value_type>)
3284 __glibcxx_requires_valid_range(__first, __last);
3285 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
3286
3287 return std::__is_sorted_until(__first, __last,
3288 __gnu_cxx::__ops::__iter_comp_iter(__comp));
3289 }
3290
3291 /**
3292 * @brief Determines min and max at once as an ordered pair.
3293 * @ingroup sorting_algorithms
3294 * @param __a A thing of arbitrary type.
3295 * @param __b Another thing of arbitrary type.
3296 * @return A pair(__b, __a) if __b is smaller than __a, pair(__a,
3297 * __b) otherwise.
3298 */
3299 template<typename _Tp>
3300 _GLIBCXX14_CONSTEXPR
3301 inline pair<const _Tp&, const _Tp&>
3302 minmax(const _Tp& __a, const _Tp& __b)
3303 {
3304 // concept requirements
3305 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
3306
3307 return __b < __a ? pair<const _Tp&, const _Tp&>(__b, __a)
3308 : pair<const _Tp&, const _Tp&>(__a, __b);
3309 }
3310
3311 /**
3312 * @brief Determines min and max at once as an ordered pair.
3313 * @ingroup sorting_algorithms
3314 * @param __a A thing of arbitrary type.
3315 * @param __b Another thing of arbitrary type.
3316 * @param __comp A @link comparison_functors comparison functor @endlink.
3317 * @return A pair(__b, __a) if __b is smaller than __a, pair(__a,
3318 * __b) otherwise.
3319 */
3320 template<typename _Tp, typename _Compare>
3321 _GLIBCXX14_CONSTEXPR
3322 inline pair<const _Tp&, const _Tp&>
3323 minmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
3324 {
3325 return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a)
3326 : pair<const _Tp&, const _Tp&>(__a, __b);
3327 }
3328
3329 template<typename _ForwardIterator, typename _Compare>
3330 _GLIBCXX14_CONSTEXPR
3331 pair<_ForwardIterator, _ForwardIterator>
3332 __minmax_element(_ForwardIterator __first, _ForwardIterator __last,
3333 _Compare __comp)
3334 {
3335 _ForwardIterator __next = __first;
3336 if (__first == __last
3337 || ++__next == __last)
3338 return std::make_pair(__first, __first);
3339
3340 _ForwardIterator __min{}, __max{};
3341 if (__comp(__next, __first))
3342 {
3343 __min = __next;
3344 __max = __first;
3345 }
3346 else
3347 {
3348 __min = __first;
3349 __max = __next;
3350 }
3351
3352 __first = __next;
3353 ++__first;
3354
3355 while (__first != __last)
3356 {
3357 __next = __first;
3358 if (++__next == __last)
3359 {
3360 if (__comp(__first, __min))
3361 __min = __first;
3362 else if (!__comp(__first, __max))
3363 __max = __first;
3364 break;
3365 }
3366
3367 if (__comp(__next, __first))
3368 {
3369 if (__comp(__next, __min))
3370 __min = __next;
3371 if (!__comp(__first, __max))
3372 __max = __first;
3373 }
3374 else
3375 {
3376 if (__comp(__first, __min))
3377 __min = __first;
3378 if (!__comp(__next, __max))
3379 __max = __next;
3380 }
3381
3382 __first = __next;
3383 ++__first;
3384 }
3385
3386 return std::make_pair(__min, __max);
3387 }
3388
3389 /**
3390 * @brief Return a pair of iterators pointing to the minimum and maximum
3391 * elements in a range.
3392 * @ingroup sorting_algorithms
3393 * @param __first Start of range.
3394 * @param __last End of range.
3395 * @return make_pair(m, M), where m is the first iterator i in
3396 * [__first, __last) such that no other element in the range is
3397 * smaller, and where M is the last iterator i in [__first, __last)
3398 * such that no other element in the range is larger.
3399 */
3400 template<typename _ForwardIterator>
3401 _GLIBCXX14_CONSTEXPR
3402 inline pair<_ForwardIterator, _ForwardIterator>
3403 minmax_element(_ForwardIterator __first, _ForwardIterator __last)
3404 {
3405 // concept requirements
3406 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3407 __glibcxx_function_requires(_LessThanComparableConcept<
3408 typename iterator_traits<_ForwardIterator>::value_type>)
3409 __glibcxx_requires_valid_range(__first, __last);
3410 __glibcxx_requires_irreflexive(__first, __last);
3411
3412 return std::__minmax_element(__first, __last,
3413 __gnu_cxx::__ops::__iter_less_iter());
3414 }
3415
3416 /**
3417 * @brief Return a pair of iterators pointing to the minimum and maximum
3418 * elements in a range.
3419 * @ingroup sorting_algorithms
3420 * @param __first Start of range.
3421 * @param __last End of range.
3422 * @param __comp Comparison functor.
3423 * @return make_pair(m, M), where m is the first iterator i in
3424 * [__first, __last) such that no other element in the range is
3425 * smaller, and where M is the last iterator i in [__first, __last)
3426 * such that no other element in the range is larger.
3427 */
3428 template<typename _ForwardIterator, typename _Compare>
3429 _GLIBCXX14_CONSTEXPR
3430 inline pair<_ForwardIterator, _ForwardIterator>
3431 minmax_element(_ForwardIterator __first, _ForwardIterator __last,
3432 _Compare __comp)
3433 {
3434 // concept requirements
3435 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3436 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3437 typename iterator_traits<_ForwardIterator>::value_type,
3438 typename iterator_traits<_ForwardIterator>::value_type>)
3439 __glibcxx_requires_valid_range(__first, __last);
3440 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
3441
3442 return std::__minmax_element(__first, __last,
3443 __gnu_cxx::__ops::__iter_comp_iter(__comp));
3444 }
3445
3446 // N2722 + DR 915.
3447 template<typename _Tp>
3448 _GLIBCXX14_CONSTEXPR
3449 inline _Tp
3450 min(initializer_list<_Tp> __l)
3451 { return *std::min_element(__l.begin(), __l.end()); }
3452
3453 template<typename _Tp, typename _Compare>
3454 _GLIBCXX14_CONSTEXPR
3455 inline _Tp
3456 min(initializer_list<_Tp> __l, _Compare __comp)
3457 { return *std::min_element(__l.begin(), __l.end(), __comp); }
3458
3459 template<typename _Tp>
3460 _GLIBCXX14_CONSTEXPR
3461 inline _Tp
3462 max(initializer_list<_Tp> __l)
3463 { return *std::max_element(__l.begin(), __l.end()); }
3464
3465 template<typename _Tp, typename _Compare>
3466 _GLIBCXX14_CONSTEXPR
3467 inline _Tp
3468 max(initializer_list<_Tp> __l, _Compare __comp)
3469 { return *std::max_element(__l.begin(), __l.end(), __comp); }
3470
3471 template<typename _Tp>
3472 _GLIBCXX14_CONSTEXPR
3473 inline pair<_Tp, _Tp>
3474 minmax(initializer_list<_Tp> __l)
3475 {
3476 pair<const _Tp*, const _Tp*> __p =
3477 std::minmax_element(__l.begin(), __l.end());
3478 return std::make_pair(*__p.first, *__p.second);
3479 }
3480
3481 template<typename _Tp, typename _Compare>
3482 _GLIBCXX14_CONSTEXPR
3483 inline pair<_Tp, _Tp>
3484 minmax(initializer_list<_Tp> __l, _Compare __comp)
3485 {
3486 pair<const _Tp*, const _Tp*> __p =
3487 std::minmax_element(__l.begin(), __l.end(), __comp);
3488 return std::make_pair(*__p.first, *__p.second);
3489 }
3490
3491 template<typename _ForwardIterator1, typename _ForwardIterator2,
3492 typename _BinaryPredicate>
3493 bool
3494 __is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
3495 _ForwardIterator2 __first2, _BinaryPredicate __pred)
3496 {
3497 // Efficiently compare identical prefixes: O(N) if sequences
3498 // have the same elements in the same order.
3499 for (; __first1 != __last1; ++__first1, (void)++__first2)
3500 if (!__pred(__first1, __first2))
3501 break;
3502
3503 if (__first1 == __last1)
3504 return true;
3505
3506 // Establish __last2 assuming equal ranges by iterating over the
3507 // rest of the list.
3508 _ForwardIterator2 __last2 = __first2;
3509 std::advance(__last2, std::distance(__first1, __last1));
3510 for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan)
3511 {
3512 if (__scan != std::__find_if(__first1, __scan,
3513 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan)))
3514 continue; // We've seen this one before.
3515
3516 auto __matches
3517 = std::__count_if(__first2, __last2,
3518 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan));
3519 if (0 == __matches ||
3520 std::__count_if(__scan, __last1,
3521 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan))
3522 != __matches)
3523 return false;
3524 }
3525 return true;
3526 }
3527
3528 /**
3529 * @brief Checks whether a permutation of the second sequence is equal
3530 * to the first sequence.
3531 * @ingroup non_mutating_algorithms
3532 * @param __first1 Start of first range.
3533 * @param __last1 End of first range.
3534 * @param __first2 Start of second range.
3535 * @return true if there exists a permutation of the elements in the range
3536 * [__first2, __first2 + (__last1 - __first1)), beginning with
3537 * ForwardIterator2 begin, such that equal(__first1, __last1, begin)
3538 * returns true; otherwise, returns false.
3539 */
3540 template<typename _ForwardIterator1, typename _ForwardIterator2>
3541 inline bool
3542 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
3543 _ForwardIterator2 __first2)
3544 {
3545 // concept requirements
3546 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
3547 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
3548 __glibcxx_function_requires(_EqualOpConcept<
3549 typename iterator_traits<_ForwardIterator1>::value_type,
3550 typename iterator_traits<_ForwardIterator2>::value_type>)
3551 __glibcxx_requires_valid_range(__first1, __last1);
3552
3553 return std::__is_permutation(__first1, __last1, __first2,
3554 __gnu_cxx::__ops::__iter_equal_to_iter());
3555 }
3556
3557 /**
3558 * @brief Checks whether a permutation of the second sequence is equal
3559 * to the first sequence.
3560 * @ingroup non_mutating_algorithms
3561 * @param __first1 Start of first range.
3562 * @param __last1 End of first range.
3563 * @param __first2 Start of second range.
3564 * @param __pred A binary predicate.
3565 * @return true if there exists a permutation of the elements in
3566 * the range [__first2, __first2 + (__last1 - __first1)),
3567 * beginning with ForwardIterator2 begin, such that
3568 * equal(__first1, __last1, __begin, __pred) returns true;
3569 * otherwise, returns false.
3570 */
3571 template<typename _ForwardIterator1, typename _ForwardIterator2,
3572 typename _BinaryPredicate>
3573 inline bool
3574 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
3575 _ForwardIterator2 __first2, _BinaryPredicate __pred)
3576 {
3577 // concept requirements
3578 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
3579 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
3580 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
3581 typename iterator_traits<_ForwardIterator1>::value_type,
3582 typename iterator_traits<_ForwardIterator2>::value_type>)
3583 __glibcxx_requires_valid_range(__first1, __last1);
3584
3585 return std::__is_permutation(__first1, __last1, __first2,
3586 __gnu_cxx::__ops::__iter_comp_iter(__pred));
3587 }
3588
3589#if __cplusplus > 201103L
3590 template<typename _ForwardIterator1, typename _ForwardIterator2,
3591 typename _BinaryPredicate>
3592 bool
3593 __is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
3594 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
3595 _BinaryPredicate __pred)
3596 {
3597 using _Cat1
3598 = typename iterator_traits<_ForwardIterator1>::iterator_category;
3599 using _Cat2
3600 = typename iterator_traits<_ForwardIterator2>::iterator_category;
3601 using _It1_is_RA = is_same<_Cat1, random_access_iterator_tag>;
3602 using _It2_is_RA = is_same<_Cat2, random_access_iterator_tag>;
3603 constexpr bool __ra_iters = _It1_is_RA() && _It2_is_RA();
3604 if (__ra_iters)
3605 {
3606 auto __d1 = std::distance(__first1, __last1);
3607 auto __d2 = std::distance(__first2, __last2);
3608 if (__d1 != __d2)
3609 return false;
3610 }
3611
3612 // Efficiently compare identical prefixes: O(N) if sequences
3613 // have the same elements in the same order.
3614 for (; __first1 != __last1 && __first2 != __last2;
3615 ++__first1, (void)++__first2)
3616 if (!__pred(__first1, __first2))
3617 break;
3618
3619 if (__ra_iters)
3620 {
3621 if (__first1 == __last1)
3622 return true;
3623 }
3624 else
3625 {
3626 auto __d1 = std::distance(__first1, __last1);
3627 auto __d2 = std::distance(__first2, __last2);
3628 if (__d1 == 0 && __d2 == 0)
3629 return true;
3630 if (__d1 != __d2)
3631 return false;
3632 }
3633
3634 for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan)
3635 {
3636 if (__scan != std::__find_if(__first1, __scan,
3637 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan)))
3638 continue; // We've seen this one before.
3639
3640 auto __matches = std::__count_if(__first2, __last2,
3641 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan));
3642 if (0 == __matches
3643 || std::__count_if(__scan, __last1,
3644 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan))
3645 != __matches)
3646 return false;
3647 }
3648 return true;
3649 }
3650
3651 /**
3652 * @brief Checks whether a permutaion of the second sequence is equal
3653 * to the first sequence.
3654 * @ingroup non_mutating_algorithms
3655 * @param __first1 Start of first range.
3656 * @param __last1 End of first range.
3657 * @param __first2 Start of second range.
3658 * @param __last2 End of first range.
3659 * @return true if there exists a permutation of the elements in the range
3660 * [__first2, __last2), beginning with ForwardIterator2 begin,
3661 * such that equal(__first1, __last1, begin) returns true;
3662 * otherwise, returns false.
3663 */
3664 template<typename _ForwardIterator1, typename _ForwardIterator2>
3665 inline bool
3666 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
3667 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
3668 {
3669 __glibcxx_requires_valid_range(__first1, __last1);
3670 __glibcxx_requires_valid_range(__first2, __last2);
3671
3672 return
3673 std::__is_permutation(__first1, __last1, __first2, __last2,
3674 __gnu_cxx::__ops::__iter_equal_to_iter());
3675 }
3676
3677 /**
3678 * @brief Checks whether a permutation of the second sequence is equal
3679 * to the first sequence.
3680 * @ingroup non_mutating_algorithms
3681 * @param __first1 Start of first range.
3682 * @param __last1 End of first range.
3683 * @param __first2 Start of second range.
3684 * @param __last2 End of first range.
3685 * @param __pred A binary predicate.
3686 * @return true if there exists a permutation of the elements in the range
3687 * [__first2, __last2), beginning with ForwardIterator2 begin,
3688 * such that equal(__first1, __last1, __begin, __pred) returns true;
3689 * otherwise, returns false.
3690 */
3691 template<typename _ForwardIterator1, typename _ForwardIterator2,
3692 typename _BinaryPredicate>
3693 inline bool
3694 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
3695 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
3696 _BinaryPredicate __pred)
3697 {
3698 __glibcxx_requires_valid_range(__first1, __last1);
3699 __glibcxx_requires_valid_range(__first2, __last2);
3700
3701 return std::__is_permutation(__first1, __last1, __first2, __last2,
3702 __gnu_cxx::__ops::__iter_comp_iter(__pred));
3703 }
3704
3705#if __cplusplus > 201402L
3706
3707#define __cpp_lib_clamp 201603
3708
3709 /**
3710 * @brief Returns the value clamped between lo and hi.
3711 * @ingroup sorting_algorithms
3712 * @param __val A value of arbitrary type.
3713 * @param __lo A lower limit of arbitrary type.
3714 * @param __hi An upper limit of arbitrary type.
3715 * @return max(__val, __lo) if __val < __hi or min(__val, __hi) otherwise.
3716 */
3717 template<typename _Tp>
3718 constexpr const _Tp&
3719 clamp(const _Tp& __val, const _Tp& __lo, const _Tp& __hi)
3720 {
3721 __glibcxx_assert(!(__hi < __lo));
3722 return (__val < __lo) ? __lo : (__hi < __val) ? __hi : __val;
3723 }
3724
3725 /**
3726 * @brief Returns the value clamped between lo and hi.
3727 * @ingroup sorting_algorithms
3728 * @param __val A value of arbitrary type.
3729 * @param __lo A lower limit of arbitrary type.
3730 * @param __hi An upper limit of arbitrary type.
3731 * @param __comp A comparison functor.
3732 * @return max(__val, __lo, __comp) if __comp(__val, __hi)
3733 * or min(__val, __hi, __comp) otherwise.
3734 */
3735 template<typename _Tp, typename _Compare>
3736 constexpr const _Tp&
3737 clamp(const _Tp& __val, const _Tp& __lo, const _Tp& __hi, _Compare __comp)
3738 {
3739 __glibcxx_assert(!__comp(__hi, __lo));
3740 return __comp(__val, __lo) ? __lo : __comp(__hi, __val) ? __hi : __val;
3741 }
3742#endif // C++17
3743#endif // C++14
3744
3745#ifdef _GLIBCXX_USE_C99_STDINT_TR1
3746 /**
3747 * @brief Generate two uniformly distributed integers using a
3748 * single distribution invocation.
3749 * @param __b0 The upper bound for the first integer.
3750 * @param __b1 The upper bound for the second integer.
3751 * @param __g A UniformRandomBitGenerator.
3752 * @return A pair (i, j) with i and j uniformly distributed
3753 * over [0, __b0) and [0, __b1), respectively.
3754 *
3755 * Requires: __b0 * __b1 <= __g.max() - __g.min().
3756 *
3757 * Using uniform_int_distribution with a range that is very
3758 * small relative to the range of the generator ends up wasting
3759 * potentially expensively generated randomness, since
3760 * uniform_int_distribution does not store leftover randomness
3761 * between invocations.
3762 *
3763 * If we know we want two integers in ranges that are sufficiently
3764 * small, we can compose the ranges, use a single distribution
3765 * invocation, and significantly reduce the waste.
3766 */
3767 template<typename _IntType, typename _UniformRandomBitGenerator>
3768 pair<_IntType, _IntType>
3769 __gen_two_uniform_ints(_IntType __b0, _IntType __b1,
3770 _UniformRandomBitGenerator&& __g)
3771 {
3772 _IntType __x
3773 = uniform_int_distribution<_IntType>{0, (__b0 * __b1) - 1}(__g);
3774 return std::make_pair(__x / __b1, __x % __b1);
3775 }
3776
3777 /**
3778 * @brief Shuffle the elements of a sequence using a uniform random
3779 * number generator.
3780 * @ingroup mutating_algorithms
3781 * @param __first A forward iterator.
3782 * @param __last A forward iterator.
3783 * @param __g A UniformRandomNumberGenerator (26.5.1.3).
3784 * @return Nothing.
3785 *
3786 * Reorders the elements in the range @p [__first,__last) using @p __g to
3787 * provide random numbers.
3788 */
3789 template<typename _RandomAccessIterator,
3790 typename _UniformRandomNumberGenerator>
3791 void
3792 shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
3793 _UniformRandomNumberGenerator&& __g)
3794 {
3795 // concept requirements
3796 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3797 _RandomAccessIterator>)
3798 __glibcxx_requires_valid_range(__first, __last);
3799
3800 if (__first == __last)
3801 return;
3802
3803 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3804 _DistanceType;
3805
3806 typedef typename std::make_unsigned<_DistanceType>::type __ud_type;
3807 typedef typename std::uniform_int_distribution<__ud_type> __distr_type;
3808 typedef typename __distr_type::param_type __p_type;
3809
3810 typedef typename remove_reference<_UniformRandomNumberGenerator>::type
3811 _Gen;
3812 typedef typename common_type<typename _Gen::result_type, __ud_type>::type
3813 __uc_type;
3814
3815 const __uc_type __urngrange = __g.max() - __g.min();
3816 const __uc_type __urange = __uc_type(__last - __first);
3817
3818 if (__urngrange / __urange >= __urange)
3819 // I.e. (__urngrange >= __urange * __urange) but without wrap issues.
3820 {
3821 _RandomAccessIterator __i = __first + 1;
3822
3823 // Since we know the range isn't empty, an even number of elements
3824 // means an uneven number of elements /to swap/, in which case we
3825 // do the first one up front:
3826
3827 if ((__urange % 2) == 0)
3828 {
3829 __distr_type __d{0, 1};
3830 std::iter_swap(__i++, __first + __d(__g));
3831 }
3832
3833 // Now we know that __last - __i is even, so we do the rest in pairs,
3834 // using a single distribution invocation to produce swap positions
3835 // for two successive elements at a time:
3836
3837 while (__i != __last)
3838 {
3839 const __uc_type __swap_range = __uc_type(__i - __first) + 1;
3840
3841 const pair<__uc_type, __uc_type> __pospos =
3842 __gen_two_uniform_ints(__swap_range, __swap_range + 1, __g);
3843
3844 std::iter_swap(__i++, __first + __pospos.first);
3845 std::iter_swap(__i++, __first + __pospos.second);
3846 }
3847
3848 return;
3849 }
3850
3851 __distr_type __d;
3852
3853 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
3854 std::iter_swap(__i, __first + __d(__g, __p_type(0, __i - __first)));
3855 }
3856#endif
3857
3858#endif // C++11
3859
3860_GLIBCXX_END_NAMESPACE_VERSION
3861
3862_GLIBCXX_BEGIN_NAMESPACE_ALGO
3863
3864 /**
3865 * @brief Apply a function to every element of a sequence.
3866 * @ingroup non_mutating_algorithms
3867 * @param __first An input iterator.
3868 * @param __last An input iterator.
3869 * @param __f A unary function object.
3870 * @return @p __f
3871 *
3872 * Applies the function object @p __f to each element in the range
3873 * @p [first,last). @p __f must not modify the order of the sequence.
3874 * If @p __f has a return value it is ignored.
3875 */
3876 template<typename _InputIterator, typename _Function>
3877 _Function
3878 for_each(_InputIterator __first, _InputIterator __last, _Function __f)
3879 {
3880 // concept requirements
3881 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
3882 __glibcxx_requires_valid_range(__first, __last);
3883 for (; __first != __last; ++__first)
3884 __f(*__first);
3885 return __f; // N.B. [alg.foreach] says std::move(f) but it's redundant.
3886 }
3887
3888 /**
3889 * @brief Find the first occurrence of a value in a sequence.
3890 * @ingroup non_mutating_algorithms
3891 * @param __first An input iterator.
3892 * @param __last An input iterator.
3893 * @param __val The value to find.
3894 * @return The first iterator @c i in the range @p [__first,__last)
3895 * such that @c *i == @p __val, or @p __last if no such iterator exists.
3896 */
3897 template<typename _InputIterator, typename _Tp>
3898 inline _InputIterator
3899 find(_InputIterator __first, _InputIterator __last,
3900 const _Tp& __val)
3901 {
3902 // concept requirements
3903 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
3904 __glibcxx_function_requires(_EqualOpConcept<
3905 typename iterator_traits<_InputIterator>::value_type, _Tp>)
3906 __glibcxx_requires_valid_range(__first, __last);
3907 return std::__find_if(__first, __last,
3908 __gnu_cxx::__ops::__iter_equals_val(__val));
3909 }
3910
3911 /**
3912 * @brief Find the first element in a sequence for which a
3913 * predicate is true.
3914 * @ingroup non_mutating_algorithms
3915 * @param __first An input iterator.
3916 * @param __last An input iterator.
3917 * @param __pred A predicate.
3918 * @return The first iterator @c i in the range @p [__first,__last)
3919 * such that @p __pred(*i) is true, or @p __last if no such iterator exists.
3920 */
3921 template<typename _InputIterator, typename _Predicate>
3922 inline _InputIterator
3923 find_if(_InputIterator __first, _InputIterator __last,
3924 _Predicate __pred)
3925 {
3926 // concept requirements
3927 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
3928 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
3929 typename iterator_traits<_InputIterator>::value_type>)
3930 __glibcxx_requires_valid_range(__first, __last);
3931
3932 return std::__find_if(__first, __last,
3933 __gnu_cxx::__ops::__pred_iter(__pred));
3934 }
3935
3936 /**
3937 * @brief Find element from a set in a sequence.
3938 * @ingroup non_mutating_algorithms
3939 * @param __first1 Start of range to search.
3940 * @param __last1 End of range to search.
3941 * @param __first2 Start of match candidates.
3942 * @param __last2 End of match candidates.
3943 * @return The first iterator @c i in the range
3944 * @p [__first1,__last1) such that @c *i == @p *(i2) such that i2 is an
3945 * iterator in [__first2,__last2), or @p __last1 if no such iterator exists.
3946 *
3947 * Searches the range @p [__first1,__last1) for an element that is
3948 * equal to some element in the range [__first2,__last2). If
3949 * found, returns an iterator in the range [__first1,__last1),
3950 * otherwise returns @p __last1.
3951 */
3952 template<typename _InputIterator, typename _ForwardIterator>
3953 _InputIterator
3954 find_first_of(_InputIterator __first1, _InputIterator __last1,
3955 _ForwardIterator __first2, _ForwardIterator __last2)
3956 {
3957 // concept requirements
3958 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
3959 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3960 __glibcxx_function_requires(_EqualOpConcept<
3961 typename iterator_traits<_InputIterator>::value_type,
3962 typename iterator_traits<_ForwardIterator>::value_type>)
3963 __glibcxx_requires_valid_range(__first1, __last1);
3964 __glibcxx_requires_valid_range(__first2, __last2);
3965
3966 for (; __first1 != __last1; ++__first1)
3967 for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter)
3968 if (*__first1 == *__iter)
3969 return __first1;
3970 return __last1;
3971 }
3972
3973 /**
3974 * @brief Find element from a set in a sequence using a predicate.
3975 * @ingroup non_mutating_algorithms
3976 * @param __first1 Start of range to search.
3977 * @param __last1 End of range to search.
3978 * @param __first2 Start of match candidates.
3979 * @param __last2 End of match candidates.
3980 * @param __comp Predicate to use.
3981 * @return The first iterator @c i in the range
3982 * @p [__first1,__last1) such that @c comp(*i, @p *(i2)) is true
3983 * and i2 is an iterator in [__first2,__last2), or @p __last1 if no
3984 * such iterator exists.
3985 *
3986
3987 * Searches the range @p [__first1,__last1) for an element that is
3988 * equal to some element in the range [__first2,__last2). If
3989 * found, returns an iterator in the range [__first1,__last1),
3990 * otherwise returns @p __last1.
3991 */
3992 template<typename _InputIterator, typename _ForwardIterator,
3993 typename _BinaryPredicate>
3994 _InputIterator
3995 find_first_of(_InputIterator __first1, _InputIterator __last1,
3996 _ForwardIterator __first2, _ForwardIterator __last2,
3997 _BinaryPredicate __comp)
3998 {
3999 // concept requirements
4000 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4001 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4002 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4003 typename iterator_traits<_InputIterator>::value_type,
4004 typename iterator_traits<_ForwardIterator>::value_type>)
4005 __glibcxx_requires_valid_range(__first1, __last1);
4006 __glibcxx_requires_valid_range(__first2, __last2);
4007
4008 for (; __first1 != __last1; ++__first1)
4009 for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter)
4010 if (__comp(*__first1, *__iter))
4011 return __first1;
4012 return __last1;
4013 }
4014
4015 /**
4016 * @brief Find two adjacent values in a sequence that are equal.
4017 * @ingroup non_mutating_algorithms
4018 * @param __first A forward iterator.
4019 * @param __last A forward iterator.
4020 * @return The first iterator @c i such that @c i and @c i+1 are both
4021 * valid iterators in @p [__first,__last) and such that @c *i == @c *(i+1),
4022 * or @p __last if no such iterator exists.
4023 */
4024 template<typename _ForwardIterator>
4025 inline _ForwardIterator
4026 adjacent_find(_ForwardIterator __first, _ForwardIterator __last)
4027 {
4028 // concept requirements
4029 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4030 __glibcxx_function_requires(_EqualityComparableConcept<
4031 typename iterator_traits<_ForwardIterator>::value_type>)
4032 __glibcxx_requires_valid_range(__first, __last);
4033
4034 return std::__adjacent_find(__first, __last,
4035 __gnu_cxx::__ops::__iter_equal_to_iter());
4036 }
4037
4038 /**
4039 * @brief Find two adjacent values in a sequence using a predicate.
4040 * @ingroup non_mutating_algorithms
4041 * @param __first A forward iterator.
4042 * @param __last A forward iterator.
4043 * @param __binary_pred A binary predicate.
4044 * @return The first iterator @c i such that @c i and @c i+1 are both
4045 * valid iterators in @p [__first,__last) and such that
4046 * @p __binary_pred(*i,*(i+1)) is true, or @p __last if no such iterator
4047 * exists.
4048 */
4049 template<typename _ForwardIterator, typename _BinaryPredicate>
4050 inline _ForwardIterator
4051 adjacent_find(_ForwardIterator __first, _ForwardIterator __last,
4052 _BinaryPredicate __binary_pred)
4053 {
4054 // concept requirements
4055 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4056 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4057 typename iterator_traits<_ForwardIterator>::value_type,
4058 typename iterator_traits<_ForwardIterator>::value_type>)
4059 __glibcxx_requires_valid_range(__first, __last);
4060
4061 return std::__adjacent_find(__first, __last,
4062 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
4063 }
4064
4065 /**
4066 * @brief Count the number of copies of a value in a sequence.
4067 * @ingroup non_mutating_algorithms
4068 * @param __first An input iterator.
4069 * @param __last An input iterator.
4070 * @param __value The value to be counted.
4071 * @return The number of iterators @c i in the range @p [__first,__last)
4072 * for which @c *i == @p __value
4073 */
4074 template<typename _InputIterator, typename _Tp>
4075 inline typename iterator_traits<_InputIterator>::difference_type
4076 count(_InputIterator __first, _InputIterator __last, const _Tp& __value)
4077 {
4078 // concept requirements
4079 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4080 __glibcxx_function_requires(_EqualOpConcept<
4081 typename iterator_traits<_InputIterator>::value_type, _Tp>)
4082 __glibcxx_requires_valid_range(__first, __last);
4083
4084 return std::__count_if(__first, __last,
4085 __gnu_cxx::__ops::__iter_equals_val(__value));
4086 }
4087
4088 /**
4089 * @brief Count the elements of a sequence for which a predicate is true.
4090 * @ingroup non_mutating_algorithms
4091 * @param __first An input iterator.
4092 * @param __last An input iterator.
4093 * @param __pred A predicate.
4094 * @return The number of iterators @c i in the range @p [__first,__last)
4095 * for which @p __pred(*i) is true.
4096 */
4097 template<typename _InputIterator, typename _Predicate>
4098 inline typename iterator_traits<_InputIterator>::difference_type
4099 count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
4100 {
4101 // concept requirements
4102 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4103 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
4104 typename iterator_traits<_InputIterator>::value_type>)
4105 __glibcxx_requires_valid_range(__first, __last);
4106
4107 return std::__count_if(__first, __last,
4108 __gnu_cxx::__ops::__pred_iter(__pred));
4109 }
4110
4111 /**
4112 * @brief Search a sequence for a matching sub-sequence.
4113 * @ingroup non_mutating_algorithms
4114 * @param __first1 A forward iterator.
4115 * @param __last1 A forward iterator.
4116 * @param __first2 A forward iterator.
4117 * @param __last2 A forward iterator.
4118 * @return The first iterator @c i in the range @p
4119 * [__first1,__last1-(__last2-__first2)) such that @c *(i+N) == @p
4120 * *(__first2+N) for each @c N in the range @p
4121 * [0,__last2-__first2), or @p __last1 if no such iterator exists.
4122 *
4123 * Searches the range @p [__first1,__last1) for a sub-sequence that
4124 * compares equal value-by-value with the sequence given by @p
4125 * [__first2,__last2) and returns an iterator to the first element
4126 * of the sub-sequence, or @p __last1 if the sub-sequence is not
4127 * found.
4128 *
4129 * Because the sub-sequence must lie completely within the range @p
4130 * [__first1,__last1) it must start at a position less than @p
4131 * __last1-(__last2-__first2) where @p __last2-__first2 is the
4132 * length of the sub-sequence.
4133 *
4134 * This means that the returned iterator @c i will be in the range
4135 * @p [__first1,__last1-(__last2-__first2))
4136 */
4137 template<typename _ForwardIterator1, typename _ForwardIterator2>
4138 inline _ForwardIterator1
4139 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4140 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
4141 {
4142 // concept requirements
4143 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
4144 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
4145 __glibcxx_function_requires(_EqualOpConcept<
4146 typename iterator_traits<_ForwardIterator1>::value_type,
4147 typename iterator_traits<_ForwardIterator2>::value_type>)
4148 __glibcxx_requires_valid_range(__first1, __last1);
4149 __glibcxx_requires_valid_range(__first2, __last2);
4150
4151 return std::__search(__first1, __last1, __first2, __last2,
4152 __gnu_cxx::__ops::__iter_equal_to_iter());
4153 }
4154
4155 /**
4156 * @brief Search a sequence for a matching sub-sequence using a predicate.
4157 * @ingroup non_mutating_algorithms
4158 * @param __first1 A forward iterator.
4159 * @param __last1 A forward iterator.
4160 * @param __first2 A forward iterator.
4161 * @param __last2 A forward iterator.
4162 * @param __predicate A binary predicate.
4163 * @return The first iterator @c i in the range
4164 * @p [__first1,__last1-(__last2-__first2)) such that
4165 * @p __predicate(*(i+N),*(__first2+N)) is true for each @c N in the range
4166 * @p [0,__last2-__first2), or @p __last1 if no such iterator exists.
4167 *
4168 * Searches the range @p [__first1,__last1) for a sub-sequence that
4169 * compares equal value-by-value with the sequence given by @p
4170 * [__first2,__last2), using @p __predicate to determine equality,
4171 * and returns an iterator to the first element of the
4172 * sub-sequence, or @p __last1 if no such iterator exists.
4173 *
4174 * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2)
4175 */
4176 template<typename _ForwardIterator1, typename _ForwardIterator2,
4177 typename _BinaryPredicate>
4178 inline _ForwardIterator1
4179 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4180 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
4181 _BinaryPredicate __predicate)
4182 {
4183 // concept requirements
4184 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
4185 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
4186 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4187 typename iterator_traits<_ForwardIterator1>::value_type,
4188 typename iterator_traits<_ForwardIterator2>::value_type>)
4189 __glibcxx_requires_valid_range(__first1, __last1);
4190 __glibcxx_requires_valid_range(__first2, __last2);
4191
4192 return std::__search(__first1, __last1, __first2, __last2,
4193 __gnu_cxx::__ops::__iter_comp_iter(__predicate));
4194 }
4195
4196 /**
4197 * @brief Search a sequence for a number of consecutive values.
4198 * @ingroup non_mutating_algorithms
4199 * @param __first A forward iterator.
4200 * @param __last A forward iterator.
4201 * @param __count The number of consecutive values.
4202 * @param __val The value to find.
4203 * @return The first iterator @c i in the range @p
4204 * [__first,__last-__count) such that @c *(i+N) == @p __val for
4205 * each @c N in the range @p [0,__count), or @p __last if no such
4206 * iterator exists.
4207 *
4208 * Searches the range @p [__first,__last) for @p count consecutive elements
4209 * equal to @p __val.
4210 */
4211 template<typename _ForwardIterator, typename _Integer, typename _Tp>
4212 inline _ForwardIterator
4213 search_n(_ForwardIterator __first, _ForwardIterator __last,
4214 _Integer __count, const _Tp& __val)
4215 {
4216 // concept requirements
4217 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4218 __glibcxx_function_requires(_EqualOpConcept<
4219 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
4220 __glibcxx_requires_valid_range(__first, __last);
4221
4222 return std::__search_n(__first, __last, __count,
4223 __gnu_cxx::__ops::__iter_equals_val(__val));
4224 }
4225
4226
4227 /**
4228 * @brief Search a sequence for a number of consecutive values using a
4229 * predicate.
4230 * @ingroup non_mutating_algorithms
4231 * @param __first A forward iterator.
4232 * @param __last A forward iterator.
4233 * @param __count The number of consecutive values.
4234 * @param __val The value to find.
4235 * @param __binary_pred A binary predicate.
4236 * @return The first iterator @c i in the range @p
4237 * [__first,__last-__count) such that @p
4238 * __binary_pred(*(i+N),__val) is true for each @c N in the range
4239 * @p [0,__count), or @p __last if no such iterator exists.
4240 *
4241 * Searches the range @p [__first,__last) for @p __count
4242 * consecutive elements for which the predicate returns true.
4243 */
4244 template<typename _ForwardIterator, typename _Integer, typename _Tp,
4245 typename _BinaryPredicate>
4246 inline _ForwardIterator
4247 search_n(_ForwardIterator __first, _ForwardIterator __last,
4248 _Integer __count, const _Tp& __val,
4249 _BinaryPredicate __binary_pred)
4250 {
4251 // concept requirements
4252 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4253 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4254 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
4255 __glibcxx_requires_valid_range(__first, __last);
4256
4257 return std::__search_n(__first, __last, __count,
4258 __gnu_cxx::__ops::__iter_comp_val(__binary_pred, __val));
4259 }
4260
4261#if __cplusplus > 201402L
4262 /** @brief Search a sequence using a Searcher object.
4263 *
4264 * @param __first A forward iterator.
4265 * @param __last A forward iterator.
4266 * @param __searcher A callable object.
4267 * @return @p __searcher(__first,__last).first
4268 */
4269 template<typename _ForwardIterator, typename _Searcher>
4270 inline _ForwardIterator
4271 search(_ForwardIterator __first, _ForwardIterator __last,
4272 const _Searcher& __searcher)
4273 { return __searcher(__first, __last).first; }
4274#endif
4275
4276 /**
4277 * @brief Perform an operation on a sequence.
4278 * @ingroup mutating_algorithms
4279 * @param __first An input iterator.
4280 * @param __last An input iterator.
4281 * @param __result An output iterator.
4282 * @param __unary_op A unary operator.
4283 * @return An output iterator equal to @p __result+(__last-__first).
4284 *
4285 * Applies the operator to each element in the input range and assigns
4286 * the results to successive elements of the output sequence.
4287 * Evaluates @p *(__result+N)=unary_op(*(__first+N)) for each @c N in the
4288 * range @p [0,__last-__first).
4289 *
4290 * @p unary_op must not alter its argument.
4291 */
4292 template<typename _InputIterator, typename _OutputIterator,
4293 typename _UnaryOperation>
4294 _OutputIterator
4295 transform(_InputIterator __first, _InputIterator __last,
4296 _OutputIterator __result, _UnaryOperation __unary_op)
4297 {
4298 // concept requirements
4299 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4300 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4301 // "the type returned by a _UnaryOperation"
4302 __typeof__(__unary_op(*__first))>)
4303 __glibcxx_requires_valid_range(__first, __last);
4304
4305 for (; __first != __last; ++__first, (void)++__result)
4306 *__result = __unary_op(*__first);
4307 return __result;
4308 }
4309
4310 /**
4311 * @brief Perform an operation on corresponding elements of two sequences.
4312 * @ingroup mutating_algorithms
4313 * @param __first1 An input iterator.
4314 * @param __last1 An input iterator.
4315 * @param __first2 An input iterator.
4316 * @param __result An output iterator.
4317 * @param __binary_op A binary operator.
4318 * @return An output iterator equal to @p result+(last-first).
4319 *
4320 * Applies the operator to the corresponding elements in the two
4321 * input ranges and assigns the results to successive elements of the
4322 * output sequence.
4323 * Evaluates @p
4324 * *(__result+N)=__binary_op(*(__first1+N),*(__first2+N)) for each
4325 * @c N in the range @p [0,__last1-__first1).
4326 *
4327 * @p binary_op must not alter either of its arguments.
4328 */
4329 template<typename _InputIterator1, typename _InputIterator2,
4330 typename _OutputIterator, typename _BinaryOperation>
4331 _OutputIterator
4332 transform(_InputIterator1 __first1, _InputIterator1 __last1,
4333 _InputIterator2 __first2, _OutputIterator __result,
4334 _BinaryOperation __binary_op)
4335 {
4336 // concept requirements
4337 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4338 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4339 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4340 // "the type returned by a _BinaryOperation"
4341 __typeof__(__binary_op(*__first1,*__first2))>)
4342 __glibcxx_requires_valid_range(__first1, __last1);
4343
4344 for (; __first1 != __last1; ++__first1, (void)++__first2, ++__result)
4345 *__result = __binary_op(*__first1, *__first2);
4346 return __result;
4347 }
4348
4349 /**
4350 * @brief Replace each occurrence of one value in a sequence with another
4351 * value.
4352 * @ingroup mutating_algorithms
4353 * @param __first A forward iterator.
4354 * @param __last A forward iterator.
4355 * @param __old_value The value to be replaced.
4356 * @param __new_value The replacement value.
4357 * @return replace() returns no value.
4358 *
4359 * For each iterator @c i in the range @p [__first,__last) if @c *i ==
4360 * @p __old_value then the assignment @c *i = @p __new_value is performed.
4361 */
4362 template<typename _ForwardIterator, typename _Tp>
4363 void
4364 replace(_ForwardIterator __first, _ForwardIterator __last,
4365 const _Tp& __old_value, const _Tp& __new_value)
4366 {
4367 // concept requirements
4368 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
4369 _ForwardIterator>)
4370 __glibcxx_function_requires(_EqualOpConcept<
4371 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
4372 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
4373 typename iterator_traits<_ForwardIterator>::value_type>)
4374 __glibcxx_requires_valid_range(__first, __last);
4375
4376 for (; __first != __last; ++__first)
4377 if (*__first == __old_value)
4378 *__first = __new_value;
4379 }
4380
4381 /**
4382 * @brief Replace each value in a sequence for which a predicate returns
4383 * true with another value.
4384 * @ingroup mutating_algorithms
4385 * @param __first A forward iterator.
4386 * @param __last A forward iterator.
4387 * @param __pred A predicate.
4388 * @param __new_value The replacement value.
4389 * @return replace_if() returns no value.
4390 *
4391 * For each iterator @c i in the range @p [__first,__last) if @p __pred(*i)
4392 * is true then the assignment @c *i = @p __new_value is performed.
4393 */
4394 template<typename _ForwardIterator, typename _Predicate, typename _Tp>
4395 void
4396 replace_if(_ForwardIterator __first, _ForwardIterator __last,
4397 _Predicate __pred, const _Tp& __new_value)
4398 {
4399 // concept requirements
4400 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
4401 _ForwardIterator>)
4402 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
4403 typename iterator_traits<_ForwardIterator>::value_type>)
4404 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
4405 typename iterator_traits<_ForwardIterator>::value_type>)
4406 __glibcxx_requires_valid_range(__first, __last);
4407
4408 for (; __first != __last; ++__first)
4409 if (__pred(*__first))
4410 *__first = __new_value;
4411 }
4412
4413 /**
4414 * @brief Assign the result of a function object to each value in a
4415 * sequence.
4416 * @ingroup mutating_algorithms
4417 * @param __first A forward iterator.
4418 * @param __last A forward iterator.
4419 * @param __gen A function object taking no arguments and returning
4420 * std::iterator_traits<_ForwardIterator>::value_type
4421 * @return generate() returns no value.
4422 *
4423 * Performs the assignment @c *i = @p __gen() for each @c i in the range
4424 * @p [__first,__last).
4425 */
4426 template<typename _ForwardIterator, typename _Generator>
4427 void
4428 generate(_ForwardIterator __first, _ForwardIterator __last,
4429 _Generator __gen)
4430 {
4431 // concept requirements
4432 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4433 __glibcxx_function_requires(_GeneratorConcept<_Generator,
4434 typename iterator_traits<_ForwardIterator>::value_type>)
4435 __glibcxx_requires_valid_range(__first, __last);
4436
4437 for (; __first != __last; ++__first)
4438 *__first = __gen();
4439 }
4440
4441 /**
4442 * @brief Assign the result of a function object to each value in a
4443 * sequence.
4444 * @ingroup mutating_algorithms
4445 * @param __first A forward iterator.
4446 * @param __n The length of the sequence.
4447 * @param __gen A function object taking no arguments and returning
4448 * std::iterator_traits<_ForwardIterator>::value_type
4449 * @return The end of the sequence, @p __first+__n
4450 *
4451 * Performs the assignment @c *i = @p __gen() for each @c i in the range
4452 * @p [__first,__first+__n).
4453 *
4454 * _GLIBCXX_RESOLVE_LIB_DEFECTS
4455 * DR 865. More algorithms that throw away information
4456 */
4457 template<typename _OutputIterator, typename _Size, typename _Generator>
4458 _OutputIterator
4459 generate_n(_OutputIterator __first, _Size __n, _Generator __gen)
4460 {
4461 // concept requirements
4462 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4463 // "the type returned by a _Generator"
4464 __typeof__(__gen())>)
4465
4466 for (__decltype(__n + 0) __niter = __n;
4467 __niter > 0; --__niter, ++__first)
4468 *__first = __gen();
4469 return __first;
4470 }
4471
4472 /**
4473 * @brief Copy a sequence, removing consecutive duplicate values.
4474 * @ingroup mutating_algorithms
4475 * @param __first An input iterator.
4476 * @param __last An input iterator.
4477 * @param __result An output iterator.
4478 * @return An iterator designating the end of the resulting sequence.
4479 *
4480 * Copies each element in the range @p [__first,__last) to the range
4481 * beginning at @p __result, except that only the first element is copied
4482 * from groups of consecutive elements that compare equal.
4483 * unique_copy() is stable, so the relative order of elements that are
4484 * copied is unchanged.
4485 *
4486 * _GLIBCXX_RESOLVE_LIB_DEFECTS
4487 * DR 241. Does unique_copy() require CopyConstructible and Assignable?
4488 *
4489 * _GLIBCXX_RESOLVE_LIB_DEFECTS
4490 * DR 538. 241 again: Does unique_copy() require CopyConstructible and
4491 * Assignable?
4492 */
4493 template<typename _InputIterator, typename _OutputIterator>
4494 inline _OutputIterator
4495 unique_copy(_InputIterator __first, _InputIterator __last,
4496 _OutputIterator __result)
4497 {
4498 // concept requirements
4499 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4500 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4501 typename iterator_traits<_InputIterator>::value_type>)
4502 __glibcxx_function_requires(_EqualityComparableConcept<
4503 typename iterator_traits<_InputIterator>::value_type>)
4504 __glibcxx_requires_valid_range(__first, __last);
4505
4506 if (__first == __last)
4507 return __result;
4508 return std::__unique_copy(__first, __last, __result,
4509 __gnu_cxx::__ops::__iter_equal_to_iter(),
4510 std::__iterator_category(__first),
4511 std::__iterator_category(__result));
4512 }
4513
4514 /**
4515 * @brief Copy a sequence, removing consecutive values using a predicate.
4516 * @ingroup mutating_algorithms
4517 * @param __first An input iterator.
4518 * @param __last An input iterator.
4519 * @param __result An output iterator.
4520 * @param __binary_pred A binary predicate.
4521 * @return An iterator designating the end of the resulting sequence.
4522 *
4523 * Copies each element in the range @p [__first,__last) to the range
4524 * beginning at @p __result, except that only the first element is copied
4525 * from groups of consecutive elements for which @p __binary_pred returns
4526 * true.
4527 * unique_copy() is stable, so the relative order of elements that are
4528 * copied is unchanged.
4529 *
4530 * _GLIBCXX_RESOLVE_LIB_DEFECTS
4531 * DR 241. Does unique_copy() require CopyConstructible and Assignable?
4532 */
4533 template<typename _InputIterator, typename _OutputIterator,
4534 typename _BinaryPredicate>
4535 inline _OutputIterator
4536 unique_copy(_InputIterator __first, _InputIterator __last,
4537 _OutputIterator __result,
4538 _BinaryPredicate __binary_pred)
4539 {
4540 // concept requirements -- predicates checked later
4541 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4542 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4543 typename iterator_traits<_InputIterator>::value_type>)
4544 __glibcxx_requires_valid_range(__first, __last);
4545
4546 if (__first == __last)
4547 return __result;
4548 return std::__unique_copy(__first, __last, __result,
4549 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred),
4550 std::__iterator_category(__first),
4551 std::__iterator_category(__result));
4552 }
4553
4554#if _GLIBCXX_HOSTED
4555 /**
4556 * @brief Randomly shuffle the elements of a sequence.
4557 * @ingroup mutating_algorithms
4558 * @param __first A forward iterator.
4559 * @param __last A forward iterator.
4560 * @return Nothing.
4561 *
4562 * Reorder the elements in the range @p [__first,__last) using a random
4563 * distribution, so that every possible ordering of the sequence is
4564 * equally likely.
4565 */
4566 template<typename _RandomAccessIterator>
4567 inline void
4568 random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
4569 {
4570 // concept requirements
4571 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4572 _RandomAccessIterator>)
4573 __glibcxx_requires_valid_range(__first, __last);
4574
4575 if (__first != __last)
4576 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
4577 {
4578 // XXX rand() % N is not uniformly distributed
4579 _RandomAccessIterator __j = __first
4580 + std::rand() % ((__i - __first) + 1);
4581 if (__i != __j)
4582 std::iter_swap(__i, __j);
4583 }
4584 }
4585#endif
4586
4587 /**
4588 * @brief Shuffle the elements of a sequence using a random number
4589 * generator.
4590 * @ingroup mutating_algorithms
4591 * @param __first A forward iterator.
4592 * @param __last A forward iterator.
4593 * @param __rand The RNG functor or function.
4594 * @return Nothing.
4595 *
4596 * Reorders the elements in the range @p [__first,__last) using @p __rand to
4597 * provide a random distribution. Calling @p __rand(N) for a positive
4598 * integer @p N should return a randomly chosen integer from the
4599 * range [0,N).
4600 */
4601 template<typename _RandomAccessIterator, typename _RandomNumberGenerator>
4602 void
4603 random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
4604#if __cplusplus >= 201103L
4605 _RandomNumberGenerator&& __rand)
4606#else
4607 _RandomNumberGenerator& __rand)
4608#endif
4609 {
4610 // concept requirements
4611 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4612 _RandomAccessIterator>)
4613 __glibcxx_requires_valid_range(__first, __last);
4614
4615 if (__first == __last)
4616 return;
4617 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
4618 {
4619 _RandomAccessIterator __j = __first + __rand((__i - __first) + 1);
4620 if (__i != __j)
4621 std::iter_swap(__i, __j);
4622 }
4623 }
4624
4625
4626 /**
4627 * @brief Move elements for which a predicate is true to the beginning
4628 * of a sequence.
4629 * @ingroup mutating_algorithms
4630 * @param __first A forward iterator.
4631 * @param __last A forward iterator.
4632 * @param __pred A predicate functor.
4633 * @return An iterator @p middle such that @p __pred(i) is true for each
4634 * iterator @p i in the range @p [__first,middle) and false for each @p i
4635 * in the range @p [middle,__last).
4636 *
4637 * @p __pred must not modify its operand. @p partition() does not preserve
4638 * the relative ordering of elements in each group, use
4639 * @p stable_partition() if this is needed.
4640 */
4641 template<typename _ForwardIterator, typename _Predicate>
4642 inline _ForwardIterator
4643 partition(_ForwardIterator __first, _ForwardIterator __last,
4644 _Predicate __pred)
4645 {
4646 // concept requirements
4647 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
4648 _ForwardIterator>)
4649 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
4650 typename iterator_traits<_ForwardIterator>::value_type>)
4651 __glibcxx_requires_valid_range(__first, __last);
4652
4653 return std::__partition(__first, __last, __pred,
4654 std::__iterator_category(__first));
4655 }
4656
4657
4658 /**
4659 * @brief Sort the smallest elements of a sequence.
4660 * @ingroup sorting_algorithms
4661 * @param __first An iterator.
4662 * @param __middle Another iterator.
4663 * @param __last Another iterator.
4664 * @return Nothing.
4665 *
4666 * Sorts the smallest @p (__middle-__first) elements in the range
4667 * @p [first,last) and moves them to the range @p [__first,__middle). The
4668 * order of the remaining elements in the range @p [__middle,__last) is
4669 * undefined.
4670 * After the sort if @e i and @e j are iterators in the range
4671 * @p [__first,__middle) such that i precedes j and @e k is an iterator in
4672 * the range @p [__middle,__last) then *j<*i and *k<*i are both false.
4673 */
4674 template<typename _RandomAccessIterator>
4675 inline void
4676 partial_sort(_RandomAccessIterator __first,
4677 _RandomAccessIterator __middle,
4678 _RandomAccessIterator __last)
4679 {
4680 // concept requirements
4681 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4682 _RandomAccessIterator>)
4683 __glibcxx_function_requires(_LessThanComparableConcept<
4684 typename iterator_traits<_RandomAccessIterator>::value_type>)
4685 __glibcxx_requires_valid_range(__first, __middle);
4686 __glibcxx_requires_valid_range(__middle, __last);
4687 __glibcxx_requires_irreflexive(__first, __last);
4688
4689 std::__partial_sort(__first, __middle, __last,
4690 __gnu_cxx::__ops::__iter_less_iter());
4691 }
4692
4693 /**
4694 * @brief Sort the smallest elements of a sequence using a predicate
4695 * for comparison.
4696 * @ingroup sorting_algorithms
4697 * @param __first An iterator.
4698 * @param __middle Another iterator.
4699 * @param __last Another iterator.
4700 * @param __comp A comparison functor.
4701 * @return Nothing.
4702 *
4703 * Sorts the smallest @p (__middle-__first) elements in the range
4704 * @p [__first,__last) and moves them to the range @p [__first,__middle). The
4705 * order of the remaining elements in the range @p [__middle,__last) is
4706 * undefined.
4707 * After the sort if @e i and @e j are iterators in the range
4708 * @p [__first,__middle) such that i precedes j and @e k is an iterator in
4709 * the range @p [__middle,__last) then @p *__comp(j,*i) and @p __comp(*k,*i)
4710 * are both false.
4711 */
4712 template<typename _RandomAccessIterator, typename _Compare>
4713 inline void
4714 partial_sort(_RandomAccessIterator __first,
4715 _RandomAccessIterator __middle,
4716 _RandomAccessIterator __last,
4717 _Compare __comp)
4718 {
4719 // concept requirements
4720 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4721 _RandomAccessIterator>)
4722 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4723 typename iterator_traits<_RandomAccessIterator>::value_type,
4724 typename iterator_traits<_RandomAccessIterator>::value_type>)
4725 __glibcxx_requires_valid_range(__first, __middle);
4726 __glibcxx_requires_valid_range(__middle, __last);
4727 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
4728
4729 std::__partial_sort(__first, __middle, __last,
4730 __gnu_cxx::__ops::__iter_comp_iter(__comp));
4731 }
4732
4733 /**
4734 * @brief Sort a sequence just enough to find a particular position.
4735 * @ingroup sorting_algorithms
4736 * @param __first An iterator.
4737 * @param __nth Another iterator.
4738 * @param __last Another iterator.
4739 * @return Nothing.
4740 *
4741 * Rearranges the elements in the range @p [__first,__last) so that @p *__nth
4742 * is the same element that would have been in that position had the
4743 * whole sequence been sorted. The elements either side of @p *__nth are
4744 * not completely sorted, but for any iterator @e i in the range
4745 * @p [__first,__nth) and any iterator @e j in the range @p [__nth,__last) it
4746 * holds that *j < *i is false.
4747 */
4748 template<typename _RandomAccessIterator>
4749 inline void
4750 nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth,
4751 _RandomAccessIterator __last)
4752 {
4753 // concept requirements
4754 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4755 _RandomAccessIterator>)
4756 __glibcxx_function_requires(_LessThanComparableConcept<
4757 typename iterator_traits<_RandomAccessIterator>::value_type>)
4758 __glibcxx_requires_valid_range(__first, __nth);
4759 __glibcxx_requires_valid_range(__nth, __last);
4760 __glibcxx_requires_irreflexive(__first, __last);
4761
4762 if (__first == __last || __nth == __last)
4763 return;
4764
4765 std::__introselect(__first, __nth, __last,
4766 std::__lg(__last - __first) * 2,
4767 __gnu_cxx::__ops::__iter_less_iter());
4768 }
4769
4770 /**
4771 * @brief Sort a sequence just enough to find a particular position
4772 * using a predicate for comparison.
4773 * @ingroup sorting_algorithms
4774 * @param __first An iterator.
4775 * @param __nth Another iterator.
4776 * @param __last Another iterator.
4777 * @param __comp A comparison functor.
4778 * @return Nothing.
4779 *
4780 * Rearranges the elements in the range @p [__first,__last) so that @p *__nth
4781 * is the same element that would have been in that position had the
4782 * whole sequence been sorted. The elements either side of @p *__nth are
4783 * not completely sorted, but for any iterator @e i in the range
4784 * @p [__first,__nth) and any iterator @e j in the range @p [__nth,__last) it
4785 * holds that @p __comp(*j,*i) is false.
4786 */
4787 template<typename _RandomAccessIterator, typename _Compare>
4788 inline void
4789 nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth,
4790 _RandomAccessIterator __last, _Compare __comp)
4791 {
4792 // concept requirements
4793 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4794 _RandomAccessIterator>)
4795 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4796 typename iterator_traits<_RandomAccessIterator>::value_type,
4797 typename iterator_traits<_RandomAccessIterator>::value_type>)
4798 __glibcxx_requires_valid_range(__first, __nth);
4799 __glibcxx_requires_valid_range(__nth, __last);
4800 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
4801
4802 if (__first == __last || __nth == __last)
4803 return;
4804
4805 std::__introselect(__first, __nth, __last,
4806 std::__lg(__last - __first) * 2,
4807 __gnu_cxx::__ops::__iter_comp_iter(__comp));
4808 }
4809
4810 /**
4811 * @brief Sort the elements of a sequence.
4812 * @ingroup sorting_algorithms
4813 * @param __first An iterator.
4814 * @param __last Another iterator.
4815 * @return Nothing.
4816 *
4817 * Sorts the elements in the range @p [__first,__last) in ascending order,
4818 * such that for each iterator @e i in the range @p [__first,__last-1),
4819 * *(i+1)<*i is false.
4820 *
4821 * The relative ordering of equivalent elements is not preserved, use
4822 * @p stable_sort() if this is needed.
4823 */
4824 template<typename _RandomAccessIterator>
4825 inline void
4826 sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
4827 {
4828 // concept requirements
4829 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4830 _RandomAccessIterator>)
4831 __glibcxx_function_requires(_LessThanComparableConcept<
4832 typename iterator_traits<_RandomAccessIterator>::value_type>)
4833 __glibcxx_requires_valid_range(__first, __last);
4834 __glibcxx_requires_irreflexive(__first, __last);
4835
4836 std::__sort(__first, __last, __gnu_cxx::__ops::__iter_less_iter());
4837 }
4838
4839 /**
4840 * @brief Sort the elements of a sequence using a predicate for comparison.
4841 * @ingroup sorting_algorithms
4842 * @param __first An iterator.
4843 * @param __last Another iterator.
4844 * @param __comp A comparison functor.
4845 * @return Nothing.
4846 *
4847 * Sorts the elements in the range @p [__first,__last) in ascending order,
4848 * such that @p __comp(*(i+1),*i) is false for every iterator @e i in the
4849 * range @p [__first,__last-1).
4850 *
4851 * The relative ordering of equivalent elements is not preserved, use
4852 * @p stable_sort() if this is needed.
4853 */
4854 template<typename _RandomAccessIterator, typename _Compare>
4855 inline void
4856 sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
4857 _Compare __comp)
4858 {
4859 // concept requirements
4860 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4861 _RandomAccessIterator>)
4862 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4863 typename iterator_traits<_RandomAccessIterator>::value_type,
4864 typename iterator_traits<_RandomAccessIterator>::value_type>)
4865 __glibcxx_requires_valid_range(__first, __last);
4866 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
4867
4868 std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
4869 }
4870
4871 template<typename _InputIterator1, typename _InputIterator2,
4872 typename _OutputIterator, typename _Compare>
4873 _OutputIterator
4874 __merge(_InputIterator1 __first1, _InputIterator1 __last1,
4875 _InputIterator2 __first2, _InputIterator2 __last2,
4876 _OutputIterator __result, _Compare __comp)
4877 {
4878 while (__first1 != __last1 && __first2 != __last2)
4879 {
4880 if (__comp(__first2, __first1))
4881 {
4882 *__result = *__first2;
4883 ++__first2;
4884 }
4885 else
4886 {
4887 *__result = *__first1;
4888 ++__first1;
4889 }
4890 ++__result;
4891 }
4892 return std::copy(__first2, __last2,
4893 std::copy(__first1, __last1, __result));
4894 }
4895
4896 /**
4897 * @brief Merges two sorted ranges.
4898 * @ingroup sorting_algorithms
4899 * @param __first1 An iterator.
4900 * @param __first2 Another iterator.
4901 * @param __last1 Another iterator.
4902 * @param __last2 Another iterator.
4903 * @param __result An iterator pointing to the end of the merged range.
4904 * @return An iterator pointing to the first element <em>not less
4905 * than</em> @e val.
4906 *
4907 * Merges the ranges @p [__first1,__last1) and @p [__first2,__last2) into
4908 * the sorted range @p [__result, __result + (__last1-__first1) +
4909 * (__last2-__first2)). Both input ranges must be sorted, and the
4910 * output range must not overlap with either of the input ranges.
4911 * The sort is @e stable, that is, for equivalent elements in the
4912 * two ranges, elements from the first range will always come
4913 * before elements from the second.
4914 */
4915 template<typename _InputIterator1, typename _InputIterator2,
4916 typename _OutputIterator>
4917 inline _OutputIterator
4918 merge(_InputIterator1 __first1, _InputIterator1 __last1,
4919 _InputIterator2 __first2, _InputIterator2 __last2,
4920 _OutputIterator __result)
4921 {
4922 // concept requirements
4923 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4924 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4925 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4926 typename iterator_traits<_InputIterator1>::value_type>)
4927 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4928 typename iterator_traits<_InputIterator2>::value_type>)
4929 __glibcxx_function_requires(_LessThanOpConcept<
4930 typename iterator_traits<_InputIterator2>::value_type,
4931 typename iterator_traits<_InputIterator1>::value_type>)
4932 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
4933 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
4934 __glibcxx_requires_irreflexive2(__first1, __last1);
4935 __glibcxx_requires_irreflexive2(__first2, __last2);
4936
4937 return _GLIBCXX_STD_A::__merge(__first1, __last1,
4938 __first2, __last2, __result,
4939 __gnu_cxx::__ops::__iter_less_iter());
4940 }
4941
4942 /**
4943 * @brief Merges two sorted ranges.
4944 * @ingroup sorting_algorithms
4945 * @param __first1 An iterator.
4946 * @param __first2 Another iterator.
4947 * @param __last1 Another iterator.
4948 * @param __last2 Another iterator.
4949 * @param __result An iterator pointing to the end of the merged range.
4950 * @param __comp A functor to use for comparisons.
4951 * @return An iterator pointing to the first element "not less
4952 * than" @e val.
4953 *
4954 * Merges the ranges @p [__first1,__last1) and @p [__first2,__last2) into
4955 * the sorted range @p [__result, __result + (__last1-__first1) +
4956 * (__last2-__first2)). Both input ranges must be sorted, and the
4957 * output range must not overlap with either of the input ranges.
4958 * The sort is @e stable, that is, for equivalent elements in the
4959 * two ranges, elements from the first range will always come
4960 * before elements from the second.
4961 *
4962 * The comparison function should have the same effects on ordering as
4963 * the function used for the initial sort.
4964 */
4965 template<typename _InputIterator1, typename _InputIterator2,
4966 typename _OutputIterator, typename _Compare>
4967 inline _OutputIterator
4968 merge(_InputIterator1 __first1, _InputIterator1 __last1,
4969 _InputIterator2 __first2, _InputIterator2 __last2,
4970 _OutputIterator __result, _Compare __comp)
4971 {
4972 // concept requirements
4973 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4974 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4975 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4976 typename iterator_traits<_InputIterator1>::value_type>)
4977 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4978 typename iterator_traits<_InputIterator2>::value_type>)
4979 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4980 typename iterator_traits<_InputIterator2>::value_type,
4981 typename iterator_traits<_InputIterator1>::value_type>)
4982 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
4983 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
4984 __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp);
4985 __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp);
4986
4987 return _GLIBCXX_STD_A::__merge(__first1, __last1,
4988 __first2, __last2, __result,
4989 __gnu_cxx::__ops::__iter_comp_iter(__comp));
4990 }
4991
4992 template<typename _RandomAccessIterator, typename _Compare>
4993 inline void
4994 __stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
4995 _Compare __comp)
4996 {
4997 typedef typename iterator_traits<_RandomAccessIterator>::value_type
4998 _ValueType;
4999 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
5000 _DistanceType;
5001
5002 typedef _Temporary_buffer<_RandomAccessIterator, _ValueType> _TmpBuf;
5003 _TmpBuf __buf(__first, __last);
5004
5005 if (__buf.begin() == 0)
5006 std::__inplace_stable_sort(__first, __last, __comp);
5007 else
5008 std::__stable_sort_adaptive(__first, __last, __buf.begin(),
5009 _DistanceType(__buf.size()), __comp);
5010 }
5011
5012 /**
5013 * @brief Sort the elements of a sequence, preserving the relative order
5014 * of equivalent elements.
5015 * @ingroup sorting_algorithms
5016 * @param __first An iterator.
5017 * @param __last Another iterator.
5018 * @return Nothing.
5019 *
5020 * Sorts the elements in the range @p [__first,__last) in ascending order,
5021 * such that for each iterator @p i in the range @p [__first,__last-1),
5022 * @p *(i+1)<*i is false.
5023 *
5024 * The relative ordering of equivalent elements is preserved, so any two
5025 * elements @p x and @p y in the range @p [__first,__last) such that
5026 * @p x<y is false and @p y<x is false will have the same relative
5027 * ordering after calling @p stable_sort().
5028 */
5029 template<typename _RandomAccessIterator>
5030 inline void
5031 stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
5032 {
5033 // concept requirements
5034 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5035 _RandomAccessIterator>)
5036 __glibcxx_function_requires(_LessThanComparableConcept<
5037 typename iterator_traits<_RandomAccessIterator>::value_type>)
5038 __glibcxx_requires_valid_range(__first, __last);
5039 __glibcxx_requires_irreflexive(__first, __last);
5040
5041 _GLIBCXX_STD_A::__stable_sort(__first, __last,
5042 __gnu_cxx::__ops::__iter_less_iter());
5043 }
5044
5045 /**
5046 * @brief Sort the elements of a sequence using a predicate for comparison,
5047 * preserving the relative order of equivalent elements.
5048 * @ingroup sorting_algorithms
5049 * @param __first An iterator.
5050 * @param __last Another iterator.
5051 * @param __comp A comparison functor.
5052 * @return Nothing.
5053 *
5054 * Sorts the elements in the range @p [__first,__last) in ascending order,
5055 * such that for each iterator @p i in the range @p [__first,__last-1),
5056 * @p __comp(*(i+1),*i) is false.
5057 *
5058 * The relative ordering of equivalent elements is preserved, so any two
5059 * elements @p x and @p y in the range @p [__first,__last) such that
5060 * @p __comp(x,y) is false and @p __comp(y,x) is false will have the same
5061 * relative ordering after calling @p stable_sort().
5062 */
5063 template<typename _RandomAccessIterator, typename _Compare>
5064 inline void
5065 stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
5066 _Compare __comp)
5067 {
5068 // concept requirements
5069 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5070 _RandomAccessIterator>)
5071 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5072 typename iterator_traits<_RandomAccessIterator>::value_type,
5073 typename iterator_traits<_RandomAccessIterator>::value_type>)
5074 __glibcxx_requires_valid_range(__first, __last);
5075 __glibcxx_requires_irreflexive_pred(__first, __last, __comp);
5076
5077 _GLIBCXX_STD_A::__stable_sort(__first, __last,
5078 __gnu_cxx::__ops::__iter_comp_iter(__comp));
5079 }
5080
5081 template<typename _InputIterator1, typename _InputIterator2,
5082 typename _OutputIterator,
5083 typename _Compare>
5084 _OutputIterator
5085 __set_union(_InputIterator1 __first1, _InputIterator1 __last1,
5086 _InputIterator2 __first2, _InputIterator2 __last2,
5087 _OutputIterator __result, _Compare __comp)
5088 {
5089 while (__first1 != __last1 && __first2 != __last2)
5090 {
5091 if (__comp(__first1, __first2))
5092 {
5093 *__result = *__first1;
5094 ++__first1;
5095 }
5096 else if (__comp(__first2, __first1))
5097 {
5098 *__result = *__first2;
5099 ++__first2;
5100 }
5101 else
5102 {
5103 *__result = *__first1;
5104 ++__first1;
5105 ++__first2;
5106 }
5107 ++__result;
5108 }
5109 return std::copy(__first2, __last2,
5110 std::copy(__first1, __last1, __result));
5111 }
5112
5113 /**
5114 * @brief Return the union of two sorted ranges.
5115 * @ingroup set_algorithms
5116 * @param __first1 Start of first range.
5117 * @param __last1 End of first range.
5118 * @param __first2 Start of second range.
5119 * @param __last2 End of second range.
5120 * @return End of the output range.
5121 * @ingroup set_algorithms
5122 *
5123 * This operation iterates over both ranges, copying elements present in
5124 * each range in order to the output range. Iterators increment for each
5125 * range. When the current element of one range is less than the other,
5126 * that element is copied and the iterator advanced. If an element is
5127 * contained in both ranges, the element from the first range is copied and
5128 * both ranges advance. The output range may not overlap either input
5129 * range.
5130 */
5131 template<typename _InputIterator1, typename _InputIterator2,
5132 typename _OutputIterator>
5133 inline _OutputIterator
5134 set_union(_InputIterator1 __first1, _InputIterator1 __last1,
5135 _InputIterator2 __first2, _InputIterator2 __last2,
5136 _OutputIterator __result)
5137 {
5138 // concept requirements
5139 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5140 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5141 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5142 typename iterator_traits<_InputIterator1>::value_type>)
5143 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5144 typename iterator_traits<_InputIterator2>::value_type>)
5145 __glibcxx_function_requires(_LessThanOpConcept<
5146 typename iterator_traits<_InputIterator1>::value_type,
5147 typename iterator_traits<_InputIterator2>::value_type>)
5148 __glibcxx_function_requires(_LessThanOpConcept<
5149 typename iterator_traits<_InputIterator2>::value_type,
5150 typename iterator_traits<_InputIterator1>::value_type>)
5151 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5152 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5153 __glibcxx_requires_irreflexive2(__first1, __last1);
5154 __glibcxx_requires_irreflexive2(__first2, __last2);
5155
5156 return _GLIBCXX_STD_A::__set_union(__first1, __last1,
5157 __first2, __last2, __result,
5158 __gnu_cxx::__ops::__iter_less_iter());
5159 }
5160
5161 /**
5162 * @brief Return the union of two sorted ranges using a comparison functor.
5163 * @ingroup set_algorithms
5164 * @param __first1 Start of first range.
5165 * @param __last1 End of first range.
5166 * @param __first2 Start of second range.
5167 * @param __last2 End of second range.
5168 * @param __comp The comparison functor.
5169 * @return End of the output range.
5170 * @ingroup set_algorithms
5171 *
5172 * This operation iterates over both ranges, copying elements present in
5173 * each range in order to the output range. Iterators increment for each
5174 * range. When the current element of one range is less than the other
5175 * according to @p __comp, that element is copied and the iterator advanced.
5176 * If an equivalent element according to @p __comp is contained in both
5177 * ranges, the element from the first range is copied and both ranges
5178 * advance. The output range may not overlap either input range.
5179 */
5180 template<typename _InputIterator1, typename _InputIterator2,
5181 typename _OutputIterator, typename _Compare>
5182 inline _OutputIterator
5183 set_union(_InputIterator1 __first1, _InputIterator1 __last1,
5184 _InputIterator2 __first2, _InputIterator2 __last2,
5185 _OutputIterator __result, _Compare __comp)
5186 {
5187 // concept requirements
5188 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5189 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5190 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5191 typename iterator_traits<_InputIterator1>::value_type>)
5192 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5193 typename iterator_traits<_InputIterator2>::value_type>)
5194 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5195 typename iterator_traits<_InputIterator1>::value_type,
5196 typename iterator_traits<_InputIterator2>::value_type>)
5197 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5198 typename iterator_traits<_InputIterator2>::value_type,
5199 typename iterator_traits<_InputIterator1>::value_type>)
5200 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
5201 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
5202 __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp);
5203 __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp);
5204
5205 return _GLIBCXX_STD_A::__set_union(__first1, __last1,
5206 __first2, __last2, __result,
5207 __gnu_cxx::__ops::__iter_comp_iter(__comp));
5208 }
5209
5210 template<typename _InputIterator1, typename _InputIterator2,
5211 typename _OutputIterator,
5212 typename _Compare>
5213 _OutputIterator
5214 __set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
5215 _InputIterator2 __first2, _InputIterator2 __last2,
5216 _OutputIterator __result, _Compare __comp)
5217 {
5218 while (__first1 != __last1 && __first2 != __last2)
5219 if (__comp(__first1, __first2))
5220 ++__first1;
5221 else if (__comp(__first2, __first1))
5222 ++__first2;
5223 else
5224 {
5225 *__result = *__first1;
5226 ++__first1;
5227 ++__first2;
5228 ++__result;
5229 }
5230 return __result;
5231 }
5232
5233 /**
5234 * @brief Return the intersection of two sorted ranges.
5235 * @ingroup set_algorithms
5236 * @param __first1 Start of first range.
5237 * @param __last1 End of first range.
5238 * @param __first2 Start of second range.
5239 * @param __last2 End of second range.
5240 * @return End of the output range.
5241 * @ingroup set_algorithms
5242 *
5243 * This operation iterates over both ranges, copying elements present in
5244 * both ranges in order to the output range. Iterators increment for each
5245 * range. When the current element of one range is less than the other,
5246 * that iterator advances. If an element is contained in both ranges, the
5247 * element from the first range is copied and both ranges advance. The
5248 * output range may not overlap either input range.
5249 */
5250 template<typename _InputIterator1, typename _InputIterator2,
5251 typename _OutputIterator>
5252 inline _OutputIterator
5253 set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
5254 _InputIterator2 __first2, _InputIterator2 __last2,
5255 _OutputIterator __result)
5256 {
5257 // concept requirements
5258 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5259 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5260 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5261 typename iterator_traits<_InputIterator1>::value_type>)
5262 __glibcxx_function_requires(_LessThanOpConcept<
5263 typename iterator_traits<_InputIterator1>::value_type,
5264 typename iterator_traits<_InputIterator2>::value_type>)
5265 __glibcxx_function_requires(_LessThanOpConcept<
5266 typename iterator_traits<_InputIterator2>::value_type,
5267 typename iterator_traits<_InputIterator1>::value_type>)
5268 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5269 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5270 __glibcxx_requires_irreflexive2(__first1, __last1);
5271 __glibcxx_requires_irreflexive2(__first2, __last2);
5272
5273 return _GLIBCXX_STD_A::__set_intersection(__first1, __last1,
5274 __first2, __last2, __result,
5275 __gnu_cxx::__ops::__iter_less_iter());
5276 }
5277
5278 /**
5279 * @brief Return the intersection of two sorted ranges using comparison
5280 * functor.
5281 * @ingroup set_algorithms
5282 * @param __first1 Start of first range.
5283 * @param __last1 End of first range.
5284 * @param __first2 Start of second range.
5285 * @param __last2 End of second range.
5286 * @param __comp The comparison functor.
5287 * @return End of the output range.
5288 * @ingroup set_algorithms
5289 *
5290 * This operation iterates over both ranges, copying elements present in
5291 * both ranges in order to the output range. Iterators increment for each
5292 * range. When the current element of one range is less than the other
5293 * according to @p __comp, that iterator advances. If an element is
5294 * contained in both ranges according to @p __comp, the element from the
5295 * first range is copied and both ranges advance. The output range may not
5296 * overlap either input range.
5297 */
5298 template<typename _InputIterator1, typename _InputIterator2,
5299 typename _OutputIterator, typename _Compare>
5300 inline _OutputIterator
5301 set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
5302 _InputIterator2 __first2, _InputIterator2 __last2,
5303 _OutputIterator __result, _Compare __comp)
5304 {
5305 // concept requirements
5306 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5307 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5308 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5309 typename iterator_traits<_InputIterator1>::value_type>)
5310 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5311 typename iterator_traits<_InputIterator1>::value_type,
5312 typename iterator_traits<_InputIterator2>::value_type>)
5313 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5314 typename iterator_traits<_InputIterator2>::value_type,
5315 typename iterator_traits<_InputIterator1>::value_type>)
5316 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
5317 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
5318 __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp);
5319 __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp);
5320
5321 return _GLIBCXX_STD_A::__set_intersection(__first1, __last1,
5322 __first2, __last2, __result,
5323 __gnu_cxx::__ops::__iter_comp_iter(__comp));
5324 }
5325
5326 template<typename _InputIterator1, typename _InputIterator2,
5327 typename _OutputIterator,
5328 typename _Compare>
5329 _OutputIterator
5330 __set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
5331 _InputIterator2 __first2, _InputIterator2 __last2,
5332 _OutputIterator __result, _Compare __comp)
5333 {
5334 while (__first1 != __last1 && __first2 != __last2)
5335 if (__comp(__first1, __first2))
5336 {
5337 *__result = *__first1;
5338 ++__first1;
5339 ++__result;
5340 }
5341 else if (__comp(__first2, __first1))
5342 ++__first2;
5343 else
5344 {
5345 ++__first1;
5346 ++__first2;
5347 }
5348 return std::copy(__first1, __last1, __result);
5349 }
5350
5351 /**
5352 * @brief Return the difference of two sorted ranges.
5353 * @ingroup set_algorithms
5354 * @param __first1 Start of first range.
5355 * @param __last1 End of first range.
5356 * @param __first2 Start of second range.
5357 * @param __last2 End of second range.
5358 * @return End of the output range.
5359 * @ingroup set_algorithms
5360 *
5361 * This operation iterates over both ranges, copying elements present in
5362 * the first range but not the second in order to the output range.
5363 * Iterators increment for each range. When the current element of the
5364 * first range is less than the second, that element is copied and the
5365 * iterator advances. If the current element of the second range is less,
5366 * the iterator advances, but no element is copied. If an element is
5367 * contained in both ranges, no elements are copied and both ranges
5368 * advance. The output range may not overlap either input range.
5369 */
5370 template<typename _InputIterator1, typename _InputIterator2,
5371 typename _OutputIterator>
5372 inline _OutputIterator
5373 set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
5374 _InputIterator2 __first2, _InputIterator2 __last2,
5375 _OutputIterator __result)
5376 {
5377 // concept requirements
5378 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5379 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5380 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5381 typename iterator_traits<_InputIterator1>::value_type>)
5382 __glibcxx_function_requires(_LessThanOpConcept<
5383 typename iterator_traits<_InputIterator1>::value_type,
5384 typename iterator_traits<_InputIterator2>::value_type>)
5385 __glibcxx_function_requires(_LessThanOpConcept<
5386 typename iterator_traits<_InputIterator2>::value_type,
5387 typename iterator_traits<_InputIterator1>::value_type>)
5388 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5389 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5390 __glibcxx_requires_irreflexive2(__first1, __last1);
5391 __glibcxx_requires_irreflexive2(__first2, __last2);
5392
5393 return _GLIBCXX_STD_A::__set_difference(__first1, __last1,
5394 __first2, __last2, __result,
5395 __gnu_cxx::__ops::__iter_less_iter());
5396 }
5397
5398 /**
5399 * @brief Return the difference of two sorted ranges using comparison
5400 * functor.
5401 * @ingroup set_algorithms
5402 * @param __first1 Start of first range.
5403 * @param __last1 End of first range.
5404 * @param __first2 Start of second range.
5405 * @param __last2 End of second range.
5406 * @param __comp The comparison functor.
5407 * @return End of the output range.
5408 * @ingroup set_algorithms
5409 *
5410 * This operation iterates over both ranges, copying elements present in
5411 * the first range but not the second in order to the output range.
5412 * Iterators increment for each range. When the current element of the
5413 * first range is less than the second according to @p __comp, that element
5414 * is copied and the iterator advances. If the current element of the
5415 * second range is less, no element is copied and the iterator advances.
5416 * If an element is contained in both ranges according to @p __comp, no
5417 * elements are copied and both ranges advance. The output range may not
5418 * overlap either input range.
5419 */
5420 template<typename _InputIterator1, typename _InputIterator2,
5421 typename _OutputIterator, typename _Compare>
5422 inline _OutputIterator
5423 set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
5424 _InputIterator2 __first2, _InputIterator2 __last2,
5425 _OutputIterator __result, _Compare __comp)
5426 {
5427 // concept requirements
5428 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5429 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5430 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5431 typename iterator_traits<_InputIterator1>::value_type>)
5432 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5433 typename iterator_traits<_InputIterator1>::value_type,
5434 typename iterator_traits<_InputIterator2>::value_type>)
5435 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5436 typename iterator_traits<_InputIterator2>::value_type,
5437 typename iterator_traits<_InputIterator1>::value_type>)
5438 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
5439 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
5440 __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp);
5441 __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp);
5442
5443 return _GLIBCXX_STD_A::__set_difference(__first1, __last1,
5444 __first2, __last2, __result,
5445 __gnu_cxx::__ops::__iter_comp_iter(__comp));
5446 }
5447
5448 template<typename _InputIterator1, typename _InputIterator2,
5449 typename _OutputIterator,
5450 typename _Compare>
5451 _OutputIterator
5452 __set_symmetric_difference(_InputIterator1 __first1,
5453 _InputIterator1 __last1,
5454 _InputIterator2 __first2,
5455 _InputIterator2 __last2,
5456 _OutputIterator __result,
5457 _Compare __comp)
5458 {
5459 while (__first1 != __last1 && __first2 != __last2)
5460 if (__comp(__first1, __first2))
5461 {
5462 *__result = *__first1;
5463 ++__first1;
5464 ++__result;
5465 }
5466 else if (__comp(__first2, __first1))
5467 {
5468 *__result = *__first2;
5469 ++__first2;
5470 ++__result;
5471 }
5472 else
5473 {
5474 ++__first1;
5475 ++__first2;
5476 }
5477 return std::copy(__first2, __last2,
5478 std::copy(__first1, __last1, __result));
5479 }
5480
5481 /**
5482 * @brief Return the symmetric difference of two sorted ranges.
5483 * @ingroup set_algorithms
5484 * @param __first1 Start of first range.
5485 * @param __last1 End of first range.
5486 * @param __first2 Start of second range.
5487 * @param __last2 End of second range.
5488 * @return End of the output range.
5489 * @ingroup set_algorithms
5490 *
5491 * This operation iterates over both ranges, copying elements present in
5492 * one range but not the other in order to the output range. Iterators
5493 * increment for each range. When the current element of one range is less
5494 * than the other, that element is copied and the iterator advances. If an
5495 * element is contained in both ranges, no elements are copied and both
5496 * ranges advance. The output range may not overlap either input range.
5497 */
5498 template<typename _InputIterator1, typename _InputIterator2,
5499 typename _OutputIterator>
5500 inline _OutputIterator
5501 set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
5502 _InputIterator2 __first2, _InputIterator2 __last2,
5503 _OutputIterator __result)
5504 {
5505 // concept requirements
5506 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5507 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5508 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5509 typename iterator_traits<_InputIterator1>::value_type>)
5510 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5511 typename iterator_traits<_InputIterator2>::value_type>)
5512 __glibcxx_function_requires(_LessThanOpConcept<
5513 typename iterator_traits<_InputIterator1>::value_type,
5514 typename iterator_traits<_InputIterator2>::value_type>)
5515 __glibcxx_function_requires(_LessThanOpConcept<
5516 typename iterator_traits<_InputIterator2>::value_type,
5517 typename iterator_traits<_InputIterator1>::value_type>)
5518 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5519 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5520 __glibcxx_requires_irreflexive2(__first1, __last1);
5521 __glibcxx_requires_irreflexive2(__first2, __last2);
5522
5523 return _GLIBCXX_STD_A::__set_symmetric_difference(__first1, __last1,
5524 __first2, __last2, __result,
5525 __gnu_cxx::__ops::__iter_less_iter());
5526 }
5527
5528 /**
5529 * @brief Return the symmetric difference of two sorted ranges using
5530 * comparison functor.
5531 * @ingroup set_algorithms
5532 * @param __first1 Start of first range.
5533 * @param __last1 End of first range.
5534 * @param __first2 Start of second range.
5535 * @param __last2 End of second range.
5536 * @param __comp The comparison functor.
5537 * @return End of the output range.
5538 * @ingroup set_algorithms
5539 *
5540 * This operation iterates over both ranges, copying elements present in
5541 * one range but not the other in order to the output range. Iterators
5542 * increment for each range. When the current element of one range is less
5543 * than the other according to @p comp, that element is copied and the
5544 * iterator advances. If an element is contained in both ranges according
5545 * to @p __comp, no elements are copied and both ranges advance. The output
5546 * range may not overlap either input range.
5547 */
5548 template<typename _InputIterator1, typename _InputIterator2,
5549 typename _OutputIterator, typename _Compare>
5550 inline _OutputIterator
5551 set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
5552 _InputIterator2 __first2, _InputIterator2 __last2,
5553 _OutputIterator __result,
5554 _Compare __comp)
5555 {
5556 // concept requirements
5557 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5558 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5559 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5560 typename iterator_traits<_InputIterator1>::value_type>)
5561 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5562 typename iterator_traits<_InputIterator2>::value_type>)
5563 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5564 typename iterator_traits<_InputIterator1>::value_type,
5565 typename iterator_traits<_InputIterator2>::value_type>)
5566 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5567 typename iterator_traits<_InputIterator2>::value_type,
5568 typename iterator_traits<_InputIterator1>::value_type>)
5569 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
5570 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
5571 __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp);
5572 __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp);
5573
5574 return _GLIBCXX_STD_A::__set_symmetric_difference(