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[gcc.git] / libstdc++-v3 / include / bits / stl_algo.h
1 // Algorithm implementation -*- C++ -*-
2
3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
4 // 2010, 2011
5 // Free Software Foundation, Inc.
6 //
7 // This file is part of the GNU ISO C++ Library. This library is free
8 // software; you can redistribute it and/or modify it under the
9 // terms of the GNU General Public License as published by the
10 // Free Software Foundation; either version 3, or (at your option)
11 // any later version.
12
13 // This library is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
17
18 // Under Section 7 of GPL version 3, you are granted additional
19 // permissions described in the GCC Runtime Library Exception, version
20 // 3.1, as published by the Free Software Foundation.
21
22 // You should have received a copy of the GNU General Public License and
23 // a copy of the GCC Runtime Library Exception along with this program;
24 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
25 // <http://www.gnu.org/licenses/>.
26
27 /*
28 *
29 * Copyright (c) 1994
30 * Hewlett-Packard Company
31 *
32 * Permission to use, copy, modify, distribute and sell this software
33 * and its documentation for any purpose is hereby granted without fee,
34 * provided that the above copyright notice appear in all copies and
35 * that both that copyright notice and this permission notice appear
36 * in supporting documentation. Hewlett-Packard Company makes no
37 * representations about the suitability of this software for any
38 * purpose. It is provided "as is" without express or implied warranty.
39 *
40 *
41 * Copyright (c) 1996
42 * Silicon Graphics Computer Systems, Inc.
43 *
44 * Permission to use, copy, modify, distribute and sell this software
45 * and its documentation for any purpose is hereby granted without fee,
46 * provided that the above copyright notice appear in all copies and
47 * that both that copyright notice and this permission notice appear
48 * in supporting documentation. Silicon Graphics makes no
49 * representations about the suitability of this software for any
50 * purpose. It is provided "as is" without express or implied warranty.
51 */
52
53 /** @file bits/stl_algo.h
54 * This is an internal header file, included by other library headers.
55 * Do not attempt to use it directly. @headername{algorithm}
56 */
57
58 #ifndef _STL_ALGO_H
59 #define _STL_ALGO_H 1
60
61 #include <cstdlib> // for rand
62 #include <bits/algorithmfwd.h>
63 #include <bits/stl_heap.h>
64 #include <bits/stl_tempbuf.h> // for _Temporary_buffer
65
66 #ifdef __GXX_EXPERIMENTAL_CXX0X__
67 #include <random> // for std::uniform_int_distribution
68 #include <functional> // for std::bind
69 #endif
70
71 // See concept_check.h for the __glibcxx_*_requires macros.
72
73 namespace std _GLIBCXX_VISIBILITY(default)
74 {
75 _GLIBCXX_BEGIN_NAMESPACE_VERSION
76
77 /// Swaps the median value of *__a, *__b and *__c to *__a
78 template<typename _Iterator>
79 void
80 __move_median_first(_Iterator __a, _Iterator __b, _Iterator __c)
81 {
82 // concept requirements
83 __glibcxx_function_requires(_LessThanComparableConcept<
84 typename iterator_traits<_Iterator>::value_type>)
85
86 if (*__a < *__b)
87 {
88 if (*__b < *__c)
89 std::iter_swap(__a, __b);
90 else if (*__a < *__c)
91 std::iter_swap(__a, __c);
92 }
93 else if (*__a < *__c)
94 return;
95 else if (*__b < *__c)
96 std::iter_swap(__a, __c);
97 else
98 std::iter_swap(__a, __b);
99 }
100
101 /// Swaps the median value of *__a, *__b and *__c under __comp to *__a
102 template<typename _Iterator, typename _Compare>
103 void
104 __move_median_first(_Iterator __a, _Iterator __b, _Iterator __c,
105 _Compare __comp)
106 {
107 // concept requirements
108 __glibcxx_function_requires(_BinaryFunctionConcept<_Compare, bool,
109 typename iterator_traits<_Iterator>::value_type,
110 typename iterator_traits<_Iterator>::value_type>)
111
112 if (__comp(*__a, *__b))
113 {
114 if (__comp(*__b, *__c))
115 std::iter_swap(__a, __b);
116 else if (__comp(*__a, *__c))
117 std::iter_swap(__a, __c);
118 }
119 else if (__comp(*__a, *__c))
120 return;
121 else if (__comp(*__b, *__c))
122 std::iter_swap(__a, __c);
123 else
124 std::iter_swap(__a, __b);
125 }
126
127 // for_each
128
129 /// This is an overload used by find() for the Input Iterator case.
130 template<typename _InputIterator, typename _Tp>
131 inline _InputIterator
132 __find(_InputIterator __first, _InputIterator __last,
133 const _Tp& __val, input_iterator_tag)
134 {
135 while (__first != __last && !(*__first == __val))
136 ++__first;
137 return __first;
138 }
139
140 /// This is an overload used by find_if() for the Input Iterator case.
141 template<typename _InputIterator, typename _Predicate>
142 inline _InputIterator
143 __find_if(_InputIterator __first, _InputIterator __last,
144 _Predicate __pred, input_iterator_tag)
145 {
146 while (__first != __last && !bool(__pred(*__first)))
147 ++__first;
148 return __first;
149 }
150
151 /// This is an overload used by find() for the RAI case.
152 template<typename _RandomAccessIterator, typename _Tp>
153 _RandomAccessIterator
154 __find(_RandomAccessIterator __first, _RandomAccessIterator __last,
155 const _Tp& __val, random_access_iterator_tag)
156 {
157 typename iterator_traits<_RandomAccessIterator>::difference_type
158 __trip_count = (__last - __first) >> 2;
159
160 for (; __trip_count > 0; --__trip_count)
161 {
162 if (*__first == __val)
163 return __first;
164 ++__first;
165
166 if (*__first == __val)
167 return __first;
168 ++__first;
169
170 if (*__first == __val)
171 return __first;
172 ++__first;
173
174 if (*__first == __val)
175 return __first;
176 ++__first;
177 }
178
179 switch (__last - __first)
180 {
181 case 3:
182 if (*__first == __val)
183 return __first;
184 ++__first;
185 case 2:
186 if (*__first == __val)
187 return __first;
188 ++__first;
189 case 1:
190 if (*__first == __val)
191 return __first;
192 ++__first;
193 case 0:
194 default:
195 return __last;
196 }
197 }
198
199 /// This is an overload used by find_if() for the RAI case.
200 template<typename _RandomAccessIterator, typename _Predicate>
201 _RandomAccessIterator
202 __find_if(_RandomAccessIterator __first, _RandomAccessIterator __last,
203 _Predicate __pred, random_access_iterator_tag)
204 {
205 typename iterator_traits<_RandomAccessIterator>::difference_type
206 __trip_count = (__last - __first) >> 2;
207
208 for (; __trip_count > 0; --__trip_count)
209 {
210 if (__pred(*__first))
211 return __first;
212 ++__first;
213
214 if (__pred(*__first))
215 return __first;
216 ++__first;
217
218 if (__pred(*__first))
219 return __first;
220 ++__first;
221
222 if (__pred(*__first))
223 return __first;
224 ++__first;
225 }
226
227 switch (__last - __first)
228 {
229 case 3:
230 if (__pred(*__first))
231 return __first;
232 ++__first;
233 case 2:
234 if (__pred(*__first))
235 return __first;
236 ++__first;
237 case 1:
238 if (__pred(*__first))
239 return __first;
240 ++__first;
241 case 0:
242 default:
243 return __last;
244 }
245 }
246
247 #ifdef __GXX_EXPERIMENTAL_CXX0X__
248 /// This is an overload used by find_if_not() for the Input Iterator case.
249 template<typename _InputIterator, typename _Predicate>
250 inline _InputIterator
251 __find_if_not(_InputIterator __first, _InputIterator __last,
252 _Predicate __pred, input_iterator_tag)
253 {
254 while (__first != __last && bool(__pred(*__first)))
255 ++__first;
256 return __first;
257 }
258
259 /// This is an overload used by find_if_not() for the RAI case.
260 template<typename _RandomAccessIterator, typename _Predicate>
261 _RandomAccessIterator
262 __find_if_not(_RandomAccessIterator __first, _RandomAccessIterator __last,
263 _Predicate __pred, random_access_iterator_tag)
264 {
265 typename iterator_traits<_RandomAccessIterator>::difference_type
266 __trip_count = (__last - __first) >> 2;
267
268 for (; __trip_count > 0; --__trip_count)
269 {
270 if (!bool(__pred(*__first)))
271 return __first;
272 ++__first;
273
274 if (!bool(__pred(*__first)))
275 return __first;
276 ++__first;
277
278 if (!bool(__pred(*__first)))
279 return __first;
280 ++__first;
281
282 if (!bool(__pred(*__first)))
283 return __first;
284 ++__first;
285 }
286
287 switch (__last - __first)
288 {
289 case 3:
290 if (!bool(__pred(*__first)))
291 return __first;
292 ++__first;
293 case 2:
294 if (!bool(__pred(*__first)))
295 return __first;
296 ++__first;
297 case 1:
298 if (!bool(__pred(*__first)))
299 return __first;
300 ++__first;
301 case 0:
302 default:
303 return __last;
304 }
305 }
306 #endif
307
308 // set_difference
309 // set_intersection
310 // set_symmetric_difference
311 // set_union
312 // for_each
313 // find
314 // find_if
315 // find_first_of
316 // adjacent_find
317 // count
318 // count_if
319 // search
320
321 /**
322 * This is an uglified
323 * search_n(_ForwardIterator, _ForwardIterator, _Integer, const _Tp&)
324 * overloaded for forward iterators.
325 */
326 template<typename _ForwardIterator, typename _Integer, typename _Tp>
327 _ForwardIterator
328 __search_n(_ForwardIterator __first, _ForwardIterator __last,
329 _Integer __count, const _Tp& __val,
330 std::forward_iterator_tag)
331 {
332 __first = _GLIBCXX_STD_A::find(__first, __last, __val);
333 while (__first != __last)
334 {
335 typename iterator_traits<_ForwardIterator>::difference_type
336 __n = __count;
337 _ForwardIterator __i = __first;
338 ++__i;
339 while (__i != __last && __n != 1 && *__i == __val)
340 {
341 ++__i;
342 --__n;
343 }
344 if (__n == 1)
345 return __first;
346 if (__i == __last)
347 return __last;
348 __first = _GLIBCXX_STD_A::find(++__i, __last, __val);
349 }
350 return __last;
351 }
352
353 /**
354 * This is an uglified
355 * search_n(_ForwardIterator, _ForwardIterator, _Integer, const _Tp&)
356 * overloaded for random access iterators.
357 */
358 template<typename _RandomAccessIter, typename _Integer, typename _Tp>
359 _RandomAccessIter
360 __search_n(_RandomAccessIter __first, _RandomAccessIter __last,
361 _Integer __count, const _Tp& __val,
362 std::random_access_iterator_tag)
363 {
364
365 typedef typename std::iterator_traits<_RandomAccessIter>::difference_type
366 _DistanceType;
367
368 _DistanceType __tailSize = __last - __first;
369 const _DistanceType __pattSize = __count;
370
371 if (__tailSize < __pattSize)
372 return __last;
373
374 const _DistanceType __skipOffset = __pattSize - 1;
375 _RandomAccessIter __lookAhead = __first + __skipOffset;
376 __tailSize -= __pattSize;
377
378 while (1) // the main loop...
379 {
380 // __lookAhead here is always pointing to the last element of next
381 // possible match.
382 while (!(*__lookAhead == __val)) // the skip loop...
383 {
384 if (__tailSize < __pattSize)
385 return __last; // Failure
386 __lookAhead += __pattSize;
387 __tailSize -= __pattSize;
388 }
389 _DistanceType __remainder = __skipOffset;
390 for (_RandomAccessIter __backTrack = __lookAhead - 1;
391 *__backTrack == __val; --__backTrack)
392 {
393 if (--__remainder == 0)
394 return (__lookAhead - __skipOffset); // Success
395 }
396 if (__remainder > __tailSize)
397 return __last; // Failure
398 __lookAhead += __remainder;
399 __tailSize -= __remainder;
400 }
401 }
402
403 // search_n
404
405 /**
406 * This is an uglified
407 * search_n(_ForwardIterator, _ForwardIterator, _Integer, const _Tp&,
408 * _BinaryPredicate)
409 * overloaded for forward iterators.
410 */
411 template<typename _ForwardIterator, typename _Integer, typename _Tp,
412 typename _BinaryPredicate>
413 _ForwardIterator
414 __search_n(_ForwardIterator __first, _ForwardIterator __last,
415 _Integer __count, const _Tp& __val,
416 _BinaryPredicate __binary_pred, std::forward_iterator_tag)
417 {
418 while (__first != __last && !bool(__binary_pred(*__first, __val)))
419 ++__first;
420
421 while (__first != __last)
422 {
423 typename iterator_traits<_ForwardIterator>::difference_type
424 __n = __count;
425 _ForwardIterator __i = __first;
426 ++__i;
427 while (__i != __last && __n != 1 && bool(__binary_pred(*__i, __val)))
428 {
429 ++__i;
430 --__n;
431 }
432 if (__n == 1)
433 return __first;
434 if (__i == __last)
435 return __last;
436 __first = ++__i;
437 while (__first != __last
438 && !bool(__binary_pred(*__first, __val)))
439 ++__first;
440 }
441 return __last;
442 }
443
444 /**
445 * This is an uglified
446 * search_n(_ForwardIterator, _ForwardIterator, _Integer, const _Tp&,
447 * _BinaryPredicate)
448 * overloaded for random access iterators.
449 */
450 template<typename _RandomAccessIter, typename _Integer, typename _Tp,
451 typename _BinaryPredicate>
452 _RandomAccessIter
453 __search_n(_RandomAccessIter __first, _RandomAccessIter __last,
454 _Integer __count, const _Tp& __val,
455 _BinaryPredicate __binary_pred, std::random_access_iterator_tag)
456 {
457
458 typedef typename std::iterator_traits<_RandomAccessIter>::difference_type
459 _DistanceType;
460
461 _DistanceType __tailSize = __last - __first;
462 const _DistanceType __pattSize = __count;
463
464 if (__tailSize < __pattSize)
465 return __last;
466
467 const _DistanceType __skipOffset = __pattSize - 1;
468 _RandomAccessIter __lookAhead = __first + __skipOffset;
469 __tailSize -= __pattSize;
470
471 while (1) // the main loop...
472 {
473 // __lookAhead here is always pointing to the last element of next
474 // possible match.
475 while (!bool(__binary_pred(*__lookAhead, __val))) // the skip loop...
476 {
477 if (__tailSize < __pattSize)
478 return __last; // Failure
479 __lookAhead += __pattSize;
480 __tailSize -= __pattSize;
481 }
482 _DistanceType __remainder = __skipOffset;
483 for (_RandomAccessIter __backTrack = __lookAhead - 1;
484 __binary_pred(*__backTrack, __val); --__backTrack)
485 {
486 if (--__remainder == 0)
487 return (__lookAhead - __skipOffset); // Success
488 }
489 if (__remainder > __tailSize)
490 return __last; // Failure
491 __lookAhead += __remainder;
492 __tailSize -= __remainder;
493 }
494 }
495
496 // find_end for forward iterators.
497 template<typename _ForwardIterator1, typename _ForwardIterator2>
498 _ForwardIterator1
499 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
500 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
501 forward_iterator_tag, forward_iterator_tag)
502 {
503 if (__first2 == __last2)
504 return __last1;
505 else
506 {
507 _ForwardIterator1 __result = __last1;
508 while (1)
509 {
510 _ForwardIterator1 __new_result
511 = _GLIBCXX_STD_A::search(__first1, __last1, __first2, __last2);
512 if (__new_result == __last1)
513 return __result;
514 else
515 {
516 __result = __new_result;
517 __first1 = __new_result;
518 ++__first1;
519 }
520 }
521 }
522 }
523
524 template<typename _ForwardIterator1, typename _ForwardIterator2,
525 typename _BinaryPredicate>
526 _ForwardIterator1
527 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
528 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
529 forward_iterator_tag, forward_iterator_tag,
530 _BinaryPredicate __comp)
531 {
532 if (__first2 == __last2)
533 return __last1;
534 else
535 {
536 _ForwardIterator1 __result = __last1;
537 while (1)
538 {
539 _ForwardIterator1 __new_result
540 = _GLIBCXX_STD_A::search(__first1, __last1, __first2,
541 __last2, __comp);
542 if (__new_result == __last1)
543 return __result;
544 else
545 {
546 __result = __new_result;
547 __first1 = __new_result;
548 ++__first1;
549 }
550 }
551 }
552 }
553
554 // find_end for bidirectional iterators (much faster).
555 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2>
556 _BidirectionalIterator1
557 __find_end(_BidirectionalIterator1 __first1,
558 _BidirectionalIterator1 __last1,
559 _BidirectionalIterator2 __first2,
560 _BidirectionalIterator2 __last2,
561 bidirectional_iterator_tag, bidirectional_iterator_tag)
562 {
563 // concept requirements
564 __glibcxx_function_requires(_BidirectionalIteratorConcept<
565 _BidirectionalIterator1>)
566 __glibcxx_function_requires(_BidirectionalIteratorConcept<
567 _BidirectionalIterator2>)
568
569 typedef reverse_iterator<_BidirectionalIterator1> _RevIterator1;
570 typedef reverse_iterator<_BidirectionalIterator2> _RevIterator2;
571
572 _RevIterator1 __rlast1(__first1);
573 _RevIterator2 __rlast2(__first2);
574 _RevIterator1 __rresult = _GLIBCXX_STD_A::search(_RevIterator1(__last1),
575 __rlast1,
576 _RevIterator2(__last2),
577 __rlast2);
578
579 if (__rresult == __rlast1)
580 return __last1;
581 else
582 {
583 _BidirectionalIterator1 __result = __rresult.base();
584 std::advance(__result, -std::distance(__first2, __last2));
585 return __result;
586 }
587 }
588
589 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
590 typename _BinaryPredicate>
591 _BidirectionalIterator1
592 __find_end(_BidirectionalIterator1 __first1,
593 _BidirectionalIterator1 __last1,
594 _BidirectionalIterator2 __first2,
595 _BidirectionalIterator2 __last2,
596 bidirectional_iterator_tag, bidirectional_iterator_tag,
597 _BinaryPredicate __comp)
598 {
599 // concept requirements
600 __glibcxx_function_requires(_BidirectionalIteratorConcept<
601 _BidirectionalIterator1>)
602 __glibcxx_function_requires(_BidirectionalIteratorConcept<
603 _BidirectionalIterator2>)
604
605 typedef reverse_iterator<_BidirectionalIterator1> _RevIterator1;
606 typedef reverse_iterator<_BidirectionalIterator2> _RevIterator2;
607
608 _RevIterator1 __rlast1(__first1);
609 _RevIterator2 __rlast2(__first2);
610 _RevIterator1 __rresult = std::search(_RevIterator1(__last1), __rlast1,
611 _RevIterator2(__last2), __rlast2,
612 __comp);
613
614 if (__rresult == __rlast1)
615 return __last1;
616 else
617 {
618 _BidirectionalIterator1 __result = __rresult.base();
619 std::advance(__result, -std::distance(__first2, __last2));
620 return __result;
621 }
622 }
623
624 /**
625 * @brief Find last matching subsequence in a sequence.
626 * @ingroup non_mutating_algorithms
627 * @param first1 Start of range to search.
628 * @param last1 End of range to search.
629 * @param first2 Start of sequence to match.
630 * @param last2 End of sequence to match.
631 * @return The last iterator @c i in the range
632 * @p [first1,last1-(last2-first2)) such that @c *(i+N) == @p *(first2+N)
633 * for each @c N in the range @p [0,last2-first2), or @p last1 if no
634 * such iterator exists.
635 *
636 * Searches the range @p [first1,last1) for a sub-sequence that compares
637 * equal value-by-value with the sequence given by @p [first2,last2) and
638 * returns an iterator to the first element of the sub-sequence, or
639 * @p last1 if the sub-sequence is not found. The sub-sequence will be the
640 * last such subsequence contained in [first,last1).
641 *
642 * Because the sub-sequence must lie completely within the range
643 * @p [first1,last1) it must start at a position less than
644 * @p last1-(last2-first2) where @p last2-first2 is the length of the
645 * sub-sequence.
646 * This means that the returned iterator @c i will be in the range
647 * @p [first1,last1-(last2-first2))
648 */
649 template<typename _ForwardIterator1, typename _ForwardIterator2>
650 inline _ForwardIterator1
651 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
652 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
653 {
654 // concept requirements
655 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
656 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
657 __glibcxx_function_requires(_EqualOpConcept<
658 typename iterator_traits<_ForwardIterator1>::value_type,
659 typename iterator_traits<_ForwardIterator2>::value_type>)
660 __glibcxx_requires_valid_range(__first1, __last1);
661 __glibcxx_requires_valid_range(__first2, __last2);
662
663 return std::__find_end(__first1, __last1, __first2, __last2,
664 std::__iterator_category(__first1),
665 std::__iterator_category(__first2));
666 }
667
668 /**
669 * @brief Find last matching subsequence in a sequence using a predicate.
670 * @ingroup non_mutating_algorithms
671 * @param first1 Start of range to search.
672 * @param last1 End of range to search.
673 * @param first2 Start of sequence to match.
674 * @param last2 End of sequence to match.
675 * @param comp The predicate to use.
676 * @return The last iterator @c i in the range
677 * @p [first1,last1-(last2-first2)) such that @c predicate(*(i+N), @p
678 * (first2+N)) is true for each @c N in the range @p [0,last2-first2), or
679 * @p last1 if no such iterator exists.
680 *
681 * Searches the range @p [first1,last1) for a sub-sequence that compares
682 * equal value-by-value with the sequence given by @p [first2,last2) using
683 * comp as a predicate and returns an iterator to the first element of the
684 * sub-sequence, or @p last1 if the sub-sequence is not found. The
685 * sub-sequence will be the last such subsequence contained in
686 * [first,last1).
687 *
688 * Because the sub-sequence must lie completely within the range
689 * @p [first1,last1) it must start at a position less than
690 * @p last1-(last2-first2) where @p last2-first2 is the length of the
691 * sub-sequence.
692 * This means that the returned iterator @c i will be in the range
693 * @p [first1,last1-(last2-first2))
694 */
695 template<typename _ForwardIterator1, typename _ForwardIterator2,
696 typename _BinaryPredicate>
697 inline _ForwardIterator1
698 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
699 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
700 _BinaryPredicate __comp)
701 {
702 // concept requirements
703 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
704 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
705 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
706 typename iterator_traits<_ForwardIterator1>::value_type,
707 typename iterator_traits<_ForwardIterator2>::value_type>)
708 __glibcxx_requires_valid_range(__first1, __last1);
709 __glibcxx_requires_valid_range(__first2, __last2);
710
711 return std::__find_end(__first1, __last1, __first2, __last2,
712 std::__iterator_category(__first1),
713 std::__iterator_category(__first2),
714 __comp);
715 }
716
717 #ifdef __GXX_EXPERIMENTAL_CXX0X__
718 /**
719 * @brief Checks that a predicate is true for all the elements
720 * of a sequence.
721 * @ingroup non_mutating_algorithms
722 * @param first An input iterator.
723 * @param last An input iterator.
724 * @param pred A predicate.
725 * @return True if the check is true, false otherwise.
726 *
727 * Returns true if @p pred is true for each element in the range
728 * @p [first,last), and false otherwise.
729 */
730 template<typename _InputIterator, typename _Predicate>
731 inline bool
732 all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
733 { return __last == std::find_if_not(__first, __last, __pred); }
734
735 /**
736 * @brief Checks that a predicate is false for all the elements
737 * of a sequence.
738 * @ingroup non_mutating_algorithms
739 * @param first An input iterator.
740 * @param last An input iterator.
741 * @param pred A predicate.
742 * @return True if the check is true, false otherwise.
743 *
744 * Returns true if @p pred is false for each element in the range
745 * @p [first,last), and false otherwise.
746 */
747 template<typename _InputIterator, typename _Predicate>
748 inline bool
749 none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
750 { return __last == _GLIBCXX_STD_A::find_if(__first, __last, __pred); }
751
752 /**
753 * @brief Checks that a predicate is false for at least an element
754 * of a sequence.
755 * @ingroup non_mutating_algorithms
756 * @param first An input iterator.
757 * @param last An input iterator.
758 * @param pred A predicate.
759 * @return True if the check is true, false otherwise.
760 *
761 * Returns true if an element exists in the range @p [first,last) such that
762 * @p pred is true, and false otherwise.
763 */
764 template<typename _InputIterator, typename _Predicate>
765 inline bool
766 any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
767 { return !std::none_of(__first, __last, __pred); }
768
769 /**
770 * @brief Find the first element in a sequence for which a
771 * predicate is false.
772 * @ingroup non_mutating_algorithms
773 * @param first An input iterator.
774 * @param last An input iterator.
775 * @param pred A predicate.
776 * @return The first iterator @c i in the range @p [first,last)
777 * such that @p pred(*i) is false, or @p last if no such iterator exists.
778 */
779 template<typename _InputIterator, typename _Predicate>
780 inline _InputIterator
781 find_if_not(_InputIterator __first, _InputIterator __last,
782 _Predicate __pred)
783 {
784 // concept requirements
785 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
786 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
787 typename iterator_traits<_InputIterator>::value_type>)
788 __glibcxx_requires_valid_range(__first, __last);
789 return std::__find_if_not(__first, __last, __pred,
790 std::__iterator_category(__first));
791 }
792
793 /**
794 * @brief Checks whether the sequence is partitioned.
795 * @ingroup mutating_algorithms
796 * @param first An input iterator.
797 * @param last An input iterator.
798 * @param pred A predicate.
799 * @return True if the range @p [first,last) is partioned by @p pred,
800 * i.e. if all elements that satisfy @p pred appear before those that
801 * do not.
802 */
803 template<typename _InputIterator, typename _Predicate>
804 inline bool
805 is_partitioned(_InputIterator __first, _InputIterator __last,
806 _Predicate __pred)
807 {
808 __first = std::find_if_not(__first, __last, __pred);
809 return std::none_of(__first, __last, __pred);
810 }
811
812 /**
813 * @brief Find the partition point of a partitioned range.
814 * @ingroup mutating_algorithms
815 * @param first An iterator.
816 * @param last Another iterator.
817 * @param pred A predicate.
818 * @return An iterator @p mid such that @p all_of(first, mid, pred)
819 * and @p none_of(mid, last, pred) are both true.
820 */
821 template<typename _ForwardIterator, typename _Predicate>
822 _ForwardIterator
823 partition_point(_ForwardIterator __first, _ForwardIterator __last,
824 _Predicate __pred)
825 {
826 // concept requirements
827 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
828 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
829 typename iterator_traits<_ForwardIterator>::value_type>)
830
831 // A specific debug-mode test will be necessary...
832 __glibcxx_requires_valid_range(__first, __last);
833
834 typedef typename iterator_traits<_ForwardIterator>::difference_type
835 _DistanceType;
836
837 _DistanceType __len = std::distance(__first, __last);
838 _DistanceType __half;
839 _ForwardIterator __middle;
840
841 while (__len > 0)
842 {
843 __half = __len >> 1;
844 __middle = __first;
845 std::advance(__middle, __half);
846 if (__pred(*__middle))
847 {
848 __first = __middle;
849 ++__first;
850 __len = __len - __half - 1;
851 }
852 else
853 __len = __half;
854 }
855 return __first;
856 }
857 #endif
858
859
860 /**
861 * @brief Copy a sequence, removing elements of a given value.
862 * @ingroup mutating_algorithms
863 * @param first An input iterator.
864 * @param last An input iterator.
865 * @param result An output iterator.
866 * @param value The value to be removed.
867 * @return An iterator designating the end of the resulting sequence.
868 *
869 * Copies each element in the range @p [first,last) not equal to @p value
870 * to the range beginning at @p result.
871 * remove_copy() is stable, so the relative order of elements that are
872 * copied is unchanged.
873 */
874 template<typename _InputIterator, typename _OutputIterator, typename _Tp>
875 _OutputIterator
876 remove_copy(_InputIterator __first, _InputIterator __last,
877 _OutputIterator __result, const _Tp& __value)
878 {
879 // concept requirements
880 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
881 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
882 typename iterator_traits<_InputIterator>::value_type>)
883 __glibcxx_function_requires(_EqualOpConcept<
884 typename iterator_traits<_InputIterator>::value_type, _Tp>)
885 __glibcxx_requires_valid_range(__first, __last);
886
887 for (; __first != __last; ++__first)
888 if (!(*__first == __value))
889 {
890 *__result = *__first;
891 ++__result;
892 }
893 return __result;
894 }
895
896 /**
897 * @brief Copy a sequence, removing elements for which a predicate is true.
898 * @ingroup mutating_algorithms
899 * @param first An input iterator.
900 * @param last An input iterator.
901 * @param result An output iterator.
902 * @param pred A predicate.
903 * @return An iterator designating the end of the resulting sequence.
904 *
905 * Copies each element in the range @p [first,last) for which
906 * @p pred returns false to the range beginning at @p result.
907 *
908 * remove_copy_if() is stable, so the relative order of elements that are
909 * copied is unchanged.
910 */
911 template<typename _InputIterator, typename _OutputIterator,
912 typename _Predicate>
913 _OutputIterator
914 remove_copy_if(_InputIterator __first, _InputIterator __last,
915 _OutputIterator __result, _Predicate __pred)
916 {
917 // concept requirements
918 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
919 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
920 typename iterator_traits<_InputIterator>::value_type>)
921 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
922 typename iterator_traits<_InputIterator>::value_type>)
923 __glibcxx_requires_valid_range(__first, __last);
924
925 for (; __first != __last; ++__first)
926 if (!bool(__pred(*__first)))
927 {
928 *__result = *__first;
929 ++__result;
930 }
931 return __result;
932 }
933
934 #ifdef __GXX_EXPERIMENTAL_CXX0X__
935 /**
936 * @brief Copy the elements of a sequence for which a predicate is true.
937 * @ingroup mutating_algorithms
938 * @param first An input iterator.
939 * @param last An input iterator.
940 * @param result An output iterator.
941 * @param pred A predicate.
942 * @return An iterator designating the end of the resulting sequence.
943 *
944 * Copies each element in the range @p [first,last) for which
945 * @p pred returns true to the range beginning at @p result.
946 *
947 * copy_if() is stable, so the relative order of elements that are
948 * copied is unchanged.
949 */
950 template<typename _InputIterator, typename _OutputIterator,
951 typename _Predicate>
952 _OutputIterator
953 copy_if(_InputIterator __first, _InputIterator __last,
954 _OutputIterator __result, _Predicate __pred)
955 {
956 // concept requirements
957 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
958 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
959 typename iterator_traits<_InputIterator>::value_type>)
960 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
961 typename iterator_traits<_InputIterator>::value_type>)
962 __glibcxx_requires_valid_range(__first, __last);
963
964 for (; __first != __last; ++__first)
965 if (__pred(*__first))
966 {
967 *__result = *__first;
968 ++__result;
969 }
970 return __result;
971 }
972
973
974 template<typename _InputIterator, typename _Size, typename _OutputIterator>
975 _OutputIterator
976 __copy_n(_InputIterator __first, _Size __n,
977 _OutputIterator __result, input_iterator_tag)
978 {
979 for (; __n > 0; --__n)
980 {
981 *__result = *__first;
982 ++__first;
983 ++__result;
984 }
985 return __result;
986 }
987
988 template<typename _RandomAccessIterator, typename _Size,
989 typename _OutputIterator>
990 inline _OutputIterator
991 __copy_n(_RandomAccessIterator __first, _Size __n,
992 _OutputIterator __result, random_access_iterator_tag)
993 { return std::copy(__first, __first + __n, __result); }
994
995 /**
996 * @brief Copies the range [first,first+n) into [result,result+n).
997 * @ingroup mutating_algorithms
998 * @param first An input iterator.
999 * @param n The number of elements to copy.
1000 * @param result An output iterator.
1001 * @return result+n.
1002 *
1003 * This inline function will boil down to a call to @c memmove whenever
1004 * possible. Failing that, if random access iterators are passed, then the
1005 * loop count will be known (and therefore a candidate for compiler
1006 * optimizations such as unrolling).
1007 */
1008 template<typename _InputIterator, typename _Size, typename _OutputIterator>
1009 inline _OutputIterator
1010 copy_n(_InputIterator __first, _Size __n, _OutputIterator __result)
1011 {
1012 // concept requirements
1013 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1014 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1015 typename iterator_traits<_InputIterator>::value_type>)
1016
1017 return std::__copy_n(__first, __n, __result,
1018 std::__iterator_category(__first));
1019 }
1020
1021 /**
1022 * @brief Copy the elements of a sequence to separate output sequences
1023 * depending on the truth value of a predicate.
1024 * @ingroup mutating_algorithms
1025 * @param first An input iterator.
1026 * @param last An input iterator.
1027 * @param out_true An output iterator.
1028 * @param out_false An output iterator.
1029 * @param pred A predicate.
1030 * @return A pair designating the ends of the resulting sequences.
1031 *
1032 * Copies each element in the range @p [first,last) for which
1033 * @p pred returns true to the range beginning at @p out_true
1034 * and each element for which @p pred returns false to @p out_false.
1035 */
1036 template<typename _InputIterator, typename _OutputIterator1,
1037 typename _OutputIterator2, typename _Predicate>
1038 pair<_OutputIterator1, _OutputIterator2>
1039 partition_copy(_InputIterator __first, _InputIterator __last,
1040 _OutputIterator1 __out_true, _OutputIterator2 __out_false,
1041 _Predicate __pred)
1042 {
1043 // concept requirements
1044 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1045 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator1,
1046 typename iterator_traits<_InputIterator>::value_type>)
1047 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator2,
1048 typename iterator_traits<_InputIterator>::value_type>)
1049 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1050 typename iterator_traits<_InputIterator>::value_type>)
1051 __glibcxx_requires_valid_range(__first, __last);
1052
1053 for (; __first != __last; ++__first)
1054 if (__pred(*__first))
1055 {
1056 *__out_true = *__first;
1057 ++__out_true;
1058 }
1059 else
1060 {
1061 *__out_false = *__first;
1062 ++__out_false;
1063 }
1064
1065 return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
1066 }
1067 #endif
1068
1069 /**
1070 * @brief Remove elements from a sequence.
1071 * @ingroup mutating_algorithms
1072 * @param first An input iterator.
1073 * @param last An input iterator.
1074 * @param value The value to be removed.
1075 * @return An iterator designating the end of the resulting sequence.
1076 *
1077 * All elements equal to @p value are removed from the range
1078 * @p [first,last).
1079 *
1080 * remove() is stable, so the relative order of elements that are
1081 * not removed is unchanged.
1082 *
1083 * Elements between the end of the resulting sequence and @p last
1084 * are still present, but their value is unspecified.
1085 */
1086 template<typename _ForwardIterator, typename _Tp>
1087 _ForwardIterator
1088 remove(_ForwardIterator __first, _ForwardIterator __last,
1089 const _Tp& __value)
1090 {
1091 // concept requirements
1092 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1093 _ForwardIterator>)
1094 __glibcxx_function_requires(_EqualOpConcept<
1095 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
1096 __glibcxx_requires_valid_range(__first, __last);
1097
1098 __first = _GLIBCXX_STD_A::find(__first, __last, __value);
1099 if(__first == __last)
1100 return __first;
1101 _ForwardIterator __result = __first;
1102 ++__first;
1103 for(; __first != __last; ++__first)
1104 if(!(*__first == __value))
1105 {
1106 *__result = _GLIBCXX_MOVE(*__first);
1107 ++__result;
1108 }
1109 return __result;
1110 }
1111
1112 /**
1113 * @brief Remove elements from a sequence using a predicate.
1114 * @ingroup mutating_algorithms
1115 * @param first A forward iterator.
1116 * @param last A forward iterator.
1117 * @param pred A predicate.
1118 * @return An iterator designating the end of the resulting sequence.
1119 *
1120 * All elements for which @p pred returns true are removed from the range
1121 * @p [first,last).
1122 *
1123 * remove_if() is stable, so the relative order of elements that are
1124 * not removed is unchanged.
1125 *
1126 * Elements between the end of the resulting sequence and @p last
1127 * are still present, but their value is unspecified.
1128 */
1129 template<typename _ForwardIterator, typename _Predicate>
1130 _ForwardIterator
1131 remove_if(_ForwardIterator __first, _ForwardIterator __last,
1132 _Predicate __pred)
1133 {
1134 // concept requirements
1135 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1136 _ForwardIterator>)
1137 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1138 typename iterator_traits<_ForwardIterator>::value_type>)
1139 __glibcxx_requires_valid_range(__first, __last);
1140
1141 __first = _GLIBCXX_STD_A::find_if(__first, __last, __pred);
1142 if(__first == __last)
1143 return __first;
1144 _ForwardIterator __result = __first;
1145 ++__first;
1146 for(; __first != __last; ++__first)
1147 if(!bool(__pred(*__first)))
1148 {
1149 *__result = _GLIBCXX_MOVE(*__first);
1150 ++__result;
1151 }
1152 return __result;
1153 }
1154
1155 /**
1156 * @brief Remove consecutive duplicate values from a sequence.
1157 * @ingroup mutating_algorithms
1158 * @param first A forward iterator.
1159 * @param last A forward iterator.
1160 * @return An iterator designating the end of the resulting sequence.
1161 *
1162 * Removes all but the first element from each group of consecutive
1163 * values that compare equal.
1164 * unique() is stable, so the relative order of elements that are
1165 * not removed is unchanged.
1166 * Elements between the end of the resulting sequence and @p last
1167 * are still present, but their value is unspecified.
1168 */
1169 template<typename _ForwardIterator>
1170 _ForwardIterator
1171 unique(_ForwardIterator __first, _ForwardIterator __last)
1172 {
1173 // concept requirements
1174 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1175 _ForwardIterator>)
1176 __glibcxx_function_requires(_EqualityComparableConcept<
1177 typename iterator_traits<_ForwardIterator>::value_type>)
1178 __glibcxx_requires_valid_range(__first, __last);
1179
1180 // Skip the beginning, if already unique.
1181 __first = _GLIBCXX_STD_A::adjacent_find(__first, __last);
1182 if (__first == __last)
1183 return __last;
1184
1185 // Do the real copy work.
1186 _ForwardIterator __dest = __first;
1187 ++__first;
1188 while (++__first != __last)
1189 if (!(*__dest == *__first))
1190 *++__dest = _GLIBCXX_MOVE(*__first);
1191 return ++__dest;
1192 }
1193
1194 /**
1195 * @brief Remove consecutive values from a sequence using a predicate.
1196 * @ingroup mutating_algorithms
1197 * @param first A forward iterator.
1198 * @param last A forward iterator.
1199 * @param binary_pred A binary predicate.
1200 * @return An iterator designating the end of the resulting sequence.
1201 *
1202 * Removes all but the first element from each group of consecutive
1203 * values for which @p binary_pred returns true.
1204 * unique() is stable, so the relative order of elements that are
1205 * not removed is unchanged.
1206 * Elements between the end of the resulting sequence and @p last
1207 * are still present, but their value is unspecified.
1208 */
1209 template<typename _ForwardIterator, typename _BinaryPredicate>
1210 _ForwardIterator
1211 unique(_ForwardIterator __first, _ForwardIterator __last,
1212 _BinaryPredicate __binary_pred)
1213 {
1214 // concept requirements
1215 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1216 _ForwardIterator>)
1217 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1218 typename iterator_traits<_ForwardIterator>::value_type,
1219 typename iterator_traits<_ForwardIterator>::value_type>)
1220 __glibcxx_requires_valid_range(__first, __last);
1221
1222 // Skip the beginning, if already unique.
1223 __first = _GLIBCXX_STD_A::adjacent_find(__first, __last, __binary_pred);
1224 if (__first == __last)
1225 return __last;
1226
1227 // Do the real copy work.
1228 _ForwardIterator __dest = __first;
1229 ++__first;
1230 while (++__first != __last)
1231 if (!bool(__binary_pred(*__dest, *__first)))
1232 *++__dest = _GLIBCXX_MOVE(*__first);
1233 return ++__dest;
1234 }
1235
1236 /**
1237 * This is an uglified unique_copy(_InputIterator, _InputIterator,
1238 * _OutputIterator)
1239 * overloaded for forward iterators and output iterator as result.
1240 */
1241 template<typename _ForwardIterator, typename _OutputIterator>
1242 _OutputIterator
1243 __unique_copy(_ForwardIterator __first, _ForwardIterator __last,
1244 _OutputIterator __result,
1245 forward_iterator_tag, output_iterator_tag)
1246 {
1247 // concept requirements -- taken care of in dispatching function
1248 _ForwardIterator __next = __first;
1249 *__result = *__first;
1250 while (++__next != __last)
1251 if (!(*__first == *__next))
1252 {
1253 __first = __next;
1254 *++__result = *__first;
1255 }
1256 return ++__result;
1257 }
1258
1259 /**
1260 * This is an uglified unique_copy(_InputIterator, _InputIterator,
1261 * _OutputIterator)
1262 * overloaded for input iterators and output iterator as result.
1263 */
1264 template<typename _InputIterator, typename _OutputIterator>
1265 _OutputIterator
1266 __unique_copy(_InputIterator __first, _InputIterator __last,
1267 _OutputIterator __result,
1268 input_iterator_tag, output_iterator_tag)
1269 {
1270 // concept requirements -- taken care of in dispatching function
1271 typename iterator_traits<_InputIterator>::value_type __value = *__first;
1272 *__result = __value;
1273 while (++__first != __last)
1274 if (!(__value == *__first))
1275 {
1276 __value = *__first;
1277 *++__result = __value;
1278 }
1279 return ++__result;
1280 }
1281
1282 /**
1283 * This is an uglified unique_copy(_InputIterator, _InputIterator,
1284 * _OutputIterator)
1285 * overloaded for input iterators and forward iterator as result.
1286 */
1287 template<typename _InputIterator, typename _ForwardIterator>
1288 _ForwardIterator
1289 __unique_copy(_InputIterator __first, _InputIterator __last,
1290 _ForwardIterator __result,
1291 input_iterator_tag, forward_iterator_tag)
1292 {
1293 // concept requirements -- taken care of in dispatching function
1294 *__result = *__first;
1295 while (++__first != __last)
1296 if (!(*__result == *__first))
1297 *++__result = *__first;
1298 return ++__result;
1299 }
1300
1301 /**
1302 * This is an uglified
1303 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1304 * _BinaryPredicate)
1305 * overloaded for forward iterators and output iterator as result.
1306 */
1307 template<typename _ForwardIterator, typename _OutputIterator,
1308 typename _BinaryPredicate>
1309 _OutputIterator
1310 __unique_copy(_ForwardIterator __first, _ForwardIterator __last,
1311 _OutputIterator __result, _BinaryPredicate __binary_pred,
1312 forward_iterator_tag, output_iterator_tag)
1313 {
1314 // concept requirements -- iterators already checked
1315 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1316 typename iterator_traits<_ForwardIterator>::value_type,
1317 typename iterator_traits<_ForwardIterator>::value_type>)
1318
1319 _ForwardIterator __next = __first;
1320 *__result = *__first;
1321 while (++__next != __last)
1322 if (!bool(__binary_pred(*__first, *__next)))
1323 {
1324 __first = __next;
1325 *++__result = *__first;
1326 }
1327 return ++__result;
1328 }
1329
1330 /**
1331 * This is an uglified
1332 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1333 * _BinaryPredicate)
1334 * overloaded for input iterators and output iterator as result.
1335 */
1336 template<typename _InputIterator, typename _OutputIterator,
1337 typename _BinaryPredicate>
1338 _OutputIterator
1339 __unique_copy(_InputIterator __first, _InputIterator __last,
1340 _OutputIterator __result, _BinaryPredicate __binary_pred,
1341 input_iterator_tag, output_iterator_tag)
1342 {
1343 // concept requirements -- iterators already checked
1344 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1345 typename iterator_traits<_InputIterator>::value_type,
1346 typename iterator_traits<_InputIterator>::value_type>)
1347
1348 typename iterator_traits<_InputIterator>::value_type __value = *__first;
1349 *__result = __value;
1350 while (++__first != __last)
1351 if (!bool(__binary_pred(__value, *__first)))
1352 {
1353 __value = *__first;
1354 *++__result = __value;
1355 }
1356 return ++__result;
1357 }
1358
1359 /**
1360 * This is an uglified
1361 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1362 * _BinaryPredicate)
1363 * overloaded for input iterators and forward iterator as result.
1364 */
1365 template<typename _InputIterator, typename _ForwardIterator,
1366 typename _BinaryPredicate>
1367 _ForwardIterator
1368 __unique_copy(_InputIterator __first, _InputIterator __last,
1369 _ForwardIterator __result, _BinaryPredicate __binary_pred,
1370 input_iterator_tag, forward_iterator_tag)
1371 {
1372 // concept requirements -- iterators already checked
1373 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1374 typename iterator_traits<_ForwardIterator>::value_type,
1375 typename iterator_traits<_InputIterator>::value_type>)
1376
1377 *__result = *__first;
1378 while (++__first != __last)
1379 if (!bool(__binary_pred(*__result, *__first)))
1380 *++__result = *__first;
1381 return ++__result;
1382 }
1383
1384 /**
1385 * This is an uglified reverse(_BidirectionalIterator,
1386 * _BidirectionalIterator)
1387 * overloaded for bidirectional iterators.
1388 */
1389 template<typename _BidirectionalIterator>
1390 void
1391 __reverse(_BidirectionalIterator __first, _BidirectionalIterator __last,
1392 bidirectional_iterator_tag)
1393 {
1394 while (true)
1395 if (__first == __last || __first == --__last)
1396 return;
1397 else
1398 {
1399 std::iter_swap(__first, __last);
1400 ++__first;
1401 }
1402 }
1403
1404 /**
1405 * This is an uglified reverse(_BidirectionalIterator,
1406 * _BidirectionalIterator)
1407 * overloaded for random access iterators.
1408 */
1409 template<typename _RandomAccessIterator>
1410 void
1411 __reverse(_RandomAccessIterator __first, _RandomAccessIterator __last,
1412 random_access_iterator_tag)
1413 {
1414 if (__first == __last)
1415 return;
1416 --__last;
1417 while (__first < __last)
1418 {
1419 std::iter_swap(__first, __last);
1420 ++__first;
1421 --__last;
1422 }
1423 }
1424
1425 /**
1426 * @brief Reverse a sequence.
1427 * @ingroup mutating_algorithms
1428 * @param first A bidirectional iterator.
1429 * @param last A bidirectional iterator.
1430 * @return reverse() returns no value.
1431 *
1432 * Reverses the order of the elements in the range @p [first,last),
1433 * so that the first element becomes the last etc.
1434 * For every @c i such that @p 0<=i<=(last-first)/2), @p reverse()
1435 * swaps @p *(first+i) and @p *(last-(i+1))
1436 */
1437 template<typename _BidirectionalIterator>
1438 inline void
1439 reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
1440 {
1441 // concept requirements
1442 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
1443 _BidirectionalIterator>)
1444 __glibcxx_requires_valid_range(__first, __last);
1445 std::__reverse(__first, __last, std::__iterator_category(__first));
1446 }
1447
1448 /**
1449 * @brief Copy a sequence, reversing its elements.
1450 * @ingroup mutating_algorithms
1451 * @param first A bidirectional iterator.
1452 * @param last A bidirectional iterator.
1453 * @param result An output iterator.
1454 * @return An iterator designating the end of the resulting sequence.
1455 *
1456 * Copies the elements in the range @p [first,last) to the range
1457 * @p [result,result+(last-first)) such that the order of the
1458 * elements is reversed.
1459 * For every @c i such that @p 0<=i<=(last-first), @p reverse_copy()
1460 * performs the assignment @p *(result+(last-first)-i) = *(first+i).
1461 * The ranges @p [first,last) and @p [result,result+(last-first))
1462 * must not overlap.
1463 */
1464 template<typename _BidirectionalIterator, typename _OutputIterator>
1465 _OutputIterator
1466 reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last,
1467 _OutputIterator __result)
1468 {
1469 // concept requirements
1470 __glibcxx_function_requires(_BidirectionalIteratorConcept<
1471 _BidirectionalIterator>)
1472 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1473 typename iterator_traits<_BidirectionalIterator>::value_type>)
1474 __glibcxx_requires_valid_range(__first, __last);
1475
1476 while (__first != __last)
1477 {
1478 --__last;
1479 *__result = *__last;
1480 ++__result;
1481 }
1482 return __result;
1483 }
1484
1485 /**
1486 * This is a helper function for the rotate algorithm specialized on RAIs.
1487 * It returns the greatest common divisor of two integer values.
1488 */
1489 template<typename _EuclideanRingElement>
1490 _EuclideanRingElement
1491 __gcd(_EuclideanRingElement __m, _EuclideanRingElement __n)
1492 {
1493 while (__n != 0)
1494 {
1495 _EuclideanRingElement __t = __m % __n;
1496 __m = __n;
1497 __n = __t;
1498 }
1499 return __m;
1500 }
1501
1502 /// This is a helper function for the rotate algorithm.
1503 template<typename _ForwardIterator>
1504 void
1505 __rotate(_ForwardIterator __first,
1506 _ForwardIterator __middle,
1507 _ForwardIterator __last,
1508 forward_iterator_tag)
1509 {
1510 if (__first == __middle || __last == __middle)
1511 return;
1512
1513 _ForwardIterator __first2 = __middle;
1514 do
1515 {
1516 std::iter_swap(__first, __first2);
1517 ++__first;
1518 ++__first2;
1519 if (__first == __middle)
1520 __middle = __first2;
1521 }
1522 while (__first2 != __last);
1523
1524 __first2 = __middle;
1525
1526 while (__first2 != __last)
1527 {
1528 std::iter_swap(__first, __first2);
1529 ++__first;
1530 ++__first2;
1531 if (__first == __middle)
1532 __middle = __first2;
1533 else if (__first2 == __last)
1534 __first2 = __middle;
1535 }
1536 }
1537
1538 /// This is a helper function for the rotate algorithm.
1539 template<typename _BidirectionalIterator>
1540 void
1541 __rotate(_BidirectionalIterator __first,
1542 _BidirectionalIterator __middle,
1543 _BidirectionalIterator __last,
1544 bidirectional_iterator_tag)
1545 {
1546 // concept requirements
1547 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
1548 _BidirectionalIterator>)
1549
1550 if (__first == __middle || __last == __middle)
1551 return;
1552
1553 std::__reverse(__first, __middle, bidirectional_iterator_tag());
1554 std::__reverse(__middle, __last, bidirectional_iterator_tag());
1555
1556 while (__first != __middle && __middle != __last)
1557 {
1558 std::iter_swap(__first, --__last);
1559 ++__first;
1560 }
1561
1562 if (__first == __middle)
1563 std::__reverse(__middle, __last, bidirectional_iterator_tag());
1564 else
1565 std::__reverse(__first, __middle, bidirectional_iterator_tag());
1566 }
1567
1568 /// This is a helper function for the rotate algorithm.
1569 template<typename _RandomAccessIterator>
1570 void
1571 __rotate(_RandomAccessIterator __first,
1572 _RandomAccessIterator __middle,
1573 _RandomAccessIterator __last,
1574 random_access_iterator_tag)
1575 {
1576 // concept requirements
1577 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1578 _RandomAccessIterator>)
1579
1580 if (__first == __middle || __last == __middle)
1581 return;
1582
1583 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
1584 _Distance;
1585 typedef typename iterator_traits<_RandomAccessIterator>::value_type
1586 _ValueType;
1587
1588 _Distance __n = __last - __first;
1589 _Distance __k = __middle - __first;
1590
1591 if (__k == __n - __k)
1592 {
1593 std::swap_ranges(__first, __middle, __middle);
1594 return;
1595 }
1596
1597 _RandomAccessIterator __p = __first;
1598
1599 for (;;)
1600 {
1601 if (__k < __n - __k)
1602 {
1603 if (__is_pod(_ValueType) && __k == 1)
1604 {
1605 _ValueType __t = _GLIBCXX_MOVE(*__p);
1606 _GLIBCXX_MOVE3(__p + 1, __p + __n, __p);
1607 *(__p + __n - 1) = _GLIBCXX_MOVE(__t);
1608 return;
1609 }
1610 _RandomAccessIterator __q = __p + __k;
1611 for (_Distance __i = 0; __i < __n - __k; ++ __i)
1612 {
1613 std::iter_swap(__p, __q);
1614 ++__p;
1615 ++__q;
1616 }
1617 __n %= __k;
1618 if (__n == 0)
1619 return;
1620 std::swap(__n, __k);
1621 __k = __n - __k;
1622 }
1623 else
1624 {
1625 __k = __n - __k;
1626 if (__is_pod(_ValueType) && __k == 1)
1627 {
1628 _ValueType __t = _GLIBCXX_MOVE(*(__p + __n - 1));
1629 _GLIBCXX_MOVE_BACKWARD3(__p, __p + __n - 1, __p + __n);
1630 *__p = _GLIBCXX_MOVE(__t);
1631 return;
1632 }
1633 _RandomAccessIterator __q = __p + __n;
1634 __p = __q - __k;
1635 for (_Distance __i = 0; __i < __n - __k; ++ __i)
1636 {
1637 --__p;
1638 --__q;
1639 std::iter_swap(__p, __q);
1640 }
1641 __n %= __k;
1642 if (__n == 0)
1643 return;
1644 std::swap(__n, __k);
1645 }
1646 }
1647 }
1648
1649 /**
1650 * @brief Rotate the elements of a sequence.
1651 * @ingroup mutating_algorithms
1652 * @param first A forward iterator.
1653 * @param middle A forward iterator.
1654 * @param last A forward iterator.
1655 * @return Nothing.
1656 *
1657 * Rotates the elements of the range @p [first,last) by @p (middle-first)
1658 * positions so that the element at @p middle is moved to @p first, the
1659 * element at @p middle+1 is moved to @first+1 and so on for each element
1660 * in the range @p [first,last).
1661 *
1662 * This effectively swaps the ranges @p [first,middle) and
1663 * @p [middle,last).
1664 *
1665 * Performs @p *(first+(n+(last-middle))%(last-first))=*(first+n) for
1666 * each @p n in the range @p [0,last-first).
1667 */
1668 template<typename _ForwardIterator>
1669 inline void
1670 rotate(_ForwardIterator __first, _ForwardIterator __middle,
1671 _ForwardIterator __last)
1672 {
1673 // concept requirements
1674 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1675 _ForwardIterator>)
1676 __glibcxx_requires_valid_range(__first, __middle);
1677 __glibcxx_requires_valid_range(__middle, __last);
1678
1679 typedef typename iterator_traits<_ForwardIterator>::iterator_category
1680 _IterType;
1681 std::__rotate(__first, __middle, __last, _IterType());
1682 }
1683
1684 /**
1685 * @brief Copy a sequence, rotating its elements.
1686 * @ingroup mutating_algorithms
1687 * @param first A forward iterator.
1688 * @param middle A forward iterator.
1689 * @param last A forward iterator.
1690 * @param result An output iterator.
1691 * @return An iterator designating the end of the resulting sequence.
1692 *
1693 * Copies the elements of the range @p [first,last) to the range
1694 * beginning at @result, rotating the copied elements by @p (middle-first)
1695 * positions so that the element at @p middle is moved to @p result, the
1696 * element at @p middle+1 is moved to @result+1 and so on for each element
1697 * in the range @p [first,last).
1698 *
1699 * Performs @p *(result+(n+(last-middle))%(last-first))=*(first+n) for
1700 * each @p n in the range @p [0,last-first).
1701 */
1702 template<typename _ForwardIterator, typename _OutputIterator>
1703 _OutputIterator
1704 rotate_copy(_ForwardIterator __first, _ForwardIterator __middle,
1705 _ForwardIterator __last, _OutputIterator __result)
1706 {
1707 // concept requirements
1708 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1709 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1710 typename iterator_traits<_ForwardIterator>::value_type>)
1711 __glibcxx_requires_valid_range(__first, __middle);
1712 __glibcxx_requires_valid_range(__middle, __last);
1713
1714 return std::copy(__first, __middle,
1715 std::copy(__middle, __last, __result));
1716 }
1717
1718 /// This is a helper function...
1719 template<typename _ForwardIterator, typename _Predicate>
1720 _ForwardIterator
1721 __partition(_ForwardIterator __first, _ForwardIterator __last,
1722 _Predicate __pred, forward_iterator_tag)
1723 {
1724 if (__first == __last)
1725 return __first;
1726
1727 while (__pred(*__first))
1728 if (++__first == __last)
1729 return __first;
1730
1731 _ForwardIterator __next = __first;
1732
1733 while (++__next != __last)
1734 if (__pred(*__next))
1735 {
1736 std::iter_swap(__first, __next);
1737 ++__first;
1738 }
1739
1740 return __first;
1741 }
1742
1743 /// This is a helper function...
1744 template<typename _BidirectionalIterator, typename _Predicate>
1745 _BidirectionalIterator
1746 __partition(_BidirectionalIterator __first, _BidirectionalIterator __last,
1747 _Predicate __pred, bidirectional_iterator_tag)
1748 {
1749 while (true)
1750 {
1751 while (true)
1752 if (__first == __last)
1753 return __first;
1754 else if (__pred(*__first))
1755 ++__first;
1756 else
1757 break;
1758 --__last;
1759 while (true)
1760 if (__first == __last)
1761 return __first;
1762 else if (!bool(__pred(*__last)))
1763 --__last;
1764 else
1765 break;
1766 std::iter_swap(__first, __last);
1767 ++__first;
1768 }
1769 }
1770
1771 // partition
1772
1773 /// This is a helper function...
1774 template<typename _ForwardIterator, typename _Predicate, typename _Distance>
1775 _ForwardIterator
1776 __inplace_stable_partition(_ForwardIterator __first,
1777 _ForwardIterator __last,
1778 _Predicate __pred, _Distance __len)
1779 {
1780 if (__len == 1)
1781 return __pred(*__first) ? __last : __first;
1782 _ForwardIterator __middle = __first;
1783 std::advance(__middle, __len / 2);
1784 _ForwardIterator __begin = std::__inplace_stable_partition(__first,
1785 __middle,
1786 __pred,
1787 __len / 2);
1788 _ForwardIterator __end = std::__inplace_stable_partition(__middle, __last,
1789 __pred,
1790 __len
1791 - __len / 2);
1792 std::rotate(__begin, __middle, __end);
1793 std::advance(__begin, std::distance(__middle, __end));
1794 return __begin;
1795 }
1796
1797 /// This is a helper function...
1798 template<typename _ForwardIterator, typename _Pointer, typename _Predicate,
1799 typename _Distance>
1800 _ForwardIterator
1801 __stable_partition_adaptive(_ForwardIterator __first,
1802 _ForwardIterator __last,
1803 _Predicate __pred, _Distance __len,
1804 _Pointer __buffer,
1805 _Distance __buffer_size)
1806 {
1807 if (__len <= __buffer_size)
1808 {
1809 _ForwardIterator __result1 = __first;
1810 _Pointer __result2 = __buffer;
1811 for (; __first != __last; ++__first)
1812 if (__pred(*__first))
1813 {
1814 *__result1 = _GLIBCXX_MOVE(*__first);
1815 ++__result1;
1816 }
1817 else
1818 {
1819 *__result2 = _GLIBCXX_MOVE(*__first);
1820 ++__result2;
1821 }
1822 _GLIBCXX_MOVE3(__buffer, __result2, __result1);
1823 return __result1;
1824 }
1825 else
1826 {
1827 _ForwardIterator __middle = __first;
1828 std::advance(__middle, __len / 2);
1829 _ForwardIterator __begin =
1830 std::__stable_partition_adaptive(__first, __middle, __pred,
1831 __len / 2, __buffer,
1832 __buffer_size);
1833 _ForwardIterator __end =
1834 std::__stable_partition_adaptive(__middle, __last, __pred,
1835 __len - __len / 2,
1836 __buffer, __buffer_size);
1837 std::rotate(__begin, __middle, __end);
1838 std::advance(__begin, std::distance(__middle, __end));
1839 return __begin;
1840 }
1841 }
1842
1843 /**
1844 * @brief Move elements for which a predicate is true to the beginning
1845 * of a sequence, preserving relative ordering.
1846 * @ingroup mutating_algorithms
1847 * @param first A forward iterator.
1848 * @param last A forward iterator.
1849 * @param pred A predicate functor.
1850 * @return An iterator @p middle such that @p pred(i) is true for each
1851 * iterator @p i in the range @p [first,middle) and false for each @p i
1852 * in the range @p [middle,last).
1853 *
1854 * Performs the same function as @p partition() with the additional
1855 * guarantee that the relative ordering of elements in each group is
1856 * preserved, so any two elements @p x and @p y in the range
1857 * @p [first,last) such that @p pred(x)==pred(y) will have the same
1858 * relative ordering after calling @p stable_partition().
1859 */
1860 template<typename _ForwardIterator, typename _Predicate>
1861 _ForwardIterator
1862 stable_partition(_ForwardIterator __first, _ForwardIterator __last,
1863 _Predicate __pred)
1864 {
1865 // concept requirements
1866 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1867 _ForwardIterator>)
1868 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1869 typename iterator_traits<_ForwardIterator>::value_type>)
1870 __glibcxx_requires_valid_range(__first, __last);
1871
1872 if (__first == __last)
1873 return __first;
1874 else
1875 {
1876 typedef typename iterator_traits<_ForwardIterator>::value_type
1877 _ValueType;
1878 typedef typename iterator_traits<_ForwardIterator>::difference_type
1879 _DistanceType;
1880
1881 _Temporary_buffer<_ForwardIterator, _ValueType> __buf(__first,
1882 __last);
1883 if (__buf.size() > 0)
1884 return
1885 std::__stable_partition_adaptive(__first, __last, __pred,
1886 _DistanceType(__buf.requested_size()),
1887 __buf.begin(),
1888 _DistanceType(__buf.size()));
1889 else
1890 return
1891 std::__inplace_stable_partition(__first, __last, __pred,
1892 _DistanceType(__buf.requested_size()));
1893 }
1894 }
1895
1896 /// This is a helper function for the sort routines.
1897 template<typename _RandomAccessIterator>
1898 void
1899 __heap_select(_RandomAccessIterator __first,
1900 _RandomAccessIterator __middle,
1901 _RandomAccessIterator __last)
1902 {
1903 std::make_heap(__first, __middle);
1904 for (_RandomAccessIterator __i = __middle; __i < __last; ++__i)
1905 if (*__i < *__first)
1906 std::__pop_heap(__first, __middle, __i);
1907 }
1908
1909 /// This is a helper function for the sort routines.
1910 template<typename _RandomAccessIterator, typename _Compare>
1911 void
1912 __heap_select(_RandomAccessIterator __first,
1913 _RandomAccessIterator __middle,
1914 _RandomAccessIterator __last, _Compare __comp)
1915 {
1916 std::make_heap(__first, __middle, __comp);
1917 for (_RandomAccessIterator __i = __middle; __i < __last; ++__i)
1918 if (__comp(*__i, *__first))
1919 std::__pop_heap(__first, __middle, __i, __comp);
1920 }
1921
1922 // partial_sort
1923
1924 /**
1925 * @brief Copy the smallest elements of a sequence.
1926 * @ingroup sorting_algorithms
1927 * @param first An iterator.
1928 * @param last Another iterator.
1929 * @param result_first A random-access iterator.
1930 * @param result_last Another random-access iterator.
1931 * @return An iterator indicating the end of the resulting sequence.
1932 *
1933 * Copies and sorts the smallest N values from the range @p [first,last)
1934 * to the range beginning at @p result_first, where the number of
1935 * elements to be copied, @p N, is the smaller of @p (last-first) and
1936 * @p (result_last-result_first).
1937 * After the sort if @p i and @j are iterators in the range
1938 * @p [result_first,result_first+N) such that @i precedes @j then
1939 * @p *j<*i is false.
1940 * The value returned is @p result_first+N.
1941 */
1942 template<typename _InputIterator, typename _RandomAccessIterator>
1943 _RandomAccessIterator
1944 partial_sort_copy(_InputIterator __first, _InputIterator __last,
1945 _RandomAccessIterator __result_first,
1946 _RandomAccessIterator __result_last)
1947 {
1948 typedef typename iterator_traits<_InputIterator>::value_type
1949 _InputValueType;
1950 typedef typename iterator_traits<_RandomAccessIterator>::value_type
1951 _OutputValueType;
1952 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
1953 _DistanceType;
1954
1955 // concept requirements
1956 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1957 __glibcxx_function_requires(_ConvertibleConcept<_InputValueType,
1958 _OutputValueType>)
1959 __glibcxx_function_requires(_LessThanOpConcept<_InputValueType,
1960 _OutputValueType>)
1961 __glibcxx_function_requires(_LessThanComparableConcept<_OutputValueType>)
1962 __glibcxx_requires_valid_range(__first, __last);
1963 __glibcxx_requires_valid_range(__result_first, __result_last);
1964
1965 if (__result_first == __result_last)
1966 return __result_last;
1967 _RandomAccessIterator __result_real_last = __result_first;
1968 while(__first != __last && __result_real_last != __result_last)
1969 {
1970 *__result_real_last = *__first;
1971 ++__result_real_last;
1972 ++__first;
1973 }
1974 std::make_heap(__result_first, __result_real_last);
1975 while (__first != __last)
1976 {
1977 if (*__first < *__result_first)
1978 std::__adjust_heap(__result_first, _DistanceType(0),
1979 _DistanceType(__result_real_last
1980 - __result_first),
1981 _InputValueType(*__first));
1982 ++__first;
1983 }
1984 std::sort_heap(__result_first, __result_real_last);
1985 return __result_real_last;
1986 }
1987
1988 /**
1989 * @brief Copy the smallest elements of a sequence using a predicate for
1990 * comparison.
1991 * @ingroup sorting_algorithms
1992 * @param first An input iterator.
1993 * @param last Another input iterator.
1994 * @param result_first A random-access iterator.
1995 * @param result_last Another random-access iterator.
1996 * @param comp A comparison functor.
1997 * @return An iterator indicating the end of the resulting sequence.
1998 *
1999 * Copies and sorts the smallest N values from the range @p [first,last)
2000 * to the range beginning at @p result_first, where the number of
2001 * elements to be copied, @p N, is the smaller of @p (last-first) and
2002 * @p (result_last-result_first).
2003 * After the sort if @p i and @j are iterators in the range
2004 * @p [result_first,result_first+N) such that @i precedes @j then
2005 * @p comp(*j,*i) is false.
2006 * The value returned is @p result_first+N.
2007 */
2008 template<typename _InputIterator, typename _RandomAccessIterator, typename _Compare>
2009 _RandomAccessIterator
2010 partial_sort_copy(_InputIterator __first, _InputIterator __last,
2011 _RandomAccessIterator __result_first,
2012 _RandomAccessIterator __result_last,
2013 _Compare __comp)
2014 {
2015 typedef typename iterator_traits<_InputIterator>::value_type
2016 _InputValueType;
2017 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2018 _OutputValueType;
2019 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
2020 _DistanceType;
2021
2022 // concept requirements
2023 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
2024 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2025 _RandomAccessIterator>)
2026 __glibcxx_function_requires(_ConvertibleConcept<_InputValueType,
2027 _OutputValueType>)
2028 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2029 _InputValueType, _OutputValueType>)
2030 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2031 _OutputValueType, _OutputValueType>)
2032 __glibcxx_requires_valid_range(__first, __last);
2033 __glibcxx_requires_valid_range(__result_first, __result_last);
2034
2035 if (__result_first == __result_last)
2036 return __result_last;
2037 _RandomAccessIterator __result_real_last = __result_first;
2038 while(__first != __last && __result_real_last != __result_last)
2039 {
2040 *__result_real_last = *__first;
2041 ++__result_real_last;
2042 ++__first;
2043 }
2044 std::make_heap(__result_first, __result_real_last, __comp);
2045 while (__first != __last)
2046 {
2047 if (__comp(*__first, *__result_first))
2048 std::__adjust_heap(__result_first, _DistanceType(0),
2049 _DistanceType(__result_real_last
2050 - __result_first),
2051 _InputValueType(*__first),
2052 __comp);
2053 ++__first;
2054 }
2055 std::sort_heap(__result_first, __result_real_last, __comp);
2056 return __result_real_last;
2057 }
2058
2059 /// This is a helper function for the sort routine.
2060 template<typename _RandomAccessIterator>
2061 void
2062 __unguarded_linear_insert(_RandomAccessIterator __last)
2063 {
2064 typename iterator_traits<_RandomAccessIterator>::value_type
2065 __val = _GLIBCXX_MOVE(*__last);
2066 _RandomAccessIterator __next = __last;
2067 --__next;
2068 while (__val < *__next)
2069 {
2070 *__last = _GLIBCXX_MOVE(*__next);
2071 __last = __next;
2072 --__next;
2073 }
2074 *__last = _GLIBCXX_MOVE(__val);
2075 }
2076
2077 /// This is a helper function for the sort routine.
2078 template<typename _RandomAccessIterator, typename _Compare>
2079 void
2080 __unguarded_linear_insert(_RandomAccessIterator __last,
2081 _Compare __comp)
2082 {
2083 typename iterator_traits<_RandomAccessIterator>::value_type
2084 __val = _GLIBCXX_MOVE(*__last);
2085 _RandomAccessIterator __next = __last;
2086 --__next;
2087 while (__comp(__val, *__next))
2088 {
2089 *__last = _GLIBCXX_MOVE(*__next);
2090 __last = __next;
2091 --__next;
2092 }
2093 *__last = _GLIBCXX_MOVE(__val);
2094 }
2095
2096 /// This is a helper function for the sort routine.
2097 template<typename _RandomAccessIterator>
2098 void
2099 __insertion_sort(_RandomAccessIterator __first,
2100 _RandomAccessIterator __last)
2101 {
2102 if (__first == __last)
2103 return;
2104
2105 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
2106 {
2107 if (*__i < *__first)
2108 {
2109 typename iterator_traits<_RandomAccessIterator>::value_type
2110 __val = _GLIBCXX_MOVE(*__i);
2111 _GLIBCXX_MOVE_BACKWARD3(__first, __i, __i + 1);
2112 *__first = _GLIBCXX_MOVE(__val);
2113 }
2114 else
2115 std::__unguarded_linear_insert(__i);
2116 }
2117 }
2118
2119 /// This is a helper function for the sort routine.
2120 template<typename _RandomAccessIterator, typename _Compare>
2121 void
2122 __insertion_sort(_RandomAccessIterator __first,
2123 _RandomAccessIterator __last, _Compare __comp)
2124 {
2125 if (__first == __last) return;
2126
2127 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
2128 {
2129 if (__comp(*__i, *__first))
2130 {
2131 typename iterator_traits<_RandomAccessIterator>::value_type
2132 __val = _GLIBCXX_MOVE(*__i);
2133 _GLIBCXX_MOVE_BACKWARD3(__first, __i, __i + 1);
2134 *__first = _GLIBCXX_MOVE(__val);
2135 }
2136 else
2137 std::__unguarded_linear_insert(__i, __comp);
2138 }
2139 }
2140
2141 /// This is a helper function for the sort routine.
2142 template<typename _RandomAccessIterator>
2143 inline void
2144 __unguarded_insertion_sort(_RandomAccessIterator __first,
2145 _RandomAccessIterator __last)
2146 {
2147 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2148 _ValueType;
2149
2150 for (_RandomAccessIterator __i = __first; __i != __last; ++__i)
2151 std::__unguarded_linear_insert(__i);
2152 }
2153
2154 /// This is a helper function for the sort routine.
2155 template<typename _RandomAccessIterator, typename _Compare>
2156 inline void
2157 __unguarded_insertion_sort(_RandomAccessIterator __first,
2158 _RandomAccessIterator __last, _Compare __comp)
2159 {
2160 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2161 _ValueType;
2162
2163 for (_RandomAccessIterator __i = __first; __i != __last; ++__i)
2164 std::__unguarded_linear_insert(__i, __comp);
2165 }
2166
2167 /**
2168 * @doctodo
2169 * This controls some aspect of the sort routines.
2170 */
2171 enum { _S_threshold = 16 };
2172
2173 /// This is a helper function for the sort routine.
2174 template<typename _RandomAccessIterator>
2175 void
2176 __final_insertion_sort(_RandomAccessIterator __first,
2177 _RandomAccessIterator __last)
2178 {
2179 if (__last - __first > int(_S_threshold))
2180 {
2181 std::__insertion_sort(__first, __first + int(_S_threshold));
2182 std::__unguarded_insertion_sort(__first + int(_S_threshold), __last);
2183 }
2184 else
2185 std::__insertion_sort(__first, __last);
2186 }
2187
2188 /// This is a helper function for the sort routine.
2189 template<typename _RandomAccessIterator, typename _Compare>
2190 void
2191 __final_insertion_sort(_RandomAccessIterator __first,
2192 _RandomAccessIterator __last, _Compare __comp)
2193 {
2194 if (__last - __first > int(_S_threshold))
2195 {
2196 std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
2197 std::__unguarded_insertion_sort(__first + int(_S_threshold), __last,
2198 __comp);
2199 }
2200 else
2201 std::__insertion_sort(__first, __last, __comp);
2202 }
2203
2204 /// This is a helper function...
2205 template<typename _RandomAccessIterator, typename _Tp>
2206 _RandomAccessIterator
2207 __unguarded_partition(_RandomAccessIterator __first,
2208 _RandomAccessIterator __last, const _Tp& __pivot)
2209 {
2210 while (true)
2211 {
2212 while (*__first < __pivot)
2213 ++__first;
2214 --__last;
2215 while (__pivot < *__last)
2216 --__last;
2217 if (!(__first < __last))
2218 return __first;
2219 std::iter_swap(__first, __last);
2220 ++__first;
2221 }
2222 }
2223
2224 /// This is a helper function...
2225 template<typename _RandomAccessIterator, typename _Tp, typename _Compare>
2226 _RandomAccessIterator
2227 __unguarded_partition(_RandomAccessIterator __first,
2228 _RandomAccessIterator __last,
2229 const _Tp& __pivot, _Compare __comp)
2230 {
2231 while (true)
2232 {
2233 while (__comp(*__first, __pivot))
2234 ++__first;
2235 --__last;
2236 while (__comp(__pivot, *__last))
2237 --__last;
2238 if (!(__first < __last))
2239 return __first;
2240 std::iter_swap(__first, __last);
2241 ++__first;
2242 }
2243 }
2244
2245 /// This is a helper function...
2246 template<typename _RandomAccessIterator>
2247 inline _RandomAccessIterator
2248 __unguarded_partition_pivot(_RandomAccessIterator __first,
2249 _RandomAccessIterator __last)
2250 {
2251 _RandomAccessIterator __mid = __first + (__last - __first) / 2;
2252 std::__move_median_first(__first, __mid, (__last - 1));
2253 return std::__unguarded_partition(__first + 1, __last, *__first);
2254 }
2255
2256
2257 /// This is a helper function...
2258 template<typename _RandomAccessIterator, typename _Compare>
2259 inline _RandomAccessIterator
2260 __unguarded_partition_pivot(_RandomAccessIterator __first,
2261 _RandomAccessIterator __last, _Compare __comp)
2262 {
2263 _RandomAccessIterator __mid = __first + (__last - __first) / 2;
2264 std::__move_median_first(__first, __mid, (__last - 1), __comp);
2265 return std::__unguarded_partition(__first + 1, __last, *__first, __comp);
2266 }
2267
2268 /// This is a helper function for the sort routine.
2269 template<typename _RandomAccessIterator, typename _Size>
2270 void
2271 __introsort_loop(_RandomAccessIterator __first,
2272 _RandomAccessIterator __last,
2273 _Size __depth_limit)
2274 {
2275 while (__last - __first > int(_S_threshold))
2276 {
2277 if (__depth_limit == 0)
2278 {
2279 _GLIBCXX_STD_A::partial_sort(__first, __last, __last);
2280 return;
2281 }
2282 --__depth_limit;
2283 _RandomAccessIterator __cut =
2284 std::__unguarded_partition_pivot(__first, __last);
2285 std::__introsort_loop(__cut, __last, __depth_limit);
2286 __last = __cut;
2287 }
2288 }
2289
2290 /// This is a helper function for the sort routine.
2291 template<typename _RandomAccessIterator, typename _Size, typename _Compare>
2292 void
2293 __introsort_loop(_RandomAccessIterator __first,
2294 _RandomAccessIterator __last,
2295 _Size __depth_limit, _Compare __comp)
2296 {
2297 while (__last - __first > int(_S_threshold))
2298 {
2299 if (__depth_limit == 0)
2300 {
2301 _GLIBCXX_STD_A::partial_sort(__first, __last, __last, __comp);
2302 return;
2303 }
2304 --__depth_limit;
2305 _RandomAccessIterator __cut =
2306 std::__unguarded_partition_pivot(__first, __last, __comp);
2307 std::__introsort_loop(__cut, __last, __depth_limit, __comp);
2308 __last = __cut;
2309 }
2310 }
2311
2312 // sort
2313
2314 template<typename _RandomAccessIterator, typename _Size>
2315 void
2316 __introselect(_RandomAccessIterator __first, _RandomAccessIterator __nth,
2317 _RandomAccessIterator __last, _Size __depth_limit)
2318 {
2319 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2320 _ValueType;
2321
2322 while (__last - __first > 3)
2323 {
2324 if (__depth_limit == 0)
2325 {
2326 std::__heap_select(__first, __nth + 1, __last);
2327
2328 // Place the nth largest element in its final position.
2329 std::iter_swap(__first, __nth);
2330 return;
2331 }
2332 --__depth_limit;
2333 _RandomAccessIterator __cut =
2334 std::__unguarded_partition_pivot(__first, __last);
2335 if (__cut <= __nth)
2336 __first = __cut;
2337 else
2338 __last = __cut;
2339 }
2340 std::__insertion_sort(__first, __last);
2341 }
2342
2343 template<typename _RandomAccessIterator, typename _Size, typename _Compare>
2344 void
2345 __introselect(_RandomAccessIterator __first, _RandomAccessIterator __nth,
2346 _RandomAccessIterator __last, _Size __depth_limit,
2347 _Compare __comp)
2348 {
2349 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2350 _ValueType;
2351
2352 while (__last - __first > 3)
2353 {
2354 if (__depth_limit == 0)
2355 {
2356 std::__heap_select(__first, __nth + 1, __last, __comp);
2357 // Place the nth largest element in its final position.
2358 std::iter_swap(__first, __nth);
2359 return;
2360 }
2361 --__depth_limit;
2362 _RandomAccessIterator __cut =
2363 std::__unguarded_partition_pivot(__first, __last, __comp);
2364 if (__cut <= __nth)
2365 __first = __cut;
2366 else
2367 __last = __cut;
2368 }
2369 std::__insertion_sort(__first, __last, __comp);
2370 }
2371
2372 // nth_element
2373
2374 // lower_bound moved to stl_algobase.h
2375
2376 /**
2377 * @brief Finds the first position in which @a val could be inserted
2378 * without changing the ordering.
2379 * @ingroup binary_search_algorithms
2380 * @param first An iterator.
2381 * @param last Another iterator.
2382 * @param val The search term.
2383 * @param comp A functor to use for comparisons.
2384 * @return An iterator pointing to the first element <em>not less
2385 * than</em> @a val, or end() if every element is less
2386 * than @a val.
2387 * @ingroup binary_search_algorithms
2388 *
2389 * The comparison function should have the same effects on ordering as
2390 * the function used for the initial sort.
2391 */
2392 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2393 _ForwardIterator
2394 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
2395 const _Tp& __val, _Compare __comp)
2396 {
2397 typedef typename iterator_traits<_ForwardIterator>::value_type
2398 _ValueType;
2399 typedef typename iterator_traits<_ForwardIterator>::difference_type
2400 _DistanceType;
2401
2402 // concept requirements
2403 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2404 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2405 _ValueType, _Tp>)
2406 __glibcxx_requires_partitioned_lower_pred(__first, __last,
2407 __val, __comp);
2408
2409 _DistanceType __len = std::distance(__first, __last);
2410
2411 while (__len > 0)
2412 {
2413 _DistanceType __half = __len >> 1;
2414 _ForwardIterator __middle = __first;
2415 std::advance(__middle, __half);
2416 if (__comp(*__middle, __val))
2417 {
2418 __first = __middle;
2419 ++__first;
2420 __len = __len - __half - 1;
2421 }
2422 else
2423 __len = __half;
2424 }
2425 return __first;
2426 }
2427
2428 /**
2429 * @brief Finds the last position in which @a val could be inserted
2430 * without changing the ordering.
2431 * @ingroup binary_search_algorithms
2432 * @param first An iterator.
2433 * @param last Another iterator.
2434 * @param val The search term.
2435 * @return An iterator pointing to the first element greater than @a val,
2436 * or end() if no elements are greater than @a val.
2437 * @ingroup binary_search_algorithms
2438 */
2439 template<typename _ForwardIterator, typename _Tp>
2440 _ForwardIterator
2441 upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2442 const _Tp& __val)
2443 {
2444 typedef typename iterator_traits<_ForwardIterator>::value_type
2445 _ValueType;
2446 typedef typename iterator_traits<_ForwardIterator>::difference_type
2447 _DistanceType;
2448
2449 // concept requirements
2450 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2451 __glibcxx_function_requires(_LessThanOpConcept<_Tp, _ValueType>)
2452 __glibcxx_requires_partitioned_upper(__first, __last, __val);
2453
2454 _DistanceType __len = std::distance(__first, __last);
2455
2456 while (__len > 0)
2457 {
2458 _DistanceType __half = __len >> 1;
2459 _ForwardIterator __middle = __first;
2460 std::advance(__middle, __half);
2461 if (__val < *__middle)
2462 __len = __half;
2463 else
2464 {
2465 __first = __middle;
2466 ++__first;
2467 __len = __len - __half - 1;
2468 }
2469 }
2470 return __first;
2471 }
2472
2473 /**
2474 * @brief Finds the last position in which @a val could be inserted
2475 * without changing the ordering.
2476 * @ingroup binary_search_algorithms
2477 * @param first An iterator.
2478 * @param last Another iterator.
2479 * @param val The search term.
2480 * @param comp A functor to use for comparisons.
2481 * @return An iterator pointing to the first element greater than @a val,
2482 * or end() if no elements are greater than @a val.
2483 * @ingroup binary_search_algorithms
2484 *
2485 * The comparison function should have the same effects on ordering as
2486 * the function used for the initial sort.
2487 */
2488 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2489 _ForwardIterator
2490 upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2491 const _Tp& __val, _Compare __comp)
2492 {
2493 typedef typename iterator_traits<_ForwardIterator>::value_type
2494 _ValueType;
2495 typedef typename iterator_traits<_ForwardIterator>::difference_type
2496 _DistanceType;
2497
2498 // concept requirements
2499 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2500 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2501 _Tp, _ValueType>)
2502 __glibcxx_requires_partitioned_upper_pred(__first, __last,
2503 __val, __comp);
2504
2505 _DistanceType __len = std::distance(__first, __last);
2506
2507 while (__len > 0)
2508 {
2509 _DistanceType __half = __len >> 1;
2510 _ForwardIterator __middle = __first;
2511 std::advance(__middle, __half);
2512 if (__comp(__val, *__middle))
2513 __len = __half;
2514 else
2515 {
2516 __first = __middle;
2517 ++__first;
2518 __len = __len - __half - 1;
2519 }
2520 }
2521 return __first;
2522 }
2523
2524 /**
2525 * @brief Finds the largest subrange in which @a val could be inserted
2526 * at any place in it without changing the ordering.
2527 * @ingroup binary_search_algorithms
2528 * @param first An iterator.
2529 * @param last Another iterator.
2530 * @param val The search term.
2531 * @return An pair of iterators defining the subrange.
2532 * @ingroup binary_search_algorithms
2533 *
2534 * This is equivalent to
2535 * @code
2536 * std::make_pair(lower_bound(first, last, val),
2537 * upper_bound(first, last, val))
2538 * @endcode
2539 * but does not actually call those functions.
2540 */
2541 template<typename _ForwardIterator, typename _Tp>
2542 pair<_ForwardIterator, _ForwardIterator>
2543 equal_range(_ForwardIterator __first, _ForwardIterator __last,
2544 const _Tp& __val)
2545 {
2546 typedef typename iterator_traits<_ForwardIterator>::value_type
2547 _ValueType;
2548 typedef typename iterator_traits<_ForwardIterator>::difference_type
2549 _DistanceType;
2550
2551 // concept requirements
2552 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2553 __glibcxx_function_requires(_LessThanOpConcept<_ValueType, _Tp>)
2554 __glibcxx_function_requires(_LessThanOpConcept<_Tp, _ValueType>)
2555 __glibcxx_requires_partitioned_lower(__first, __last, __val);
2556 __glibcxx_requires_partitioned_upper(__first, __last, __val);
2557
2558 _DistanceType __len = std::distance(__first, __last);
2559
2560 while (__len > 0)
2561 {
2562 _DistanceType __half = __len >> 1;
2563 _ForwardIterator __middle = __first;
2564 std::advance(__middle, __half);
2565 if (*__middle < __val)
2566 {
2567 __first = __middle;
2568 ++__first;
2569 __len = __len - __half - 1;
2570 }
2571 else if (__val < *__middle)
2572 __len = __half;
2573 else
2574 {
2575 _ForwardIterator __left = std::lower_bound(__first, __middle,
2576 __val);
2577 std::advance(__first, __len);
2578 _ForwardIterator __right = std::upper_bound(++__middle, __first,
2579 __val);
2580 return pair<_ForwardIterator, _ForwardIterator>(__left, __right);
2581 }
2582 }
2583 return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
2584 }
2585
2586 /**
2587 * @brief Finds the largest subrange in which @a val could be inserted
2588 * at any place in it without changing the ordering.
2589 * @param first An iterator.
2590 * @param last Another iterator.
2591 * @param val The search term.
2592 * @param comp A functor to use for comparisons.
2593 * @return An pair of iterators defining the subrange.
2594 * @ingroup binary_search_algorithms
2595 *
2596 * This is equivalent to
2597 * @code
2598 * std::make_pair(lower_bound(first, last, val, comp),
2599 * upper_bound(first, last, val, comp))
2600 * @endcode
2601 * but does not actually call those functions.
2602 */
2603 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2604 pair<_ForwardIterator, _ForwardIterator>
2605 equal_range(_ForwardIterator __first, _ForwardIterator __last,
2606 const _Tp& __val, _Compare __comp)
2607 {
2608 typedef typename iterator_traits<_ForwardIterator>::value_type
2609 _ValueType;
2610 typedef typename iterator_traits<_ForwardIterator>::difference_type
2611 _DistanceType;
2612
2613 // concept requirements
2614 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2615 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2616 _ValueType, _Tp>)
2617 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2618 _Tp, _ValueType>)
2619 __glibcxx_requires_partitioned_lower_pred(__first, __last,
2620 __val, __comp);
2621 __glibcxx_requires_partitioned_upper_pred(__first, __last,
2622 __val, __comp);
2623
2624 _DistanceType __len = std::distance(__first, __last);
2625
2626 while (__len > 0)
2627 {
2628 _DistanceType __half = __len >> 1;
2629 _ForwardIterator __middle = __first;
2630 std::advance(__middle, __half);
2631 if (__comp(*__middle, __val))
2632 {
2633 __first = __middle;
2634 ++__first;
2635 __len = __len - __half - 1;
2636 }
2637 else if (__comp(__val, *__middle))
2638 __len = __half;
2639 else
2640 {
2641 _ForwardIterator __left = std::lower_bound(__first, __middle,
2642 __val, __comp);
2643 std::advance(__first, __len);
2644 _ForwardIterator __right = std::upper_bound(++__middle, __first,
2645 __val, __comp);
2646 return pair<_ForwardIterator, _ForwardIterator>(__left, __right);
2647 }
2648 }
2649 return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
2650 }
2651
2652 /**
2653 * @brief Determines whether an element exists in a range.
2654 * @ingroup binary_search_algorithms
2655 * @param first An iterator.
2656 * @param last Another iterator.
2657 * @param val The search term.
2658 * @return True if @a val (or its equivalent) is in [@a first,@a last ].
2659 *
2660 * Note that this does not actually return an iterator to @a val. For
2661 * that, use std::find or a container's specialized find member functions.
2662 */
2663 template<typename _ForwardIterator, typename _Tp>
2664 bool
2665 binary_search(_ForwardIterator __first, _ForwardIterator __last,
2666 const _Tp& __val)
2667 {
2668 typedef typename iterator_traits<_ForwardIterator>::value_type
2669 _ValueType;
2670
2671 // concept requirements
2672 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2673 __glibcxx_function_requires(_LessThanOpConcept<_Tp, _ValueType>)
2674 __glibcxx_requires_partitioned_lower(__first, __last, __val);
2675 __glibcxx_requires_partitioned_upper(__first, __last, __val);
2676
2677 _ForwardIterator __i = std::lower_bound(__first, __last, __val);
2678 return __i != __last && !(__val < *__i);
2679 }
2680
2681 /**
2682 * @brief Determines whether an element exists in a range.
2683 * @ingroup binary_search_algorithms
2684 * @param first An iterator.
2685 * @param last Another iterator.
2686 * @param val The search term.
2687 * @param comp A functor to use for comparisons.
2688 * @return True if @a val (or its equivalent) is in [@a first,@a last ].
2689 *
2690 * Note that this does not actually return an iterator to @a val. For
2691 * that, use std::find or a container's specialized find member functions.
2692 *
2693 * The comparison function should have the same effects on ordering as
2694 * the function used for the initial sort.
2695 */
2696 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2697 bool
2698 binary_search(_ForwardIterator __first, _ForwardIterator __last,
2699 const _Tp& __val, _Compare __comp)
2700 {
2701 typedef typename iterator_traits<_ForwardIterator>::value_type
2702 _ValueType;
2703
2704 // concept requirements
2705 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2706 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2707 _Tp, _ValueType>)
2708 __glibcxx_requires_partitioned_lower_pred(__first, __last,
2709 __val, __comp);
2710 __glibcxx_requires_partitioned_upper_pred(__first, __last,
2711 __val, __comp);
2712
2713 _ForwardIterator __i = std::lower_bound(__first, __last, __val, __comp);
2714 return __i != __last && !bool(__comp(__val, *__i));
2715 }
2716
2717 // merge
2718
2719 /// This is a helper function for the merge routines.
2720 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
2721 typename _BidirectionalIterator3>
2722 _BidirectionalIterator3
2723 __move_merge_backward(_BidirectionalIterator1 __first1,
2724 _BidirectionalIterator1 __last1,
2725 _BidirectionalIterator2 __first2,
2726 _BidirectionalIterator2 __last2,
2727 _BidirectionalIterator3 __result)
2728 {
2729 if (__first1 == __last1)
2730 return _GLIBCXX_MOVE_BACKWARD3(__first2, __last2, __result);
2731 if (__first2 == __last2)
2732 return _GLIBCXX_MOVE_BACKWARD3(__first1, __last1, __result);
2733 --__last1;
2734 --__last2;
2735 while (true)
2736 {
2737 if (*__last2 < *__last1)
2738 {
2739 *--__result = _GLIBCXX_MOVE(*__last1);
2740 if (__first1 == __last1)
2741 return _GLIBCXX_MOVE_BACKWARD3(__first2, ++__last2, __result);
2742 --__last1;
2743 }
2744 else
2745 {
2746 *--__result = _GLIBCXX_MOVE(*__last2);
2747 if (__first2 == __last2)
2748 return _GLIBCXX_MOVE_BACKWARD3(__first1, ++__last1, __result);
2749 --__last2;
2750 }
2751 }
2752 }
2753
2754 /// This is a helper function for the merge routines.
2755 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
2756 typename _BidirectionalIterator3, typename _Compare>
2757 _BidirectionalIterator3
2758 __move_merge_backward(_BidirectionalIterator1 __first1,
2759 _BidirectionalIterator1 __last1,
2760 _BidirectionalIterator2 __first2,
2761 _BidirectionalIterator2 __last2,
2762 _BidirectionalIterator3 __result,
2763 _Compare __comp)
2764 {
2765 if (__first1 == __last1)
2766 return _GLIBCXX_MOVE_BACKWARD3(__first2, __last2, __result);
2767 if (__first2 == __last2)
2768 return _GLIBCXX_MOVE_BACKWARD3(__first1, __last1, __result);
2769 --__last1;
2770 --__last2;
2771 while (true)
2772 {
2773 if (__comp(*__last2, *__last1))
2774 {
2775 *--__result = _GLIBCXX_MOVE(*__last1);
2776 if (__first1 == __last1)
2777 return _GLIBCXX_MOVE_BACKWARD3(__first2, ++__last2, __result);
2778 --__last1;
2779 }
2780 else
2781 {
2782 *--__result = _GLIBCXX_MOVE(*__last2);
2783 if (__first2 == __last2)
2784 return _GLIBCXX_MOVE_BACKWARD3(__first1, ++__last1, __result);
2785 --__last2;
2786 }
2787 }
2788 }
2789
2790 /// This is a helper function for the merge routines.
2791 template<typename _InputIterator1, typename _InputIterator2,
2792 typename _OutputIterator>
2793 _OutputIterator
2794 __move_merge(_InputIterator1 __first1, _InputIterator1 __last1,
2795 _InputIterator2 __first2, _InputIterator2 __last2,
2796 _OutputIterator __result)
2797 {
2798 while (__first1 != __last1 && __first2 != __last2)
2799 {
2800 if (*__first2 < *__first1)
2801 {
2802 *__result = _GLIBCXX_MOVE(*__first2);
2803 ++__first2;
2804 }
2805 else
2806 {
2807 *__result = _GLIBCXX_MOVE(*__first1);
2808 ++__first1;
2809 }
2810 ++__result;
2811 }
2812 return _GLIBCXX_MOVE3(__first2, __last2,
2813 _GLIBCXX_MOVE3(__first1, __last1,
2814 __result));
2815 }
2816
2817 /// This is a helper function for the merge routines.
2818 template<typename _InputIterator1, typename _InputIterator2,
2819 typename _OutputIterator, typename _Compare>
2820 _OutputIterator
2821 __move_merge(_InputIterator1 __first1, _InputIterator1 __last1,
2822 _InputIterator2 __first2, _InputIterator2 __last2,
2823 _OutputIterator __result, _Compare __comp)
2824 {
2825 while (__first1 != __last1 && __first2 != __last2)
2826 {
2827 if (__comp(*__first2, *__first1))
2828 {
2829 *__result = _GLIBCXX_MOVE(*__first2);
2830 ++__first2;
2831 }
2832 else
2833 {
2834 *__result = _GLIBCXX_MOVE(*__first1);
2835 ++__first1;
2836 }
2837 ++__result;
2838 }
2839 return _GLIBCXX_MOVE3(__first2, __last2,
2840 _GLIBCXX_MOVE3(__first1, __last1,
2841 __result));
2842 }
2843
2844
2845 /// This is a helper function for the merge routines.
2846 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
2847 typename _Distance>
2848 _BidirectionalIterator1
2849 __rotate_adaptive(_BidirectionalIterator1 __first,
2850 _BidirectionalIterator1 __middle,
2851 _BidirectionalIterator1 __last,
2852 _Distance __len1, _Distance __len2,
2853 _BidirectionalIterator2 __buffer,
2854 _Distance __buffer_size)
2855 {
2856 _BidirectionalIterator2 __buffer_end;
2857 if (__len1 > __len2 && __len2 <= __buffer_size)
2858 {
2859 __buffer_end = _GLIBCXX_MOVE3(__middle, __last, __buffer);
2860 _GLIBCXX_MOVE_BACKWARD3(__first, __middle, __last);
2861 return _GLIBCXX_MOVE3(__buffer, __buffer_end, __first);
2862 }
2863 else if (__len1 <= __buffer_size)
2864 {
2865 __buffer_end = _GLIBCXX_MOVE3(__first, __middle, __buffer);
2866 _GLIBCXX_MOVE3(__middle, __last, __first);
2867 return _GLIBCXX_MOVE_BACKWARD3(__buffer, __buffer_end, __last);
2868 }
2869 else
2870 {
2871 std::rotate(__first, __middle, __last);
2872 std::advance(__first, std::distance(__middle, __last));
2873 return __first;
2874 }
2875 }
2876
2877 /// This is a helper function for the merge routines.
2878 template<typename _BidirectionalIterator, typename _Distance,
2879 typename _Pointer>
2880 void
2881 __merge_adaptive(_BidirectionalIterator __first,
2882 _BidirectionalIterator __middle,
2883 _BidirectionalIterator __last,
2884 _Distance __len1, _Distance __len2,
2885 _Pointer __buffer, _Distance __buffer_size)
2886 {
2887 if (__len1 <= __len2 && __len1 <= __buffer_size)
2888 {
2889 _Pointer __buffer_end = _GLIBCXX_MOVE3(__first, __middle, __buffer);
2890 std::__move_merge(__buffer, __buffer_end, __middle, __last, __first);
2891 }
2892 else if (__len2 <= __buffer_size)
2893 {
2894 _Pointer __buffer_end = _GLIBCXX_MOVE3(__middle, __last, __buffer);
2895 std::__move_merge_backward(__first, __middle, __buffer,
2896 __buffer_end, __last);
2897 }
2898 else
2899 {
2900 _BidirectionalIterator __first_cut = __first;
2901 _BidirectionalIterator __second_cut = __middle;
2902 _Distance __len11 = 0;
2903 _Distance __len22 = 0;
2904 if (__len1 > __len2)
2905 {
2906 __len11 = __len1 / 2;
2907 std::advance(__first_cut, __len11);
2908 __second_cut = std::lower_bound(__middle, __last,
2909 *__first_cut);
2910 __len22 = std::distance(__middle, __second_cut);
2911 }
2912 else
2913 {
2914 __len22 = __len2 / 2;
2915 std::advance(__second_cut, __len22);
2916 __first_cut = std::upper_bound(__first, __middle,
2917 *__second_cut);
2918 __len11 = std::distance(__first, __first_cut);
2919 }
2920 _BidirectionalIterator __new_middle =
2921 std::__rotate_adaptive(__first_cut, __middle, __second_cut,
2922 __len1 - __len11, __len22, __buffer,
2923 __buffer_size);
2924 std::__merge_adaptive(__first, __first_cut, __new_middle, __len11,
2925 __len22, __buffer, __buffer_size);
2926 std::__merge_adaptive(__new_middle, __second_cut, __last,
2927 __len1 - __len11,
2928 __len2 - __len22, __buffer, __buffer_size);
2929 }
2930 }
2931
2932 /// This is a helper function for the merge routines.
2933 template<typename _BidirectionalIterator, typename _Distance,
2934 typename _Pointer, typename _Compare>
2935 void
2936 __merge_adaptive(_BidirectionalIterator __first,
2937 _BidirectionalIterator __middle,
2938 _BidirectionalIterator __last,
2939 _Distance __len1, _Distance __len2,
2940 _Pointer __buffer, _Distance __buffer_size,
2941 _Compare __comp)
2942 {
2943 if (__len1 <= __len2 && __len1 <= __buffer_size)
2944 {
2945 _Pointer __buffer_end = _GLIBCXX_MOVE3(__first, __middle, __buffer);
2946 std::__move_merge(__buffer, __buffer_end, __middle, __last,
2947 __first, __comp);
2948 }
2949 else if (__len2 <= __buffer_size)
2950 {
2951 _Pointer __buffer_end = _GLIBCXX_MOVE3(__middle, __last, __buffer);
2952 std::__move_merge_backward(__first, __middle, __buffer, __buffer_end,
2953 __last, __comp);
2954 }
2955 else
2956 {
2957 _BidirectionalIterator __first_cut = __first;
2958 _BidirectionalIterator __second_cut = __middle;
2959 _Distance __len11 = 0;
2960 _Distance __len22 = 0;
2961 if (__len1 > __len2)
2962 {
2963 __len11 = __len1 / 2;
2964 std::advance(__first_cut, __len11);
2965 __second_cut = std::lower_bound(__middle, __last, *__first_cut,
2966 __comp);
2967 __len22 = std::distance(__middle, __second_cut);
2968 }
2969 else
2970 {
2971 __len22 = __len2 / 2;
2972 std::advance(__second_cut, __len22);
2973 __first_cut = std::upper_bound(__first, __middle, *__second_cut,
2974 __comp);
2975 __len11 = std::distance(__first, __first_cut);
2976 }
2977 _BidirectionalIterator __new_middle =
2978 std::__rotate_adaptive(__first_cut, __middle, __second_cut,
2979 __len1 - __len11, __len22, __buffer,
2980 __buffer_size);
2981 std::__merge_adaptive(__first, __first_cut, __new_middle, __len11,
2982 __len22, __buffer, __buffer_size, __comp);
2983 std::__merge_adaptive(__new_middle, __second_cut, __last,
2984 __len1 - __len11,
2985 __len2 - __len22, __buffer,
2986 __buffer_size, __comp);
2987 }
2988 }
2989
2990 /// This is a helper function for the merge routines.
2991 template<typename _BidirectionalIterator, typename _Distance>
2992 void
2993 __merge_without_buffer(_BidirectionalIterator __first,
2994 _BidirectionalIterator __middle,
2995 _BidirectionalIterator __last,
2996 _Distance __len1, _Distance __len2)
2997 {
2998 if (__len1 == 0 || __len2 == 0)
2999 return;
3000 if (__len1 + __len2 == 2)
3001 {
3002 if (*__middle < *__first)
3003 std::iter_swap(__first, __middle);
3004 return;
3005 }
3006 _BidirectionalIterator __first_cut = __first;
3007 _BidirectionalIterator __second_cut = __middle;
3008 _Distance __len11 = 0;
3009 _Distance __len22 = 0;
3010 if (__len1 > __len2)
3011 {
3012 __len11 = __len1 / 2;
3013 std::advance(__first_cut, __len11);
3014 __second_cut = std::lower_bound(__middle, __last, *__first_cut);
3015 __len22 = std::distance(__middle, __second_cut);
3016 }
3017 else
3018 {
3019 __len22 = __len2 / 2;
3020 std::advance(__second_cut, __len22);
3021 __first_cut = std::upper_bound(__first, __middle, *__second_cut);
3022 __len11 = std::distance(__first, __first_cut);
3023 }
3024 std::rotate(__first_cut, __middle, __second_cut);
3025 _BidirectionalIterator __new_middle = __first_cut;
3026 std::advance(__new_middle, std::distance(__middle, __second_cut));
3027 std::__merge_without_buffer(__first, __first_cut, __new_middle,
3028 __len11, __len22);
3029 std::__merge_without_buffer(__new_middle, __second_cut, __last,
3030 __len1 - __len11, __len2 - __len22);
3031 }
3032
3033 /// This is a helper function for the merge routines.
3034 template<typename _BidirectionalIterator, typename _Distance,
3035 typename _Compare>
3036 void
3037 __merge_without_buffer(_BidirectionalIterator __first,
3038 _BidirectionalIterator __middle,
3039 _BidirectionalIterator __last,
3040 _Distance __len1, _Distance __len2,
3041 _Compare __comp)
3042 {
3043 if (__len1 == 0 || __len2 == 0)
3044 return;
3045 if (__len1 + __len2 == 2)
3046 {
3047 if (__comp(*__middle, *__first))
3048 std::iter_swap(__first, __middle);
3049 return;
3050 }
3051 _BidirectionalIterator __first_cut = __first;
3052 _BidirectionalIterator __second_cut = __middle;
3053 _Distance __len11 = 0;
3054 _Distance __len22 = 0;
3055 if (__len1 > __len2)
3056 {
3057 __len11 = __len1 / 2;
3058 std::advance(__first_cut, __len11);
3059 __second_cut = std::lower_bound(__middle, __last, *__first_cut,
3060 __comp);
3061 __len22 = std::distance(__middle, __second_cut);
3062 }
3063 else
3064 {
3065 __len22 = __len2 / 2;
3066 std::advance(__second_cut, __len22);
3067 __first_cut = std::upper_bound(__first, __middle, *__second_cut,
3068 __comp);
3069 __len11 = std::distance(__first, __first_cut);
3070 }
3071 std::rotate(__first_cut, __middle, __second_cut);
3072 _BidirectionalIterator __new_middle = __first_cut;
3073 std::advance(__new_middle, std::distance(__middle, __second_cut));
3074 std::__merge_without_buffer(__first, __first_cut, __new_middle,
3075 __len11, __len22, __comp);
3076 std::__merge_without_buffer(__new_middle, __second_cut, __last,
3077 __len1 - __len11, __len2 - __len22, __comp);
3078 }
3079
3080 /**
3081 * @brief Merges two sorted ranges in place.
3082 * @ingroup sorting_algorithms
3083 * @param first An iterator.
3084 * @param middle Another iterator.
3085 * @param last Another iterator.
3086 * @return Nothing.
3087 *
3088 * Merges two sorted and consecutive ranges, [first,middle) and
3089 * [middle,last), and puts the result in [first,last). The output will
3090 * be sorted. The sort is @e stable, that is, for equivalent
3091 * elements in the two ranges, elements from the first range will always
3092 * come before elements from the second.
3093 *
3094 * If enough additional memory is available, this takes (last-first)-1
3095 * comparisons. Otherwise an NlogN algorithm is used, where N is
3096 * distance(first,last).
3097 */
3098 template<typename _BidirectionalIterator>
3099 void
3100 inplace_merge(_BidirectionalIterator __first,
3101 _BidirectionalIterator __middle,
3102 _BidirectionalIterator __last)
3103 {
3104 typedef typename iterator_traits<_BidirectionalIterator>::value_type
3105 _ValueType;
3106 typedef typename iterator_traits<_BidirectionalIterator>::difference_type
3107 _DistanceType;
3108
3109 // concept requirements
3110 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
3111 _BidirectionalIterator>)
3112 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
3113 __glibcxx_requires_sorted(__first, __middle);
3114 __glibcxx_requires_sorted(__middle, __last);
3115
3116 if (__first == __middle || __middle == __last)
3117 return;
3118
3119 _DistanceType __len1 = std::distance(__first, __middle);
3120 _DistanceType __len2 = std::distance(__middle, __last);
3121
3122 _Temporary_buffer<_BidirectionalIterator, _ValueType> __buf(__first,
3123 __last);
3124 if (__buf.begin() == 0)
3125 std::__merge_without_buffer(__first, __middle, __last, __len1, __len2);
3126 else
3127 std::__merge_adaptive(__first, __middle, __last, __len1, __len2,
3128 __buf.begin(), _DistanceType(__buf.size()));
3129 }
3130
3131 /**
3132 * @brief Merges two sorted ranges in place.
3133 * @ingroup sorting_algorithms
3134 * @param first An iterator.
3135 * @param middle Another iterator.
3136 * @param last Another iterator.
3137 * @param comp A functor to use for comparisons.
3138 * @return Nothing.
3139 *
3140 * Merges two sorted and consecutive ranges, [first,middle) and
3141 * [middle,last), and puts the result in [first,last). The output will
3142 * be sorted. The sort is @e stable, that is, for equivalent
3143 * elements in the two ranges, elements from the first range will always
3144 * come before elements from the second.
3145 *
3146 * If enough additional memory is available, this takes (last-first)-1
3147 * comparisons. Otherwise an NlogN algorithm is used, where N is
3148 * distance(first,last).
3149 *
3150 * The comparison function should have the same effects on ordering as
3151 * the function used for the initial sort.
3152 */
3153 template<typename _BidirectionalIterator, typename _Compare>
3154 void
3155 inplace_merge(_BidirectionalIterator __first,
3156 _BidirectionalIterator __middle,
3157 _BidirectionalIterator __last,
3158 _Compare __comp)
3159 {
3160 typedef typename iterator_traits<_BidirectionalIterator>::value_type
3161 _ValueType;
3162 typedef typename iterator_traits<_BidirectionalIterator>::difference_type
3163 _DistanceType;
3164
3165 // concept requirements
3166 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
3167 _BidirectionalIterator>)
3168 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3169 _ValueType, _ValueType>)
3170 __glibcxx_requires_sorted_pred(__first, __middle, __comp);
3171 __glibcxx_requires_sorted_pred(__middle, __last, __comp);
3172
3173 if (__first == __middle || __middle == __last)
3174 return;
3175
3176 const _DistanceType __len1 = std::distance(__first, __middle);
3177 const _DistanceType __len2 = std::distance(__middle, __last);
3178
3179 _Temporary_buffer<_BidirectionalIterator, _ValueType> __buf(__first,
3180 __last);
3181 if (__buf.begin() == 0)
3182 std::__merge_without_buffer(__first, __middle, __last, __len1,
3183 __len2, __comp);
3184 else
3185 std::__merge_adaptive(__first, __middle, __last, __len1, __len2,
3186 __buf.begin(), _DistanceType(__buf.size()),
3187 __comp);
3188 }
3189
3190 template<typename _RandomAccessIterator1, typename _RandomAccessIterator2,
3191 typename _Distance>
3192 void
3193 __merge_sort_loop(_RandomAccessIterator1 __first,
3194 _RandomAccessIterator1 __last,
3195 _RandomAccessIterator2 __result,
3196 _Distance __step_size)
3197 {
3198 const _Distance __two_step = 2 * __step_size;
3199
3200 while (__last - __first >= __two_step)
3201 {
3202 __result = std::__move_merge(__first, __first + __step_size,
3203 __first + __step_size,
3204 __first + __two_step, __result);
3205 __first += __two_step;
3206 }
3207
3208 __step_size = std::min(_Distance(__last - __first), __step_size);
3209 std::__move_merge(__first, __first + __step_size,
3210 __first + __step_size, __last, __result);
3211 }
3212
3213 template<typename _RandomAccessIterator1, typename _RandomAccessIterator2,
3214 typename _Distance, typename _Compare>
3215 void
3216 __merge_sort_loop(_RandomAccessIterator1 __first,
3217 _RandomAccessIterator1 __last,
3218 _RandomAccessIterator2 __result, _Distance __step_size,
3219 _Compare __comp)
3220 {
3221 const _Distance __two_step = 2 * __step_size;
3222
3223 while (__last - __first >= __two_step)
3224 {
3225 __result = std::__move_merge(__first, __first + __step_size,
3226 __first + __step_size,
3227 __first + __two_step,
3228 __result, __comp);
3229 __first += __two_step;
3230 }
3231 __step_size = std::min(_Distance(__last - __first), __step_size);
3232
3233 std::__move_merge(__first,__first + __step_size,
3234 __first + __step_size, __last, __result, __comp);
3235 }
3236
3237 template<typename _RandomAccessIterator, typename _Distance>
3238 void
3239 __chunk_insertion_sort(_RandomAccessIterator __first,
3240 _RandomAccessIterator __last,
3241 _Distance __chunk_size)
3242 {
3243 while (__last - __first >= __chunk_size)
3244 {
3245 std::__insertion_sort(__first, __first + __chunk_size);
3246 __first += __chunk_size;
3247 }
3248 std::__insertion_sort(__first, __last);
3249 }
3250
3251 template<typename _RandomAccessIterator, typename _Distance,
3252 typename _Compare>
3253 void
3254 __chunk_insertion_sort(_RandomAccessIterator __first,
3255 _RandomAccessIterator __last,
3256 _Distance __chunk_size, _Compare __comp)
3257 {
3258 while (__last - __first >= __chunk_size)
3259 {
3260 std::__insertion_sort(__first, __first + __chunk_size, __comp);
3261 __first += __chunk_size;
3262 }
3263 std::__insertion_sort(__first, __last, __comp);
3264 }
3265
3266 enum { _S_chunk_size = 7 };
3267
3268 template<typename _RandomAccessIterator, typename _Pointer>
3269 void
3270 __merge_sort_with_buffer(_RandomAccessIterator __first,
3271 _RandomAccessIterator __last,
3272 _Pointer __buffer)
3273 {
3274 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3275 _Distance;
3276
3277 const _Distance __len = __last - __first;
3278 const _Pointer __buffer_last = __buffer + __len;
3279
3280 _Distance __step_size = _S_chunk_size;
3281 std::__chunk_insertion_sort(__first, __last, __step_size);
3282
3283 while (__step_size < __len)
3284 {
3285 std::__merge_sort_loop(__first, __last, __buffer, __step_size);
3286 __step_size *= 2;
3287 std::__merge_sort_loop(__buffer, __buffer_last, __first, __step_size);
3288 __step_size *= 2;
3289 }
3290 }
3291
3292 template<typename _RandomAccessIterator, typename _Pointer, typename _Compare>
3293 void
3294 __merge_sort_with_buffer(_RandomAccessIterator __first,
3295 _RandomAccessIterator __last,
3296 _Pointer __buffer, _Compare __comp)
3297 {
3298 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3299 _Distance;
3300
3301 const _Distance __len = __last - __first;
3302 const _Pointer __buffer_last = __buffer + __len;
3303
3304 _Distance __step_size = _S_chunk_size;
3305 std::__chunk_insertion_sort(__first, __last, __step_size, __comp);
3306
3307 while (__step_size < __len)
3308 {
3309 std::__merge_sort_loop(__first, __last, __buffer,
3310 __step_size, __comp);
3311 __step_size *= 2;
3312 std::__merge_sort_loop(__buffer, __buffer_last, __first,
3313 __step_size, __comp);
3314 __step_size *= 2;
3315 }
3316 }
3317
3318 template<typename _RandomAccessIterator, typename _Pointer,
3319 typename _Distance>
3320 void
3321 __stable_sort_adaptive(_RandomAccessIterator __first,
3322 _RandomAccessIterator __last,
3323 _Pointer __buffer, _Distance __buffer_size)
3324 {
3325 const _Distance __len = (__last - __first + 1) / 2;
3326 const _RandomAccessIterator __middle = __first + __len;
3327 if (__len > __buffer_size)
3328 {
3329 std::__stable_sort_adaptive(__first, __middle,
3330 __buffer, __buffer_size);
3331 std::__stable_sort_adaptive(__middle, __last,
3332 __buffer, __buffer_size);
3333 }
3334 else
3335 {
3336 std::__merge_sort_with_buffer(__first, __middle, __buffer);
3337 std::__merge_sort_with_buffer(__middle, __last, __buffer);
3338 }
3339 std::__merge_adaptive(__first, __middle, __last,
3340 _Distance(__middle - __first),
3341 _Distance(__last - __middle),
3342 __buffer, __buffer_size);
3343 }
3344
3345 template<typename _RandomAccessIterator, typename _Pointer,
3346 typename _Distance, typename _Compare>
3347 void
3348 __stable_sort_adaptive(_RandomAccessIterator __first,
3349 _RandomAccessIterator __last,
3350 _Pointer __buffer, _Distance __buffer_size,
3351 _Compare __comp)
3352 {
3353 const _Distance __len = (__last - __first + 1) / 2;
3354 const _RandomAccessIterator __middle = __first + __len;
3355 if (__len > __buffer_size)
3356 {
3357 std::__stable_sort_adaptive(__first, __middle, __buffer,
3358 __buffer_size, __comp);
3359 std::__stable_sort_adaptive(__middle, __last, __buffer,
3360 __buffer_size, __comp);
3361 }
3362 else
3363 {
3364 std::__merge_sort_with_buffer(__first, __middle, __buffer, __comp);
3365 std::__merge_sort_with_buffer(__middle, __last, __buffer, __comp);
3366 }
3367 std::__merge_adaptive(__first, __middle, __last,
3368 _Distance(__middle - __first),
3369 _Distance(__last - __middle),
3370 __buffer, __buffer_size,
3371 __comp);
3372 }
3373
3374 /// This is a helper function for the stable sorting routines.
3375 template<typename _RandomAccessIterator>
3376 void
3377 __inplace_stable_sort(_RandomAccessIterator __first,
3378 _RandomAccessIterator __last)
3379 {
3380 if (__last - __first < 15)
3381 {
3382 std::__insertion_sort(__first, __last);
3383 return;
3384 }
3385 _RandomAccessIterator __middle = __first + (__last - __first) / 2;
3386 std::__inplace_stable_sort(__first, __middle);
3387 std::__inplace_stable_sort(__middle, __last);
3388 std::__merge_without_buffer(__first, __middle, __last,
3389 __middle - __first,
3390 __last - __middle);
3391 }
3392
3393 /// This is a helper function for the stable sorting routines.
3394 template<typename _RandomAccessIterator, typename _Compare>
3395 void
3396 __inplace_stable_sort(_RandomAccessIterator __first,
3397 _RandomAccessIterator __last, _Compare __comp)
3398 {
3399 if (__last - __first < 15)
3400 {
3401 std::__insertion_sort(__first, __last, __comp);
3402 return;
3403 }
3404 _RandomAccessIterator __middle = __first + (__last - __first) / 2;
3405 std::__inplace_stable_sort(__first, __middle, __comp);
3406 std::__inplace_stable_sort(__middle, __last, __comp);
3407 std::__merge_without_buffer(__first, __middle, __last,
3408 __middle - __first,
3409 __last - __middle,
3410 __comp);
3411 }
3412
3413 // stable_sort
3414
3415 // Set algorithms: includes, set_union, set_intersection, set_difference,
3416 // set_symmetric_difference. All of these algorithms have the precondition
3417 // that their input ranges are sorted and the postcondition that their output
3418 // ranges are sorted.
3419
3420 /**
3421 * @brief Determines whether all elements of a sequence exists in a range.
3422 * @param first1 Start of search range.
3423 * @param last1 End of search range.
3424 * @param first2 Start of sequence
3425 * @param last2 End of sequence.
3426 * @return True if each element in [first2,last2) is contained in order
3427 * within [first1,last1). False otherwise.
3428 * @ingroup set_algorithms
3429 *
3430 * This operation expects both [first1,last1) and [first2,last2) to be
3431 * sorted. Searches for the presence of each element in [first2,last2)
3432 * within [first1,last1). The iterators over each range only move forward,
3433 * so this is a linear algorithm. If an element in [first2,last2) is not
3434 * found before the search iterator reaches @a last2, false is returned.
3435 */
3436 template<typename _InputIterator1, typename _InputIterator2>
3437 bool
3438 includes(_InputIterator1 __first1, _InputIterator1 __last1,
3439 _InputIterator2 __first2, _InputIterator2 __last2)
3440 {
3441 typedef typename iterator_traits<_InputIterator1>::value_type
3442 _ValueType1;
3443 typedef typename iterator_traits<_InputIterator2>::value_type
3444 _ValueType2;
3445
3446 // concept requirements
3447 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
3448 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
3449 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
3450 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
3451 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
3452 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
3453
3454 while (__first1 != __last1 && __first2 != __last2)
3455 if (*__first2 < *__first1)
3456 return false;
3457 else if(*__first1 < *__first2)
3458 ++__first1;
3459 else
3460 ++__first1, ++__first2;
3461
3462 return __first2 == __last2;
3463 }
3464
3465 /**
3466 * @brief Determines whether all elements of a sequence exists in a range
3467 * using comparison.
3468 * @ingroup set_algorithms
3469 * @param first1 Start of search range.
3470 * @param last1 End of search range.
3471 * @param first2 Start of sequence
3472 * @param last2 End of sequence.
3473 * @param comp Comparison function to use.
3474 * @return True if each element in [first2,last2) is contained in order
3475 * within [first1,last1) according to comp. False otherwise.
3476 * @ingroup set_algorithms
3477 *
3478 * This operation expects both [first1,last1) and [first2,last2) to be
3479 * sorted. Searches for the presence of each element in [first2,last2)
3480 * within [first1,last1), using comp to decide. The iterators over each
3481 * range only move forward, so this is a linear algorithm. If an element
3482 * in [first2,last2) is not found before the search iterator reaches @a
3483 * last2, false is returned.
3484 */
3485 template<typename _InputIterator1, typename _InputIterator2,
3486 typename _Compare>
3487 bool
3488 includes(_InputIterator1 __first1, _InputIterator1 __last1,
3489 _InputIterator2 __first2, _InputIterator2 __last2,
3490 _Compare __comp)
3491 {
3492 typedef typename iterator_traits<_InputIterator1>::value_type
3493 _ValueType1;
3494 typedef typename iterator_traits<_InputIterator2>::value_type
3495 _ValueType2;
3496
3497 // concept requirements
3498 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
3499 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
3500 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3501 _ValueType1, _ValueType2>)
3502 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3503 _ValueType2, _ValueType1>)
3504 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
3505 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
3506
3507 while (__first1 != __last1 && __first2 != __last2)
3508 if (__comp(*__first2, *__first1))
3509 return false;
3510 else if(__comp(*__first1, *__first2))
3511 ++__first1;
3512 else
3513 ++__first1, ++__first2;
3514
3515 return __first2 == __last2;
3516 }
3517
3518 // nth_element
3519 // merge
3520 // set_difference
3521 // set_intersection
3522 // set_union
3523 // stable_sort
3524 // set_symmetric_difference
3525 // min_element
3526 // max_element
3527
3528 /**
3529 * @brief Permute range into the next @a dictionary ordering.
3530 * @ingroup sorting_algorithms
3531 * @param first Start of range.
3532 * @param last End of range.
3533 * @return False if wrapped to first permutation, true otherwise.
3534 *
3535 * Treats all permutations of the range as a set of @a dictionary sorted
3536 * sequences. Permutes the current sequence into the next one of this set.
3537 * Returns true if there are more sequences to generate. If the sequence
3538 * is the largest of the set, the smallest is generated and false returned.
3539 */
3540 template<typename _BidirectionalIterator>
3541 bool
3542 next_permutation(_BidirectionalIterator __first,
3543 _BidirectionalIterator __last)
3544 {
3545 // concept requirements
3546 __glibcxx_function_requires(_BidirectionalIteratorConcept<
3547 _BidirectionalIterator>)
3548 __glibcxx_function_requires(_LessThanComparableConcept<
3549 typename iterator_traits<_BidirectionalIterator>::value_type>)
3550 __glibcxx_requires_valid_range(__first, __last);
3551
3552 if (__first == __last)
3553 return false;
3554 _BidirectionalIterator __i = __first;
3555 ++__i;
3556 if (__i == __last)
3557 return false;
3558 __i = __last;
3559 --__i;
3560
3561 for(;;)
3562 {
3563 _BidirectionalIterator __ii = __i;
3564 --__i;
3565 if (*__i < *__ii)
3566 {
3567 _BidirectionalIterator __j = __last;
3568 while (!(*__i < *--__j))
3569 {}
3570 std::iter_swap(__i, __j);
3571 std::reverse(__ii, __last);
3572 return true;
3573 }
3574 if (__i == __first)
3575 {
3576 std::reverse(__first, __last);
3577 return false;
3578 }
3579 }
3580 }
3581
3582 /**
3583 * @brief Permute range into the next @a dictionary ordering using
3584 * comparison functor.
3585 * @ingroup sorting_algorithms
3586 * @param first Start of range.
3587 * @param last End of range.
3588 * @param comp A comparison functor.
3589 * @return False if wrapped to first permutation, true otherwise.
3590 *
3591 * Treats all permutations of the range [first,last) as a set of
3592 * @a dictionary sorted sequences ordered by @a comp. Permutes the current
3593 * sequence into the next one of this set. Returns true if there are more
3594 * sequences to generate. If the sequence is the largest of the set, the
3595 * smallest is generated and false returned.
3596 */
3597 template<typename _BidirectionalIterator, typename _Compare>
3598 bool
3599 next_permutation(_BidirectionalIterator __first,
3600 _BidirectionalIterator __last, _Compare __comp)
3601 {
3602 // concept requirements
3603 __glibcxx_function_requires(_BidirectionalIteratorConcept<
3604 _BidirectionalIterator>)
3605 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3606 typename iterator_traits<_BidirectionalIterator>::value_type,
3607 typename iterator_traits<_BidirectionalIterator>::value_type>)
3608 __glibcxx_requires_valid_range(__first, __last);
3609
3610 if (__first == __last)
3611 return false;
3612 _BidirectionalIterator __i = __first;
3613 ++__i;
3614 if (__i == __last)
3615 return false;
3616 __i = __last;
3617 --__i;
3618
3619 for(;;)
3620 {
3621 _BidirectionalIterator __ii = __i;
3622 --__i;
3623 if (__comp(*__i, *__ii))
3624 {
3625 _BidirectionalIterator __j = __last;
3626 while (!bool(__comp(*__i, *--__j)))
3627 {}
3628 std::iter_swap(__i, __j);
3629 std::reverse(__ii, __last);
3630 return true;
3631 }
3632 if (__i == __first)
3633 {
3634 std::reverse(__first, __last);
3635 return false;
3636 }
3637 }
3638 }
3639
3640 /**
3641 * @brief Permute range into the previous @a dictionary ordering.
3642 * @ingroup sorting_algorithms
3643 * @param first Start of range.
3644 * @param last End of range.
3645 * @return False if wrapped to last permutation, true otherwise.
3646 *
3647 * Treats all permutations of the range as a set of @a dictionary sorted
3648 * sequences. Permutes the current sequence into the previous one of this
3649 * set. Returns true if there are more sequences to generate. If the
3650 * sequence is the smallest of the set, the largest is generated and false
3651 * returned.
3652 */
3653 template<typename _BidirectionalIterator>
3654 bool
3655 prev_permutation(_BidirectionalIterator __first,
3656 _BidirectionalIterator __last)
3657 {
3658 // concept requirements
3659 __glibcxx_function_requires(_BidirectionalIteratorConcept<
3660 _BidirectionalIterator>)
3661 __glibcxx_function_requires(_LessThanComparableConcept<
3662 typename iterator_traits<_BidirectionalIterator>::value_type>)
3663 __glibcxx_requires_valid_range(__first, __last);
3664
3665 if (__first == __last)
3666 return false;
3667 _BidirectionalIterator __i = __first;
3668 ++__i;
3669 if (__i == __last)
3670 return false;
3671 __i = __last;
3672 --__i;
3673
3674 for(;;)
3675 {
3676 _BidirectionalIterator __ii = __i;
3677 --__i;
3678 if (*__ii < *__i)
3679 {
3680 _BidirectionalIterator __j = __last;
3681 while (!(*--__j < *__i))
3682 {}
3683 std::iter_swap(__i, __j);
3684 std::reverse(__ii, __last);
3685 return true;
3686 }
3687 if (__i == __first)
3688 {
3689 std::reverse(__first, __last);
3690 return false;
3691 }
3692 }
3693 }
3694
3695 /**
3696 * @brief Permute range into the previous @a dictionary ordering using
3697 * comparison functor.
3698 * @ingroup sorting_algorithms
3699 * @param first Start of range.
3700 * @param last End of range.
3701 * @param comp A comparison functor.
3702 * @return False if wrapped to last permutation, true otherwise.
3703 *
3704 * Treats all permutations of the range [first,last) as a set of
3705 * @a dictionary sorted sequences ordered by @a comp. Permutes the current
3706 * sequence into the previous one of this set. Returns true if there are
3707 * more sequences to generate. If the sequence is the smallest of the set,
3708 * the largest is generated and false returned.
3709 */
3710 template<typename _BidirectionalIterator, typename _Compare>
3711 bool
3712 prev_permutation(_BidirectionalIterator __first,
3713 _BidirectionalIterator __last, _Compare __comp)
3714 {
3715 // concept requirements
3716 __glibcxx_function_requires(_BidirectionalIteratorConcept<
3717 _BidirectionalIterator>)
3718 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3719 typename iterator_traits<_BidirectionalIterator>::value_type,
3720 typename iterator_traits<_BidirectionalIterator>::value_type>)
3721 __glibcxx_requires_valid_range(__first, __last);
3722
3723 if (__first == __last)
3724 return false;
3725 _BidirectionalIterator __i = __first;
3726 ++__i;
3727 if (__i == __last)
3728 return false;
3729 __i = __last;
3730 --__i;
3731
3732 for(;;)
3733 {
3734 _BidirectionalIterator __ii = __i;
3735 --__i;
3736 if (__comp(*__ii, *__i))
3737 {
3738 _BidirectionalIterator __j = __last;
3739 while (!bool(__comp(*--__j, *__i)))
3740 {}
3741 std::iter_swap(__i, __j);
3742 std::reverse(__ii, __last);
3743 return true;
3744 }
3745 if (__i == __first)
3746 {
3747 std::reverse(__first, __last);
3748 return false;
3749 }
3750 }
3751 }
3752
3753 // replace
3754 // replace_if
3755
3756 /**
3757 * @brief Copy a sequence, replacing each element of one value with another
3758 * value.
3759 * @param first An input iterator.
3760 * @param last An input iterator.
3761 * @param result An output iterator.
3762 * @param old_value The value to be replaced.
3763 * @param new_value The replacement value.
3764 * @return The end of the output sequence, @p result+(last-first).
3765 *
3766 * Copies each element in the input range @p [first,last) to the
3767 * output range @p [result,result+(last-first)) replacing elements
3768 * equal to @p old_value with @p new_value.
3769 */
3770 template<typename _InputIterator, typename _OutputIterator, typename _Tp>
3771 _OutputIterator
3772 replace_copy(_InputIterator __first, _InputIterator __last,
3773 _OutputIterator __result,
3774 const _Tp& __old_value, const _Tp& __new_value)
3775 {
3776 // concept requirements
3777 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
3778 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
3779 typename iterator_traits<_InputIterator>::value_type>)
3780 __glibcxx_function_requires(_EqualOpConcept<
3781 typename iterator_traits<_InputIterator>::value_type, _Tp>)
3782 __glibcxx_requires_valid_range(__first, __last);
3783
3784 for (; __first != __last; ++__first, ++__result)
3785 if (*__first == __old_value)
3786 *__result = __new_value;
3787 else
3788 *__result = *__first;
3789 return __result;
3790 }
3791
3792 /**
3793 * @brief Copy a sequence, replacing each value for which a predicate
3794 * returns true with another value.
3795 * @ingroup mutating_algorithms
3796 * @param first An input iterator.
3797 * @param last An input iterator.
3798 * @param result An output iterator.
3799 * @param pred A predicate.
3800 * @param new_value The replacement value.
3801 * @return The end of the output sequence, @p result+(last-first).
3802 *
3803 * Copies each element in the range @p [first,last) to the range
3804 * @p [result,result+(last-first)) replacing elements for which
3805 * @p pred returns true with @p new_value.
3806 */
3807 template<typename _InputIterator, typename _OutputIterator,
3808 typename _Predicate, typename _Tp>
3809 _OutputIterator
3810 replace_copy_if(_InputIterator __first, _InputIterator __last,
3811 _OutputIterator __result,
3812 _Predicate __pred, const _Tp& __new_value)
3813 {
3814 // concept requirements
3815 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
3816 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
3817 typename iterator_traits<_InputIterator>::value_type>)
3818 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
3819 typename iterator_traits<_InputIterator>::value_type>)
3820 __glibcxx_requires_valid_range(__first, __last);
3821
3822 for (; __first != __last; ++__first, ++__result)
3823 if (__pred(*__first))
3824 *__result = __new_value;
3825 else
3826 *__result = *__first;
3827 return __result;
3828 }
3829
3830 #ifdef __GXX_EXPERIMENTAL_CXX0X__
3831 /**
3832 * @brief Determines whether the elements of a sequence are sorted.
3833 * @ingroup sorting_algorithms
3834 * @param first An iterator.
3835 * @param last Another iterator.
3836 * @return True if the elements are sorted, false otherwise.
3837 */
3838 template<typename _ForwardIterator>
3839 inline bool
3840 is_sorted(_ForwardIterator __first, _ForwardIterator __last)
3841 { return std::is_sorted_until(__first, __last) == __last; }
3842
3843 /**
3844 * @brief Determines whether the elements of a sequence are sorted
3845 * according to a comparison functor.
3846 * @ingroup sorting_algorithms
3847 * @param first An iterator.
3848 * @param last Another iterator.
3849 * @param comp A comparison functor.
3850 * @return True if the elements are sorted, false otherwise.
3851 */
3852 template<typename _ForwardIterator, typename _Compare>
3853 inline bool
3854 is_sorted(_ForwardIterator __first, _ForwardIterator __last,
3855 _Compare __comp)
3856 { return std::is_sorted_until(__first, __last, __comp) == __last; }
3857
3858 /**
3859 * @brief Determines the end of a sorted sequence.
3860 * @ingroup sorting_algorithms
3861 * @param first An iterator.
3862 * @param last Another iterator.
3863 * @return An iterator pointing to the last iterator i in [first, last)
3864 * for which the range [first, i) is sorted.
3865 */
3866 template<typename _ForwardIterator>
3867 _ForwardIterator
3868 is_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
3869 {
3870 // concept requirements
3871 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3872 __glibcxx_function_requires(_LessThanComparableConcept<
3873 typename iterator_traits<_ForwardIterator>::value_type>)
3874 __glibcxx_requires_valid_range(__first, __last);
3875
3876 if (__first == __last)
3877 return __last;
3878
3879 _ForwardIterator __next = __first;
3880 for (++__next; __next != __last; __first = __next, ++__next)
3881 if (*__next < *__first)
3882 return __next;
3883 return __next;
3884 }
3885
3886 /**
3887 * @brief Determines the end of a sorted sequence using comparison functor.
3888 * @ingroup sorting_algorithms
3889 * @param first An iterator.
3890 * @param last Another iterator.
3891 * @param comp A comparison functor.
3892 * @return An iterator pointing to the last iterator i in [first, last)
3893 * for which the range [first, i) is sorted.
3894 */
3895 template<typename _ForwardIterator, typename _Compare>
3896 _ForwardIterator
3897 is_sorted_until(_ForwardIterator __first, _ForwardIterator __last,
3898 _Compare __comp)
3899 {
3900 // concept requirements
3901 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3902 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3903 typename iterator_traits<_ForwardIterator>::value_type,
3904 typename iterator_traits<_ForwardIterator>::value_type>)
3905 __glibcxx_requires_valid_range(__first, __last);
3906
3907 if (__first == __last)
3908 return __last;
3909
3910 _ForwardIterator __next = __first;
3911 for (++__next; __next != __last; __first = __next, ++__next)
3912 if (__comp(*__next, *__first))
3913 return __next;
3914 return __next;
3915 }
3916
3917 /**
3918 * @brief Determines min and max at once as an ordered pair.
3919 * @ingroup sorting_algorithms
3920 * @param a A thing of arbitrary type.
3921 * @param b Another thing of arbitrary type.
3922 * @return A pair(b, a) if b is smaller than a, pair(a, b) otherwise.
3923 */
3924 template<typename _Tp>
3925 inline pair<const _Tp&, const _Tp&>
3926 minmax(const _Tp& __a, const _Tp& __b)
3927 {
3928 // concept requirements
3929 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
3930
3931 return __b < __a ? pair<const _Tp&, const _Tp&>(__b, __a)
3932 : pair<const _Tp&, const _Tp&>(__a, __b);
3933 }
3934
3935 /**
3936 * @brief Determines min and max at once as an ordered pair.
3937 * @ingroup sorting_algorithms
3938 * @param a A thing of arbitrary type.
3939 * @param b Another thing of arbitrary type.
3940 * @param comp A @link comparison_functor comparison functor@endlink.
3941 * @return A pair(b, a) if b is smaller than a, pair(a, b) otherwise.
3942 */
3943 template<typename _Tp, typename _Compare>
3944 inline pair<const _Tp&, const _Tp&>
3945 minmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
3946 {
3947 return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a)
3948 : pair<const _Tp&, const _Tp&>(__a, __b);
3949 }
3950
3951 /**
3952 * @brief Return a pair of iterators pointing to the minimum and maximum
3953 * elements in a range.
3954 * @ingroup sorting_algorithms
3955 * @param first Start of range.
3956 * @param last End of range.
3957 * @return make_pair(m, M), where m is the first iterator i in
3958 * [first, last) such that no other element in the range is
3959 * smaller, and where M is the last iterator i in [first, last)
3960 * such that no other element in the range is larger.
3961 */
3962 template<typename _ForwardIterator>
3963 pair<_ForwardIterator, _ForwardIterator>
3964 minmax_element(_ForwardIterator __first, _ForwardIterator __last)
3965 {
3966 // concept requirements
3967 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3968 __glibcxx_function_requires(_LessThanComparableConcept<
3969 typename iterator_traits<_ForwardIterator>::value_type>)
3970 __glibcxx_requires_valid_range(__first, __last);
3971
3972 _ForwardIterator __next = __first;
3973 if (__first == __last
3974 || ++__next == __last)
3975 return std::make_pair(__first, __first);
3976
3977 _ForwardIterator __min, __max;
3978 if (*__next < *__first)
3979 {
3980 __min = __next;
3981 __max = __first;
3982 }
3983 else
3984 {
3985 __min = __first;
3986 __max = __next;
3987 }
3988
3989 __first = __next;
3990 ++__first;
3991
3992 while (__first != __last)
3993 {
3994 __next = __first;
3995 if (++__next == __last)
3996 {
3997 if (*__first < *__min)
3998 __min = __first;
3999 else if (!(*__first < *__max))
4000 __max = __first;
4001 break;
4002 }
4003
4004 if (*__next < *__first)
4005 {
4006 if (*__next < *__min)
4007 __min = __next;
4008 if (!(*__first < *__max))
4009 __max = __first;
4010 }
4011 else
4012 {
4013 if (*__first < *__min)
4014 __min = __first;
4015 if (!(*__next < *__max))
4016 __max = __next;
4017 }
4018
4019 __first = __next;
4020 ++__first;
4021 }
4022
4023 return std::make_pair(__min, __max);
4024 }
4025
4026 /**
4027 * @brief Return a pair of iterators pointing to the minimum and maximum
4028 * elements in a range.
4029 * @ingroup sorting_algorithms
4030 * @param first Start of range.
4031 * @param last End of range.
4032 * @param comp Comparison functor.
4033 * @return make_pair(m, M), where m is the first iterator i in
4034 * [first, last) such that no other element in the range is
4035 * smaller, and where M is the last iterator i in [first, last)
4036 * such that no other element in the range is larger.
4037 */
4038 template<typename _ForwardIterator, typename _Compare>
4039 pair<_ForwardIterator, _ForwardIterator>
4040 minmax_element(_ForwardIterator __first, _ForwardIterator __last,
4041 _Compare __comp)
4042 {
4043 // concept requirements
4044 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4045 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4046 typename iterator_traits<_ForwardIterator>::value_type,
4047 typename iterator_traits<_ForwardIterator>::value_type>)
4048 __glibcxx_requires_valid_range(__first, __last);
4049
4050 _ForwardIterator __next = __first;
4051 if (__first == __last
4052 || ++__next == __last)
4053 return std::make_pair(__first, __first);
4054
4055 _ForwardIterator __min, __max;
4056 if (__comp(*__next, *__first))
4057 {
4058 __min = __next;
4059 __max = __first;
4060 }
4061 else
4062 {
4063 __min = __first;
4064 __max = __next;
4065 }
4066
4067 __first = __next;
4068 ++__first;
4069
4070 while (__first != __last)
4071 {
4072 __next = __first;
4073 if (++__next == __last)
4074 {
4075 if (__comp(*__first, *__min))
4076 __min = __first;
4077 else if (!__comp(*__first, *__max))
4078 __max = __first;
4079 break;
4080 }
4081
4082 if (__comp(*__next, *__first))
4083 {
4084 if (__comp(*__next, *__min))
4085 __min = __next;
4086 if (!__comp(*__first, *__max))
4087 __max = __first;
4088 }
4089 else
4090 {
4091 if (__comp(*__first, *__min))
4092 __min = __first;
4093 if (!__comp(*__next, *__max))
4094 __max = __next;
4095 }
4096
4097 __first = __next;
4098 ++__first;
4099 }
4100
4101 return std::make_pair(__min, __max);
4102 }
4103
4104 // N2722 + DR 915.
4105 template<typename _Tp>
4106 inline _Tp
4107 min(initializer_list<_Tp> __l)
4108 { return *std::min_element(__l.begin(), __l.end()); }
4109
4110 template<typename _Tp, typename _Compare>
4111 inline _Tp
4112 min(initializer_list<_Tp> __l, _Compare __comp)
4113 { return *std::min_element(__l.begin(), __l.end(), __comp); }
4114
4115 template<typename _Tp>
4116 inline _Tp
4117 max(initializer_list<_Tp> __l)
4118 { return *std::max_element(__l.begin(), __l.end()); }
4119
4120 template<typename _Tp, typename _Compare>
4121 inline _Tp
4122 max(initializer_list<_Tp> __l, _Compare __comp)
4123 { return *std::max_element(__l.begin(), __l.end(), __comp); }
4124
4125 template<typename _Tp>
4126 inline pair<_Tp, _Tp>
4127 minmax(initializer_list<_Tp> __l)
4128 {
4129 pair<const _Tp*, const _Tp*> __p =
4130 std::minmax_element(__l.begin(), __l.end());
4131 return std::make_pair(*__p.first, *__p.second);
4132 }
4133
4134 template<typename _Tp, typename _Compare>
4135 inline pair<_Tp, _Tp>
4136 minmax(initializer_list<_Tp> __l, _Compare __comp)
4137 {
4138 pair<const _Tp*, const _Tp*> __p =
4139 std::minmax_element(__l.begin(), __l.end(), __comp);
4140 return std::make_pair(*__p.first, *__p.second);
4141 }
4142
4143 /**
4144 * @brief Checks whether a permutaion of the second sequence is equal
4145 * to the first sequence.
4146 * @ingroup non_mutating_algorithms
4147 * @param first1 Start of first range.
4148 * @param last1 End of first range.
4149 * @param first2 Start of second range.
4150 * @return true if there exists a permutation of the elements in the range
4151 * [first2, first2 + (last1 - first1)), beginning with
4152 * ForwardIterator2 begin, such that equal(first1, last1, begin)
4153 * returns true; otherwise, returns false.
4154 */
4155 template<typename _ForwardIterator1, typename _ForwardIterator2>
4156 bool
4157 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4158 _ForwardIterator2 __first2)
4159 {
4160 // Efficiently compare identical prefixes: O(N) if sequences
4161 // have the same elements in the same order.
4162 for (; __first1 != __last1; ++__first1, ++__first2)
4163 if (!(*__first1 == *__first2))
4164 break;
4165
4166 if (__first1 == __last1)
4167 return true;
4168
4169 // Establish __last2 assuming equal ranges by iterating over the
4170 // rest of the list.
4171 _ForwardIterator2 __last2 = __first2;
4172 std::advance(__last2, std::distance(__first1, __last1));
4173 for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan)
4174 {
4175 if (__scan != _GLIBCXX_STD_A::find(__first1, __scan, *__scan))
4176 continue; // We've seen this one before.
4177
4178 auto __matches = std::count(__first2, __last2, *__scan);
4179 if (0 == __matches
4180 || std::count(__scan, __last1, *__scan) != __matches)
4181 return false;
4182 }
4183 return true;
4184 }
4185
4186 /**
4187 * @brief Checks whether a permutation of the second sequence is equal
4188 * to the first sequence.
4189 * @ingroup non_mutating_algorithms
4190 * @param first1 Start of first range.
4191 * @param last1 End of first range.
4192 * @param first2 Start of second range.
4193 * @param pred A binary predicate.
4194 * @return true if there exists a permutation of the elements in the range
4195 * [first2, first2 + (last1 - first1)), beginning with
4196 * ForwardIterator2 begin, such that equal(first1, last1, begin,
4197 * pred) returns true; otherwise, returns false.
4198 */
4199 template<typename _ForwardIterator1, typename _ForwardIterator2,
4200 typename _BinaryPredicate>
4201 bool
4202 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4203 _ForwardIterator2 __first2, _BinaryPredicate __pred)
4204 {
4205 // Efficiently compare identical prefixes: O(N) if sequences
4206 // have the same elements in the same order.
4207 for (; __first1 != __last1; ++__first1, ++__first2)
4208 if (!bool(__pred(*__first1, *__first2)))
4209 break;
4210
4211 if (__first1 == __last1)
4212 return true;
4213
4214 // Establish __last2 assuming equal ranges by iterating over the
4215 // rest of the list.
4216 _ForwardIterator2 __last2 = __first2;
4217 std::advance(__last2, std::distance(__first1, __last1));
4218 for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan)
4219 {
4220 using std::placeholders::_1;
4221
4222 if (__scan != _GLIBCXX_STD_A::find_if(__first1, __scan,
4223 std::bind(__pred, _1, *__scan)))
4224 continue; // We've seen this one before.
4225
4226 auto __matches = std::count_if(__first2, __last2,
4227 std::bind(__pred, _1, *__scan));
4228 if (0 == __matches
4229 || std::count_if(__scan, __last1,
4230 std::bind(__pred, _1, *__scan)) != __matches)
4231 return false;
4232 }
4233 return true;
4234 }
4235
4236 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
4237 /**
4238 * @brief Shuffle the elements of a sequence using a uniform random
4239 * number generator.
4240 * @ingroup mutating_algorithms
4241 * @param first A forward iterator.
4242 * @param last A forward iterator.
4243 * @param g A UniformRandomNumberGenerator (26.5.1.3).
4244 * @return Nothing.
4245 *
4246 * Reorders the elements in the range @p [first,last) using @p g to
4247 * provide random numbers.
4248 */
4249 template<typename _RandomAccessIterator,
4250 typename _UniformRandomNumberGenerator>
4251 void
4252 shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
4253 _UniformRandomNumberGenerator&& __g)
4254 {
4255 // concept requirements
4256 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
4257 _RandomAccessIterator>)
4258 __glibcxx_requires_valid_range(__first, __last);
4259
4260 if (__first == __last)
4261 return;
4262
4263 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
4264 _DistanceType;
4265
4266 typedef typename std::make_unsigned<_DistanceType>::type __ud_type;
4267 typedef typename std::uniform_int_distribution<__ud_type> __distr_type;
4268 typedef typename __distr_type::param_type __p_type;
4269 __distr_type __d;
4270
4271 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
4272 std::iter_swap(__i, __first + __d(__g, __p_type(0, __i - __first)));
4273 }
4274 #endif
4275
4276 #endif // __GXX_EXPERIMENTAL_CXX0X__
4277
4278 _GLIBCXX_END_NAMESPACE_VERSION
4279
4280 _GLIBCXX_BEGIN_NAMESPACE_ALGO
4281
4282 /**
4283 * @brief Apply a function to every element of a sequence.
4284 * @ingroup non_mutating_algorithms
4285 * @param first An input iterator.
4286 * @param last An input iterator.
4287 * @param f A unary function object.
4288 * @return @p f (std::move(@p f) in C++0x).
4289 *
4290 * Applies the function object @p f to each element in the range
4291 * @p [first,last). @p f must not modify the order of the sequence.
4292 * If @p f has a return value it is ignored.
4293 */
4294 template<typename _InputIterator, typename _Function>
4295 _Function
4296 for_each(_InputIterator __first, _InputIterator __last, _Function __f)
4297 {
4298 // concept requirements
4299 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4300 __glibcxx_requires_valid_range(__first, __last);
4301 for (; __first != __last; ++__first)
4302 __f(*__first);
4303 return _GLIBCXX_MOVE(__f);
4304 }
4305
4306 /**
4307 * @brief Find the first occurrence of a value in a sequence.
4308 * @ingroup non_mutating_algorithms
4309 * @param first An input iterator.
4310 * @param last An input iterator.
4311 * @param val The value to find.
4312 * @return The first iterator @c i in the range @p [first,last)
4313 * such that @c *i == @p val, or @p last if no such iterator exists.
4314 */
4315 template<typename _InputIterator, typename _Tp>
4316 inline _InputIterator
4317 find(_InputIterator __first, _InputIterator __last,
4318 const _Tp& __val)
4319 {
4320 // concept requirements
4321 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4322 __glibcxx_function_requires(_EqualOpConcept<
4323 typename iterator_traits<_InputIterator>::value_type, _Tp>)
4324 __glibcxx_requires_valid_range(__first, __last);
4325 return std::__find(__first, __last, __val,
4326 std::__iterator_category(__first));
4327 }
4328
4329 /**
4330 * @brief Find the first element in a sequence for which a
4331 * predicate is true.
4332 * @ingroup non_mutating_algorithms
4333 * @param first An input iterator.
4334 * @param last An input iterator.
4335 * @param pred A predicate.
4336 * @return The first iterator @c i in the range @p [first,last)
4337 * such that @p pred(*i) is true, or @p last if no such iterator exists.
4338 */
4339 template<typename _InputIterator, typename _Predicate>
4340 inline _InputIterator
4341 find_if(_InputIterator __first, _InputIterator __last,
4342 _Predicate __pred)
4343 {
4344 // concept requirements
4345 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4346 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
4347 typename iterator_traits<_InputIterator>::value_type>)
4348 __glibcxx_requires_valid_range(__first, __last);
4349 return std::__find_if(__first, __last, __pred,
4350 std::__iterator_category(__first));
4351 }
4352
4353 /**
4354 * @brief Find element from a set in a sequence.
4355 * @ingroup non_mutating_algorithms
4356 * @param first1 Start of range to search.
4357 * @param last1 End of range to search.
4358 * @param first2 Start of match candidates.
4359 * @param last2 End of match candidates.
4360 * @return The first iterator @c i in the range
4361 * @p [first1,last1) such that @c *i == @p *(i2) such that i2 is an
4362 * iterator in [first2,last2), or @p last1 if no such iterator exists.
4363 *
4364 * Searches the range @p [first1,last1) for an element that is equal to
4365 * some element in the range [first2,last2). If found, returns an iterator
4366 * in the range [first1,last1), otherwise returns @p last1.
4367 */
4368 template<typename _InputIterator, typename _ForwardIterator>
4369 _InputIterator
4370 find_first_of(_InputIterator __first1, _InputIterator __last1,
4371 _ForwardIterator __first2, _ForwardIterator __last2)
4372 {
4373 // concept requirements
4374 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4375 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4376 __glibcxx_function_requires(_EqualOpConcept<
4377 typename iterator_traits<_InputIterator>::value_type,
4378 typename iterator_traits<_ForwardIterator>::value_type>)
4379 __glibcxx_requires_valid_range(__first1, __last1);
4380 __glibcxx_requires_valid_range(__first2, __last2);
4381
4382 for (; __first1 != __last1; ++__first1)
4383 for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter)
4384 if (*__first1 == *__iter)
4385 return __first1;
4386 return __last1;
4387 }
4388
4389 /**
4390 * @brief Find element from a set in a sequence using a predicate.
4391 * @ingroup non_mutating_algorithms
4392 * @param first1 Start of range to search.
4393 * @param last1 End of range to search.
4394 * @param first2 Start of match candidates.
4395 * @param last2 End of match candidates.
4396 * @param comp Predicate to use.
4397 * @return The first iterator @c i in the range
4398 * @p [first1,last1) such that @c comp(*i, @p *(i2)) is true and i2 is an
4399 * iterator in [first2,last2), or @p last1 if no such iterator exists.
4400 *
4401
4402 * Searches the range @p [first1,last1) for an element that is
4403 * equal to some element in the range [first2,last2). If found,
4404 * returns an iterator in the range [first1,last1), otherwise
4405 * returns @p last1.
4406 */
4407 template<typename _InputIterator, typename _ForwardIterator,
4408 typename _BinaryPredicate>
4409 _InputIterator
4410 find_first_of(_InputIterator __first1, _InputIterator __last1,
4411 _ForwardIterator __first2, _ForwardIterator __last2,
4412 _BinaryPredicate __comp)
4413 {
4414 // concept requirements
4415 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4416 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4417 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4418 typename iterator_traits<_InputIterator>::value_type,
4419 typename iterator_traits<_ForwardIterator>::value_type>)
4420 __glibcxx_requires_valid_range(__first1, __last1);
4421 __glibcxx_requires_valid_range(__first2, __last2);
4422
4423 for (; __first1 != __last1; ++__first1)
4424 for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter)
4425 if (__comp(*__first1, *__iter))
4426 return __first1;
4427 return __last1;
4428 }
4429
4430 /**
4431 * @brief Find two adjacent values in a sequence that are equal.
4432 * @ingroup non_mutating_algorithms
4433 * @param first A forward iterator.
4434 * @param last A forward iterator.
4435 * @return The first iterator @c i such that @c i and @c i+1 are both
4436 * valid iterators in @p [first,last) and such that @c *i == @c *(i+1),
4437 * or @p last if no such iterator exists.
4438 */
4439 template<typename _ForwardIterator>
4440 _ForwardIterator
4441 adjacent_find(_ForwardIterator __first, _ForwardIterator __last)
4442 {
4443 // concept requirements
4444 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4445 __glibcxx_function_requires(_EqualityComparableConcept<
4446 typename iterator_traits<_ForwardIterator>::value_type>)
4447 __glibcxx_requires_valid_range(__first, __last);
4448 if (__first == __last)
4449 return __last;
4450 _ForwardIterator __next = __first;
4451 while(++__next != __last)
4452 {
4453 if (*__first == *__next)
4454 return __first;
4455 __first = __next;
4456 }
4457 return __last;
4458 }
4459
4460 /**
4461 * @brief Find two adjacent values in a sequence using a predicate.
4462 * @ingroup non_mutating_algorithms
4463 * @param first A forward iterator.
4464 * @param last A forward iterator.
4465 * @param binary_pred A binary predicate.
4466 * @return The first iterator @c i such that @c i and @c i+1 are both
4467 * valid iterators in @p [first,last) and such that
4468 * @p binary_pred(*i,*(i+1)) is true, or @p last if no such iterator
4469 * exists.
4470 */
4471 template<typename _ForwardIterator, typename _BinaryPredicate>
4472 _ForwardIterator
4473 adjacent_find(_ForwardIterator __first, _ForwardIterator __last,
4474 _BinaryPredicate __binary_pred)
4475 {
4476 // concept requirements
4477 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4478 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4479 typename iterator_traits<_ForwardIterator>::value_type,
4480 typename iterator_traits<_ForwardIterator>::value_type>)
4481 __glibcxx_requires_valid_range(__first, __last);
4482 if (__first == __last)
4483 return __last;
4484 _ForwardIterator __next = __first;
4485 while(++__next != __last)
4486 {
4487 if (__binary_pred(*__first, *__next))
4488 return __first;
4489 __first = __next;
4490 }
4491 return __last;
4492 }
4493
4494 /**
4495 * @brief Count the number of copies of a value in a sequence.
4496 * @ingroup non_mutating_algorithms
4497 * @param first An input iterator.
4498 * @param last An input iterator.
4499 * @param value The value to be counted.
4500 * @return The number of iterators @c i in the range @p [first,last)
4501 * for which @c *i == @p value
4502 */
4503 template<typename _InputIterator, typename _Tp>
4504 typename iterator_traits<_InputIterator>::difference_type
4505 count(_InputIterator __first, _InputIterator __last, const _Tp& __value)
4506 {
4507 // concept requirements
4508 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4509 __glibcxx_function_requires(_EqualOpConcept<
4510 typename iterator_traits<_InputIterator>::value_type, _Tp>)
4511 __glibcxx_requires_valid_range(__first, __last);
4512 typename iterator_traits<_InputIterator>::difference_type __n = 0;
4513 for (; __first != __last; ++__first)
4514 if (*__first == __value)
4515 ++__n;
4516 return __n;
4517 }
4518
4519 /**
4520 * @brief Count the elements of a sequence for which a predicate is true.
4521 * @ingroup non_mutating_algorithms
4522 * @param first An input iterator.
4523 * @param last An input iterator.
4524 * @param pred A predicate.
4525 * @return The number of iterators @c i in the range @p [first,last)
4526 * for which @p pred(*i) is true.
4527 */
4528 template<typename _InputIterator, typename _Predicate>
4529 typename iterator_traits<_InputIterator>::difference_type
4530 count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
4531 {
4532 // concept requirements
4533 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4534 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
4535 typename iterator_traits<_InputIterator>::value_type>)
4536 __glibcxx_requires_valid_range(__first, __last);
4537 typename iterator_traits<_InputIterator>::difference_type __n = 0;
4538 for (; __first != __last; ++__first)
4539 if (__pred(*__first))
4540 ++__n;
4541 return __n;
4542 }
4543
4544 /**
4545 * @brief Search a sequence for a matching sub-sequence.
4546 * @ingroup non_mutating_algorithms
4547 * @param first1 A forward iterator.
4548 * @param last1 A forward iterator.
4549 * @param first2 A forward iterator.
4550 * @param last2 A forward iterator.
4551 * @return The first iterator @c i in the range
4552 * @p [first1,last1-(last2-first2)) such that @c *(i+N) == @p *(first2+N)
4553 * for each @c N in the range @p [0,last2-first2), or @p last1 if no
4554 * such iterator exists.
4555 *
4556 * Searches the range @p [first1,last1) for a sub-sequence that compares
4557 * equal value-by-value with the sequence given by @p [first2,last2) and
4558 * returns an iterator to the first element of the sub-sequence, or
4559 * @p last1 if the sub-sequence is not found.
4560 *
4561 * Because the sub-sequence must lie completely within the range
4562 * @p [first1,last1) it must start at a position less than
4563 * @p last1-(last2-first2) where @p last2-first2 is the length of the
4564 * sub-sequence.
4565 * This means that the returned iterator @c i will be in the range
4566 * @p [first1,last1-(last2-first2))
4567 */
4568 template<typename _ForwardIterator1, typename _ForwardIterator2>
4569 _ForwardIterator1
4570 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4571 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
4572 {
4573 // concept requirements
4574 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
4575 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
4576 __glibcxx_function_requires(_EqualOpConcept<
4577 typename iterator_traits<_ForwardIterator1>::value_type,
4578 typename iterator_traits<_ForwardIterator2>::value_type>)
4579 __glibcxx_requires_valid_range(__first1, __last1);
4580 __glibcxx_requires_valid_range(__first2, __last2);
4581
4582 // Test for empty ranges
4583 if (__first1 == __last1 || __first2 == __last2)
4584 return __first1;
4585
4586 // Test for a pattern of length 1.
4587 _ForwardIterator2 __p1(__first2);
4588 if (++__p1 == __last2)
4589 return _GLIBCXX_STD_A::find(__first1, __last1, *__first2);
4590
4591 // General case.
4592 _ForwardIterator2 __p;
4593 _ForwardIterator1 __current = __first1;
4594
4595 for (;;)
4596 {
4597 __first1 = _GLIBCXX_STD_A::find(__first1, __last1, *__first2);
4598 if (__first1 == __last1)
4599 return __last1;
4600
4601 __p = __p1;
4602 __current = __first1;
4603 if (++__current == __last1)
4604 return __last1;
4605
4606 while (*__current == *__p)
4607 {
4608 if (++__p == __last2)
4609 return __first1;
4610 if (++__current == __last1)
4611 return __last1;
4612 }
4613 ++__first1;
4614 }
4615 return __first1;
4616 }
4617
4618 /**
4619 * @brief Search a sequence for a matching sub-sequence using a predicate.
4620 * @ingroup non_mutating_algorithms
4621 * @param first1 A forward iterator.
4622 * @param last1 A forward iterator.
4623 * @param first2 A forward iterator.
4624 * @param last2 A forward iterator.
4625 * @param predicate A binary predicate.
4626 * @return The first iterator @c i in the range
4627 * @p [first1,last1-(last2-first2)) such that
4628 * @p predicate(*(i+N),*(first2+N)) is true for each @c N in the range
4629 * @p [0,last2-first2), or @p last1 if no such iterator exists.
4630 *
4631 * Searches the range @p [first1,last1) for a sub-sequence that compares
4632 * equal value-by-value with the sequence given by @p [first2,last2),
4633 * using @p predicate to determine equality, and returns an iterator
4634 * to the first element of the sub-sequence, or @p last1 if no such
4635 * iterator exists.
4636 *
4637 * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2)
4638 */
4639 template<typename _ForwardIterator1, typename _ForwardIterator2,
4640 typename _BinaryPredicate>
4641 _ForwardIterator1
4642 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4643 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
4644 _BinaryPredicate __predicate)
4645 {
4646 // concept requirements
4647 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
4648 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
4649 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4650 typename iterator_traits<_ForwardIterator1>::value_type,
4651 typename iterator_traits<_ForwardIterator2>::value_type>)
4652 __glibcxx_requires_valid_range(__first1, __last1);
4653 __glibcxx_requires_valid_range(__first2, __last2);
4654
4655 // Test for empty ranges
4656 if (__first1 == __last1 || __first2 == __last2)
4657 return __first1;
4658
4659 // Test for a pattern of length 1.
4660 _ForwardIterator2 __p1(__first2);
4661 if (++__p1 == __last2)
4662 {
4663 while (__first1 != __last1
4664 && !bool(__predicate(*__first1, *__first2)))
4665 ++__first1;
4666 return __first1;
4667 }
4668
4669 // General case.
4670 _ForwardIterator2 __p;
4671 _ForwardIterator1 __current = __first1;
4672
4673 for (;;)
4674 {
4675 while (__first1 != __last1
4676 && !bool(__predicate(*__first1, *__first2)))
4677 ++__first1;
4678 if (__first1 == __last1)
4679 return __last1;
4680
4681 __p = __p1;
4682 __current = __first1;
4683 if (++__current == __last1)
4684 return __last1;
4685
4686 while (__predicate(*__current, *__p))
4687 {
4688 if (++__p == __last2)
4689 return __first1;
4690 if (++__current == __last1)
4691 return __last1;
4692 }
4693 ++__first1;
4694 }
4695 return __first1;
4696 }
4697
4698
4699 /**
4700 * @brief Search a sequence for a number of consecutive values.
4701 * @ingroup non_mutating_algorithms
4702 * @param first A forward iterator.
4703 * @param last A forward iterator.
4704 * @param count The number of consecutive values.
4705 * @param val The value to find.
4706 * @return The first iterator @c i in the range @p [first,last-count)
4707 * such that @c *(i+N) == @p val for each @c N in the range @p [0,count),
4708 * or @p last if no such iterator exists.
4709 *
4710 * Searches the range @p [first,last) for @p count consecutive elements
4711 * equal to @p val.
4712 */
4713 template<typename _ForwardIterator, typename _Integer, typename _Tp>
4714 _ForwardIterator
4715 search_n(_ForwardIterator __first, _ForwardIterator __last,
4716 _Integer __count, const _Tp& __val)
4717 {
4718 // concept requirements
4719 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4720 __glibcxx_function_requires(_EqualOpConcept<
4721 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
4722 __glibcxx_requires_valid_range(__first, __last);
4723
4724 if (__count <= 0)
4725 return __first;
4726 if (__count == 1)
4727 return _GLIBCXX_STD_A::find(__first, __last, __val);
4728 return std::__search_n(__first, __last, __count, __val,
4729 std::__iterator_category(__first));
4730 }
4731
4732
4733 /**
4734 * @brief Search a sequence for a number of consecutive values using a
4735 * predicate.
4736 * @ingroup non_mutating_algorithms
4737 * @param first A forward iterator.
4738 * @param last A forward iterator.
4739 * @param count The number of consecutive values.
4740 * @param val The value to find.
4741 * @param binary_pred A binary predicate.
4742 * @return The first iterator @c i in the range @p [first,last-count)
4743 * such that @p binary_pred(*(i+N),val) is true for each @c N in the
4744 * range @p [0,count), or @p last if no such iterator exists.
4745 *
4746 * Searches the range @p [first,last) for @p count consecutive elements
4747 * for which the predicate returns true.
4748 */
4749 template<typename _ForwardIterator, typename _Integer, typename _Tp,
4750 typename _BinaryPredicate>
4751 _ForwardIterator
4752 search_n(_ForwardIterator __first, _ForwardIterator __last,
4753 _Integer __count, const _Tp& __val,
4754 _BinaryPredicate __binary_pred)
4755 {
4756 // concept requirements
4757 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4758 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4759 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
4760 __glibcxx_requires_valid_range(__first, __last);
4761
4762 if (__count <= 0)
4763 return __first;
4764 if (__count == 1)
4765 {
4766 while (__first != __last && !bool(__binary_pred(*__first, __val)))
4767 ++__first;
4768 return __first;
4769 }
4770 return std::__search_n(__first, __last, __count, __val, __binary_pred,
4771 std::__iterator_category(__first));
4772 }
4773
4774
4775 /**
4776 * @brief Perform an operation on a sequence.
4777 * @ingroup mutating_algorithms
4778 * @param first An input iterator.
4779 * @param last An input iterator.
4780 * @param result An output iterator.
4781 * @param unary_op A unary operator.
4782 * @return An output iterator equal to @p result+(last-first).
4783 *
4784 * Applies the operator to each element in the input range and assigns
4785 * the results to successive elements of the output sequence.
4786 * Evaluates @p *(result+N)=unary_op(*(first+N)) for each @c N in the
4787 * range @p [0,last-first).
4788 *
4789 * @p unary_op must not alter its argument.
4790 */
4791 template<typename _InputIterator, typename _OutputIterator,
4792 typename _UnaryOperation>
4793 _OutputIterator
4794 transform(_InputIterator __first, _InputIterator __last,
4795 _OutputIterator __result, _UnaryOperation __unary_op)
4796 {
4797 // concept requirements
4798 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4799 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4800 // "the type returned by a _UnaryOperation"
4801 __typeof__(__unary_op(*__first))>)
4802 __glibcxx_requires_valid_range(__first, __last);
4803
4804 for (; __first != __last; ++__first, ++__result)
4805 *__result = __unary_op(*__first);
4806 return __result;
4807 }
4808
4809 /**
4810 * @brief Perform an operation on corresponding elements of two sequences.
4811 * @ingroup mutating_algorithms
4812 * @param first1 An input iterator.
4813 * @param last1 An input iterator.
4814 * @param first2 An input iterator.
4815 * @param result An output iterator.
4816 * @param binary_op A binary operator.
4817 * @return An output iterator equal to @p result+(last-first).
4818 *
4819 * Applies the operator to the corresponding elements in the two
4820 * input ranges and assigns the results to successive elements of the
4821 * output sequence.
4822 * Evaluates @p *(result+N)=binary_op(*(first1+N),*(first2+N)) for each
4823 * @c N in the range @p [0,last1-first1).
4824 *
4825 * @p binary_op must not alter either of its arguments.
4826 */
4827 template<typename _InputIterator1, typename _InputIterator2,
4828 typename _OutputIterator, typename _BinaryOperation>
4829 _OutputIterator
4830 transform(_InputIterator1 __first1, _InputIterator1 __last1,
4831 _InputIterator2 __first2, _OutputIterator __result,
4832 _BinaryOperation __binary_op)
4833 {
4834 // concept requirements
4835 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4836 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4837 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4838 // "the type returned by a _BinaryOperation"
4839 __typeof__(__binary_op(*__first1,*__first2))>)
4840 __glibcxx_requires_valid_range(__first1, __last1);
4841
4842 for (; __first1 != __last1; ++__first1, ++__first2, ++__result)
4843 *__result = __binary_op(*__first1, *__first2);
4844 return __result;
4845 }
4846
4847 /**
4848 * @brief Replace each occurrence of one value in a sequence with another
4849 * value.
4850 * @ingroup mutating_algorithms
4851 * @param first A forward iterator.
4852 * @param last A forward iterator.
4853 * @param old_value The value to be replaced.
4854 * @param new_value The replacement value.
4855 * @return replace() returns no value.
4856 *
4857 * For each iterator @c i in the range @p [first,last) if @c *i ==
4858 * @p old_value then the assignment @c *i = @p new_value is performed.
4859 */
4860 template<typename _ForwardIterator, typename _Tp>
4861 void
4862 replace(_ForwardIterator __first, _ForwardIterator __last,
4863 const _Tp& __old_value, const _Tp& __new_value)
4864 {
4865 // concept requirements
4866 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
4867 _ForwardIterator>)
4868 __glibcxx_function_requires(_EqualOpConcept<
4869 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
4870 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
4871 typename iterator_traits<_ForwardIterator>::value_type>)
4872 __glibcxx_requires_valid_range(__first, __last);
4873
4874 for (; __first != __last; ++__first)
4875 if (*__first == __old_value)
4876 *__first = __new_value;
4877 }
4878
4879 /**
4880 * @brief Replace each value in a sequence for which a predicate returns
4881 * true with another value.
4882 * @ingroup mutating_algorithms
4883 * @param first A forward iterator.
4884 * @param last A forward iterator.
4885 * @param pred A predicate.
4886 * @param new_value The replacement value.
4887 * @return replace_if() returns no value.
4888 *
4889 * For each iterator @c i in the range @p [first,last) if @p pred(*i)
4890 * is true then the assignment @c *i = @p new_value is performed.
4891 */
4892 template<typename _ForwardIterator, typename _Predicate, typename _Tp>
4893 void
4894 replace_if(_ForwardIterator __first, _ForwardIterator __last,
4895 _Predicate __pred, const _Tp& __new_value)
4896 {
4897 // concept requirements
4898 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
4899 _ForwardIterator>)
4900 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
4901 typename iterator_traits<_ForwardIterator>::value_type>)
4902 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
4903 typename iterator_traits<_ForwardIterator>::value_type>)
4904 __glibcxx_requires_valid_range(__first, __last);
4905
4906 for (; __first != __last; ++__first)
4907 if (__pred(*__first))
4908 *__first = __new_value;
4909 }
4910
4911 /**
4912 * @brief Assign the result of a function object to each value in a
4913 * sequence.
4914 * @ingroup mutating_algorithms
4915 * @param first A forward iterator.
4916 * @param last A forward iterator.
4917 * @param gen A function object taking no arguments and returning
4918 * std::iterator_traits<_ForwardIterator>::value_type
4919 * @return generate() returns no value.
4920 *
4921 * Performs the assignment @c *i = @p gen() for each @c i in the range
4922 * @p [first,last).
4923 */
4924 template<typename _ForwardIterator, typename _Generator>
4925 void
4926 generate(_ForwardIterator __first, _ForwardIterator __last,
4927 _Generator __gen)
4928 {
4929 // concept requirements
4930 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4931 __glibcxx_function_requires(_GeneratorConcept<_Generator,
4932 typename iterator_traits<_ForwardIterator>::value_type>)
4933 __glibcxx_requires_valid_range(__first, __last);
4934
4935 for (; __first != __last; ++__first)
4936 *__first = __gen();
4937 }
4938
4939 /**
4940 * @brief Assign the result of a function object to each value in a
4941 * sequence.
4942 * @ingroup mutating_algorithms
4943 * @param first A forward iterator.
4944 * @param n The length of the sequence.
4945 * @param gen A function object taking no arguments and returning
4946 * std::iterator_traits<_ForwardIterator>::value_type
4947 * @return The end of the sequence, @p first+n
4948 *
4949 * Performs the assignment @c *i = @p gen() for each @c i in the range
4950 * @p [first,first+n).
4951 *
4952 * _GLIBCXX_RESOLVE_LIB_DEFECTS
4953 * DR 865. More algorithms that throw away information
4954 */
4955 template<typename _OutputIterator, typename _Size, typename _Generator>
4956 _OutputIterator
4957 generate_n(_OutputIterator __first, _Size __n, _Generator __gen)
4958 {
4959 // concept requirements
4960 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4961 // "the type returned by a _Generator"
4962 __typeof__(__gen())>)
4963
4964 for (__decltype(__n + 0) __niter = __n;
4965 __niter > 0; --__niter, ++__first)
4966 *__first = __gen();
4967 return __first;
4968 }
4969
4970
4971 /**
4972 * @brief Copy a sequence, removing consecutive duplicate values.
4973 * @ingroup mutating_algorithms
4974 * @param first An input iterator.
4975 * @param last An input iterator.
4976 * @param result An output iterator.
4977 * @return An iterator designating the end of the resulting sequence.
4978 *
4979 * Copies each element in the range @p [first,last) to the range
4980 * beginning at @p result, except that only the first element is copied
4981 * from groups of consecutive elements that compare equal.
4982 * unique_copy() is stable, so the relative order of elements that are
4983 * copied is unchanged.
4984 *
4985 * _GLIBCXX_RESOLVE_LIB_DEFECTS
4986 * DR 241. Does unique_copy() require CopyConstructible and Assignable?
4987 *
4988 * _GLIBCXX_RESOLVE_LIB_DEFECTS
4989 * DR 538. 241 again: Does unique_copy() require CopyConstructible and
4990 * Assignable?
4991 */
4992 template<typename _InputIterator, typename _OutputIterator>
4993 inline _OutputIterator
4994 unique_copy(_InputIterator __first, _InputIterator __last,
4995 _OutputIterator __result)
4996 {
4997 // concept requirements
4998 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4999 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5000 typename iterator_traits<_InputIterator>::value_type>)
5001 __glibcxx_function_requires(_EqualityComparableConcept<
5002 typename iterator_traits<_InputIterator>::value_type>)
5003 __glibcxx_requires_valid_range(__first, __last);
5004
5005 if (__first == __last)
5006 return __result;
5007 return std::__unique_copy(__first, __last, __result,
5008 std::__iterator_category(__first),
5009 std::__iterator_category(__result));
5010 }
5011
5012 /**
5013 * @brief Copy a sequence, removing consecutive values using a predicate.
5014 * @ingroup mutating_algorithms
5015 * @param first An input iterator.
5016 * @param last An input iterator.
5017 * @param result An output iterator.
5018 * @param binary_pred A binary predicate.
5019 * @return An iterator designating the end of the resulting sequence.
5020 *
5021 * Copies each element in the range @p [first,last) to the range
5022 * beginning at @p result, except that only the first element is copied
5023 * from groups of consecutive elements for which @p binary_pred returns
5024 * true.
5025 * unique_copy() is stable, so the relative order of elements that are
5026 * copied is unchanged.
5027 *
5028 * _GLIBCXX_RESOLVE_LIB_DEFECTS
5029 * DR 241. Does unique_copy() require CopyConstructible and Assignable?
5030 */
5031 template<typename _InputIterator, typename _OutputIterator,
5032 typename _BinaryPredicate>
5033 inline _OutputIterator
5034 unique_copy(_InputIterator __first, _InputIterator __last,
5035 _OutputIterator __result,
5036 _BinaryPredicate __binary_pred)
5037 {
5038 // concept requirements -- predicates checked later
5039 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
5040 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5041 typename iterator_traits<_InputIterator>::value_type>)
5042 __glibcxx_requires_valid_range(__first, __last);
5043
5044 if (__first == __last)
5045 return __result;
5046 return std::__unique_copy(__first, __last, __result, __binary_pred,
5047 std::__iterator_category(__first),
5048 std::__iterator_category(__result));
5049 }
5050
5051
5052 /**
5053 * @brief Randomly shuffle the elements of a sequence.
5054 * @ingroup mutating_algorithms
5055 * @param first A forward iterator.
5056 * @param last A forward iterator.
5057 * @return Nothing.
5058 *
5059 * Reorder the elements in the range @p [first,last) using a random
5060 * distribution, so that every possible ordering of the sequence is
5061 * equally likely.
5062 */
5063 template<typename _RandomAccessIterator>
5064 inline void
5065 random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
5066 {
5067 // concept requirements
5068 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5069 _RandomAccessIterator>)
5070 __glibcxx_requires_valid_range(__first, __last);
5071
5072 if (__first != __last)
5073 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
5074 std::iter_swap(__i, __first + (std::rand() % ((__i - __first) + 1)));
5075 }
5076
5077 /**
5078 * @brief Shuffle the elements of a sequence using a random number
5079 * generator.
5080 * @ingroup mutating_algorithms
5081 * @param first A forward iterator.
5082 * @param last A forward iterator.
5083 * @param rand The RNG functor or function.
5084 * @return Nothing.
5085 *
5086 * Reorders the elements in the range @p [first,last) using @p rand to
5087 * provide a random distribution. Calling @p rand(N) for a positive
5088 * integer @p N should return a randomly chosen integer from the
5089 * range [0,N).
5090 */
5091 template<typename _RandomAccessIterator, typename _RandomNumberGenerator>
5092 void
5093 random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
5094 #ifdef __GXX_EXPERIMENTAL_CXX0X__
5095 _RandomNumberGenerator&& __rand)
5096 #else
5097 _RandomNumberGenerator& __rand)
5098 #endif
5099 {
5100 // concept requirements
5101 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5102 _RandomAccessIterator>)
5103 __glibcxx_requires_valid_range(__first, __last);
5104
5105 if (__first == __last)
5106 return;
5107 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
5108 std::iter_swap(__i, __first + __rand((__i - __first) + 1));
5109 }
5110
5111
5112 /**
5113 * @brief Move elements for which a predicate is true to the beginning
5114 * of a sequence.
5115 * @ingroup mutating_algorithms
5116 * @param first A forward iterator.
5117 * @param last A forward iterator.
5118 * @param pred A predicate functor.
5119 * @return An iterator @p middle such that @p pred(i) is true for each
5120 * iterator @p i in the range @p [first,middle) and false for each @p i
5121 * in the range @p [middle,last).
5122 *
5123 * @p pred must not modify its operand. @p partition() does not preserve
5124 * the relative ordering of elements in each group, use
5125 * @p stable_partition() if this is needed.
5126 */
5127 template<typename _ForwardIterator, typename _Predicate>
5128 inline _ForwardIterator
5129 partition(_ForwardIterator __first, _ForwardIterator __last,
5130 _Predicate __pred)
5131 {
5132 // concept requirements
5133 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
5134 _ForwardIterator>)
5135 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
5136 typename iterator_traits<_ForwardIterator>::value_type>)
5137 __glibcxx_requires_valid_range(__first, __last);
5138
5139 return std::__partition(__first, __last, __pred,
5140 std::__iterator_category(__first));
5141 }
5142
5143
5144
5145 /**
5146 * @brief Sort the smallest elements of a sequence.
5147 * @ingroup sorting_algorithms
5148 * @param first An iterator.
5149 * @param middle Another iterator.
5150 * @param last Another iterator.
5151 * @return Nothing.
5152 *
5153 * Sorts the smallest @p (middle-first) elements in the range
5154 * @p [first,last) and moves them to the range @p [first,middle). The
5155 * order of the remaining elements in the range @p [middle,last) is
5156 * undefined.
5157 * After the sort if @p i and @j are iterators in the range
5158 * @p [first,middle) such that @i precedes @j and @k is an iterator in
5159 * the range @p [middle,last) then @p *j<*i and @p *k<*i are both false.
5160 */
5161 template<typename _RandomAccessIterator>
5162 inline void
5163 partial_sort(_RandomAccessIterator __first,
5164 _RandomAccessIterator __middle,
5165 _RandomAccessIterator __last)
5166 {
5167 typedef typename iterator_traits<_RandomAccessIterator>::value_type
5168 _ValueType;
5169
5170 // concept requirements
5171 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5172 _RandomAccessIterator>)
5173 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
5174 __glibcxx_requires_valid_range(__first, __middle);
5175 __glibcxx_requires_valid_range(__middle, __last);
5176
5177 std::__heap_select(__first, __middle, __last);
5178 std::sort_heap(__first, __middle);
5179 }
5180
5181 /**
5182 * @brief Sort the smallest elements of a sequence using a predicate
5183 * for comparison.
5184 * @ingroup sorting_algorithms
5185 * @param first An iterator.
5186 * @param middle Another iterator.
5187 * @param last Another iterator.
5188 * @param comp A comparison functor.
5189 * @return Nothing.
5190 *
5191 * Sorts the smallest @p (middle-first) elements in the range
5192 * @p [first,last) and moves them to the range @p [first,middle). The
5193 * order of the remaining elements in the range @p [middle,last) is
5194 * undefined.
5195 * After the sort if @p i and @j are iterators in the range
5196 * @p [first,middle) such that @i precedes @j and @k is an iterator in
5197 * the range @p [middle,last) then @p *comp(j,*i) and @p comp(*k,*i)
5198 * are both false.
5199 */
5200 template<typename _RandomAccessIterator, typename _Compare>
5201 inline void
5202 partial_sort(_RandomAccessIterator __first,
5203 _RandomAccessIterator __middle,
5204 _RandomAccessIterator __last,
5205 _Compare __comp)
5206 {
5207 typedef typename iterator_traits<_RandomAccessIterator>::value_type
5208 _ValueType;
5209
5210 // concept requirements
5211 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5212 _RandomAccessIterator>)
5213 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5214 _ValueType, _ValueType>)
5215 __glibcxx_requires_valid_range(__first, __middle);
5216 __glibcxx_requires_valid_range(__middle, __last);
5217
5218 std::__heap_select(__first, __middle, __last, __comp);
5219 std::sort_heap(__first, __middle, __comp);
5220 }
5221
5222 /**
5223 * @brief Sort a sequence just enough to find a particular position.
5224 * @ingroup sorting_algorithms
5225 * @param first An iterator.
5226 * @param nth Another iterator.
5227 * @param last Another iterator.
5228 * @return Nothing.
5229 *
5230 * Rearranges the elements in the range @p [first,last) so that @p *nth
5231 * is the same element that would have been in that position had the
5232 * whole sequence been sorted.
5233 * whole sequence been sorted. The elements either side of @p *nth are
5234 * not completely sorted, but for any iterator @i in the range
5235 * @p [first,nth) and any iterator @j in the range @p [nth,last) it
5236 * holds that @p *j<*i is false.
5237 */
5238 template<typename _RandomAccessIterator>
5239 inline void
5240 nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth,
5241 _RandomAccessIterator __last)
5242 {
5243 typedef typename iterator_traits<_RandomAccessIterator>::value_type
5244 _ValueType;
5245
5246 // concept requirements
5247 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5248 _RandomAccessIterator>)
5249 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
5250 __glibcxx_requires_valid_range(__first, __nth);
5251 __glibcxx_requires_valid_range(__nth, __last);
5252
5253 if (__first == __last || __nth == __last)
5254 return;
5255
5256 std::__introselect(__first, __nth, __last,
5257 std::__lg(__last - __first) * 2);
5258 }
5259
5260 /**
5261 * @brief Sort a sequence just enough to find a particular position
5262 * using a predicate for comparison.
5263 * @ingroup sorting_algorithms
5264 * @param first An iterator.
5265 * @param nth Another iterator.
5266 * @param last Another iterator.
5267 * @param comp A comparison functor.
5268 * @return Nothing.
5269 *
5270 * Rearranges the elements in the range @p [first,last) so that @p *nth
5271 * is the same element that would have been in that position had the
5272 * whole sequence been sorted. The elements either side of @p *nth are
5273 * not completely sorted, but for any iterator @i in the range
5274 * @p [first,nth) and any iterator @j in the range @p [nth,last) it
5275 * holds that @p comp(*j,*i) is false.
5276 */
5277 template<typename _RandomAccessIterator, typename _Compare>
5278 inline void
5279 nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth,
5280 _RandomAccessIterator __last, _Compare __comp)
5281 {
5282 typedef typename iterator_traits<_RandomAccessIterator>::value_type
5283 _ValueType;
5284
5285 // concept requirements
5286 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5287 _RandomAccessIterator>)
5288 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5289 _ValueType, _ValueType>)
5290 __glibcxx_requires_valid_range(__first, __nth);
5291 __glibcxx_requires_valid_range(__nth, __last);
5292
5293 if (__first == __last || __nth == __last)
5294 return;
5295
5296 std::__introselect(__first, __nth, __last,
5297 std::__lg(__last - __first) * 2, __comp);
5298 }
5299
5300
5301 /**
5302 * @brief Sort the elements of a sequence.
5303 * @ingroup sorting_algorithms
5304 * @param first An iterator.
5305 * @param last Another iterator.
5306 * @return Nothing.
5307 *
5308 * Sorts the elements in the range @p [first,last) in ascending order,
5309 * such that @p *(i+1)<*i is false for each iterator @p i in the range
5310 * @p [first,last-1).
5311 *
5312 * The relative ordering of equivalent elements is not preserved, use
5313 * @p stable_sort() if this is needed.
5314 */
5315 template<typename _RandomAccessIterator>
5316 inline void
5317 sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
5318 {
5319 typedef typename iterator_traits<_RandomAccessIterator>::value_type
5320 _ValueType;
5321
5322 // concept requirements
5323 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5324 _RandomAccessIterator>)
5325 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
5326 __glibcxx_requires_valid_range(__first, __last);
5327
5328 if (__first != __last)
5329 {
5330 std::__introsort_loop(__first, __last,
5331 std::__lg(__last - __first) * 2);
5332 std::__final_insertion_sort(__first, __last);
5333 }
5334 }
5335
5336 /**
5337 * @brief Sort the elements of a sequence using a predicate for comparison.
5338 * @ingroup sorting_algorithms
5339 * @param first An iterator.
5340 * @param last Another iterator.
5341 * @param comp A comparison functor.
5342 * @return Nothing.
5343 *
5344 * Sorts the elements in the range @p [first,last) in ascending order,
5345 * such that @p comp(*(i+1),*i) is false for every iterator @p i in the
5346 * range @p [first,last-1).
5347 *
5348 * The relative ordering of equivalent elements is not preserved, use
5349 * @p stable_sort() if this is needed.
5350 */
5351 template<typename _RandomAccessIterator, typename _Compare>
5352 inline void
5353 sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
5354 _Compare __comp)
5355 {
5356 typedef typename iterator_traits<_RandomAccessIterator>::value_type
5357 _ValueType;
5358
5359 // concept requirements
5360 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5361 _RandomAccessIterator>)
5362 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _ValueType,
5363 _ValueType>)
5364 __glibcxx_requires_valid_range(__first, __last);
5365
5366 if (__first != __last)
5367 {
5368 std::__introsort_loop(__first, __last,
5369 std::__lg(__last - __first) * 2, __comp);
5370 std::__final_insertion_sort(__first, __last, __comp);
5371 }
5372 }
5373
5374 /**
5375 * @brief Merges two sorted ranges.
5376 * @ingroup sorting_algorithms
5377 * @param first1 An iterator.
5378 * @param first2 Another iterator.
5379 * @param last1 Another iterator.
5380 * @param last2 Another iterator.
5381 * @param result An iterator pointing to the end of the merged range.
5382 * @return An iterator pointing to the first element <em>not less
5383 * than</em> @a val.
5384 *
5385 * Merges the ranges [first1,last1) and [first2,last2) into the sorted range
5386 * [result, result + (last1-first1) + (last2-first2)). Both input ranges
5387 * must be sorted, and the output range must not overlap with either of
5388 * the input ranges. The sort is @e stable, that is, for equivalent
5389 * elements in the two ranges, elements from the first range will always
5390 * come before elements from the second.
5391 */
5392 template<typename _InputIterator1, typename _InputIterator2,
5393 typename _OutputIterator>
5394 _OutputIterator
5395 merge(_InputIterator1 __first1, _InputIterator1 __last1,
5396 _InputIterator2 __first2, _InputIterator2 __last2,
5397 _OutputIterator __result)
5398 {
5399 typedef typename iterator_traits<_InputIterator1>::value_type
5400 _ValueType1;
5401 typedef typename iterator_traits<_InputIterator2>::value_type
5402 _ValueType2;
5403
5404 // concept requirements
5405 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5406 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5407 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5408 _ValueType1>)
5409 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5410 _ValueType2>)
5411 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
5412 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5413 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5414
5415 while (__first1 != __last1 && __first2 != __last2)
5416 {
5417 if (*__first2 < *__first1)
5418 {
5419 *__result = *__first2;
5420 ++__first2;
5421 }
5422 else
5423 {
5424 *__result = *__first1;
5425 ++__first1;
5426 }
5427 ++__result;
5428 }
5429 return std::copy(__first2, __last2, std::copy(__first1, __last1,
5430 __result));
5431 }
5432
5433 /**
5434 * @brief Merges two sorted ranges.
5435 * @ingroup sorting_algorithms
5436 * @param first1 An iterator.
5437 * @param first2 Another iterator.
5438 * @param last1 Another iterator.
5439 * @param last2 Another iterator.
5440 * @param result An iterator pointing to the end of the merged range.
5441 * @param comp A functor to use for comparisons.
5442 * @return An iterator pointing to the first element "not less
5443 * than" @a val.
5444 *
5445 * Merges the ranges [first1,last1) and [first2,last2) into the sorted range
5446 * [result, result + (last1-first1) + (last2-first2)). Both input ranges
5447 * must be sorted, and the output range must not overlap with either of
5448 * the input ranges. The sort is @e stable, that is, for equivalent
5449 * elements in the two ranges, elements from the first range will always
5450 * come before elements from the second.
5451 *
5452 * The comparison function should have the same effects on ordering as
5453 * the function used for the initial sort.
5454 */
5455 template<typename _InputIterator1, typename _InputIterator2,
5456 typename _OutputIterator, typename _Compare>
5457 _OutputIterator
5458 merge(_InputIterator1 __first1, _InputIterator1 __last1,
5459 _InputIterator2 __first2, _InputIterator2 __last2,
5460 _OutputIterator __result, _Compare __comp)
5461 {
5462 typedef typename iterator_traits<_InputIterator1>::value_type
5463 _ValueType1;
5464 typedef typename iterator_traits<_InputIterator2>::value_type
5465 _ValueType2;
5466
5467 // concept requirements
5468 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5469 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5470 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5471 _ValueType1>)
5472 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5473 _ValueType2>)
5474 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5475 _ValueType2, _ValueType1>)
5476 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
5477 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
5478
5479 while (__first1 != __last1 && __first2 != __last2)
5480 {
5481 if (__comp(*__first2, *__first1))
5482 {
5483 *__result = *__first2;
5484 ++__first2;
5485 }
5486 else
5487 {
5488 *__result = *__first1;
5489 ++__first1;
5490 }
5491 ++__result;
5492 }
5493 return std::copy(__first2, __last2, std::copy(__first1, __last1,
5494 __result));
5495 }
5496
5497
5498 /**
5499 * @brief Sort the elements of a sequence, preserving the relative order
5500 * of equivalent elements.
5501 * @ingroup sorting_algorithms
5502 * @param first An iterator.
5503 * @param last Another iterator.
5504 * @return Nothing.
5505 *
5506 * Sorts the elements in the range @p [first,last) in ascending order,
5507 * such that @p *(i+1)<*i is false for each iterator @p i in the range
5508 * @p [first,last-1).
5509 *
5510 * The relative ordering of equivalent elements is preserved, so any two
5511 * elements @p x and @p y in the range @p [first,last) such that
5512 * @p x<y is false and @p y<x is false will have the same relative
5513 * ordering after calling @p stable_sort().
5514 */
5515 template<typename _RandomAccessIterator>
5516 inline void
5517 stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
5518 {
5519 typedef typename iterator_traits<_RandomAccessIterator>::value_type
5520 _ValueType;
5521 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
5522 _DistanceType;
5523
5524 // concept requirements
5525 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5526 _RandomAccessIterator>)
5527 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
5528 __glibcxx_requires_valid_range(__first, __last);
5529
5530 _Temporary_buffer<_RandomAccessIterator, _ValueType> __buf(__first,
5531 __last);
5532 if (__buf.begin() == 0)
5533 std::__inplace_stable_sort(__first, __last);
5534 else
5535 std::__stable_sort_adaptive(__first, __last, __buf.begin(),
5536 _DistanceType(__buf.size()));
5537 }
5538
5539 /**
5540 * @brief Sort the elements of a sequence using a predicate for comparison,
5541 * preserving the relative order of equivalent elements.
5542 * @ingroup sorting_algorithms
5543 * @param first An iterator.
5544 * @param last Another iterator.
5545 * @param comp A comparison functor.
5546 * @return Nothing.
5547 *
5548 * Sorts the elements in the range @p [first,last) in ascending order,
5549 * such that @p comp(*(i+1),*i) is false for each iterator @p i in the
5550 * range @p [first,last-1).
5551 *
5552 * The relative ordering of equivalent elements is preserved, so any two
5553 * elements @p x and @p y in the range @p [first,last) such that
5554 * @p comp(x,y) is false and @p comp(y,x) is false will have the same
5555 * relative ordering after calling @p stable_sort().
5556 */
5557 template<typename _RandomAccessIterator, typename _Compare>
5558 inline void
5559 stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
5560 _Compare __comp)
5561 {
5562 typedef typename iterator_traits<_RandomAccessIterator>::value_type
5563 _ValueType;
5564 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
5565 _DistanceType;
5566
5567 // concept requirements
5568 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
5569 _RandomAccessIterator>)
5570 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5571 _ValueType,
5572 _ValueType>)
5573 __glibcxx_requires_valid_range(__first, __last);
5574
5575 _Temporary_buffer<_RandomAccessIterator, _ValueType> __buf(__first,
5576 __last);
5577 if (__buf.begin() == 0)
5578 std::__inplace_stable_sort(__first, __last, __comp);
5579 else
5580 std::__stable_sort_adaptive(__first, __last, __buf.begin(),
5581 _DistanceType(__buf.size()), __comp);
5582 }
5583
5584
5585 /**
5586 * @brief Return the union of two sorted ranges.
5587 * @ingroup set_algorithms
5588 * @param first1 Start of first range.
5589 * @param last1 End of first range.
5590 * @param first2 Start of second range.
5591 * @param last2 End of second range.
5592 * @return End of the output range.
5593 * @ingroup set_algorithms
5594 *
5595 * This operation iterates over both ranges, copying elements present in
5596 * each range in order to the output range. Iterators increment for each
5597 * range. When the current element of one range is less than the other,
5598 * that element is copied and the iterator advanced. If an element is
5599 * contained in both ranges, the element from the first range is copied and
5600 * both ranges advance. The output range may not overlap either input
5601 * range.
5602 */
5603 template<typename _InputIterator1, typename _InputIterator2,
5604 typename _OutputIterator>
5605 _OutputIterator
5606 set_union(_InputIterator1 __first1, _InputIterator1 __last1,
5607 _InputIterator2 __first2, _InputIterator2 __last2,
5608 _OutputIterator __result)
5609 {
5610 typedef typename iterator_traits<_InputIterator1>::value_type
5611 _ValueType1;
5612 typedef typename iterator_traits<_InputIterator2>::value_type
5613 _ValueType2;
5614
5615 // concept requirements
5616 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5617 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5618 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5619 _ValueType1>)
5620 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5621 _ValueType2>)
5622 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
5623 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
5624 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5625 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5626
5627 while (__first1 != __last1 && __first2 != __last2)
5628 {
5629 if (*__first1 < *__first2)
5630 {
5631 *__result = *__first1;
5632 ++__first1;
5633 }
5634 else if (*__first2 < *__first1)
5635 {
5636 *__result = *__first2;
5637 ++__first2;
5638 }
5639 else
5640 {
5641 *__result = *__first1;
5642 ++__first1;
5643 ++__first2;
5644 }
5645 ++__result;
5646 }
5647 return std::copy(__first2, __last2, std::copy(__first1, __last1,
5648 __result));
5649 }
5650
5651 /**
5652 * @brief Return the union of two sorted ranges using a comparison functor.
5653 * @ingroup set_algorithms
5654 * @param first1 Start of first range.
5655 * @param last1 End of first range.
5656 * @param first2 Start of second range.
5657 * @param last2 End of second range.
5658 * @param comp The comparison functor.
5659 * @return End of the output range.
5660 * @ingroup set_algorithms
5661 *
5662 * This operation iterates over both ranges, copying elements present in
5663 * each range in order to the output range. Iterators increment for each
5664 * range. When the current element of one range is less than the other
5665 * according to @a comp, that element is copied and the iterator advanced.
5666 * If an equivalent element according to @a comp is contained in both
5667 * ranges, the element from the first range is copied and both ranges
5668 * advance. The output range may not overlap either input range.
5669 */
5670 template<typename _InputIterator1, typename _InputIterator2,
5671 typename _OutputIterator, typename _Compare>
5672 _OutputIterator
5673 set_union(_InputIterator1 __first1, _InputIterator1 __last1,
5674 _InputIterator2 __first2, _InputIterator2 __last2,
5675 _OutputIterator __result, _Compare __comp)
5676 {
5677 typedef typename iterator_traits<_InputIterator1>::value_type
5678 _ValueType1;
5679 typedef typename iterator_traits<_InputIterator2>::value_type
5680 _ValueType2;
5681
5682 // concept requirements
5683 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5684 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5685 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5686 _ValueType1>)
5687 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5688 _ValueType2>)
5689 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5690 _ValueType1, _ValueType2>)
5691 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5692 _ValueType2, _ValueType1>)
5693 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
5694 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
5695
5696 while (__first1 != __last1 && __first2 != __last2)
5697 {
5698 if (__comp(*__first1, *__first2))
5699 {
5700 *__result = *__first1;
5701 ++__first1;
5702 }
5703 else if (__comp(*__first2, *__first1))
5704 {
5705 *__result = *__first2;
5706 ++__first2;
5707 }
5708 else
5709 {
5710 *__result = *__first1;
5711 ++__first1;
5712 ++__first2;
5713 }
5714 ++__result;
5715 }
5716 return std::copy(__first2, __last2, std::copy(__first1, __last1,
5717 __result));
5718 }
5719
5720 /**
5721 * @brief Return the intersection of two sorted ranges.
5722 * @ingroup set_algorithms
5723 * @param first1 Start of first range.
5724 * @param last1 End of first range.
5725 * @param first2 Start of second range.
5726 * @param last2 End of second range.
5727 * @return End of the output range.
5728 * @ingroup set_algorithms
5729 *
5730 * This operation iterates over both ranges, copying elements present in
5731 * both ranges in order to the output range. Iterators increment for each
5732 * range. When the current element of one range is less than the other,
5733 * that iterator advances. If an element is contained in both ranges, the
5734 * element from the first range is copied and both ranges advance. The
5735 * output range may not overlap either input range.
5736 */
5737 template<typename _InputIterator1, typename _InputIterator2,
5738 typename _OutputIterator>
5739 _OutputIterator
5740 set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
5741 _InputIterator2 __first2, _InputIterator2 __last2,
5742 _OutputIterator __result)
5743 {
5744 typedef typename iterator_traits<_InputIterator1>::value_type
5745 _ValueType1;
5746 typedef typename iterator_traits<_InputIterator2>::value_type
5747 _ValueType2;
5748
5749 // concept requirements
5750 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5751 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5752 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5753 _ValueType1>)
5754 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
5755 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
5756 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5757 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5758
5759 while (__first1 != __last1 && __first2 != __last2)
5760 if (*__first1 < *__first2)
5761 ++__first1;
5762 else if (*__first2 < *__first1)
5763 ++__first2;
5764 else
5765 {
5766 *__result = *__first1;
5767 ++__first1;
5768 ++__first2;
5769 ++__result;
5770 }
5771 return __result;
5772 }
5773
5774 /**
5775 * @brief Return the intersection of two sorted ranges using comparison
5776 * functor.
5777 * @ingroup set_algorithms
5778 * @param first1 Start of first range.
5779 * @param last1 End of first range.
5780 * @param first2 Start of second range.
5781 * @param last2 End of second range.
5782 * @param comp The comparison functor.
5783 * @return End of the output range.
5784 * @ingroup set_algorithms
5785 *
5786 * This operation iterates over both ranges, copying elements present in
5787 * both ranges in order to the output range. Iterators increment for each
5788 * range. When the current element of one range is less than the other
5789 * according to @a comp, that iterator advances. If an element is
5790 * contained in both ranges according to @a comp, the element from the
5791 * first range is copied and both ranges advance. The output range may not
5792 * overlap either input range.
5793 */
5794 template<typename _InputIterator1, typename _InputIterator2,
5795 typename _OutputIterator, typename _Compare>
5796 _OutputIterator
5797 set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
5798 _InputIterator2 __first2, _InputIterator2 __last2,
5799 _OutputIterator __result, _Compare __comp)
5800 {
5801 typedef typename iterator_traits<_InputIterator1>::value_type
5802 _ValueType1;
5803 typedef typename iterator_traits<_InputIterator2>::value_type
5804 _ValueType2;
5805
5806 // concept requirements
5807 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5808 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5809 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5810 _ValueType1>)
5811 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5812 _ValueType1, _ValueType2>)
5813 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5814 _ValueType2, _ValueType1>)
5815 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
5816 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
5817
5818 while (__first1 != __last1 && __first2 != __last2)
5819 if (__comp(*__first1, *__first2))
5820 ++__first1;
5821 else if (__comp(*__first2, *__first1))
5822 ++__first2;
5823 else
5824 {
5825 *__result = *__first1;
5826 ++__first1;
5827 ++__first2;
5828 ++__result;
5829 }
5830 return __result;
5831 }
5832
5833 /**
5834 * @brief Return the difference of two sorted ranges.
5835 * @ingroup set_algorithms
5836 * @param first1 Start of first range.
5837 * @param last1 End of first range.
5838 * @param first2 Start of second range.
5839 * @param last2 End of second range.
5840 * @return End of the output range.
5841 * @ingroup set_algorithms
5842 *
5843 * This operation iterates over both ranges, copying elements present in
5844 * the first range but not the second in order to the output range.
5845 * Iterators increment for each range. When the current element of the
5846 * first range is less than the second, that element is copied and the
5847 * iterator advances. If the current element of the second range is less,
5848 * the iterator advances, but no element is copied. If an element is
5849 * contained in both ranges, no elements are copied and both ranges
5850 * advance. The output range may not overlap either input range.
5851 */
5852 template<typename _InputIterator1, typename _InputIterator2,
5853 typename _OutputIterator>
5854 _OutputIterator
5855 set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
5856 _InputIterator2 __first2, _InputIterator2 __last2,
5857 _OutputIterator __result)
5858 {
5859 typedef typename iterator_traits<_InputIterator1>::value_type
5860 _ValueType1;
5861 typedef typename iterator_traits<_InputIterator2>::value_type
5862 _ValueType2;
5863
5864 // concept requirements
5865 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5866 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5867 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5868 _ValueType1>)
5869 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
5870 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
5871 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5872 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5873
5874 while (__first1 != __last1 && __first2 != __last2)
5875 if (*__first1 < *__first2)
5876 {
5877 *__result = *__first1;
5878 ++__first1;
5879 ++__result;
5880 }
5881 else if (*__first2 < *__first1)
5882 ++__first2;
5883 else
5884 {
5885 ++__first1;
5886 ++__first2;
5887 }
5888 return std::copy(__first1, __last1, __result);
5889 }
5890
5891 /**
5892 * @brief Return the difference of two sorted ranges using comparison
5893 * functor.
5894 * @ingroup set_algorithms
5895 * @param first1 Start of first range.
5896 * @param last1 End of first range.
5897 * @param first2 Start of second range.
5898 * @param last2 End of second range.
5899 * @param comp The comparison functor.
5900 * @return End of the output range.
5901 * @ingroup set_algorithms
5902 *
5903 * This operation iterates over both ranges, copying elements present in
5904 * the first range but not the second in order to the output range.
5905 * Iterators increment for each range. When the current element of the
5906 * first range is less than the second according to @a comp, that element
5907 * is copied and the iterator advances. If the current element of the
5908 * second range is less, no element is copied and the iterator advances.
5909 * If an element is contained in both ranges according to @a comp, no
5910 * elements are copied and both ranges advance. The output range may not
5911 * overlap either input range.
5912 */
5913 template<typename _InputIterator1, typename _InputIterator2,
5914 typename _OutputIterator, typename _Compare>
5915 _OutputIterator
5916 set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
5917 _InputIterator2 __first2, _InputIterator2 __last2,
5918 _OutputIterator __result, _Compare __comp)
5919 {
5920 typedef typename iterator_traits<_InputIterator1>::value_type
5921 _ValueType1;
5922 typedef typename iterator_traits<_InputIterator2>::value_type
5923 _ValueType2;
5924
5925 // concept requirements
5926 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5927 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5928 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5929 _ValueType1>)
5930 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5931 _ValueType1, _ValueType2>)
5932 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
5933 _ValueType2, _ValueType1>)
5934 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
5935 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
5936
5937 while (__first1 != __last1 && __first2 != __last2)
5938 if (__comp(*__first1, *__first2))
5939 {
5940 *__result = *__first1;
5941 ++__first1;
5942 ++__result;
5943 }
5944 else if (__comp(*__first2, *__first1))
5945 ++__first2;
5946 else
5947 {
5948 ++__first1;
5949 ++__first2;
5950 }
5951 return std::copy(__first1, __last1, __result);
5952 }
5953
5954 /**
5955 * @brief Return the symmetric difference of two sorted ranges.
5956 * @ingroup set_algorithms
5957 * @param first1 Start of first range.
5958 * @param last1 End of first range.
5959 * @param first2 Start of second range.
5960 * @param last2 End of second range.
5961 * @return End of the output range.
5962 * @ingroup set_algorithms
5963 *
5964 * This operation iterates over both ranges, copying elements present in
5965 * one range but not the other in order to the output range. Iterators
5966 * increment for each range. When the current element of one range is less
5967 * than the other, that element is copied and the iterator advances. If an
5968 * element is contained in both ranges, no elements are copied and both
5969 * ranges advance. The output range may not overlap either input range.
5970 */
5971 template<typename _InputIterator1, typename _InputIterator2,
5972 typename _OutputIterator>
5973 _OutputIterator
5974 set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
5975 _InputIterator2 __first2, _InputIterator2 __last2,
5976 _OutputIterator __result)
5977 {
5978 typedef typename iterator_traits<_InputIterator1>::value_type
5979 _ValueType1;
5980 typedef typename iterator_traits<_InputIterator2>::value_type
5981 _ValueType2;
5982
5983 // concept requirements
5984 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
5985 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
5986 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5987 _ValueType1>)
5988 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
5989 _ValueType2>)
5990 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
5991 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
5992 __glibcxx_requires_sorted_set(__first1, __last1, __first2);
5993 __glibcxx_requires_sorted_set(__first2, __last2, __first1);
5994
5995 while (__first1 != __last1 && __first2 != __last2)
5996 if (*__first1 < *__first2)
5997 {
5998 *__result = *__first1;
5999 ++__first1;
6000 ++__result;
6001 }
6002 else if (*__first2 < *__first1)
6003 {
6004 *__result = *__first2;
6005 ++__first2;
6006 ++__result;
6007 }
6008 else
6009 {
6010 ++__first1;
6011 ++__first2;
6012 }
6013 return std::copy(__first2, __last2, std::copy(__first1,
6014 __last1, __result));
6015 }
6016
6017 /**
6018 * @brief Return the symmetric difference of two sorted ranges using
6019 * comparison functor.
6020 * @ingroup set_algorithms
6021 * @param first1 Start of first range.
6022 * @param last1 End of first range.
6023 * @param first2 Start of second range.
6024 * @param last2 End of second range.
6025 * @param comp The comparison functor.
6026 * @return End of the output range.
6027 * @ingroup set_algorithms
6028 *
6029 * This operation iterates over both ranges, copying elements present in
6030 * one range but not the other in order to the output range. Iterators
6031 * increment for each range. When the current element of one range is less
6032 * than the other according to @a comp, that element is copied and the
6033 * iterator advances. If an element is contained in both ranges according
6034 * to @a comp, no elements are copied and both ranges advance. The output
6035 * range may not overlap either input range.
6036 */
6037 template<typename _InputIterator1, typename _InputIterator2,
6038 typename _OutputIterator, typename _Compare>
6039 _OutputIterator
6040 set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
6041 _InputIterator2 __first2, _InputIterator2 __last2,
6042 _OutputIterator __result,
6043 _Compare __comp)
6044 {
6045 typedef typename iterator_traits<_InputIterator1>::value_type
6046 _ValueType1;
6047 typedef typename iterator_traits<_InputIterator2>::value_type
6048 _ValueType2;
6049
6050 // concept requirements
6051 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
6052 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
6053 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
6054 _ValueType1>)
6055 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
6056 _ValueType2>)
6057 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
6058 _ValueType1, _ValueType2>)
6059 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
6060 _ValueType2, _ValueType1>)
6061 __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp);
6062 __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp);
6063
6064 while (__first1 != __last1 && __first2 != __last2)
6065 if (__comp(*__first1, *__first2))
6066 {
6067 *__result = *__first1;
6068 ++__first1;
6069 ++__result;
6070 }
6071 else if (__comp(*__first2, *__first1))
6072 {
6073 *__result = *__first2;
6074 ++__first2;
6075 ++__result;
6076 }
6077 else
6078 {
6079 ++__first1;
6080 ++__first2;
6081 }
6082 return std::copy(__first2, __last2,
6083 std::copy(__first1, __last1, __result));
6084 }
6085
6086
6087 /**
6088 * @brief Return the minimum element in a range.
6089 * @ingroup sorting_algorithms
6090 * @param first Start of range.
6091 * @param last End of range.
6092 * @return Iterator referencing the first instance of the smallest value.
6093 */
6094 template<typename _ForwardIterator>
6095 _ForwardIterator
6096 min_element(_ForwardIterator __first, _ForwardIterator __last)
6097 {
6098 // concept requirements
6099 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
6100 __glibcxx_function_requires(_LessThanComparableConcept<
6101 typename iterator_traits<_ForwardIterator>::value_type>)
6102 __glibcxx_requires_valid_range(__first, __last);
6103
6104 if (__first == __last)
6105 return __first;
6106 _ForwardIterator __result = __first;
6107 while (++__first != __last)
6108 if (*__first < *__result)
6109 __result = __first;
6110 return __result;
6111 }
6112
6113 /**
6114 * @brief Return the minimum element in a range using comparison functor.
6115 * @ingroup sorting_algorithms
6116 * @param first Start of range.
6117 * @param last End of range.
6118 * @param comp Comparison functor.
6119 * @return Iterator referencing the first instance of the smallest value
6120 * according to comp.
6121 */
6122 template<typename _ForwardIterator, typename _Compare>
6123 _ForwardIterator
6124 min_element(_ForwardIterator __first, _ForwardIterator __last,
6125 _Compare __comp)
6126 {
6127 // concept requirements
6128 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
6129 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
6130 typename iterator_traits<_ForwardIterator>::value_type,
6131 typename iterator_traits<_ForwardIterator>::value_type>)
6132 __glibcxx_requires_valid_range(__first, __last);
6133
6134 if (__first == __last)
6135 return __first;
6136 _ForwardIterator __result = __first;
6137 while (++__first != __last)
6138 if (__comp(*__first, *__result))
6139 __result = __first;
6140 return __result;
6141 }
6142
6143 /**
6144 * @brief Return the maximum element in a range.
6145 * @ingroup sorting_algorithms
6146 * @param first Start of range.
6147 * @param last End of range.
6148 * @return Iterator referencing the first instance of the largest value.
6149 */
6150 template<typename _ForwardIterator>
6151 _ForwardIterator
6152 max_element(_ForwardIterator __first, _ForwardIterator __last)
6153 {
6154 // concept requirements
6155 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
6156 __glibcxx_function_requires(_LessThanComparableConcept<
6157 typename iterator_traits<_ForwardIterator>::value_type>)
6158 __glibcxx_requires_valid_range(__first, __last);
6159
6160 if (__first == __last)
6161 return __first;
6162 _ForwardIterator __result = __first;
6163 while (++__first != __last)
6164 if (*__result < *__first)
6165 __result = __first;
6166 return __result;
6167 }
6168
6169 /**
6170 * @brief Return the maximum element in a range using comparison functor.
6171 * @ingroup sorting_algorithms
6172 * @param first Start of range.
6173 * @param last End of range.
6174 * @param comp Comparison functor.
6175 * @return Iterator referencing the first instance of the largest value
6176 * according to comp.
6177 */
6178 template<typename _ForwardIterator, typename _Compare>
6179 _ForwardIterator
6180 max_element(_ForwardIterator __first, _ForwardIterator __last,
6181 _Compare __comp)
6182 {
6183 // concept requirements
6184 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
6185 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
6186 typename iterator_traits<_ForwardIterator>::value_type,
6187 typename iterator_traits<_ForwardIterator>::value_type>)
6188 __glibcxx_requires_valid_range(__first, __last);
6189
6190 if (__first == __last) return __first;
6191 _ForwardIterator __result = __first;
6192 while (++__first != __last)
6193 if (__comp(*__result, *__first))
6194 __result = __first;
6195 return __result;
6196 }
6197
6198 _GLIBCXX_END_NAMESPACE_ALGO
6199 } // namespace std
6200
6201 #endif /* _STL_ALGO_H */