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stl_algo.h: Additional minor tweaks.
[gcc.git] / libstdc++-v3 / include / bits / stl_algo.h
1 // Algorithm implementation -*- C++ -*-
2
3 // Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 2, or (at your option)
9 // any later version.
10
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING. If not, write to the Free
18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19 // USA.
20
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction. Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License. This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
29
30 /*
31 *
32 * Copyright (c) 1994
33 * Hewlett-Packard Company
34 *
35 * Permission to use, copy, modify, distribute and sell this software
36 * and its documentation for any purpose is hereby granted without fee,
37 * provided that the above copyright notice appear in all copies and
38 * that both that copyright notice and this permission notice appear
39 * in supporting documentation. Hewlett-Packard Company makes no
40 * representations about the suitability of this software for any
41 * purpose. It is provided "as is" without express or implied warranty.
42 *
43 *
44 * Copyright (c) 1996
45 * Silicon Graphics Computer Systems, Inc.
46 *
47 * Permission to use, copy, modify, distribute and sell this software
48 * and its documentation for any purpose is hereby granted without fee,
49 * provided that the above copyright notice appear in all copies and
50 * that both that copyright notice and this permission notice appear
51 * in supporting documentation. Silicon Graphics makes no
52 * representations about the suitability of this software for any
53 * purpose. It is provided "as is" without express or implied warranty.
54 */
55
56 /** @file stl_algo.h
57 * This is an internal header file, included by other library headers.
58 * You should not attempt to use it directly.
59 */
60
61 #ifndef _ALGO_H
62 #define _ALGO_H 1
63
64 #include <bits/stl_heap.h>
65 #include <bits/stl_tempbuf.h> // for _Temporary_buffer
66 #include <debug/debug.h>
67
68 // See concept_check.h for the __glibcxx_*_requires macros.
69
70 namespace std
71 {
72 /**
73 * @brief Find the median of three values.
74 * @param a A value.
75 * @param b A value.
76 * @param c A value.
77 * @return One of @p a, @p b or @p c.
78 *
79 * If @c {l,m,n} is some convolution of @p {a,b,c} such that @c l<=m<=n
80 * then the value returned will be @c m.
81 * This is an SGI extension.
82 * @ingroup SGIextensions
83 */
84 template<typename _Tp>
85 inline const _Tp&
86 __median(const _Tp& __a, const _Tp& __b, const _Tp& __c)
87 {
88 // concept requirements
89 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
90 if (__a < __b)
91 if (__b < __c)
92 return __b;
93 else if (__a < __c)
94 return __c;
95 else
96 return __a;
97 else if (__a < __c)
98 return __a;
99 else if (__b < __c)
100 return __c;
101 else
102 return __b;
103 }
104
105 /**
106 * @brief Find the median of three values using a predicate for comparison.
107 * @param a A value.
108 * @param b A value.
109 * @param c A value.
110 * @param comp A binary predicate.
111 * @return One of @p a, @p b or @p c.
112 *
113 * If @c {l,m,n} is some convolution of @p {a,b,c} such that @p comp(l,m)
114 * and @p comp(m,n) are both true then the value returned will be @c m.
115 * This is an SGI extension.
116 * @ingroup SGIextensions
117 */
118 template<typename _Tp, typename _Compare>
119 inline const _Tp&
120 __median(const _Tp& __a, const _Tp& __b, const _Tp& __c, _Compare __comp)
121 {
122 // concept requirements
123 __glibcxx_function_requires(_BinaryFunctionConcept<_Compare,bool,_Tp,_Tp>)
124 if (__comp(__a, __b))
125 if (__comp(__b, __c))
126 return __b;
127 else if (__comp(__a, __c))
128 return __c;
129 else
130 return __a;
131 else if (__comp(__a, __c))
132 return __a;
133 else if (__comp(__b, __c))
134 return __c;
135 else
136 return __b;
137 }
138
139 /**
140 * @brief Apply a function to every element of a sequence.
141 * @param first An input iterator.
142 * @param last An input iterator.
143 * @param f A unary function object.
144 * @return @p f.
145 *
146 * Applies the function object @p f to each element in the range
147 * @p [first,last). @p f must not modify the order of the sequence.
148 * If @p f has a return value it is ignored.
149 */
150 template<typename _InputIterator, typename _Function>
151 _Function
152 for_each(_InputIterator __first, _InputIterator __last, _Function __f)
153 {
154 // concept requirements
155 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
156 __glibcxx_requires_valid_range(__first, __last);
157 for ( ; __first != __last; ++__first)
158 __f(*__first);
159 return __f;
160 }
161
162 /**
163 * @if maint
164 * This is an overload used by find() for the Input Iterator case.
165 * @endif
166 */
167 template<typename _InputIterator, typename _Tp>
168 inline _InputIterator
169 find(_InputIterator __first, _InputIterator __last,
170 const _Tp& __val, input_iterator_tag)
171 {
172 while (__first != __last && !(*__first == __val))
173 ++__first;
174 return __first;
175 }
176
177 /**
178 * @if maint
179 * This is an overload used by find_if() for the Input Iterator case.
180 * @endif
181 */
182 template<typename _InputIterator, typename _Predicate>
183 inline _InputIterator
184 find_if(_InputIterator __first, _InputIterator __last,
185 _Predicate __pred, input_iterator_tag)
186 {
187 while (__first != __last && !__pred(*__first))
188 ++__first;
189 return __first;
190 }
191
192 /**
193 * @if maint
194 * This is an overload used by find() for the RAI case.
195 * @endif
196 */
197 template<typename _RandomAccessIterator, typename _Tp>
198 _RandomAccessIterator
199 find(_RandomAccessIterator __first, _RandomAccessIterator __last,
200 const _Tp& __val, random_access_iterator_tag)
201 {
202 typename iterator_traits<_RandomAccessIterator>::difference_type
203 __trip_count = (__last - __first) >> 2;
204
205 for ( ; __trip_count > 0 ; --__trip_count)
206 {
207 if (*__first == __val)
208 return __first;
209 ++__first;
210
211 if (*__first == __val)
212 return __first;
213 ++__first;
214
215 if (*__first == __val)
216 return __first;
217 ++__first;
218
219 if (*__first == __val)
220 return __first;
221 ++__first;
222 }
223
224 switch (__last - __first)
225 {
226 case 3:
227 if (*__first == __val)
228 return __first;
229 ++__first;
230 case 2:
231 if (*__first == __val)
232 return __first;
233 ++__first;
234 case 1:
235 if (*__first == __val)
236 return __first;
237 ++__first;
238 case 0:
239 default:
240 return __last;
241 }
242 }
243
244 /**
245 * @if maint
246 * This is an overload used by find_if() for the RAI case.
247 * @endif
248 */
249 template<typename _RandomAccessIterator, typename _Predicate>
250 _RandomAccessIterator
251 find_if(_RandomAccessIterator __first, _RandomAccessIterator __last,
252 _Predicate __pred, random_access_iterator_tag)
253 {
254 typename iterator_traits<_RandomAccessIterator>::difference_type
255 __trip_count = (__last - __first) >> 2;
256
257 for ( ; __trip_count > 0 ; --__trip_count)
258 {
259 if (__pred(*__first))
260 return __first;
261 ++__first;
262
263 if (__pred(*__first))
264 return __first;
265 ++__first;
266
267 if (__pred(*__first))
268 return __first;
269 ++__first;
270
271 if (__pred(*__first))
272 return __first;
273 ++__first;
274 }
275
276 switch (__last - __first)
277 {
278 case 3:
279 if (__pred(*__first))
280 return __first;
281 ++__first;
282 case 2:
283 if (__pred(*__first))
284 return __first;
285 ++__first;
286 case 1:
287 if (__pred(*__first))
288 return __first;
289 ++__first;
290 case 0:
291 default:
292 return __last;
293 }
294 }
295
296 /**
297 * @brief Find the first occurrence of a value in a sequence.
298 * @param first An input iterator.
299 * @param last An input iterator.
300 * @param val The value to find.
301 * @return The first iterator @c i in the range @p [first,last)
302 * such that @c *i == @p val, or @p last if no such iterator exists.
303 */
304 template<typename _InputIterator, typename _Tp>
305 inline _InputIterator
306 find(_InputIterator __first, _InputIterator __last,
307 const _Tp& __val)
308 {
309 // concept requirements
310 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
311 __glibcxx_function_requires(_EqualOpConcept<
312 typename iterator_traits<_InputIterator>::value_type, _Tp>)
313 __glibcxx_requires_valid_range(__first, __last);
314 return std::find(__first, __last, __val,
315 std::__iterator_category(__first));
316 }
317
318 /**
319 * @brief Find the first element in a sequence for which a predicate is true.
320 * @param first An input iterator.
321 * @param last An input iterator.
322 * @param pred A predicate.
323 * @return The first iterator @c i in the range @p [first,last)
324 * such that @p pred(*i) is true, or @p last if no such iterator exists.
325 */
326 template<typename _InputIterator, typename _Predicate>
327 inline _InputIterator
328 find_if(_InputIterator __first, _InputIterator __last,
329 _Predicate __pred)
330 {
331 // concept requirements
332 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
333 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
334 typename iterator_traits<_InputIterator>::value_type>)
335 __glibcxx_requires_valid_range(__first, __last);
336 return std::find_if(__first, __last, __pred,
337 std::__iterator_category(__first));
338 }
339
340 /**
341 * @brief Find two adjacent values in a sequence that are equal.
342 * @param first A forward iterator.
343 * @param last A forward iterator.
344 * @return The first iterator @c i such that @c i and @c i+1 are both
345 * valid iterators in @p [first,last) and such that @c *i == @c *(i+1),
346 * or @p last if no such iterator exists.
347 */
348 template<typename _ForwardIterator>
349 _ForwardIterator
350 adjacent_find(_ForwardIterator __first, _ForwardIterator __last)
351 {
352 // concept requirements
353 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
354 __glibcxx_function_requires(_EqualityComparableConcept<
355 typename iterator_traits<_ForwardIterator>::value_type>)
356 __glibcxx_requires_valid_range(__first, __last);
357 if (__first == __last)
358 return __last;
359 _ForwardIterator __next = __first;
360 while(++__next != __last)
361 {
362 if (*__first == *__next)
363 return __first;
364 __first = __next;
365 }
366 return __last;
367 }
368
369 /**
370 * @brief Find two adjacent values in a sequence using a predicate.
371 * @param first A forward iterator.
372 * @param last A forward iterator.
373 * @param binary_pred A binary predicate.
374 * @return The first iterator @c i such that @c i and @c i+1 are both
375 * valid iterators in @p [first,last) and such that
376 * @p binary_pred(*i,*(i+1)) is true, or @p last if no such iterator
377 * exists.
378 */
379 template<typename _ForwardIterator, typename _BinaryPredicate>
380 _ForwardIterator
381 adjacent_find(_ForwardIterator __first, _ForwardIterator __last,
382 _BinaryPredicate __binary_pred)
383 {
384 // concept requirements
385 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
386 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
387 typename iterator_traits<_ForwardIterator>::value_type,
388 typename iterator_traits<_ForwardIterator>::value_type>)
389 __glibcxx_requires_valid_range(__first, __last);
390 if (__first == __last)
391 return __last;
392 _ForwardIterator __next = __first;
393 while(++__next != __last)
394 {
395 if (__binary_pred(*__first, *__next))
396 return __first;
397 __first = __next;
398 }
399 return __last;
400 }
401
402 /**
403 * @brief Count the number of copies of a value in a sequence.
404 * @param first An input iterator.
405 * @param last An input iterator.
406 * @param value The value to be counted.
407 * @return The number of iterators @c i in the range @p [first,last)
408 * for which @c *i == @p value
409 */
410 template<typename _InputIterator, typename _Tp>
411 typename iterator_traits<_InputIterator>::difference_type
412 count(_InputIterator __first, _InputIterator __last, const _Tp& __value)
413 {
414 // concept requirements
415 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
416 __glibcxx_function_requires(_EqualityComparableConcept<
417 typename iterator_traits<_InputIterator>::value_type >)
418 __glibcxx_function_requires(_EqualityComparableConcept<_Tp>)
419 __glibcxx_requires_valid_range(__first, __last);
420 typename iterator_traits<_InputIterator>::difference_type __n = 0;
421 for ( ; __first != __last; ++__first)
422 if (*__first == __value)
423 ++__n;
424 return __n;
425 }
426
427 /**
428 * @brief Count the elements of a sequence for which a predicate is true.
429 * @param first An input iterator.
430 * @param last An input iterator.
431 * @param pred A predicate.
432 * @return The number of iterators @c i in the range @p [first,last)
433 * for which @p pred(*i) is true.
434 */
435 template<typename _InputIterator, typename _Predicate>
436 typename iterator_traits<_InputIterator>::difference_type
437 count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
438 {
439 // concept requirements
440 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
441 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
442 typename iterator_traits<_InputIterator>::value_type>)
443 __glibcxx_requires_valid_range(__first, __last);
444 typename iterator_traits<_InputIterator>::difference_type __n = 0;
445 for ( ; __first != __last; ++__first)
446 if (__pred(*__first))
447 ++__n;
448 return __n;
449 }
450
451 /**
452 * @brief Search a sequence for a matching sub-sequence.
453 * @param first1 A forward iterator.
454 * @param last1 A forward iterator.
455 * @param first2 A forward iterator.
456 * @param last2 A forward iterator.
457 * @return The first iterator @c i in the range
458 * @p [first1,last1-(last2-first2)) such that @c *(i+N) == @p *(first2+N)
459 * for each @c N in the range @p [0,last2-first2), or @p last1 if no
460 * such iterator exists.
461 *
462 * Searches the range @p [first1,last1) for a sub-sequence that compares
463 * equal value-by-value with the sequence given by @p [first2,last2) and
464 * returns an iterator to the first element of the sub-sequence, or
465 * @p last1 if the sub-sequence is not found.
466 *
467 * Because the sub-sequence must lie completely within the range
468 * @p [first1,last1) it must start at a position less than
469 * @p last1-(last2-first2) where @p last2-first2 is the length of the
470 * sub-sequence.
471 * This means that the returned iterator @c i will be in the range
472 * @p [first1,last1-(last2-first2))
473 */
474 template<typename _ForwardIterator1, typename _ForwardIterator2>
475 _ForwardIterator1
476 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
477 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
478 {
479 // concept requirements
480 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
481 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
482 __glibcxx_function_requires(_EqualOpConcept<
483 typename iterator_traits<_ForwardIterator1>::value_type,
484 typename iterator_traits<_ForwardIterator2>::value_type>)
485 __glibcxx_requires_valid_range(__first1, __last1);
486 __glibcxx_requires_valid_range(__first2, __last2);
487 // Test for empty ranges
488 if (__first1 == __last1 || __first2 == __last2)
489 return __first1;
490
491 // Test for a pattern of length 1.
492 _ForwardIterator2 __tmp(__first2);
493 ++__tmp;
494 if (__tmp == __last2)
495 return std::find(__first1, __last1, *__first2);
496
497 // General case.
498 _ForwardIterator2 __p1, __p;
499 __p1 = __first2; ++__p1;
500 _ForwardIterator1 __current = __first1;
501
502 while (__first1 != __last1)
503 {
504 __first1 = std::find(__first1, __last1, *__first2);
505 if (__first1 == __last1)
506 return __last1;
507
508 __p = __p1;
509 __current = __first1;
510 if (++__current == __last1)
511 return __last1;
512
513 while (*__current == *__p)
514 {
515 if (++__p == __last2)
516 return __first1;
517 if (++__current == __last1)
518 return __last1;
519 }
520 ++__first1;
521 }
522 return __first1;
523 }
524
525 /**
526 * @brief Search a sequence for a matching sub-sequence using a predicate.
527 * @param first1 A forward iterator.
528 * @param last1 A forward iterator.
529 * @param first2 A forward iterator.
530 * @param last2 A forward iterator.
531 * @param predicate A binary predicate.
532 * @return The first iterator @c i in the range
533 * @p [first1,last1-(last2-first2)) such that
534 * @p predicate(*(i+N),*(first2+N)) is true for each @c N in the range
535 * @p [0,last2-first2), or @p last1 if no such iterator exists.
536 *
537 * Searches the range @p [first1,last1) for a sub-sequence that compares
538 * equal value-by-value with the sequence given by @p [first2,last2),
539 * using @p predicate to determine equality, and returns an iterator
540 * to the first element of the sub-sequence, or @p last1 if no such
541 * iterator exists.
542 *
543 * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2)
544 */
545 template<typename _ForwardIterator1, typename _ForwardIterator2,
546 typename _BinaryPredicate>
547 _ForwardIterator1
548 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
549 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
550 _BinaryPredicate __predicate)
551 {
552 // concept requirements
553 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
554 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
555 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
556 typename iterator_traits<_ForwardIterator1>::value_type,
557 typename iterator_traits<_ForwardIterator2>::value_type>)
558 __glibcxx_requires_valid_range(__first1, __last1);
559 __glibcxx_requires_valid_range(__first2, __last2);
560
561 // Test for empty ranges
562 if (__first1 == __last1 || __first2 == __last2)
563 return __first1;
564
565 // Test for a pattern of length 1.
566 _ForwardIterator2 __tmp(__first2);
567 ++__tmp;
568 if (__tmp == __last2)
569 {
570 while (__first1 != __last1 && !__predicate(*__first1, *__first2))
571 ++__first1;
572 return __first1;
573 }
574
575 // General case.
576 _ForwardIterator2 __p1, __p;
577 __p1 = __first2; ++__p1;
578 _ForwardIterator1 __current = __first1;
579
580 while (__first1 != __last1)
581 {
582 while (__first1 != __last1)
583 {
584 if (__predicate(*__first1, *__first2))
585 break;
586 ++__first1;
587 }
588 while (__first1 != __last1 && !__predicate(*__first1, *__first2))
589 ++__first1;
590 if (__first1 == __last1)
591 return __last1;
592
593 __p = __p1;
594 __current = __first1;
595 if (++__current == __last1)
596 return __last1;
597
598 while (__predicate(*__current, *__p))
599 {
600 if (++__p == __last2)
601 return __first1;
602 if (++__current == __last1)
603 return __last1;
604 }
605 ++__first1;
606 }
607 return __first1;
608 }
609
610 /**
611 * @brief Search a sequence for a number of consecutive values.
612 * @param first A forward iterator.
613 * @param last A forward iterator.
614 * @param count The number of consecutive values.
615 * @param val The value to find.
616 * @return The first iterator @c i in the range @p [first,last-count)
617 * such that @c *(i+N) == @p val for each @c N in the range @p [0,count),
618 * or @p last if no such iterator exists.
619 *
620 * Searches the range @p [first,last) for @p count consecutive elements
621 * equal to @p val.
622 */
623 template<typename _ForwardIterator, typename _Integer, typename _Tp>
624 _ForwardIterator
625 search_n(_ForwardIterator __first, _ForwardIterator __last,
626 _Integer __count, const _Tp& __val)
627 {
628 // concept requirements
629 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
630 __glibcxx_function_requires(_EqualityComparableConcept<
631 typename iterator_traits<_ForwardIterator>::value_type>)
632 __glibcxx_function_requires(_EqualityComparableConcept<_Tp>)
633 __glibcxx_requires_valid_range(__first, __last);
634
635 if (__count <= 0)
636 return __first;
637 else
638 {
639 __first = std::find(__first, __last, __val);
640 while (__first != __last)
641 {
642 typename iterator_traits<_ForwardIterator>::difference_type
643 __n = __count;
644 _ForwardIterator __i = __first;
645 ++__i;
646 while (__i != __last && __n != 1 && *__i == __val)
647 {
648 ++__i;
649 --__n;
650 }
651 if (__n == 1)
652 return __first;
653 else
654 __first = std::find(__i, __last, __val);
655 }
656 return __last;
657 }
658 }
659
660 /**
661 * @brief Search a sequence for a number of consecutive values using a
662 * predicate.
663 * @param first A forward iterator.
664 * @param last A forward iterator.
665 * @param count The number of consecutive values.
666 * @param val The value to find.
667 * @param binary_pred A binary predicate.
668 * @return The first iterator @c i in the range @p [first,last-count)
669 * such that @p binary_pred(*(i+N),val) is true for each @c N in the
670 * range @p [0,count), or @p last if no such iterator exists.
671 *
672 * Searches the range @p [first,last) for @p count consecutive elements
673 * for which the predicate returns true.
674 */
675 template<typename _ForwardIterator, typename _Integer, typename _Tp,
676 typename _BinaryPredicate>
677 _ForwardIterator
678 search_n(_ForwardIterator __first, _ForwardIterator __last,
679 _Integer __count, const _Tp& __val,
680 _BinaryPredicate __binary_pred)
681 {
682 // concept requirements
683 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
684 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
685 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
686 __glibcxx_requires_valid_range(__first, __last);
687
688 if (__count <= 0)
689 return __first;
690 else
691 {
692 while (__first != __last)
693 {
694 if (__binary_pred(*__first, __val))
695 break;
696 ++__first;
697 }
698 while (__first != __last)
699 {
700 typename iterator_traits<_ForwardIterator>::difference_type
701 __n = __count;
702 _ForwardIterator __i = __first;
703 ++__i;
704 while (__i != __last && __n != 1 && __binary_pred(*__i, __val))
705 {
706 ++__i;
707 --__n;
708 }
709 if (__n == 1)
710 return __first;
711 else
712 {
713 while (__i != __last)
714 {
715 if (__binary_pred(*__i, __val))
716 break;
717 ++__i;
718 }
719 __first = __i;
720 }
721 }
722 return __last;
723 }
724 }
725
726 /**
727 * @brief Swap the elements of two sequences.
728 * @param first1 A forward iterator.
729 * @param last1 A forward iterator.
730 * @param first2 A forward iterator.
731 * @return An iterator equal to @p first2+(last1-first1).
732 *
733 * Swaps each element in the range @p [first1,last1) with the
734 * corresponding element in the range @p [first2,(last1-first1)).
735 * The ranges must not overlap.
736 */
737 template<typename _ForwardIterator1, typename _ForwardIterator2>
738 _ForwardIterator2
739 swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
740 _ForwardIterator2 __first2)
741 {
742 // concept requirements
743 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
744 _ForwardIterator1>)
745 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
746 _ForwardIterator2>)
747 __glibcxx_function_requires(_ConvertibleConcept<
748 typename iterator_traits<_ForwardIterator1>::value_type,
749 typename iterator_traits<_ForwardIterator2>::value_type>)
750 __glibcxx_function_requires(_ConvertibleConcept<
751 typename iterator_traits<_ForwardIterator2>::value_type,
752 typename iterator_traits<_ForwardIterator1>::value_type>)
753 __glibcxx_requires_valid_range(__first1, __last1);
754
755 for ( ; __first1 != __last1; ++__first1, ++__first2)
756 std::iter_swap(__first1, __first2);
757 return __first2;
758 }
759
760 /**
761 * @brief Perform an operation on a sequence.
762 * @param first An input iterator.
763 * @param last An input iterator.
764 * @param result An output iterator.
765 * @param unary_op A unary operator.
766 * @return An output iterator equal to @p result+(last-first).
767 *
768 * Applies the operator to each element in the input range and assigns
769 * the results to successive elements of the output sequence.
770 * Evaluates @p *(result+N)=unary_op(*(first+N)) for each @c N in the
771 * range @p [0,last-first).
772 *
773 * @p unary_op must not alter its argument.
774 */
775 template<typename _InputIterator, typename _OutputIterator,
776 typename _UnaryOperation>
777 _OutputIterator
778 transform(_InputIterator __first, _InputIterator __last,
779 _OutputIterator __result, _UnaryOperation __unary_op)
780 {
781 // concept requirements
782 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
783 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
784 // "the type returned by a _UnaryOperation"
785 __typeof__(__unary_op(*__first))>)
786 __glibcxx_requires_valid_range(__first, __last);
787
788 for ( ; __first != __last; ++__first, ++__result)
789 *__result = __unary_op(*__first);
790 return __result;
791 }
792
793 /**
794 * @brief Perform an operation on corresponding elements of two sequences.
795 * @param first1 An input iterator.
796 * @param last1 An input iterator.
797 * @param first2 An input iterator.
798 * @param result An output iterator.
799 * @param binary_op A binary operator.
800 * @return An output iterator equal to @p result+(last-first).
801 *
802 * Applies the operator to the corresponding elements in the two
803 * input ranges and assigns the results to successive elements of the
804 * output sequence.
805 * Evaluates @p *(result+N)=binary_op(*(first1+N),*(first2+N)) for each
806 * @c N in the range @p [0,last1-first1).
807 *
808 * @p binary_op must not alter either of its arguments.
809 */
810 template<typename _InputIterator1, typename _InputIterator2,
811 typename _OutputIterator, typename _BinaryOperation>
812 _OutputIterator
813 transform(_InputIterator1 __first1, _InputIterator1 __last1,
814 _InputIterator2 __first2, _OutputIterator __result,
815 _BinaryOperation __binary_op)
816 {
817 // concept requirements
818 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
819 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
820 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
821 // "the type returned by a _BinaryOperation"
822 __typeof__(__binary_op(*__first1,*__first2))>)
823 __glibcxx_requires_valid_range(__first1, __last1);
824
825 for ( ; __first1 != __last1; ++__first1, ++__first2, ++__result)
826 *__result = __binary_op(*__first1, *__first2);
827 return __result;
828 }
829
830 /**
831 * @brief Replace each occurrence of one value in a sequence with another
832 * value.
833 * @param first A forward iterator.
834 * @param last A forward iterator.
835 * @param old_value The value to be replaced.
836 * @param new_value The replacement value.
837 * @return replace() returns no value.
838 *
839 * For each iterator @c i in the range @p [first,last) if @c *i ==
840 * @p old_value then the assignment @c *i = @p new_value is performed.
841 */
842 template<typename _ForwardIterator, typename _Tp>
843 void
844 replace(_ForwardIterator __first, _ForwardIterator __last,
845 const _Tp& __old_value, const _Tp& __new_value)
846 {
847 // concept requirements
848 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
849 _ForwardIterator>)
850 __glibcxx_function_requires(_EqualOpConcept<
851 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
852 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
853 typename iterator_traits<_ForwardIterator>::value_type>)
854 __glibcxx_requires_valid_range(__first, __last);
855
856 for ( ; __first != __last; ++__first)
857 if (*__first == __old_value)
858 *__first = __new_value;
859 }
860
861 /**
862 * @brief Replace each value in a sequence for which a predicate returns
863 * true with another value.
864 * @param first A forward iterator.
865 * @param last A forward iterator.
866 * @param pred A predicate.
867 * @param new_value The replacement value.
868 * @return replace_if() returns no value.
869 *
870 * For each iterator @c i in the range @p [first,last) if @p pred(*i)
871 * is true then the assignment @c *i = @p new_value is performed.
872 */
873 template<typename _ForwardIterator, typename _Predicate, typename _Tp>
874 void
875 replace_if(_ForwardIterator __first, _ForwardIterator __last,
876 _Predicate __pred, const _Tp& __new_value)
877 {
878 // concept requirements
879 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
880 _ForwardIterator>)
881 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
882 typename iterator_traits<_ForwardIterator>::value_type>)
883 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
884 typename iterator_traits<_ForwardIterator>::value_type>)
885 __glibcxx_requires_valid_range(__first, __last);
886
887 for ( ; __first != __last; ++__first)
888 if (__pred(*__first))
889 *__first = __new_value;
890 }
891
892 /**
893 * @brief Copy a sequence, replacing each element of one value with another
894 * value.
895 * @param first An input iterator.
896 * @param last An input iterator.
897 * @param result An output iterator.
898 * @param old_value The value to be replaced.
899 * @param new_value The replacement value.
900 * @return The end of the output sequence, @p result+(last-first).
901 *
902 * Copies each element in the input range @p [first,last) to the
903 * output range @p [result,result+(last-first)) replacing elements
904 * equal to @p old_value with @p new_value.
905 */
906 template<typename _InputIterator, typename _OutputIterator, typename _Tp>
907 _OutputIterator
908 replace_copy(_InputIterator __first, _InputIterator __last,
909 _OutputIterator __result,
910 const _Tp& __old_value, const _Tp& __new_value)
911 {
912 // concept requirements
913 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
914 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
915 typename iterator_traits<_InputIterator>::value_type>)
916 __glibcxx_function_requires(_EqualOpConcept<
917 typename iterator_traits<_InputIterator>::value_type, _Tp>)
918 __glibcxx_requires_valid_range(__first, __last);
919
920 for ( ; __first != __last; ++__first, ++__result)
921 *__result = *__first == __old_value ? __new_value : *__first;
922 return __result;
923 }
924
925 /**
926 * @brief Copy a sequence, replacing each value for which a predicate
927 * returns true with another value.
928 * @param first An input iterator.
929 * @param last An input iterator.
930 * @param result An output iterator.
931 * @param pred A predicate.
932 * @param new_value The replacement value.
933 * @return The end of the output sequence, @p result+(last-first).
934 *
935 * Copies each element in the range @p [first,last) to the range
936 * @p [result,result+(last-first)) replacing elements for which
937 * @p pred returns true with @p new_value.
938 */
939 template<typename _InputIterator, typename _OutputIterator,
940 typename _Predicate, typename _Tp>
941 _OutputIterator
942 replace_copy_if(_InputIterator __first, _InputIterator __last,
943 _OutputIterator __result,
944 _Predicate __pred, const _Tp& __new_value)
945 {
946 // concept requirements
947 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
948 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
949 typename iterator_traits<_InputIterator>::value_type>)
950 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
951 typename iterator_traits<_InputIterator>::value_type>)
952 __glibcxx_requires_valid_range(__first, __last);
953
954 for ( ; __first != __last; ++__first, ++__result)
955 *__result = __pred(*__first) ? __new_value : *__first;
956 return __result;
957 }
958
959 /**
960 * @brief Assign the result of a function object to each value in a
961 * sequence.
962 * @param first A forward iterator.
963 * @param last A forward iterator.
964 * @param gen A function object taking no arguments.
965 * @return generate() returns no value.
966 *
967 * Performs the assignment @c *i = @p gen() for each @c i in the range
968 * @p [first,last).
969 */
970 template<typename _ForwardIterator, typename _Generator>
971 void
972 generate(_ForwardIterator __first, _ForwardIterator __last,
973 _Generator __gen)
974 {
975 // concept requirements
976 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
977 __glibcxx_function_requires(_GeneratorConcept<_Generator,
978 typename iterator_traits<_ForwardIterator>::value_type>)
979 __glibcxx_requires_valid_range(__first, __last);
980
981 for ( ; __first != __last; ++__first)
982 *__first = __gen();
983 }
984
985 /**
986 * @brief Assign the result of a function object to each value in a
987 * sequence.
988 * @param first A forward iterator.
989 * @param n The length of the sequence.
990 * @param gen A function object taking no arguments.
991 * @return The end of the sequence, @p first+n
992 *
993 * Performs the assignment @c *i = @p gen() for each @c i in the range
994 * @p [first,first+n).
995 */
996 template<typename _OutputIterator, typename _Size, typename _Generator>
997 _OutputIterator
998 generate_n(_OutputIterator __first, _Size __n, _Generator __gen)
999 {
1000 // concept requirements
1001 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1002 // "the type returned by a _Generator"
1003 __typeof__(__gen())>)
1004
1005 for ( ; __n > 0; --__n, ++__first)
1006 *__first = __gen();
1007 return __first;
1008 }
1009
1010 /**
1011 * @brief Copy a sequence, removing elements of a given value.
1012 * @param first An input iterator.
1013 * @param last An input iterator.
1014 * @param result An output iterator.
1015 * @param value The value to be removed.
1016 * @return An iterator designating the end of the resulting sequence.
1017 *
1018 * Copies each element in the range @p [first,last) not equal to @p value
1019 * to the range beginning at @p result.
1020 * remove_copy() is stable, so the relative order of elements that are
1021 * copied is unchanged.
1022 */
1023 template<typename _InputIterator, typename _OutputIterator, typename _Tp>
1024 _OutputIterator
1025 remove_copy(_InputIterator __first, _InputIterator __last,
1026 _OutputIterator __result, const _Tp& __value)
1027 {
1028 // concept requirements
1029 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1030 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1031 typename iterator_traits<_InputIterator>::value_type>)
1032 __glibcxx_function_requires(_EqualOpConcept<
1033 typename iterator_traits<_InputIterator>::value_type, _Tp>)
1034 __glibcxx_requires_valid_range(__first, __last);
1035
1036 for ( ; __first != __last; ++__first)
1037 if (!(*__first == __value))
1038 {
1039 *__result = *__first;
1040 ++__result;
1041 }
1042 return __result;
1043 }
1044
1045 /**
1046 * @brief Copy a sequence, removing elements for which a predicate is true.
1047 * @param first An input iterator.
1048 * @param last An input iterator.
1049 * @param result An output iterator.
1050 * @param pred A predicate.
1051 * @return An iterator designating the end of the resulting sequence.
1052 *
1053 * Copies each element in the range @p [first,last) for which
1054 * @p pred returns true to the range beginning at @p result.
1055 *
1056 * remove_copy_if() is stable, so the relative order of elements that are
1057 * copied is unchanged.
1058 */
1059 template<typename _InputIterator, typename _OutputIterator,
1060 typename _Predicate>
1061 _OutputIterator
1062 remove_copy_if(_InputIterator __first, _InputIterator __last,
1063 _OutputIterator __result, _Predicate __pred)
1064 {
1065 // concept requirements
1066 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1067 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1068 typename iterator_traits<_InputIterator>::value_type>)
1069 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1070 typename iterator_traits<_InputIterator>::value_type>)
1071 __glibcxx_requires_valid_range(__first, __last);
1072
1073 for ( ; __first != __last; ++__first)
1074 if (!__pred(*__first))
1075 {
1076 *__result = *__first;
1077 ++__result;
1078 }
1079 return __result;
1080 }
1081
1082 /**
1083 * @brief Remove elements from a sequence.
1084 * @param first An input iterator.
1085 * @param last An input iterator.
1086 * @param value The value to be removed.
1087 * @return An iterator designating the end of the resulting sequence.
1088 *
1089 * All elements equal to @p value are removed from the range
1090 * @p [first,last).
1091 *
1092 * remove() is stable, so the relative order of elements that are
1093 * not removed is unchanged.
1094 *
1095 * Elements between the end of the resulting sequence and @p last
1096 * are still present, but their value is unspecified.
1097 */
1098 template<typename _ForwardIterator, typename _Tp>
1099 _ForwardIterator
1100 remove(_ForwardIterator __first, _ForwardIterator __last,
1101 const _Tp& __value)
1102 {
1103 // concept requirements
1104 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1105 _ForwardIterator>)
1106 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
1107 typename iterator_traits<_ForwardIterator>::value_type>)
1108 __glibcxx_function_requires(_EqualOpConcept<
1109 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
1110 __glibcxx_requires_valid_range(__first, __last);
1111
1112 __first = std::find(__first, __last, __value);
1113 _ForwardIterator __i = __first;
1114 return __first == __last ? __first
1115 : std::remove_copy(++__i, __last,
1116 __first, __value);
1117 }
1118
1119 /**
1120 * @brief Remove elements from a sequence using a predicate.
1121 * @param first A forward iterator.
1122 * @param last A forward iterator.
1123 * @param pred A predicate.
1124 * @return An iterator designating the end of the resulting sequence.
1125 *
1126 * All elements for which @p pred returns true are removed from the range
1127 * @p [first,last).
1128 *
1129 * remove_if() is stable, so the relative order of elements that are
1130 * not removed is unchanged.
1131 *
1132 * Elements between the end of the resulting sequence and @p last
1133 * are still present, but their value is unspecified.
1134 */
1135 template<typename _ForwardIterator, typename _Predicate>
1136 _ForwardIterator
1137 remove_if(_ForwardIterator __first, _ForwardIterator __last,
1138 _Predicate __pred)
1139 {
1140 // concept requirements
1141 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1142 _ForwardIterator>)
1143 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1144 typename iterator_traits<_ForwardIterator>::value_type>)
1145 __glibcxx_requires_valid_range(__first, __last);
1146
1147 __first = std::find_if(__first, __last, __pred);
1148 _ForwardIterator __i = __first;
1149 return __first == __last ? __first
1150 : std::remove_copy_if(++__i, __last,
1151 __first, __pred);
1152 }
1153
1154 /**
1155 * @if maint
1156 * This is an uglified unique_copy(_InputIterator, _InputIterator,
1157 * _OutputIterator)
1158 * overloaded for output iterators.
1159 * @endif
1160 */
1161 template<typename _InputIterator, typename _OutputIterator>
1162 _OutputIterator
1163 __unique_copy(_InputIterator __first, _InputIterator __last,
1164 _OutputIterator __result,
1165 output_iterator_tag)
1166 {
1167 // concept requirements -- taken care of in dispatching function
1168 typename iterator_traits<_InputIterator>::value_type __value = *__first;
1169 *__result = __value;
1170 while (++__first != __last)
1171 if (!(__value == *__first))
1172 {
1173 __value = *__first;
1174 *++__result = __value;
1175 }
1176 return ++__result;
1177 }
1178
1179 /**
1180 * @if maint
1181 * This is an uglified unique_copy(_InputIterator, _InputIterator,
1182 * _OutputIterator)
1183 * overloaded for forward iterators.
1184 * @endif
1185 */
1186 template<typename _InputIterator, typename _ForwardIterator>
1187 _ForwardIterator
1188 __unique_copy(_InputIterator __first, _InputIterator __last,
1189 _ForwardIterator __result,
1190 forward_iterator_tag)
1191 {
1192 // concept requirements -- taken care of in dispatching function
1193 *__result = *__first;
1194 while (++__first != __last)
1195 if (!(*__result == *__first))
1196 *++__result = *__first;
1197 return ++__result;
1198 }
1199
1200 /**
1201 * @if maint
1202 * This is an uglified
1203 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1204 * _BinaryPredicate)
1205 * overloaded for output iterators.
1206 * @endif
1207 */
1208 template<typename _InputIterator, typename _OutputIterator,
1209 typename _BinaryPredicate>
1210 _OutputIterator
1211 __unique_copy(_InputIterator __first, _InputIterator __last,
1212 _OutputIterator __result,
1213 _BinaryPredicate __binary_pred,
1214 output_iterator_tag)
1215 {
1216 // concept requirements -- iterators already checked
1217 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1218 typename iterator_traits<_InputIterator>::value_type,
1219 typename iterator_traits<_InputIterator>::value_type>)
1220
1221 typename iterator_traits<_InputIterator>::value_type __value = *__first;
1222 *__result = __value;
1223 while (++__first != __last)
1224 if (!__binary_pred(__value, *__first))
1225 {
1226 __value = *__first;
1227 *++__result = __value;
1228 }
1229 return ++__result;
1230 }
1231
1232 /**
1233 * @if maint
1234 * This is an uglified
1235 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1236 * _BinaryPredicate)
1237 * overloaded for forward iterators.
1238 * @endif
1239 */
1240 template<typename _InputIterator, typename _ForwardIterator,
1241 typename _BinaryPredicate>
1242 _ForwardIterator
1243 __unique_copy(_InputIterator __first, _InputIterator __last,
1244 _ForwardIterator __result,
1245 _BinaryPredicate __binary_pred,
1246 forward_iterator_tag)
1247 {
1248 // concept requirements -- iterators already checked
1249 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1250 typename iterator_traits<_ForwardIterator>::value_type,
1251 typename iterator_traits<_InputIterator>::value_type>)
1252
1253 *__result = *__first;
1254 while (++__first != __last)
1255 if (!__binary_pred(*__result, *__first)) *++__result = *__first;
1256 return ++__result;
1257 }
1258
1259 /**
1260 * @brief Copy a sequence, removing consecutive duplicate values.
1261 * @param first An input iterator.
1262 * @param last An input iterator.
1263 * @param result An output iterator.
1264 * @return An iterator designating the end of the resulting sequence.
1265 *
1266 * Copies each element in the range @p [first,last) to the range
1267 * beginning at @p result, except that only the first element is copied
1268 * from groups of consecutive elements that compare equal.
1269 * unique_copy() is stable, so the relative order of elements that are
1270 * copied is unchanged.
1271 */
1272 template<typename _InputIterator, typename _OutputIterator>
1273 inline _OutputIterator
1274 unique_copy(_InputIterator __first, _InputIterator __last,
1275 _OutputIterator __result)
1276 {
1277 // concept requirements
1278 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1279 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1280 typename iterator_traits<_InputIterator>::value_type>)
1281 __glibcxx_function_requires(_EqualityComparableConcept<
1282 typename iterator_traits<_InputIterator>::value_type>)
1283 __glibcxx_requires_valid_range(__first, __last);
1284
1285 typedef typename iterator_traits<_OutputIterator>::iterator_category
1286 _IterType;
1287
1288 if (__first == __last) return __result;
1289 return std::__unique_copy(__first, __last, __result, _IterType());
1290 }
1291
1292 /**
1293 * @brief Copy a sequence, removing consecutive values using a predicate.
1294 * @param first An input iterator.
1295 * @param last An input iterator.
1296 * @param result An output iterator.
1297 * @param binary_pred A binary predicate.
1298 * @return An iterator designating the end of the resulting sequence.
1299 *
1300 * Copies each element in the range @p [first,last) to the range
1301 * beginning at @p result, except that only the first element is copied
1302 * from groups of consecutive elements for which @p binary_pred returns
1303 * true.
1304 * unique_copy() is stable, so the relative order of elements that are
1305 * copied is unchanged.
1306 */
1307 template<typename _InputIterator, typename _OutputIterator,
1308 typename _BinaryPredicate>
1309 inline _OutputIterator
1310 unique_copy(_InputIterator __first, _InputIterator __last,
1311 _OutputIterator __result,
1312 _BinaryPredicate __binary_pred)
1313 {
1314 // concept requirements -- predicates checked later
1315 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1316 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1317 typename iterator_traits<_InputIterator>::value_type>)
1318 __glibcxx_requires_valid_range(__first, __last);
1319
1320 typedef typename iterator_traits<_OutputIterator>::iterator_category
1321 _IterType;
1322
1323 if (__first == __last) return __result;
1324 return std::__unique_copy(__first, __last, __result,
1325 __binary_pred, _IterType());
1326 }
1327
1328 /**
1329 * @brief Remove consecutive duplicate values from a sequence.
1330 * @param first A forward iterator.
1331 * @param last A forward iterator.
1332 * @return An iterator designating the end of the resulting sequence.
1333 *
1334 * Removes all but the first element from each group of consecutive
1335 * values that compare equal.
1336 * unique() is stable, so the relative order of elements that are
1337 * not removed is unchanged.
1338 * Elements between the end of the resulting sequence and @p last
1339 * are still present, but their value is unspecified.
1340 */
1341 template<typename _ForwardIterator>
1342 _ForwardIterator
1343 unique(_ForwardIterator __first, _ForwardIterator __last)
1344 {
1345 // concept requirements
1346 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1347 _ForwardIterator>)
1348 __glibcxx_function_requires(_EqualityComparableConcept<
1349 typename iterator_traits<_ForwardIterator>::value_type>)
1350 __glibcxx_requires_valid_range(__first, __last);
1351
1352 // Skip the beginning, if already unique.
1353 __first = std::adjacent_find(__first, __last);
1354 if (__first == __last)
1355 return __last;
1356
1357 // Do the real copy work.
1358 _ForwardIterator __dest = __first;
1359 ++__first;
1360 while (++__first != __last)
1361 if (!(*__dest == *__first))
1362 *++__dest = *__first;
1363 return ++__dest;
1364 }
1365
1366 /**
1367 * @brief Remove consecutive values from a sequence using a predicate.
1368 * @param first A forward iterator.
1369 * @param last A forward iterator.
1370 * @param binary_pred A binary predicate.
1371 * @return An iterator designating the end of the resulting sequence.
1372 *
1373 * Removes all but the first element from each group of consecutive
1374 * values for which @p binary_pred returns true.
1375 * unique() is stable, so the relative order of elements that are
1376 * not removed is unchanged.
1377 * Elements between the end of the resulting sequence and @p last
1378 * are still present, but their value is unspecified.
1379 */
1380 template<typename _ForwardIterator, typename _BinaryPredicate>
1381 _ForwardIterator
1382 unique(_ForwardIterator __first, _ForwardIterator __last,
1383 _BinaryPredicate __binary_pred)
1384 {
1385 // concept requirements
1386 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1387 _ForwardIterator>)
1388 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1389 typename iterator_traits<_ForwardIterator>::value_type,
1390 typename iterator_traits<_ForwardIterator>::value_type>)
1391 __glibcxx_requires_valid_range(__first, __last);
1392
1393 // Skip the beginning, if already unique.
1394 __first = std::adjacent_find(__first, __last, __binary_pred);
1395 if (__first == __last)
1396 return __last;
1397
1398 // Do the real copy work.
1399 _ForwardIterator __dest = __first;
1400 ++__first;
1401 while (++__first != __last)
1402 if (!__binary_pred(*__dest, *__first))
1403 *++__dest = *__first;
1404 return ++__dest;
1405 }
1406
1407 /**
1408 * @if maint
1409 * This is an uglified reverse(_BidirectionalIterator,
1410 * _BidirectionalIterator)
1411 * overloaded for bidirectional iterators.
1412 * @endif
1413 */
1414 template<typename _BidirectionalIterator>
1415 void
1416 __reverse(_BidirectionalIterator __first, _BidirectionalIterator __last,
1417 bidirectional_iterator_tag)
1418 {
1419 while (true)
1420 if (__first == __last || __first == --__last)
1421 return;
1422 else
1423 std::iter_swap(__first++, __last);
1424 }
1425
1426 /**
1427 * @if maint
1428 * This is an uglified reverse(_BidirectionalIterator,
1429 * _BidirectionalIterator)
1430 * overloaded for bidirectional iterators.
1431 * @endif
1432 */
1433 template<typename _RandomAccessIterator>
1434 void
1435 __reverse(_RandomAccessIterator __first, _RandomAccessIterator __last,
1436 random_access_iterator_tag)
1437 {
1438 while (__first < __last)
1439 std::iter_swap(__first++, --__last);
1440 }
1441
1442 /**
1443 * @brief Reverse a sequence.
1444 * @param first A bidirectional iterator.
1445 * @param last A bidirectional iterator.
1446 * @return reverse() returns no value.
1447 *
1448 * Reverses the order of the elements in the range @p [first,last),
1449 * so that the first element becomes the last etc.
1450 * For every @c i such that @p 0<=i<=(last-first)/2), @p reverse()
1451 * swaps @p *(first+i) and @p *(last-(i+1))
1452 */
1453 template<typename _BidirectionalIterator>
1454 inline void
1455 reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
1456 {
1457 // concept requirements
1458 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
1459 _BidirectionalIterator>)
1460 __glibcxx_requires_valid_range(__first, __last);
1461 std::__reverse(__first, __last, std::__iterator_category(__first));
1462 }
1463
1464 /**
1465 * @brief Copy a sequence, reversing its elements.
1466 * @param first A bidirectional iterator.
1467 * @param last A bidirectional iterator.
1468 * @param result An output iterator.
1469 * @return An iterator designating the end of the resulting sequence.
1470 *
1471 * Copies the elements in the range @p [first,last) to the range
1472 * @p [result,result+(last-first)) such that the order of the
1473 * elements is reversed.
1474 * For every @c i such that @p 0<=i<=(last-first), @p reverse_copy()
1475 * performs the assignment @p *(result+(last-first)-i) = *(first+i).
1476 * The ranges @p [first,last) and @p [result,result+(last-first))
1477 * must not overlap.
1478 */
1479 template<typename _BidirectionalIterator, typename _OutputIterator>
1480 _OutputIterator
1481 reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last,
1482 _OutputIterator __result)
1483 {
1484 // concept requirements
1485 __glibcxx_function_requires(_BidirectionalIteratorConcept<
1486 _BidirectionalIterator>)
1487 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1488 typename iterator_traits<_BidirectionalIterator>::value_type>)
1489 __glibcxx_requires_valid_range(__first, __last);
1490
1491 while (__first != __last)
1492 {
1493 --__last;
1494 *__result = *__last;
1495 ++__result;
1496 }
1497 return __result;
1498 }
1499
1500
1501 /**
1502 * @if maint
1503 * This is a helper function for the rotate algorithm specialized on RAIs.
1504 * It returns the greatest common divisor of two integer values.
1505 * @endif
1506 */
1507 template<typename _EuclideanRingElement>
1508 _EuclideanRingElement
1509 __gcd(_EuclideanRingElement __m, _EuclideanRingElement __n)
1510 {
1511 while (__n != 0)
1512 {
1513 _EuclideanRingElement __t = __m % __n;
1514 __m = __n;
1515 __n = __t;
1516 }
1517 return __m;
1518 }
1519
1520 /**
1521 * @if maint
1522 * This is a helper function for the rotate algorithm.
1523 * @endif
1524 */
1525 template<typename _ForwardIterator>
1526 void
1527 __rotate(_ForwardIterator __first,
1528 _ForwardIterator __middle,
1529 _ForwardIterator __last,
1530 forward_iterator_tag)
1531 {
1532 if ((__first == __middle) || (__last == __middle))
1533 return;
1534
1535 _ForwardIterator __first2 = __middle;
1536 do
1537 {
1538 swap(*__first++, *__first2++);
1539 if (__first == __middle)
1540 __middle = __first2;
1541 }
1542 while (__first2 != __last);
1543
1544 __first2 = __middle;
1545
1546 while (__first2 != __last)
1547 {
1548 swap(*__first++, *__first2++);
1549 if (__first == __middle)
1550 __middle = __first2;
1551 else if (__first2 == __last)
1552 __first2 = __middle;
1553 }
1554 }
1555
1556 /**
1557 * @if maint
1558 * This is a helper function for the rotate algorithm.
1559 * @endif
1560 */
1561 template<typename _BidirectionalIterator>
1562 void
1563 __rotate(_BidirectionalIterator __first,
1564 _BidirectionalIterator __middle,
1565 _BidirectionalIterator __last,
1566 bidirectional_iterator_tag)
1567 {
1568 // concept requirements
1569 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
1570 _BidirectionalIterator>)
1571
1572 if ((__first == __middle) || (__last == __middle))
1573 return;
1574
1575 std::__reverse(__first, __middle, bidirectional_iterator_tag());
1576 std::__reverse(__middle, __last, bidirectional_iterator_tag());
1577
1578 while (__first != __middle && __middle != __last)
1579 swap(*__first++, *--__last);
1580
1581 if (__first == __middle)
1582 std::__reverse(__middle, __last, bidirectional_iterator_tag());
1583 else
1584 std::__reverse(__first, __middle, bidirectional_iterator_tag());
1585 }
1586
1587 /**
1588 * @if maint
1589 * This is a helper function for the rotate algorithm.
1590 * @endif
1591 */
1592 template<typename _RandomAccessIterator>
1593 void
1594 __rotate(_RandomAccessIterator __first,
1595 _RandomAccessIterator __middle,
1596 _RandomAccessIterator __last,
1597 random_access_iterator_tag)
1598 {
1599 // concept requirements
1600 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1601 _RandomAccessIterator>)
1602
1603 if ((__first == __middle) || (__last == __middle))
1604 return;
1605
1606 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
1607 _Distance;
1608 typedef typename iterator_traits<_RandomAccessIterator>::value_type
1609 _ValueType;
1610
1611 const _Distance __n = __last - __first;
1612 const _Distance __k = __middle - __first;
1613 const _Distance __l = __n - __k;
1614
1615 if (__k == __l)
1616 {
1617 std::swap_ranges(__first, __middle, __middle);
1618 return;
1619 }
1620
1621 const _Distance __d = __gcd(__n, __k);
1622
1623 for (_Distance __i = 0; __i < __d; __i++)
1624 {
1625 const _ValueType __tmp = *__first;
1626 _RandomAccessIterator __p = __first;
1627
1628 if (__k < __l)
1629 {
1630 for (_Distance __j = 0; __j < __l / __d; __j++)
1631 {
1632 if (__p > __first + __l)
1633 {
1634 *__p = *(__p - __l);
1635 __p -= __l;
1636 }
1637
1638 *__p = *(__p + __k);
1639 __p += __k;
1640 }
1641 }
1642 else
1643 {
1644 for (_Distance __j = 0; __j < __k / __d - 1; __j ++)
1645 {
1646 if (__p < __last - __k)
1647 {
1648 *__p = *(__p + __k);
1649 __p += __k;
1650 }
1651 *__p = * (__p - __l);
1652 __p -= __l;
1653 }
1654 }
1655
1656 *__p = __tmp;
1657 ++__first;
1658 }
1659 }
1660
1661 /**
1662 * @brief Rotate the elements of a sequence.
1663 * @param first A forward iterator.
1664 * @param middle A forward iterator.
1665 * @param last A forward iterator.
1666 * @return Nothing.
1667 *
1668 * Rotates the elements of the range @p [first,last) by @p (middle-first)
1669 * positions so that the element at @p middle is moved to @p first, the
1670 * element at @p middle+1 is moved to @first+1 and so on for each element
1671 * in the range @p [first,last).
1672 *
1673 * This effectively swaps the ranges @p [first,middle) and
1674 * @p [middle,last).
1675 *
1676 * Performs @p *(first+(n+(last-middle))%(last-first))=*(first+n) for
1677 * each @p n in the range @p [0,last-first).
1678 */
1679 template<typename _ForwardIterator>
1680 inline void
1681 rotate(_ForwardIterator __first, _ForwardIterator __middle,
1682 _ForwardIterator __last)
1683 {
1684 // concept requirements
1685 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1686 _ForwardIterator>)
1687 __glibcxx_requires_valid_range(__first, __middle);
1688 __glibcxx_requires_valid_range(__middle, __last);
1689
1690 typedef typename iterator_traits<_ForwardIterator>::iterator_category
1691 _IterType;
1692 std::__rotate(__first, __middle, __last, _IterType());
1693 }
1694
1695 /**
1696 * @brief Copy a sequence, rotating its elements.
1697 * @param first A forward iterator.
1698 * @param middle A forward iterator.
1699 * @param last A forward iterator.
1700 * @param result An output iterator.
1701 * @return An iterator designating the end of the resulting sequence.
1702 *
1703 * Copies the elements of the range @p [first,last) to the range
1704 * beginning at @result, rotating the copied elements by @p (middle-first)
1705 * positions so that the element at @p middle is moved to @p result, the
1706 * element at @p middle+1 is moved to @result+1 and so on for each element
1707 * in the range @p [first,last).
1708 *
1709 * Performs @p *(result+(n+(last-middle))%(last-first))=*(first+n) for
1710 * each @p n in the range @p [0,last-first).
1711 */
1712 template<typename _ForwardIterator, typename _OutputIterator>
1713 _OutputIterator
1714 rotate_copy(_ForwardIterator __first, _ForwardIterator __middle,
1715 _ForwardIterator __last, _OutputIterator __result)
1716 {
1717 // concept requirements
1718 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1719 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1720 typename iterator_traits<_ForwardIterator>::value_type>)
1721 __glibcxx_requires_valid_range(__first, __middle);
1722 __glibcxx_requires_valid_range(__middle, __last);
1723
1724 return std::copy(__first, __middle, copy(__middle, __last, __result));
1725 }
1726
1727 /**
1728 * @brief Randomly shuffle the elements of a sequence.
1729 * @param first A forward iterator.
1730 * @param last A forward iterator.
1731 * @return Nothing.
1732 *
1733 * Reorder the elements in the range @p [first,last) using a random
1734 * distribution, so that every possible ordering of the sequence is
1735 * equally likely.
1736 */
1737 template<typename _RandomAccessIterator>
1738 inline void
1739 random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
1740 {
1741 // concept requirements
1742 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1743 _RandomAccessIterator>)
1744 __glibcxx_requires_valid_range(__first, __last);
1745
1746 if (__first != __last)
1747 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
1748 std::iter_swap(__i, __first + (std::rand() % ((__i - __first) + 1)));
1749 }
1750
1751 /**
1752 * @brief Shuffle the elements of a sequence using a random number
1753 * generator.
1754 * @param first A forward iterator.
1755 * @param last A forward iterator.
1756 * @param rand The RNG functor or function.
1757 * @return Nothing.
1758 *
1759 * Reorders the elements in the range @p [first,last) using @p rand to
1760 * provide a random distribution. Calling @p rand(N) for a positive
1761 * integer @p N should return a randomly chosen integer from the
1762 * range [0,N).
1763 */
1764 template<typename _RandomAccessIterator, typename _RandomNumberGenerator>
1765 void
1766 random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
1767 _RandomNumberGenerator& __rand)
1768 {
1769 // concept requirements
1770 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1771 _RandomAccessIterator>)
1772 __glibcxx_requires_valid_range(__first, __last);
1773
1774 if (__first == __last)
1775 return;
1776 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
1777 std::iter_swap(__i, __first + __rand((__i - __first) + 1));
1778 }
1779
1780
1781 /**
1782 * @if maint
1783 * This is a helper function...
1784 * @endif
1785 */
1786 template<typename _ForwardIterator, typename _Predicate>
1787 _ForwardIterator
1788 __partition(_ForwardIterator __first, _ForwardIterator __last,
1789 _Predicate __pred,
1790 forward_iterator_tag)
1791 {
1792 if (__first == __last)
1793 return __first;
1794
1795 while (__pred(*__first))
1796 if (++__first == __last)
1797 return __first;
1798
1799 _ForwardIterator __next = __first;
1800
1801 while (++__next != __last)
1802 if (__pred(*__next))
1803 {
1804 swap(*__first, *__next);
1805 ++__first;
1806 }
1807
1808 return __first;
1809 }
1810
1811 /**
1812 * @if maint
1813 * This is a helper function...
1814 * @endif
1815 */
1816 template<typename _BidirectionalIterator, typename _Predicate>
1817 _BidirectionalIterator
1818 __partition(_BidirectionalIterator __first, _BidirectionalIterator __last,
1819 _Predicate __pred,
1820 bidirectional_iterator_tag)
1821 {
1822 while (true)
1823 {
1824 while (true)
1825 if (__first == __last)
1826 return __first;
1827 else if (__pred(*__first))
1828 ++__first;
1829 else
1830 break;
1831 --__last;
1832 while (true)
1833 if (__first == __last)
1834 return __first;
1835 else if (!__pred(*__last))
1836 --__last;
1837 else
1838 break;
1839 std::iter_swap(__first, __last);
1840 ++__first;
1841 }
1842 }
1843
1844 /**
1845 * @brief Move elements for which a predicate is true to the beginning
1846 * of a sequence.
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 * @p pred must not modify its operand. @p partition() does not preserve
1855 * the relative ordering of elements in each group, use
1856 * @p stable_partition() if this is needed.
1857 */
1858 template<typename _ForwardIterator, typename _Predicate>
1859 inline _ForwardIterator
1860 partition(_ForwardIterator __first, _ForwardIterator __last,
1861 _Predicate __pred)
1862 {
1863 // concept requirements
1864 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1865 _ForwardIterator>)
1866 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1867 typename iterator_traits<_ForwardIterator>::value_type>)
1868 __glibcxx_requires_valid_range(__first, __last);
1869
1870 return std::__partition(__first, __last, __pred,
1871 std::__iterator_category(__first));
1872 }
1873
1874
1875 /**
1876 * @if maint
1877 * This is a helper function...
1878 * @endif
1879 */
1880 template<typename _ForwardIterator, typename _Predicate, typename _Distance>
1881 _ForwardIterator
1882 __inplace_stable_partition(_ForwardIterator __first,
1883 _ForwardIterator __last,
1884 _Predicate __pred, _Distance __len)
1885 {
1886 if (__len == 1)
1887 return __pred(*__first) ? __last : __first;
1888 _ForwardIterator __middle = __first;
1889 std::advance(__middle, __len / 2);
1890 _ForwardIterator __begin = std::__inplace_stable_partition(__first,
1891 __middle,
1892 __pred,
1893 __len / 2);
1894 _ForwardIterator __end = std::__inplace_stable_partition(__middle, __last,
1895 __pred,
1896 __len
1897 - __len / 2);
1898 std::rotate(__begin, __middle, __end);
1899 std::advance(__begin, std::distance(__middle, __end));
1900 return __begin;
1901 }
1902
1903 /**
1904 * @if maint
1905 * This is a helper function...
1906 * @endif
1907 */
1908 template<typename _ForwardIterator, typename _Pointer, typename _Predicate,
1909 typename _Distance>
1910 _ForwardIterator
1911 __stable_partition_adaptive(_ForwardIterator __first,
1912 _ForwardIterator __last,
1913 _Predicate __pred, _Distance __len,
1914 _Pointer __buffer,
1915 _Distance __buffer_size)
1916 {
1917 if (__len <= __buffer_size)
1918 {
1919 _ForwardIterator __result1 = __first;
1920 _Pointer __result2 = __buffer;
1921 for ( ; __first != __last ; ++__first)
1922 if (__pred(*__first))
1923 {
1924 *__result1 = *__first;
1925 ++__result1;
1926 }
1927 else
1928 {
1929 *__result2 = *__first;
1930 ++__result2;
1931 }
1932 std::copy(__buffer, __result2, __result1);
1933 return __result1;
1934 }
1935 else
1936 {
1937 _ForwardIterator __middle = __first;
1938 std::advance(__middle, __len / 2);
1939 _ForwardIterator __begin =
1940 std::__stable_partition_adaptive(__first, __middle, __pred,
1941 __len / 2, __buffer,
1942 __buffer_size);
1943 _ForwardIterator __end =
1944 std::__stable_partition_adaptive(__middle, __last, __pred,
1945 __len - __len / 2,
1946 __buffer, __buffer_size);
1947 std::rotate(__begin, __middle, __end);
1948 std::advance(__begin, std::distance(__middle, __end));
1949 return __begin;
1950 }
1951 }
1952
1953 /**
1954 * @brief Move elements for which a predicate is true to the beginning
1955 * of a sequence, preserving relative ordering.
1956 * @param first A forward iterator.
1957 * @param last A forward iterator.
1958 * @param pred A predicate functor.
1959 * @return An iterator @p middle such that @p pred(i) is true for each
1960 * iterator @p i in the range @p [first,middle) and false for each @p i
1961 * in the range @p [middle,last).
1962 *
1963 * Performs the same function as @p partition() with the additional
1964 * guarantee that the relative ordering of elements in each group is
1965 * preserved, so any two elements @p x and @p y in the range
1966 * @p [first,last) such that @p pred(x)==pred(y) will have the same
1967 * relative ordering after calling @p stable_partition().
1968 */
1969 template<typename _ForwardIterator, typename _Predicate>
1970 _ForwardIterator
1971 stable_partition(_ForwardIterator __first, _ForwardIterator __last,
1972 _Predicate __pred)
1973 {
1974 // concept requirements
1975 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1976 _ForwardIterator>)
1977 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1978 typename iterator_traits<_ForwardIterator>::value_type>)
1979 __glibcxx_requires_valid_range(__first, __last);
1980
1981 if (__first == __last)
1982 return __first;
1983 else
1984 {
1985 typedef typename iterator_traits<_ForwardIterator>::value_type
1986 _ValueType;
1987 typedef typename iterator_traits<_ForwardIterator>::difference_type
1988 _DistanceType;
1989
1990 _Temporary_buffer<_ForwardIterator, _ValueType> __buf(__first,
1991 __last);
1992 if (__buf.size() > 0)
1993 return
1994 std::__stable_partition_adaptive(__first, __last, __pred,
1995 _DistanceType(__buf.requested_size()),
1996 __buf.begin(), __buf.size());
1997 else
1998 return
1999 std::__inplace_stable_partition(__first, __last, __pred,
2000 _DistanceType(__buf.requested_size()));
2001 }
2002 }
2003
2004 /**
2005 * @if maint
2006 * This is a helper function...
2007 * @endif
2008 */
2009 template<typename _RandomAccessIterator, typename _Tp>
2010 _RandomAccessIterator
2011 __unguarded_partition(_RandomAccessIterator __first,
2012 _RandomAccessIterator __last, _Tp __pivot)
2013 {
2014 while (true)
2015 {
2016 while (*__first < __pivot)
2017 ++__first;
2018 --__last;
2019 while (__pivot < *__last)
2020 --__last;
2021 if (!(__first < __last))
2022 return __first;
2023 std::iter_swap(__first, __last);
2024 ++__first;
2025 }
2026 }
2027
2028 /**
2029 * @if maint
2030 * This is a helper function...
2031 * @endif
2032 */
2033 template<typename _RandomAccessIterator, typename _Tp, typename _Compare>
2034 _RandomAccessIterator
2035 __unguarded_partition(_RandomAccessIterator __first,
2036 _RandomAccessIterator __last,
2037 _Tp __pivot, _Compare __comp)
2038 {
2039 while (true)
2040 {
2041 while (__comp(*__first, __pivot))
2042 ++__first;
2043 --__last;
2044 while (__comp(__pivot, *__last))
2045 --__last;
2046 if (!(__first < __last))
2047 return __first;
2048 std::iter_swap(__first, __last);
2049 ++__first;
2050 }
2051 }
2052
2053 /**
2054 * @if maint
2055 * @doctodo
2056 * This controls some aspect of the sort routines.
2057 * @endif
2058 */
2059 enum { _S_threshold = 16 };
2060
2061 /**
2062 * @if maint
2063 * This is a helper function for the sort routine.
2064 * @endif
2065 */
2066 template<typename _RandomAccessIterator, typename _Tp>
2067 void
2068 __unguarded_linear_insert(_RandomAccessIterator __last, _Tp __val)
2069 {
2070 _RandomAccessIterator __next = __last;
2071 --__next;
2072 while (__val < *__next)
2073 {
2074 *__last = *__next;
2075 __last = __next;
2076 --__next;
2077 }
2078 *__last = __val;
2079 }
2080
2081 /**
2082 * @if maint
2083 * This is a helper function for the sort routine.
2084 * @endif
2085 */
2086 template<typename _RandomAccessIterator, typename _Tp, typename _Compare>
2087 void
2088 __unguarded_linear_insert(_RandomAccessIterator __last, _Tp __val,
2089 _Compare __comp)
2090 {
2091 _RandomAccessIterator __next = __last;
2092 --__next;
2093 while (__comp(__val, *__next))
2094 {
2095 *__last = *__next;
2096 __last = __next;
2097 --__next;
2098 }
2099 *__last = __val;
2100 }
2101
2102 /**
2103 * @if maint
2104 * This is a helper function for the sort routine.
2105 * @endif
2106 */
2107 template<typename _RandomAccessIterator>
2108 void
2109 __insertion_sort(_RandomAccessIterator __first,
2110 _RandomAccessIterator __last)
2111 {
2112 if (__first == __last)
2113 return;
2114
2115 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
2116 {
2117 typename iterator_traits<_RandomAccessIterator>::value_type
2118 __val = *__i;
2119 if (__val < *__first)
2120 {
2121 std::copy_backward(__first, __i, __i + 1);
2122 *__first = __val;
2123 }
2124 else
2125 std::__unguarded_linear_insert(__i, __val);
2126 }
2127 }
2128
2129 /**
2130 * @if maint
2131 * This is a helper function for the sort routine.
2132 * @endif
2133 */
2134 template<typename _RandomAccessIterator, typename _Compare>
2135 void
2136 __insertion_sort(_RandomAccessIterator __first,
2137 _RandomAccessIterator __last, _Compare __comp)
2138 {
2139 if (__first == __last) return;
2140
2141 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
2142 {
2143 typename iterator_traits<_RandomAccessIterator>::value_type
2144 __val = *__i;
2145 if (__comp(__val, *__first))
2146 {
2147 std::copy_backward(__first, __i, __i + 1);
2148 *__first = __val;
2149 }
2150 else
2151 std::__unguarded_linear_insert(__i, __val, __comp);
2152 }
2153 }
2154
2155 /**
2156 * @if maint
2157 * This is a helper function for the sort routine.
2158 * @endif
2159 */
2160 template<typename _RandomAccessIterator>
2161 inline void
2162 __unguarded_insertion_sort(_RandomAccessIterator __first,
2163 _RandomAccessIterator __last)
2164 {
2165 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2166 _ValueType;
2167
2168 for (_RandomAccessIterator __i = __first; __i != __last; ++__i)
2169 std::__unguarded_linear_insert(__i, _ValueType(*__i));
2170 }
2171
2172 /**
2173 * @if maint
2174 * This is a helper function for the sort routine.
2175 * @endif
2176 */
2177 template<typename _RandomAccessIterator, typename _Compare>
2178 inline void
2179 __unguarded_insertion_sort(_RandomAccessIterator __first,
2180 _RandomAccessIterator __last, _Compare __comp)
2181 {
2182 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2183 _ValueType;
2184
2185 for (_RandomAccessIterator __i = __first; __i != __last; ++__i)
2186 std::__unguarded_linear_insert(__i, _ValueType(*__i), __comp);
2187 }
2188
2189 /**
2190 * @if maint
2191 * This is a helper function for the sort routine.
2192 * @endif
2193 */
2194 template<typename _RandomAccessIterator>
2195 void
2196 __final_insertion_sort(_RandomAccessIterator __first,
2197 _RandomAccessIterator __last)
2198 {
2199 if (__last - __first > _S_threshold)
2200 {
2201 std::__insertion_sort(__first, __first + _S_threshold);
2202 std::__unguarded_insertion_sort(__first + _S_threshold, __last);
2203 }
2204 else
2205 std::__insertion_sort(__first, __last);
2206 }
2207
2208 /**
2209 * @if maint
2210 * This is a helper function for the sort routine.
2211 * @endif
2212 */
2213 template<typename _RandomAccessIterator, typename _Compare>
2214 void
2215 __final_insertion_sort(_RandomAccessIterator __first,
2216 _RandomAccessIterator __last, _Compare __comp)
2217 {
2218 if (__last - __first > _S_threshold)
2219 {
2220 std::__insertion_sort(__first, __first + _S_threshold, __comp);
2221 std::__unguarded_insertion_sort(__first + _S_threshold, __last,
2222 __comp);
2223 }
2224 else
2225 std::__insertion_sort(__first, __last, __comp);
2226 }
2227
2228 /**
2229 * @if maint
2230 * This is a helper function for the sort routine.
2231 * @endif
2232 */
2233 template<typename _Size>
2234 inline _Size
2235 __lg(_Size __n)
2236 {
2237 _Size __k;
2238 for (__k = 0; __n != 1; __n >>= 1)
2239 ++__k;
2240 return __k;
2241 }
2242
2243 /**
2244 * @brief Sort the smallest elements of a sequence.
2245 * @param first An iterator.
2246 * @param middle Another iterator.
2247 * @param last Another iterator.
2248 * @return Nothing.
2249 *
2250 * Sorts the smallest @p (middle-first) elements in the range
2251 * @p [first,last) and moves them to the range @p [first,middle). The
2252 * order of the remaining elements in the range @p [middle,last) is
2253 * undefined.
2254 * After the sort if @p i and @j are iterators in the range
2255 * @p [first,middle) such that @i precedes @j and @k is an iterator in
2256 * the range @p [middle,last) then @p *j<*i and @p *k<*i are both false.
2257 */
2258 template<typename _RandomAccessIterator>
2259 void
2260 partial_sort(_RandomAccessIterator __first,
2261 _RandomAccessIterator __middle,
2262 _RandomAccessIterator __last)
2263 {
2264 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2265 _ValueType;
2266
2267 // concept requirements
2268 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2269 _RandomAccessIterator>)
2270 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
2271 __glibcxx_requires_valid_range(__first, __middle);
2272 __glibcxx_requires_valid_range(__middle, __last);
2273
2274 std::make_heap(__first, __middle);
2275 for (_RandomAccessIterator __i = __middle; __i < __last; ++__i)
2276 if (*__i < *__first)
2277 std::__pop_heap(__first, __middle, __i, _ValueType(*__i));
2278 std::sort_heap(__first, __middle);
2279 }
2280
2281 /**
2282 * @brief Sort the smallest elements of a sequence using a predicate
2283 * for comparison.
2284 * @param first An iterator.
2285 * @param middle Another iterator.
2286 * @param last Another iterator.
2287 * @param comp A comparison functor.
2288 * @return Nothing.
2289 *
2290 * Sorts the smallest @p (middle-first) elements in the range
2291 * @p [first,last) and moves them to the range @p [first,middle). The
2292 * order of the remaining elements in the range @p [middle,last) is
2293 * undefined.
2294 * After the sort if @p i and @j are iterators in the range
2295 * @p [first,middle) such that @i precedes @j and @k is an iterator in
2296 * the range @p [middle,last) then @p *comp(j,*i) and @p comp(*k,*i)
2297 * are both false.
2298 */
2299 template<typename _RandomAccessIterator, typename _Compare>
2300 void
2301 partial_sort(_RandomAccessIterator __first,
2302 _RandomAccessIterator __middle,
2303 _RandomAccessIterator __last,
2304 _Compare __comp)
2305 {
2306 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2307 _ValueType;
2308
2309 // concept requirements
2310 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2311 _RandomAccessIterator>)
2312 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2313 _ValueType, _ValueType>)
2314 __glibcxx_requires_valid_range(__first, __middle);
2315 __glibcxx_requires_valid_range(__middle, __last);
2316
2317 std::make_heap(__first, __middle, __comp);
2318 for (_RandomAccessIterator __i = __middle; __i < __last; ++__i)
2319 if (__comp(*__i, *__first))
2320 std::__pop_heap(__first, __middle, __i, _ValueType(*__i), __comp);
2321 std::sort_heap(__first, __middle, __comp);
2322 }
2323
2324 /**
2325 * @brief Copy the smallest elements of a sequence.
2326 * @param first An iterator.
2327 * @param last Another iterator.
2328 * @param result_first A random-access iterator.
2329 * @param result_last Another random-access iterator.
2330 * @return An iterator indicating the end of the resulting sequence.
2331 *
2332 * Copies and sorts the smallest N values from the range @p [first,last)
2333 * to the range beginning at @p result_first, where the number of
2334 * elements to be copied, @p N, is the smaller of @p (last-first) and
2335 * @p (result_last-result_first).
2336 * After the sort if @p i and @j are iterators in the range
2337 * @p [result_first,result_first+N) such that @i precedes @j then
2338 * @p *j<*i is false.
2339 * The value returned is @p result_first+N.
2340 */
2341 template<typename _InputIterator, typename _RandomAccessIterator>
2342 _RandomAccessIterator
2343 partial_sort_copy(_InputIterator __first, _InputIterator __last,
2344 _RandomAccessIterator __result_first,
2345 _RandomAccessIterator __result_last)
2346 {
2347 typedef typename iterator_traits<_InputIterator>::value_type
2348 _InputValueType;
2349 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2350 _OutputValueType;
2351 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
2352 _DistanceType;
2353
2354 // concept requirements
2355 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
2356 __glibcxx_function_requires(_ConvertibleConcept<_InputValueType,
2357 _OutputValueType>)
2358 __glibcxx_function_requires(_LessThanComparableConcept<_OutputValueType>)
2359 __glibcxx_function_requires(_LessThanComparableConcept<_InputValueType>)
2360 __glibcxx_requires_valid_range(__first, __last);
2361 __glibcxx_requires_valid_range(__result_first, __result_last);
2362
2363 if (__result_first == __result_last)
2364 return __result_last;
2365 _RandomAccessIterator __result_real_last = __result_first;
2366 while(__first != __last && __result_real_last != __result_last)
2367 {
2368 *__result_real_last = *__first;
2369 ++__result_real_last;
2370 ++__first;
2371 }
2372 std::make_heap(__result_first, __result_real_last);
2373 while (__first != __last)
2374 {
2375 if (*__first < *__result_first)
2376 std::__adjust_heap(__result_first, _DistanceType(0),
2377 _DistanceType(__result_real_last
2378 - __result_first),
2379 _InputValueType(*__first));
2380 ++__first;
2381 }
2382 std::sort_heap(__result_first, __result_real_last);
2383 return __result_real_last;
2384 }
2385
2386 /**
2387 * @brief Copy the smallest elements of a sequence using a predicate for
2388 * comparison.
2389 * @param first An input iterator.
2390 * @param last Another input iterator.
2391 * @param result_first A random-access iterator.
2392 * @param result_last Another random-access iterator.
2393 * @param comp A comparison functor.
2394 * @return An iterator indicating the end of the resulting sequence.
2395 *
2396 * Copies and sorts the smallest N values from the range @p [first,last)
2397 * to the range beginning at @p result_first, where the number of
2398 * elements to be copied, @p N, is the smaller of @p (last-first) and
2399 * @p (result_last-result_first).
2400 * After the sort if @p i and @j are iterators in the range
2401 * @p [result_first,result_first+N) such that @i precedes @j then
2402 * @p comp(*j,*i) is false.
2403 * The value returned is @p result_first+N.
2404 */
2405 template<typename _InputIterator, typename _RandomAccessIterator, typename _Compare>
2406 _RandomAccessIterator
2407 partial_sort_copy(_InputIterator __first, _InputIterator __last,
2408 _RandomAccessIterator __result_first,
2409 _RandomAccessIterator __result_last,
2410 _Compare __comp)
2411 {
2412 typedef typename iterator_traits<_InputIterator>::value_type
2413 _InputValueType;
2414 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2415 _OutputValueType;
2416 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
2417 _DistanceType;
2418
2419 // concept requirements
2420 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
2421 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2422 _RandomAccessIterator>)
2423 __glibcxx_function_requires(_ConvertibleConcept<_InputValueType,
2424 _OutputValueType>)
2425 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2426 _OutputValueType, _OutputValueType>)
2427 __glibcxx_requires_valid_range(__first, __last);
2428 __glibcxx_requires_valid_range(__result_first, __result_last);
2429
2430 if (__result_first == __result_last)
2431 return __result_last;
2432 _RandomAccessIterator __result_real_last = __result_first;
2433 while(__first != __last && __result_real_last != __result_last)
2434 {
2435 *__result_real_last = *__first;
2436 ++__result_real_last;
2437 ++__first;
2438 }
2439 std::make_heap(__result_first, __result_real_last, __comp);
2440 while (__first != __last)
2441 {
2442 if (__comp(*__first, *__result_first))
2443 std::__adjust_heap(__result_first, _DistanceType(0),
2444 _DistanceType(__result_real_last
2445 - __result_first),
2446 _InputValueType(*__first),
2447 __comp);
2448 ++__first;
2449 }
2450 std::sort_heap(__result_first, __result_real_last, __comp);
2451 return __result_real_last;
2452 }
2453
2454 /**
2455 * @if maint
2456 * This is a helper function for the sort routine.
2457 * @endif
2458 */
2459 template<typename _RandomAccessIterator, typename _Size>
2460 void
2461 __introsort_loop(_RandomAccessIterator __first,
2462 _RandomAccessIterator __last,
2463 _Size __depth_limit)
2464 {
2465 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2466 _ValueType;
2467
2468 while (__last - __first > _S_threshold)
2469 {
2470 if (__depth_limit == 0)
2471 {
2472 std::partial_sort(__first, __last, __last);
2473 return;
2474 }
2475 --__depth_limit;
2476 _RandomAccessIterator __cut =
2477 std::__unguarded_partition(__first, __last,
2478 _ValueType(std::__median(*__first,
2479 *(__first
2480 + (__last
2481 - __first)
2482 / 2),
2483 *(__last
2484 - 1))));
2485 std::__introsort_loop(__cut, __last, __depth_limit);
2486 __last = __cut;
2487 }
2488 }
2489
2490 /**
2491 * @if maint
2492 * This is a helper function for the sort routine.
2493 * @endif
2494 */
2495 template<typename _RandomAccessIterator, typename _Size, typename _Compare>
2496 void
2497 __introsort_loop(_RandomAccessIterator __first,
2498 _RandomAccessIterator __last,
2499 _Size __depth_limit, _Compare __comp)
2500 {
2501 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2502 _ValueType;
2503
2504 while (__last - __first > _S_threshold)
2505 {
2506 if (__depth_limit == 0)
2507 {
2508 std::partial_sort(__first, __last, __last, __comp);
2509 return;
2510 }
2511 --__depth_limit;
2512 _RandomAccessIterator __cut =
2513 std::__unguarded_partition(__first, __last,
2514 _ValueType(std::__median(*__first,
2515 *(__first
2516 + (__last
2517 - __first)
2518 / 2),
2519 *(__last - 1),
2520 __comp)),
2521 __comp);
2522 std::__introsort_loop(__cut, __last, __depth_limit, __comp);
2523 __last = __cut;
2524 }
2525 }
2526
2527 /**
2528 * @brief Sort the elements of a sequence.
2529 * @param first An iterator.
2530 * @param last Another iterator.
2531 * @return Nothing.
2532 *
2533 * Sorts the elements in the range @p [first,last) in ascending order,
2534 * such that @p *(i+1)<*i is false for each iterator @p i in the range
2535 * @p [first,last-1).
2536 *
2537 * The relative ordering of equivalent elements is not preserved, use
2538 * @p stable_sort() if this is needed.
2539 */
2540 template<typename _RandomAccessIterator>
2541 inline void
2542 sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
2543 {
2544 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2545 _ValueType;
2546
2547 // concept requirements
2548 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2549 _RandomAccessIterator>)
2550 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
2551 __glibcxx_requires_valid_range(__first, __last);
2552
2553 if (__first != __last)
2554 {
2555 std::__introsort_loop(__first, __last, __lg(__last - __first) * 2);
2556 std::__final_insertion_sort(__first, __last);
2557 }
2558 }
2559
2560 /**
2561 * @brief Sort the elements of a sequence using a predicate for comparison.
2562 * @param first An iterator.
2563 * @param last Another iterator.
2564 * @param comp A comparison functor.
2565 * @return Nothing.
2566 *
2567 * Sorts the elements in the range @p [first,last) in ascending order,
2568 * such that @p comp(*(i+1),*i) is false for every iterator @p i in the
2569 * range @p [first,last-1).
2570 *
2571 * The relative ordering of equivalent elements is not preserved, use
2572 * @p stable_sort() if this is needed.
2573 */
2574 template<typename _RandomAccessIterator, typename _Compare>
2575 inline void
2576 sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
2577 _Compare __comp)
2578 {
2579 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2580 _ValueType;
2581
2582 // concept requirements
2583 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2584 _RandomAccessIterator>)
2585 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _ValueType,
2586 _ValueType>)
2587 __glibcxx_requires_valid_range(__first, __last);
2588
2589 if (__first != __last)
2590 {
2591 std::__introsort_loop(__first, __last, __lg(__last - __first) * 2,
2592 __comp);
2593 std::__final_insertion_sort(__first, __last, __comp);
2594 }
2595 }
2596
2597 /**
2598 * @brief Finds the first position in which @a val could be inserted
2599 * without changing the ordering.
2600 * @param first An iterator.
2601 * @param last Another iterator.
2602 * @param val The search term.
2603 * @return An iterator pointing to the first element "not less than" @a val,
2604 * or end() if every element is less than @a val.
2605 * @ingroup binarysearch
2606 */
2607 template<typename _ForwardIterator, typename _Tp>
2608 _ForwardIterator
2609 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
2610 const _Tp& __val)
2611 {
2612 typedef typename iterator_traits<_ForwardIterator>::value_type
2613 _ValueType;
2614 typedef typename iterator_traits<_ForwardIterator>::difference_type
2615 _DistanceType;
2616
2617 // concept requirements
2618 // Note that these are slightly stricter than those of the 4-argument
2619 // version, defined next. The difference is in the strictness of the
2620 // comparison operations... so for looser checking, define your own
2621 // comparison function, as was intended.
2622 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2623 __glibcxx_function_requires(_SameTypeConcept<_Tp, _ValueType>)
2624 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
2625 __glibcxx_requires_partitioned(__first, __last, __val);
2626
2627 _DistanceType __len = std::distance(__first, __last);
2628 _DistanceType __half;
2629 _ForwardIterator __middle;
2630
2631 while (__len > 0)
2632 {
2633 __half = __len >> 1;
2634 __middle = __first;
2635 std::advance(__middle, __half);
2636 if (*__middle < __val)
2637 {
2638 __first = __middle;
2639 ++__first;
2640 __len = __len - __half - 1;
2641 }
2642 else
2643 __len = __half;
2644 }
2645 return __first;
2646 }
2647
2648 /**
2649 * @brief Finds the first position in which @a val could be inserted
2650 * without changing the ordering.
2651 * @param first An iterator.
2652 * @param last Another iterator.
2653 * @param val The search term.
2654 * @param comp A functor to use for comparisons.
2655 * @return An iterator pointing to the first element "not less than" @a val,
2656 * or end() if every element is less than @a val.
2657 * @ingroup binarysearch
2658 *
2659 * The comparison function should have the same effects on ordering as
2660 * the function used for the initial sort.
2661 */
2662 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2663 _ForwardIterator
2664 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
2665 const _Tp& __val, _Compare __comp)
2666 {
2667 typedef typename iterator_traits<_ForwardIterator>::value_type
2668 _ValueType;
2669 typedef typename iterator_traits<_ForwardIterator>::difference_type
2670 _DistanceType;
2671
2672 // concept requirements
2673 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2674 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2675 _ValueType, _Tp>)
2676 __glibcxx_requires_partitioned_pred(__first, __last, __val, __comp);
2677
2678 _DistanceType __len = std::distance(__first, __last);
2679 _DistanceType __half;
2680 _ForwardIterator __middle;
2681
2682 while (__len > 0)
2683 {
2684 __half = __len >> 1;
2685 __middle = __first;
2686 std::advance(__middle, __half);
2687 if (__comp(*__middle, __val))
2688 {
2689 __first = __middle;
2690 ++__first;
2691 __len = __len - __half - 1;
2692 }
2693 else
2694 __len = __half;
2695 }
2696 return __first;
2697 }
2698
2699 /**
2700 * @brief Finds the last position in which @a val could be inserted
2701 * without changing the ordering.
2702 * @param first An iterator.
2703 * @param last Another iterator.
2704 * @param val The search term.
2705 * @return An iterator pointing to the first element greater than @a val,
2706 * or end() if no elements are greater than @a val.
2707 * @ingroup binarysearch
2708 */
2709 template<typename _ForwardIterator, typename _Tp>
2710 _ForwardIterator
2711 upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2712 const _Tp& __val)
2713 {
2714 typedef typename iterator_traits<_ForwardIterator>::value_type
2715 _ValueType;
2716 typedef typename iterator_traits<_ForwardIterator>::difference_type
2717 _DistanceType;
2718
2719 // concept requirements
2720 // See comments on lower_bound.
2721 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2722 __glibcxx_function_requires(_SameTypeConcept<_Tp, _ValueType>)
2723 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
2724 __glibcxx_requires_partitioned(__first, __last, __val);
2725
2726 _DistanceType __len = std::distance(__first, __last);
2727 _DistanceType __half;
2728 _ForwardIterator __middle;
2729
2730 while (__len > 0)
2731 {
2732 __half = __len >> 1;
2733 __middle = __first;
2734 std::advance(__middle, __half);
2735 if (__val < *__middle)
2736 __len = __half;
2737 else
2738 {
2739 __first = __middle;
2740 ++__first;
2741 __len = __len - __half - 1;
2742 }
2743 }
2744 return __first;
2745 }
2746
2747 /**
2748 * @brief Finds the last position in which @a val could be inserted
2749 * without changing the ordering.
2750 * @param first An iterator.
2751 * @param last Another iterator.
2752 * @param val The search term.
2753 * @param comp A functor to use for comparisons.
2754 * @return An iterator pointing to the first element greater than @a val,
2755 * or end() if no elements are greater than @a val.
2756 * @ingroup binarysearch
2757 *
2758 * The comparison function should have the same effects on ordering as
2759 * the function used for the initial sort.
2760 */
2761 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2762 _ForwardIterator
2763 upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2764 const _Tp& __val, _Compare __comp)
2765 {
2766 typedef typename iterator_traits<_ForwardIterator>::value_type
2767 _ValueType;
2768 typedef typename iterator_traits<_ForwardIterator>::difference_type
2769 _DistanceType;
2770
2771 // concept requirements
2772 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2773 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2774 _Tp, _ValueType>)
2775 __glibcxx_requires_partitioned_pred(__first, __last, __val, __comp);
2776
2777 _DistanceType __len = std::distance(__first, __last);
2778 _DistanceType __half;
2779 _ForwardIterator __middle;
2780
2781 while (__len > 0)
2782 {
2783 __half = __len >> 1;
2784 __middle = __first;
2785 std::advance(__middle, __half);
2786 if (__comp(__val, *__middle))
2787 __len = __half;
2788 else
2789 {
2790 __first = __middle;
2791 ++__first;
2792 __len = __len - __half - 1;
2793 }
2794 }
2795 return __first;
2796 }
2797
2798 /**
2799 * @if maint
2800 * This is a helper function for the merge routines.
2801 * @endif
2802 */
2803 template<typename _BidirectionalIterator, typename _Distance>
2804 void
2805 __merge_without_buffer(_BidirectionalIterator __first,
2806 _BidirectionalIterator __middle,
2807 _BidirectionalIterator __last,
2808 _Distance __len1, _Distance __len2)
2809 {
2810 if (__len1 == 0 || __len2 == 0)
2811 return;
2812 if (__len1 + __len2 == 2)
2813 {
2814 if (*__middle < *__first)
2815 std::iter_swap(__first, __middle);
2816 return;
2817 }
2818 _BidirectionalIterator __first_cut = __first;
2819 _BidirectionalIterator __second_cut = __middle;
2820 _Distance __len11 = 0;
2821 _Distance __len22 = 0;
2822 if (__len1 > __len2)
2823 {
2824 __len11 = __len1 / 2;
2825 std::advance(__first_cut, __len11);
2826 __second_cut = std::lower_bound(__middle, __last, *__first_cut);
2827 __len22 = std::distance(__middle, __second_cut);
2828 }
2829 else
2830 {
2831 __len22 = __len2 / 2;
2832 std::advance(__second_cut, __len22);
2833 __first_cut = std::upper_bound(__first, __middle, *__second_cut);
2834 __len11 = std::distance(__first, __first_cut);
2835 }
2836 std::rotate(__first_cut, __middle, __second_cut);
2837 _BidirectionalIterator __new_middle = __first_cut;
2838 std::advance(__new_middle, std::distance(__middle, __second_cut));
2839 std::__merge_without_buffer(__first, __first_cut, __new_middle,
2840 __len11, __len22);
2841 std::__merge_without_buffer(__new_middle, __second_cut, __last,
2842 __len1 - __len11, __len2 - __len22);
2843 }
2844
2845 /**
2846 * @if maint
2847 * This is a helper function for the merge routines.
2848 * @endif
2849 */
2850 template<typename _BidirectionalIterator, typename _Distance,
2851 typename _Compare>
2852 void
2853 __merge_without_buffer(_BidirectionalIterator __first,
2854 _BidirectionalIterator __middle,
2855 _BidirectionalIterator __last,
2856 _Distance __len1, _Distance __len2,
2857 _Compare __comp)
2858 {
2859 if (__len1 == 0 || __len2 == 0)
2860 return;
2861 if (__len1 + __len2 == 2)
2862 {
2863 if (__comp(*__middle, *__first))
2864 std::iter_swap(__first, __middle);
2865 return;
2866 }
2867 _BidirectionalIterator __first_cut = __first;
2868 _BidirectionalIterator __second_cut = __middle;
2869 _Distance __len11 = 0;
2870 _Distance __len22 = 0;
2871 if (__len1 > __len2)
2872 {
2873 __len11 = __len1 / 2;
2874 std::advance(__first_cut, __len11);
2875 __second_cut = std::lower_bound(__middle, __last, *__first_cut,
2876 __comp);
2877 __len22 = std::distance(__middle, __second_cut);
2878 }
2879 else
2880 {
2881 __len22 = __len2 / 2;
2882 std::advance(__second_cut, __len22);
2883 __first_cut = std::upper_bound(__first, __middle, *__second_cut,
2884 __comp);
2885 __len11 = std::distance(__first, __first_cut);
2886 }
2887 std::rotate(__first_cut, __middle, __second_cut);
2888 _BidirectionalIterator __new_middle = __first_cut;
2889 std::advance(__new_middle, std::distance(__middle, __second_cut));
2890 std::__merge_without_buffer(__first, __first_cut, __new_middle,
2891 __len11, __len22, __comp);
2892 std::__merge_without_buffer(__new_middle, __second_cut, __last,
2893 __len1 - __len11, __len2 - __len22, __comp);
2894 }
2895
2896 /**
2897 * @if maint
2898 * This is a helper function for the stable sorting routines.
2899 * @endif
2900 */
2901 template<typename _RandomAccessIterator>
2902 void
2903 __inplace_stable_sort(_RandomAccessIterator __first,
2904 _RandomAccessIterator __last)
2905 {
2906 if (__last - __first < 15)
2907 {
2908 std::__insertion_sort(__first, __last);
2909 return;
2910 }
2911 _RandomAccessIterator __middle = __first + (__last - __first) / 2;
2912 std::__inplace_stable_sort(__first, __middle);
2913 std::__inplace_stable_sort(__middle, __last);
2914 std::__merge_without_buffer(__first, __middle, __last,
2915 __middle - __first,
2916 __last - __middle);
2917 }
2918
2919 /**
2920 * @if maint
2921 * This is a helper function for the stable sorting routines.
2922 * @endif
2923 */
2924 template<typename _RandomAccessIterator, typename _Compare>
2925 void
2926 __inplace_stable_sort(_RandomAccessIterator __first,
2927 _RandomAccessIterator __last, _Compare __comp)
2928 {
2929 if (__last - __first < 15)
2930 {
2931 std::__insertion_sort(__first, __last, __comp);
2932 return;
2933 }
2934 _RandomAccessIterator __middle = __first + (__last - __first) / 2;
2935 std::__inplace_stable_sort(__first, __middle, __comp);
2936 std::__inplace_stable_sort(__middle, __last, __comp);
2937 std::__merge_without_buffer(__first, __middle, __last,
2938 __middle - __first,
2939 __last - __middle,
2940 __comp);
2941 }
2942
2943 /**
2944 * @brief Merges two sorted ranges.
2945 * @param first1 An iterator.
2946 * @param first2 Another iterator.
2947 * @param last1 Another iterator.
2948 * @param last2 Another iterator.
2949 * @param result An iterator pointing to the end of the merged range.
2950 * @return An iterator pointing to the first element "not less than" @a val.
2951 *
2952 * Merges the ranges [first1,last1) and [first2,last2) into the sorted range
2953 * [result, result + (last1-first1) + (last2-first2)). Both input ranges
2954 * must be sorted, and the output range must not overlap with either of
2955 * the input ranges. The sort is @e stable, that is, for equivalent
2956 * elements in the two ranges, elements from the first range will always
2957 * come before elements from the second.
2958 */
2959 template<typename _InputIterator1, typename _InputIterator2,
2960 typename _OutputIterator>
2961 _OutputIterator
2962 merge(_InputIterator1 __first1, _InputIterator1 __last1,
2963 _InputIterator2 __first2, _InputIterator2 __last2,
2964 _OutputIterator __result)
2965 {
2966 // concept requirements
2967 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2968 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2969 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
2970 typename iterator_traits<_InputIterator1>::value_type>)
2971 __glibcxx_function_requires(_SameTypeConcept<
2972 typename iterator_traits<_InputIterator1>::value_type,
2973 typename iterator_traits<_InputIterator2>::value_type>)
2974 __glibcxx_function_requires(_LessThanComparableConcept<
2975 typename iterator_traits<_InputIterator1>::value_type>)
2976 __glibcxx_requires_sorted(__first1, __last1);
2977 __glibcxx_requires_sorted(__first2, __last2);
2978
2979 while (__first1 != __last1 && __first2 != __last2)
2980 {
2981 if (*__first2 < *__first1)
2982 {
2983 *__result = *__first2;
2984 ++__first2;
2985 }
2986 else
2987 {
2988 *__result = *__first1;
2989 ++__first1;
2990 }
2991 ++__result;
2992 }
2993 return std::copy(__first2, __last2, std::copy(__first1, __last1,
2994 __result));
2995 }
2996
2997 /**
2998 * @brief Merges two sorted ranges.
2999 * @param first1 An iterator.
3000 * @param first2 Another iterator.
3001 * @param last1 Another iterator.
3002 * @param last2 Another iterator.
3003 * @param result An iterator pointing to the end of the merged range.
3004 * @param comp A functor to use for comparisons.
3005 * @return An iterator pointing to the first element "not less than" @a val.
3006 *
3007 * Merges the ranges [first1,last1) and [first2,last2) into the sorted range
3008 * [result, result + (last1-first1) + (last2-first2)). Both input ranges
3009 * must be sorted, and the output range must not overlap with either of
3010 * the input ranges. The sort is @e stable, that is, for equivalent
3011 * elements in the two ranges, elements from the first range will always
3012 * come before elements from the second.
3013 *
3014 * The comparison function should have the same effects on ordering as
3015 * the function used for the initial sort.
3016 */
3017 template<typename _InputIterator1, typename _InputIterator2,
3018 typename _OutputIterator, typename _Compare>
3019 _OutputIterator
3020 merge(_InputIterator1 __first1, _InputIterator1 __last1,
3021 _InputIterator2 __first2, _InputIterator2 __last2,
3022 _OutputIterator __result, _Compare __comp)
3023 {
3024 // concept requirements
3025 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
3026 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
3027 __glibcxx_function_requires(_SameTypeConcept<
3028 typename iterator_traits<_InputIterator1>::value_type,
3029 typename iterator_traits<_InputIterator2>::value_type>)
3030 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
3031 typename iterator_traits<_InputIterator1>::value_type>)
3032 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3033 typename iterator_traits<_InputIterator1>::value_type,
3034 typename iterator_traits<_InputIterator2>::value_type>)
3035 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
3036 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
3037
3038 while (__first1 != __last1 && __first2 != __last2)
3039 {
3040 if (__comp(*__first2, *__first1))
3041 {
3042 *__result = *__first2;
3043 ++__first2;
3044 }
3045 else
3046 {
3047 *__result = *__first1;
3048 ++__first1;
3049 }
3050 ++__result;
3051 }
3052 return std::copy(__first2, __last2, std::copy(__first1, __last1,
3053 __result));
3054 }
3055
3056 template<typename _RandomAccessIterator1, typename _RandomAccessIterator2,
3057 typename _Distance>
3058 void
3059 __merge_sort_loop(_RandomAccessIterator1 __first,
3060 _RandomAccessIterator1 __last,
3061 _RandomAccessIterator2 __result,
3062 _Distance __step_size)
3063 {
3064 const _Distance __two_step = 2 * __step_size;
3065
3066 while (__last - __first >= __two_step)
3067 {
3068 __result = std::merge(__first, __first + __step_size,
3069 __first + __step_size, __first + __two_step,
3070 __result);
3071 __first += __two_step;
3072 }
3073
3074 __step_size = std::min(_Distance(__last - __first), __step_size);
3075 std::merge(__first, __first + __step_size, __first + __step_size, __last,
3076 __result);
3077 }
3078
3079 template<typename _RandomAccessIterator1, typename _RandomAccessIterator2,
3080 typename _Distance, typename _Compare>
3081 void
3082 __merge_sort_loop(_RandomAccessIterator1 __first,
3083 _RandomAccessIterator1 __last,
3084 _RandomAccessIterator2 __result, _Distance __step_size,
3085 _Compare __comp)
3086 {
3087 const _Distance __two_step = 2 * __step_size;
3088
3089 while (__last - __first >= __two_step)
3090 {
3091 __result = std::merge(__first, __first + __step_size,
3092 __first + __step_size, __first + __two_step,
3093 __result,
3094 __comp);
3095 __first += __two_step;
3096 }
3097 __step_size = std::min(_Distance(__last - __first), __step_size);
3098
3099 std::merge(__first, __first + __step_size,
3100 __first + __step_size, __last,
3101 __result,
3102 __comp);
3103 }
3104
3105 enum { _S_chunk_size = 7 };
3106
3107 template<typename _RandomAccessIterator, typename _Distance>
3108 void
3109 __chunk_insertion_sort(_RandomAccessIterator __first,
3110 _RandomAccessIterator __last,
3111 _Distance __chunk_size)
3112 {
3113 while (__last - __first >= __chunk_size)
3114 {
3115 std::__insertion_sort(__first, __first + __chunk_size);
3116 __first += __chunk_size;
3117 }
3118 std::__insertion_sort(__first, __last);
3119 }
3120
3121 template<typename _RandomAccessIterator, typename _Distance, typename _Compare>
3122 void
3123 __chunk_insertion_sort(_RandomAccessIterator __first,
3124 _RandomAccessIterator __last,
3125 _Distance __chunk_size, _Compare __comp)
3126 {
3127 while (__last - __first >= __chunk_size)
3128 {
3129 std::__insertion_sort(__first, __first + __chunk_size, __comp);
3130 __first += __chunk_size;
3131 }
3132 std::__insertion_sort(__first, __last, __comp);
3133 }
3134
3135 template<typename _RandomAccessIterator, typename _Pointer>
3136 void
3137 __merge_sort_with_buffer(_RandomAccessIterator __first,
3138 _RandomAccessIterator __last,
3139 _Pointer __buffer)
3140 {
3141 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3142 _Distance;
3143
3144 const _Distance __len = __last - __first;
3145 const _Pointer __buffer_last = __buffer + __len;
3146
3147 _Distance __step_size = _S_chunk_size;
3148 std::__chunk_insertion_sort(__first, __last, __step_size);
3149
3150 while (__step_size < __len)
3151 {
3152 std::__merge_sort_loop(__first, __last, __buffer, __step_size);
3153 __step_size *= 2;
3154 std::__merge_sort_loop(__buffer, __buffer_last, __first, __step_size);
3155 __step_size *= 2;
3156 }
3157 }
3158
3159 template<typename _RandomAccessIterator, typename _Pointer, typename _Compare>
3160 void
3161 __merge_sort_with_buffer(_RandomAccessIterator __first,
3162 _RandomAccessIterator __last,
3163 _Pointer __buffer, _Compare __comp)
3164 {
3165 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3166 _Distance;
3167
3168 const _Distance __len = __last - __first;
3169 const _Pointer __buffer_last = __buffer + __len;
3170
3171 _Distance __step_size = _S_chunk_size;
3172 std::__chunk_insertion_sort(__first, __last, __step_size, __comp);
3173
3174 while (__step_size < __len)
3175 {
3176 std::__merge_sort_loop(__first, __last, __buffer,
3177 __step_size, __comp);
3178 __step_size *= 2;
3179 std::__merge_sort_loop(__buffer, __buffer_last, __first,
3180 __step_size, __comp);
3181 __step_size *= 2;
3182 }
3183 }
3184
3185 /**
3186 * @if maint
3187 * This is a helper function for the merge routines.
3188 * @endif
3189 */
3190 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
3191 typename _BidirectionalIterator3>
3192 _BidirectionalIterator3
3193 __merge_backward(_BidirectionalIterator1 __first1,
3194 _BidirectionalIterator1 __last1,
3195 _BidirectionalIterator2 __first2,
3196 _BidirectionalIterator2 __last2,
3197 _BidirectionalIterator3 __result)
3198 {
3199 if (__first1 == __last1)
3200 return std::copy_backward(__first2, __last2, __result);
3201 if (__first2 == __last2)
3202 return std::copy_backward(__first1, __last1, __result);
3203 --__last1;
3204 --__last2;
3205 while (true)
3206 {
3207 if (*__last2 < *__last1)
3208 {
3209 *--__result = *__last1;
3210 if (__first1 == __last1)
3211 return std::copy_backward(__first2, ++__last2, __result);
3212 --__last1;
3213 }
3214 else
3215 {
3216 *--__result = *__last2;
3217 if (__first2 == __last2)
3218 return std::copy_backward(__first1, ++__last1, __result);
3219 --__last2;
3220 }
3221 }
3222 }
3223
3224 /**
3225 * @if maint
3226 * This is a helper function for the merge routines.
3227 * @endif
3228 */
3229 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
3230 typename _BidirectionalIterator3, typename _Compare>
3231 _BidirectionalIterator3
3232 __merge_backward(_BidirectionalIterator1 __first1,
3233 _BidirectionalIterator1 __last1,
3234 _BidirectionalIterator2 __first2,
3235 _BidirectionalIterator2 __last2,
3236 _BidirectionalIterator3 __result,
3237 _Compare __comp)
3238 {
3239 if (__first1 == __last1)
3240 return std::copy_backward(__first2, __last2, __result);
3241 if (__first2 == __last2)
3242 return std::copy_backward(__first1, __last1, __result);
3243 --__last1;
3244 --__last2;
3245 while (true)
3246 {
3247 if (__comp(*__last2, *__last1))
3248 {
3249 *--__result = *__last1;
3250 if (__first1 == __last1)
3251 return std::copy_backward(__first2, ++__last2, __result);
3252 --__last1;
3253 }
3254 else
3255 {
3256 *--__result = *__last2;
3257 if (__first2 == __last2)
3258 return std::copy_backward(__first1, ++__last1, __result);
3259 --__last2;
3260 }
3261 }
3262 }
3263
3264 /**
3265 * @if maint
3266 * This is a helper function for the merge routines.
3267 * @endif
3268 */
3269 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
3270 typename _Distance>
3271 _BidirectionalIterator1
3272 __rotate_adaptive(_BidirectionalIterator1 __first,
3273 _BidirectionalIterator1 __middle,
3274 _BidirectionalIterator1 __last,
3275 _Distance __len1, _Distance __len2,
3276 _BidirectionalIterator2 __buffer,
3277 _Distance __buffer_size)
3278 {
3279 _BidirectionalIterator2 __buffer_end;
3280 if (__len1 > __len2 && __len2 <= __buffer_size)
3281 {
3282 __buffer_end = std::copy(__middle, __last, __buffer);
3283 std::copy_backward(__first, __middle, __last);
3284 return std::copy(__buffer, __buffer_end, __first);
3285 }
3286 else if (__len1 <= __buffer_size)
3287 {
3288 __buffer_end = std::copy(__first, __middle, __buffer);
3289 std::copy(__middle, __last, __first);
3290 return std::copy_backward(__buffer, __buffer_end, __last);
3291 }
3292 else
3293 {
3294 std::rotate(__first, __middle, __last);
3295 std::advance(__first, std::distance(__middle, __last));
3296 return __first;
3297 }
3298 }
3299
3300 /**
3301 * @if maint
3302 * This is a helper function for the merge routines.
3303 * @endif
3304 */
3305 template<typename _BidirectionalIterator, typename _Distance,
3306 typename _Pointer>
3307 void
3308 __merge_adaptive(_BidirectionalIterator __first,
3309 _BidirectionalIterator __middle,
3310 _BidirectionalIterator __last,
3311 _Distance __len1, _Distance __len2,
3312 _Pointer __buffer, _Distance __buffer_size)
3313 {
3314 if (__len1 <= __len2 && __len1 <= __buffer_size)
3315 {
3316 _Pointer __buffer_end = std::copy(__first, __middle, __buffer);
3317 std::merge(__buffer, __buffer_end, __middle, __last, __first);
3318 }
3319 else if (__len2 <= __buffer_size)
3320 {
3321 _Pointer __buffer_end = std::copy(__middle, __last, __buffer);
3322 std::__merge_backward(__first, __middle, __buffer,
3323 __buffer_end, __last);
3324 }
3325 else
3326 {
3327 _BidirectionalIterator __first_cut = __first;
3328 _BidirectionalIterator __second_cut = __middle;
3329 _Distance __len11 = 0;
3330 _Distance __len22 = 0;
3331 if (__len1 > __len2)
3332 {
3333 __len11 = __len1 / 2;
3334 std::advance(__first_cut, __len11);
3335 __second_cut = std::lower_bound(__middle, __last,
3336 *__first_cut);
3337 __len22 = std::distance(__middle, __second_cut);
3338 }
3339 else
3340 {
3341 __len22 = __len2 / 2;
3342 std::advance(__second_cut, __len22);
3343 __first_cut = std::upper_bound(__first, __middle,
3344 *__second_cut);
3345 __len11 = std::distance(__first, __first_cut);
3346 }
3347 _BidirectionalIterator __new_middle =
3348 std::__rotate_adaptive(__first_cut, __middle, __second_cut,
3349 __len1 - __len11, __len22, __buffer,
3350 __buffer_size);
3351 std::__merge_adaptive(__first, __first_cut, __new_middle, __len11,
3352 __len22, __buffer, __buffer_size);
3353 std::__merge_adaptive(__new_middle, __second_cut, __last,
3354 __len1 - __len11,
3355 __len2 - __len22, __buffer, __buffer_size);
3356 }
3357 }
3358
3359 /**
3360 * @if maint
3361 * This is a helper function for the merge routines.
3362 * @endif
3363 */
3364 template<typename _BidirectionalIterator, typename _Distance, typename _Pointer,
3365 typename _Compare>
3366 void
3367 __merge_adaptive(_BidirectionalIterator __first,
3368 _BidirectionalIterator __middle,
3369 _BidirectionalIterator __last,
3370 _Distance __len1, _Distance __len2,
3371 _Pointer __buffer, _Distance __buffer_size,
3372 _Compare __comp)
3373 {
3374 if (__len1 <= __len2 && __len1 <= __buffer_size)
3375 {
3376 _Pointer __buffer_end = std::copy(__first, __middle, __buffer);
3377 std::merge(__buffer, __buffer_end, __middle, __last, __first, __comp);
3378 }
3379 else if (__len2 <= __buffer_size)
3380 {
3381 _Pointer __buffer_end = std::copy(__middle, __last, __buffer);
3382 std::__merge_backward(__first, __middle, __buffer, __buffer_end,
3383 __last, __comp);
3384 }
3385 else
3386 {
3387 _BidirectionalIterator __first_cut = __first;
3388 _BidirectionalIterator __second_cut = __middle;
3389 _Distance __len11 = 0;
3390 _Distance __len22 = 0;
3391 if (__len1 > __len2)
3392 {
3393 __len11 = __len1 / 2;
3394 std::advance(__first_cut, __len11);
3395 __second_cut = std::lower_bound(__middle, __last, *__first_cut,
3396 __comp);
3397 __len22 = std::distance(__middle, __second_cut);
3398 }
3399 else
3400 {
3401 __len22 = __len2 / 2;
3402 std::advance(__second_cut, __len22);
3403 __first_cut = std::upper_bound(__first, __middle, *__second_cut,
3404 __comp);
3405 __len11 = std::distance(__first, __first_cut);
3406 }
3407 _BidirectionalIterator __new_middle =
3408 std::__rotate_adaptive(__first_cut, __middle, __second_cut,
3409 __len1 - __len11, __len22, __buffer,
3410 __buffer_size);
3411 std::__merge_adaptive(__first, __first_cut, __new_middle, __len11,
3412 __len22, __buffer, __buffer_size, __comp);
3413 std::__merge_adaptive(__new_middle, __second_cut, __last,
3414 __len1 - __len11,
3415 __len2 - __len22, __buffer,
3416 __buffer_size, __comp);
3417 }
3418 }
3419
3420 /**
3421 * @brief Merges two sorted ranges in place.
3422 * @param first An iterator.
3423 * @param middle Another iterator.
3424 * @param last Another iterator.
3425 * @return Nothing.
3426 *
3427 * Merges two sorted and consecutive ranges, [first,middle) and
3428 * [middle,last), and puts the result in [first,last). The output will
3429 * be sorted. The sort is @e stable, that is, for equivalent
3430 * elements in the two ranges, elements from the first range will always
3431 * come before elements from the second.
3432 *
3433 * If enough additional memory is available, this takes (last-first)-1
3434 * comparisons. Otherwise an NlogN algorithm is used, where N is
3435 * distance(first,last).
3436 */
3437 template<typename _BidirectionalIterator>
3438 void
3439 inplace_merge(_BidirectionalIterator __first,
3440 _BidirectionalIterator __middle,
3441 _BidirectionalIterator __last)
3442 {
3443 typedef typename iterator_traits<_BidirectionalIterator>::value_type
3444 _ValueType;
3445 typedef typename iterator_traits<_BidirectionalIterator>::difference_type
3446 _DistanceType;
3447
3448 // concept requirements
3449 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
3450 _BidirectionalIterator>)
3451 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
3452 __glibcxx_requires_sorted(__first, __middle);
3453 __glibcxx_requires_sorted(__middle, __last);
3454
3455 if (__first == __middle || __middle == __last)
3456 return;
3457
3458 _DistanceType __len1 = std::distance(__first, __middle);
3459 _DistanceType __len2 = std::distance(__middle, __last);
3460
3461 _Temporary_buffer<_BidirectionalIterator, _ValueType> __buf(__first,
3462 __last);
3463 if (__buf.begin() == 0)
3464 std::__merge_without_buffer(__first, __middle, __last, __len1, __len2);
3465 else
3466 std::__merge_adaptive(__first, __middle, __last, __len1, __len2,
3467 __buf.begin(), _DistanceType(__buf.size()));
3468 }
3469
3470 /**
3471 * @brief Merges two sorted ranges in place.
3472 * @param first An iterator.
3473 * @param middle Another iterator.
3474 * @param last Another iterator.
3475 * @param comp A functor to use for comparisons.
3476 * @return Nothing.
3477 *
3478 * Merges two sorted and consecutive ranges, [first,middle) and
3479 * [middle,last), and puts the result in [first,last). The output will
3480 * be sorted. The sort is @e stable, that is, for equivalent
3481 * elements in the two ranges, elements from the first range will always
3482 * come before elements from the second.
3483 *
3484 * If enough additional memory is available, this takes (last-first)-1
3485 * comparisons. Otherwise an NlogN algorithm is used, where N is
3486 * distance(first,last).
3487 *
3488 * The comparison function should have the same effects on ordering as
3489 * the function used for the initial sort.
3490 */
3491 template<typename _BidirectionalIterator, typename _Compare>
3492 void
3493 inplace_merge(_BidirectionalIterator __first,
3494 _BidirectionalIterator __middle,
3495 _BidirectionalIterator __last,
3496 _Compare __comp)
3497 {
3498 typedef typename iterator_traits<_BidirectionalIterator>::value_type
3499 _ValueType;
3500 typedef typename iterator_traits<_BidirectionalIterator>::difference_type
3501 _DistanceType;
3502
3503 // concept requirements
3504 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
3505 _BidirectionalIterator>)
3506 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3507 _ValueType, _ValueType>)
3508 __glibcxx_requires_sorted_pred(__first, __middle, __comp);
3509 __glibcxx_requires_sorted_pred(__middle, __last, __comp);
3510
3511 if (__first == __middle || __middle == __last)
3512 return;
3513
3514 const _DistanceType __len1 = std::distance(__first, __middle);
3515 const _DistanceType __len2 = std::distance(__middle, __last);
3516
3517 _Temporary_buffer<_BidirectionalIterator, _ValueType> __buf(__first,
3518 __last);
3519 if (__buf.begin() == 0)
3520 std::__merge_without_buffer(__first, __middle, __last, __len1,
3521 __len2, __comp);
3522 else
3523 std::__merge_adaptive(__first, __middle, __last, __len1, __len2,
3524 __buf.begin(), _DistanceType(__buf.size()),
3525 __comp);
3526 }
3527
3528 template<typename _RandomAccessIterator, typename _Pointer,
3529 typename _Distance>
3530 void
3531 __stable_sort_adaptive(_RandomAccessIterator __first,
3532 _RandomAccessIterator __last,
3533 _Pointer __buffer, _Distance __buffer_size)
3534 {
3535 const _Distance __len = (__last - __first + 1) / 2;
3536 const _RandomAccessIterator __middle = __first + __len;
3537 if (__len > __buffer_size)
3538 {
3539 std::__stable_sort_adaptive(__first, __middle,
3540 __buffer, __buffer_size);
3541 std::__stable_sort_adaptive(__middle, __last,
3542 __buffer, __buffer_size);
3543 }
3544 else
3545 {
3546 std::__merge_sort_with_buffer(__first, __middle, __buffer);
3547 std::__merge_sort_with_buffer(__middle, __last, __buffer);
3548 }
3549 std::__merge_adaptive(__first, __middle, __last,
3550 _Distance(__middle - __first),
3551 _Distance(__last - __middle),
3552 __buffer, __buffer_size);
3553 }
3554
3555 template<typename _RandomAccessIterator, typename _Pointer,
3556 typename _Distance, typename _Compare>
3557 void
3558 __stable_sort_adaptive(_RandomAccessIterator __first,
3559 _RandomAccessIterator __last,
3560 _Pointer __buffer, _Distance __buffer_size,
3561 _Compare __comp)
3562 {
3563 const _Distance __len = (__last - __first + 1) / 2;
3564 const _RandomAccessIterator __middle = __first + __len;
3565 if (__len > __buffer_size)
3566 {
3567 std::__stable_sort_adaptive(__first, __middle, __buffer,
3568 __buffer_size, __comp);
3569 std::__stable_sort_adaptive(__middle, __last, __buffer,
3570 __buffer_size, __comp);
3571 }
3572 else
3573 {
3574 std::__merge_sort_with_buffer(__first, __middle, __buffer, __comp);
3575 std::__merge_sort_with_buffer(__middle, __last, __buffer, __comp);
3576 }
3577 std::__merge_adaptive(__first, __middle, __last,
3578 _Distance(__middle - __first),
3579 _Distance(__last - __middle),
3580 __buffer, __buffer_size,
3581 __comp);
3582 }
3583
3584 /**
3585 * @brief Sort the elements of a sequence, preserving the relative order
3586 * of equivalent elements.
3587 * @param first An iterator.
3588 * @param last Another iterator.
3589 * @return Nothing.
3590 *
3591 * Sorts the elements in the range @p [first,last) in ascending order,
3592 * such that @p *(i+1)<*i is false for each iterator @p i in the range
3593 * @p [first,last-1).
3594 *
3595 * The relative ordering of equivalent elements is preserved, so any two
3596 * elements @p x and @p y in the range @p [first,last) such that
3597 * @p x<y is false and @p y<x is false will have the same relative
3598 * ordering after calling @p stable_sort().
3599 */
3600 template<typename _RandomAccessIterator>
3601 inline void
3602 stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
3603 {
3604 typedef typename iterator_traits<_RandomAccessIterator>::value_type
3605 _ValueType;
3606 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3607 _DistanceType;
3608
3609 // concept requirements
3610 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3611 _RandomAccessIterator>)
3612 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
3613 __glibcxx_requires_valid_range(__first, __last);
3614
3615 _Temporary_buffer<_RandomAccessIterator, _ValueType>
3616 buf(__first, __last);
3617 if (buf.begin() == 0)
3618 std::__inplace_stable_sort(__first, __last);
3619 else
3620 std::__stable_sort_adaptive(__first, __last, buf.begin(),
3621 _DistanceType(buf.size()));
3622 }
3623
3624 /**
3625 * @brief Sort the elements of a sequence using a predicate for comparison,
3626 * preserving the relative order of equivalent elements.
3627 * @param first An iterator.
3628 * @param last Another iterator.
3629 * @param comp A comparison functor.
3630 * @return Nothing.
3631 *
3632 * Sorts the elements in the range @p [first,last) in ascending order,
3633 * such that @p comp(*(i+1),*i) is false for each iterator @p i in the
3634 * range @p [first,last-1).
3635 *
3636 * The relative ordering of equivalent elements is preserved, so any two
3637 * elements @p x and @p y in the range @p [first,last) such that
3638 * @p comp(x,y) is false and @p comp(y,x) is false will have the same
3639 * relative ordering after calling @p stable_sort().
3640 */
3641 template<typename _RandomAccessIterator, typename _Compare>
3642 inline void
3643 stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
3644 _Compare __comp)
3645 {
3646 typedef typename iterator_traits<_RandomAccessIterator>::value_type
3647 _ValueType;
3648 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3649 _DistanceType;
3650
3651 // concept requirements
3652 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3653 _RandomAccessIterator>)
3654 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3655 _ValueType,
3656 _ValueType>)
3657 __glibcxx_requires_valid_range(__first, __last);
3658
3659 _Temporary_buffer<_RandomAccessIterator, _ValueType> buf(__first, __last);
3660 if (buf.begin() == 0)
3661 std::__inplace_stable_sort(__first, __last, __comp);
3662 else
3663 std::__stable_sort_adaptive(__first, __last, buf.begin(),
3664 _DistanceType(buf.size()), __comp);
3665 }
3666
3667 /**
3668 * @brief Sort a sequence just enough to find a particular position.
3669 * @param first An iterator.
3670 * @param nth Another iterator.
3671 * @param last Another iterator.
3672 * @return Nothing.
3673 *
3674 * Rearranges the elements in the range @p [first,last) so that @p *nth
3675 * is the same element that would have been in that position had the
3676 * whole sequence been sorted.
3677 * whole sequence been sorted. The elements either side of @p *nth are
3678 * not completely sorted, but for any iterator @i in the range
3679 * @p [first,nth) and any iterator @j in the range @p [nth,last) it
3680 * holds that @p *j<*i is false.
3681 */
3682 template<typename _RandomAccessIterator>
3683 void
3684 nth_element(_RandomAccessIterator __first,
3685 _RandomAccessIterator __nth,
3686 _RandomAccessIterator __last)
3687 {
3688 typedef typename iterator_traits<_RandomAccessIterator>::value_type
3689 _ValueType;
3690
3691 // concept requirements
3692 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3693 _RandomAccessIterator>)
3694 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
3695 __glibcxx_requires_valid_range(__first, __nth);
3696 __glibcxx_requires_valid_range(__nth, __last);
3697
3698 while (__last - __first > 3)
3699 {
3700 _RandomAccessIterator __cut =
3701 std::__unguarded_partition(__first, __last,
3702 _ValueType(std::__median(*__first,
3703 *(__first
3704 + (__last
3705 - __first)
3706 / 2),
3707 *(__last
3708 - 1))));
3709 if (__cut <= __nth)
3710 __first = __cut;
3711 else
3712 __last = __cut;
3713 }
3714 std::__insertion_sort(__first, __last);
3715 }
3716
3717 /**
3718 * @brief Sort a sequence just enough to find a particular position
3719 * using a predicate for comparison.
3720 * @param first An iterator.
3721 * @param nth Another iterator.
3722 * @param last Another iterator.
3723 * @param comp A comparison functor.
3724 * @return Nothing.
3725 *
3726 * Rearranges the elements in the range @p [first,last) so that @p *nth
3727 * is the same element that would have been in that position had the
3728 * whole sequence been sorted. The elements either side of @p *nth are
3729 * not completely sorted, but for any iterator @i in the range
3730 * @p [first,nth) and any iterator @j in the range @p [nth,last) it
3731 * holds that @p comp(*j,*i) is false.
3732 */
3733 template<typename _RandomAccessIterator, typename _Compare>
3734 void
3735 nth_element(_RandomAccessIterator __first,
3736 _RandomAccessIterator __nth,
3737 _RandomAccessIterator __last,
3738 _Compare __comp)
3739 {
3740 typedef typename iterator_traits<_RandomAccessIterator>::value_type
3741 _ValueType;
3742
3743 // concept requirements
3744 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3745 _RandomAccessIterator>)
3746 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3747 _ValueType, _ValueType>)
3748 __glibcxx_requires_valid_range(__first, __nth);
3749 __glibcxx_requires_valid_range(__nth, __last);
3750
3751 while (__last - __first > 3)
3752 {
3753 _RandomAccessIterator __cut =
3754 std::__unguarded_partition(__first, __last,
3755 _ValueType(std::__median(*__first,
3756 *(__first
3757 + (__last
3758 - __first)
3759 / 2),
3760 *(__last - 1),
3761 __comp)), __comp);
3762 if (__cut <= __nth)
3763 __first = __cut;
3764 else
3765 __last = __cut;
3766 }
3767 std::__insertion_sort(__first, __last, __comp);
3768 }
3769
3770 /**
3771 * @brief Finds the largest subrange in which @a val could be inserted
3772 * at any place in it without changing the ordering.
3773 * @param first An iterator.
3774 * @param last Another iterator.
3775 * @param val The search term.
3776 * @return An pair of iterators defining the subrange.
3777 * @ingroup binarysearch
3778 *
3779 * This is equivalent to
3780 * @code
3781 * std::make_pair(lower_bound(first, last, val),
3782 * upper_bound(first, last, val))
3783 * @endcode
3784 * but does not actually call those functions.
3785 */
3786 template<typename _ForwardIterator, typename _Tp>
3787 pair<_ForwardIterator, _ForwardIterator>
3788 equal_range(_ForwardIterator __first, _ForwardIterator __last,
3789 const _Tp& __val)
3790 {
3791 typedef typename iterator_traits<_ForwardIterator>::value_type
3792 _ValueType;
3793 typedef typename iterator_traits<_ForwardIterator>::difference_type
3794 _DistanceType;
3795
3796 // concept requirements
3797 // See comments on lower_bound.
3798 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3799 __glibcxx_function_requires(_SameTypeConcept<_Tp, _ValueType>)
3800 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
3801 __glibcxx_requires_partitioned(__first, __last, __val);
3802
3803 _DistanceType __len = std::distance(__first, __last);
3804 _DistanceType __half;
3805 _ForwardIterator __middle, __left, __right;
3806
3807 while (__len > 0)
3808 {
3809 __half = __len >> 1;
3810 __middle = __first;
3811 std::advance(__middle, __half);
3812 if (*__middle < __val)
3813 {
3814 __first = __middle;
3815 ++__first;
3816 __len = __len - __half - 1;
3817 }
3818 else if (__val < *__middle)
3819 __len = __half;
3820 else
3821 {
3822 __left = std::lower_bound(__first, __middle, __val);
3823 std::advance(__first, __len);
3824 __right = std::upper_bound(++__middle, __first, __val);
3825 return pair<_ForwardIterator, _ForwardIterator>(__left, __right);
3826 }
3827 }
3828 return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
3829 }
3830
3831 /**
3832 * @brief Finds the largest subrange in which @a val could be inserted
3833 * at any place in it without changing the ordering.
3834 * @param first An iterator.
3835 * @param last Another iterator.
3836 * @param val The search term.
3837 * @param comp A functor to use for comparisons.
3838 * @return An pair of iterators defining the subrange.
3839 * @ingroup binarysearch
3840 *
3841 * This is equivalent to
3842 * @code
3843 * std::make_pair(lower_bound(first, last, val, comp),
3844 * upper_bound(first, last, val, comp))
3845 * @endcode
3846 * but does not actually call those functions.
3847 */
3848 template<typename _ForwardIterator, typename _Tp, typename _Compare>
3849 pair<_ForwardIterator, _ForwardIterator>
3850 equal_range(_ForwardIterator __first, _ForwardIterator __last,
3851 const _Tp& __val,
3852 _Compare __comp)
3853 {
3854 typedef typename iterator_traits<_ForwardIterator>::value_type
3855 _ValueType;
3856 typedef typename iterator_traits<_ForwardIterator>::difference_type
3857 _DistanceType;
3858
3859 // concept requirements
3860 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3861 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3862 _ValueType, _Tp>)
3863 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3864 _Tp, _ValueType>)
3865 __glibcxx_requires_partitioned_pred(__first, __last, __val, __comp);
3866
3867 _DistanceType __len = std::distance(__first, __last);
3868 _DistanceType __half;
3869 _ForwardIterator __middle, __left, __right;
3870
3871 while (__len > 0)
3872 {
3873 __half = __len >> 1;
3874 __middle = __first;
3875 std::advance(__middle, __half);
3876 if (__comp(*__middle, __val))
3877 {
3878 __first = __middle;
3879 ++__first;
3880 __len = __len - __half - 1;
3881 }
3882 else if (__comp(__val, *__middle))
3883 __len = __half;
3884 else
3885 {
3886 __left = std::lower_bound(__first, __middle, __val, __comp);
3887 std::advance(__first, __len);
3888 __right = std::upper_bound(++__middle, __first, __val, __comp);
3889 return pair<_ForwardIterator, _ForwardIterator>(__left, __right);
3890 }
3891 }
3892 return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
3893 }
3894
3895 /**
3896 * @brief Determines whether an element exists in a range.
3897 * @param first An iterator.
3898 * @param last Another iterator.
3899 * @param val The search term.
3900 * @return True if @a val (or its equivelent) is in [@a first,@a last ].
3901 * @ingroup binarysearch
3902 *
3903 * Note that this does not actually return an iterator to @a val. For
3904 * that, use std::find or a container's specialized find member functions.
3905 */
3906 template<typename _ForwardIterator, typename _Tp>
3907 bool
3908 binary_search(_ForwardIterator __first, _ForwardIterator __last,
3909 const _Tp& __val)
3910 {
3911 // concept requirements
3912 // See comments on lower_bound.
3913 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3914 __glibcxx_function_requires(_SameTypeConcept<_Tp,
3915 typename iterator_traits<_ForwardIterator>::value_type>)
3916 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
3917 __glibcxx_requires_partitioned(__first, __last, __val);
3918
3919 _ForwardIterator __i = std::lower_bound(__first, __last, __val);
3920 return __i != __last && !(__val < *__i);
3921 }
3922
3923 /**
3924 * @brief Determines whether an element exists in a range.
3925 * @param first An iterator.
3926 * @param last Another iterator.
3927 * @param val The search term.
3928 * @param comp A functor to use for comparisons.
3929 * @return True if @a val (or its equivelent) is in [@a first,@a last ].
3930 * @ingroup binarysearch
3931 *
3932 * Note that this does not actually return an iterator to @a val. For
3933 * that, use std::find or a container's specialized find member functions.
3934 *
3935 * The comparison function should have the same effects on ordering as
3936 * the function used for the initial sort.
3937 */
3938 template<typename _ForwardIterator, typename _Tp, typename _Compare>
3939 bool
3940 binary_search(_ForwardIterator __first, _ForwardIterator __last,
3941 const _Tp& __val, _Compare __comp)
3942 {
3943 // concept requirements
3944 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3945 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3946 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
3947 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _Tp,
3948 typename iterator_traits<_ForwardIterator>::value_type>)
3949 __glibcxx_requires_partitioned_pred(__first, __last, __val, __comp);
3950
3951 _ForwardIterator __i = std::lower_bound(__first, __last, __val, __comp);
3952 return __i != __last && !__comp(__val, *__i);
3953 }
3954
3955 // Set algorithms: includes, set_union, set_intersection, set_difference,
3956 // set_symmetric_difference. All of these algorithms have the precondition
3957 // that their input ranges are sorted and the postcondition that their output
3958 // ranges are sorted.
3959
3960 /**
3961 * @brief Determines whether all elements of a sequence exists in a range.
3962 * @param first1 Start of search range.
3963 * @param last1 End of search range.
3964 * @param first2 Start of sequence
3965 * @param last2 End of sequence.
3966 * @return True if each element in [first2,last2) is contained in order
3967 * within [first1,last1). False otherwise.
3968 * @ingroup setoperations
3969 *
3970 * This operation expects both [first1,last1) and [first2,last2) to be
3971 * sorted. Searches for the presence of each element in [first2,last2)
3972 * within [first1,last1). The iterators over each range only move forward,
3973 * so this is a linear algorithm. If an element in [first2,last2) is not
3974 * found before the search iterator reaches @a last2, false is returned.
3975 */
3976 template<typename _InputIterator1, typename _InputIterator2>
3977 bool
3978 includes(_InputIterator1 __first1, _InputIterator1 __last1,
3979 _InputIterator2 __first2, _InputIterator2 __last2)
3980 {
3981 // concept requirements
3982 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
3983 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
3984 __glibcxx_function_requires(_SameTypeConcept<
3985 typename iterator_traits<_InputIterator1>::value_type,
3986 typename iterator_traits<_InputIterator2>::value_type>)
3987 __glibcxx_function_requires(_LessThanComparableConcept<
3988 typename iterator_traits<_InputIterator1>::value_type>)
3989 __glibcxx_requires_sorted(__first1, __last1);
3990 __glibcxx_requires_sorted(__first2, __last2);
3991
3992 while (__first1 != __last1 && __first2 != __last2)
3993 if (*__first2 < *__first1)
3994 return false;
3995 else if(*__first1 < *__first2)
3996 ++__first1;
3997 else
3998 ++__first1, ++__first2;
3999
4000 return __first2 == __last2;
4001 }
4002
4003 /**
4004 * @brief Determines whether all elements of a sequence exists in a range
4005 * using comparison.
4006 * @param first1 Start of search range.
4007 * @param last1 End of search range.
4008 * @param first2 Start of sequence
4009 * @param last2 End of sequence.
4010 * @param comp Comparison function to use.
4011 * @return True if each element in [first2,last2) is contained in order
4012 * within [first1,last1) according to comp. False otherwise.
4013 * @ingroup setoperations
4014 *
4015 * This operation expects both [first1,last1) and [first2,last2) to be
4016 * sorted. Searches for the presence of each element in [first2,last2)
4017 * within [first1,last1), using comp to decide. The iterators over each
4018 * range only move forward, so this is a linear algorithm. If an element
4019 * in [first2,last2) is not found before the search iterator reaches @a
4020 * last2, false is returned.
4021 */
4022 template<typename _InputIterator1, typename _InputIterator2,
4023 typename _Compare>
4024 bool
4025 includes(_InputIterator1 __first1, _InputIterator1 __last1,
4026 _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
4027 {
4028 // concept requirements
4029 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4030 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4031 __glibcxx_function_requires(_SameTypeConcept<
4032 typename iterator_traits<_InputIterator1>::value_type,
4033 typename iterator_traits<_InputIterator2>::value_type>)
4034 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4035 typename iterator_traits<_InputIterator1>::value_type,
4036 typename iterator_traits<_InputIterator2>::value_type>)
4037 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4038 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4039
4040 while (__first1 != __last1 && __first2 != __last2)
4041 if (__comp(*__first2, *__first1))
4042 return false;
4043 else if(__comp(*__first1, *__first2))
4044 ++__first1;
4045 else
4046 ++__first1, ++__first2;
4047
4048 return __first2 == __last2;
4049 }
4050
4051 /**
4052 * @brief Return the union of two sorted ranges.
4053 * @param first1 Start of first range.
4054 * @param last1 End of first range.
4055 * @param first2 Start of second range.
4056 * @param last2 End of second range.
4057 * @return End of the output range.
4058 * @ingroup setoperations
4059 *
4060 * This operation iterates over both ranges, copying elements present in
4061 * each range in order to the output range. Iterators increment for each
4062 * range. When the current element of one range is less than the other,
4063 * that element is copied and the iterator advanced. If an element is
4064 * contained in both ranges, the element from the first range is copied and
4065 * both ranges advance. The output range may not overlap either input
4066 * range.
4067 */
4068 template<typename _InputIterator1, typename _InputIterator2,
4069 typename _OutputIterator>
4070 _OutputIterator
4071 set_union(_InputIterator1 __first1, _InputIterator1 __last1,
4072 _InputIterator2 __first2, _InputIterator2 __last2,
4073 _OutputIterator __result)
4074 {
4075 // concept requirements
4076 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4077 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4078 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4079 typename iterator_traits<_InputIterator1>::value_type>)
4080 __glibcxx_function_requires(_SameTypeConcept<
4081 typename iterator_traits<_InputIterator1>::value_type,
4082 typename iterator_traits<_InputIterator2>::value_type>)
4083 __glibcxx_function_requires(_LessThanComparableConcept<
4084 typename iterator_traits<_InputIterator1>::value_type>)
4085 __glibcxx_requires_sorted(__first1, __last1);
4086 __glibcxx_requires_sorted(__first2, __last2);
4087
4088 while (__first1 != __last1 && __first2 != __last2)
4089 {
4090 if (*__first1 < *__first2)
4091 {
4092 *__result = *__first1;
4093 ++__first1;
4094 }
4095 else if (*__first2 < *__first1)
4096 {
4097 *__result = *__first2;
4098 ++__first2;
4099 }
4100 else
4101 {
4102 *__result = *__first1;
4103 ++__first1;
4104 ++__first2;
4105 }
4106 ++__result;
4107 }
4108 return std::copy(__first2, __last2, std::copy(__first1, __last1,
4109 __result));
4110 }
4111
4112 /**
4113 * @brief Return the union of two sorted ranges using a comparison functor.
4114 * @param first1 Start of first range.
4115 * @param last1 End of first range.
4116 * @param first2 Start of second range.
4117 * @param last2 End of second range.
4118 * @param comp The comparison functor.
4119 * @return End of the output range.
4120 * @ingroup setoperations
4121 *
4122 * This operation iterates over both ranges, copying elements present in
4123 * each range in order to the output range. Iterators increment for each
4124 * range. When the current element of one range is less than the other
4125 * according to @a comp, that element is copied and the iterator advanced.
4126 * If an equivalent element according to @a comp is contained in both
4127 * ranges, the element from the first range is copied and both ranges
4128 * advance. The output range may not overlap either input range.
4129 */
4130 template<typename _InputIterator1, typename _InputIterator2,
4131 typename _OutputIterator, typename _Compare>
4132 _OutputIterator
4133 set_union(_InputIterator1 __first1, _InputIterator1 __last1,
4134 _InputIterator2 __first2, _InputIterator2 __last2,
4135 _OutputIterator __result, _Compare __comp)
4136 {
4137 // concept requirements
4138 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4139 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4140 __glibcxx_function_requires(_SameTypeConcept<
4141 typename iterator_traits<_InputIterator1>::value_type,
4142 typename iterator_traits<_InputIterator2>::value_type>)
4143 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4144 typename iterator_traits<_InputIterator1>::value_type>)
4145 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4146 typename iterator_traits<_InputIterator1>::value_type,
4147 typename iterator_traits<_InputIterator2>::value_type>)
4148 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4149 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4150
4151 while (__first1 != __last1 && __first2 != __last2)
4152 {
4153 if (__comp(*__first1, *__first2))
4154 {
4155 *__result = *__first1;
4156 ++__first1;
4157 }
4158 else if (__comp(*__first2, *__first1))
4159 {
4160 *__result = *__first2;
4161 ++__first2;
4162 }
4163 else
4164 {
4165 *__result = *__first1;
4166 ++__first1;
4167 ++__first2;
4168 }
4169 ++__result;
4170 }
4171 return std::copy(__first2, __last2, std::copy(__first1, __last1,
4172 __result));
4173 }
4174
4175 /**
4176 * @brief Return the intersection of two sorted ranges.
4177 * @param first1 Start of first range.
4178 * @param last1 End of first range.
4179 * @param first2 Start of second range.
4180 * @param last2 End of second range.
4181 * @return End of the output range.
4182 * @ingroup setoperations
4183 *
4184 * This operation iterates over both ranges, copying elements present in
4185 * both ranges in order to the output range. Iterators increment for each
4186 * range. When the current element of one range is less than the other,
4187 * that iterator advances. If an element is contained in both ranges, the
4188 * element from the first range is copied and both ranges advance. The
4189 * output range may not overlap either input range.
4190 */
4191 template<typename _InputIterator1, typename _InputIterator2,
4192 typename _OutputIterator>
4193 _OutputIterator
4194 set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
4195 _InputIterator2 __first2, _InputIterator2 __last2,
4196 _OutputIterator __result)
4197 {
4198 // concept requirements
4199 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4200 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4201 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4202 typename iterator_traits<_InputIterator1>::value_type>)
4203 __glibcxx_function_requires(_SameTypeConcept<
4204 typename iterator_traits<_InputIterator1>::value_type,
4205 typename iterator_traits<_InputIterator2>::value_type>)
4206 __glibcxx_function_requires(_LessThanComparableConcept<
4207 typename iterator_traits<_InputIterator1>::value_type>)
4208 __glibcxx_requires_sorted(__first1, __last1);
4209 __glibcxx_requires_sorted(__first2, __last2);
4210
4211 while (__first1 != __last1 && __first2 != __last2)
4212 if (*__first1 < *__first2)
4213 ++__first1;
4214 else if (*__first2 < *__first1)
4215 ++__first2;
4216 else
4217 {
4218 *__result = *__first1;
4219 ++__first1;
4220 ++__first2;
4221 ++__result;
4222 }
4223 return __result;
4224 }
4225
4226 /**
4227 * @brief Return the intersection of two sorted ranges using comparison
4228 * functor.
4229 * @param first1 Start of first range.
4230 * @param last1 End of first range.
4231 * @param first2 Start of second range.
4232 * @param last2 End of second range.
4233 * @param comp The comparison functor.
4234 * @return End of the output range.
4235 * @ingroup setoperations
4236 *
4237 * This operation iterates over both ranges, copying elements present in
4238 * both ranges in order to the output range. Iterators increment for each
4239 * range. When the current element of one range is less than the other
4240 * according to @a comp, that iterator advances. If an element is
4241 * contained in both ranges according to @a comp, the element from the
4242 * first range is copied and both ranges advance. The output range may not
4243 * overlap either input range.
4244 */
4245 template<typename _InputIterator1, typename _InputIterator2,
4246 typename _OutputIterator, typename _Compare>
4247 _OutputIterator
4248 set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
4249 _InputIterator2 __first2, _InputIterator2 __last2,
4250 _OutputIterator __result, _Compare __comp)
4251 {
4252 // concept requirements
4253 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4254 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4255 __glibcxx_function_requires(_SameTypeConcept<
4256 typename iterator_traits<_InputIterator1>::value_type,
4257 typename iterator_traits<_InputIterator2>::value_type>)
4258 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4259 typename iterator_traits<_InputIterator1>::value_type>)
4260 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4261 typename iterator_traits<_InputIterator1>::value_type,
4262 typename iterator_traits<_InputIterator2>::value_type>)
4263 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4264 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4265
4266 while (__first1 != __last1 && __first2 != __last2)
4267 if (__comp(*__first1, *__first2))
4268 ++__first1;
4269 else if (__comp(*__first2, *__first1))
4270 ++__first2;
4271 else
4272 {
4273 *__result = *__first1;
4274 ++__first1;
4275 ++__first2;
4276 ++__result;
4277 }
4278 return __result;
4279 }
4280
4281 /**
4282 * @brief Return the difference of two sorted ranges.
4283 * @param first1 Start of first range.
4284 * @param last1 End of first range.
4285 * @param first2 Start of second range.
4286 * @param last2 End of second range.
4287 * @return End of the output range.
4288 * @ingroup setoperations
4289 *
4290 * This operation iterates over both ranges, copying elements present in
4291 * the first range but not the second in order to the output range.
4292 * Iterators increment for each range. When the current element of the
4293 * first range is less than the second, that element is copied and the
4294 * iterator advances. If the current element of the second range is less,
4295 * the iterator advances, but no element is copied. If an element is
4296 * contained in both ranges, no elements are copied and both ranges
4297 * advance. The output range may not overlap either input range.
4298 */
4299 template<typename _InputIterator1, typename _InputIterator2,
4300 typename _OutputIterator>
4301 _OutputIterator
4302 set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
4303 _InputIterator2 __first2, _InputIterator2 __last2,
4304 _OutputIterator __result)
4305 {
4306 // concept requirements
4307 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4308 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4309 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4310 typename iterator_traits<_InputIterator1>::value_type>)
4311 __glibcxx_function_requires(_SameTypeConcept<
4312 typename iterator_traits<_InputIterator1>::value_type,
4313 typename iterator_traits<_InputIterator2>::value_type>)
4314 __glibcxx_function_requires(_LessThanComparableConcept<
4315 typename iterator_traits<_InputIterator1>::value_type>)
4316 __glibcxx_requires_sorted(__first1, __last1);
4317 __glibcxx_requires_sorted(__first2, __last2);
4318
4319 while (__first1 != __last1 && __first2 != __last2)
4320 if (*__first1 < *__first2)
4321 {
4322 *__result = *__first1;
4323 ++__first1;
4324 ++__result;
4325 }
4326 else if (*__first2 < *__first1)
4327 ++__first2;
4328 else
4329 {
4330 ++__first1;
4331 ++__first2;
4332 }
4333 return std::copy(__first1, __last1, __result);
4334 }
4335
4336 /**
4337 * @brief Return the difference of two sorted ranges using comparison
4338 * functor.
4339 * @param first1 Start of first range.
4340 * @param last1 End of first range.
4341 * @param first2 Start of second range.
4342 * @param last2 End of second range.
4343 * @param comp The comparison functor.
4344 * @return End of the output range.
4345 * @ingroup setoperations
4346 *
4347 * This operation iterates over both ranges, copying elements present in
4348 * the first range but not the second in order to the output range.
4349 * Iterators increment for each range. When the current element of the
4350 * first range is less than the second according to @a comp, that element
4351 * is copied and the iterator advances. If the current element of the
4352 * second range is less, no element is copied and the iterator advances.
4353 * If an element is contained in both ranges according to @a comp, no
4354 * elements are copied and both ranges advance. The output range may not
4355 * overlap either input range.
4356 */
4357 template<typename _InputIterator1, typename _InputIterator2,
4358 typename _OutputIterator, typename _Compare>
4359 _OutputIterator
4360 set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
4361 _InputIterator2 __first2, _InputIterator2 __last2,
4362 _OutputIterator __result, _Compare __comp)
4363 {
4364 // concept requirements
4365 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4366 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4367 __glibcxx_function_requires(_SameTypeConcept<
4368 typename iterator_traits<_InputIterator1>::value_type,
4369 typename iterator_traits<_InputIterator2>::value_type>)
4370 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4371 typename iterator_traits<_InputIterator1>::value_type>)
4372 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4373 typename iterator_traits<_InputIterator1>::value_type,
4374 typename iterator_traits<_InputIterator2>::value_type>)
4375 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4376 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4377
4378 while (__first1 != __last1 && __first2 != __last2)
4379 if (__comp(*__first1, *__first2))
4380 {
4381 *__result = *__first1;
4382 ++__first1;
4383 ++__result;
4384 }
4385 else if (__comp(*__first2, *__first1))
4386 ++__first2;
4387 else
4388 {
4389 ++__first1;
4390 ++__first2;
4391 }
4392 return std::copy(__first1, __last1, __result);
4393 }
4394
4395 /**
4396 * @brief Return the symmetric difference of two sorted ranges.
4397 * @param first1 Start of first range.
4398 * @param last1 End of first range.
4399 * @param first2 Start of second range.
4400 * @param last2 End of second range.
4401 * @return End of the output range.
4402 * @ingroup setoperations
4403 *
4404 * This operation iterates over both ranges, copying elements present in
4405 * one range but not the other in order to the output range. Iterators
4406 * increment for each range. When the current element of one range is less
4407 * than the other, that element is copied and the iterator advances. If an
4408 * element is contained in both ranges, no elements are copied and both
4409 * ranges advance. The output range may not overlap either input range.
4410 */
4411 template<typename _InputIterator1, typename _InputIterator2,
4412 typename _OutputIterator>
4413 _OutputIterator
4414 set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
4415 _InputIterator2 __first2, _InputIterator2 __last2,
4416 _OutputIterator __result)
4417 {
4418 // concept requirements
4419 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4420 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4421 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4422 typename iterator_traits<_InputIterator1>::value_type>)
4423 __glibcxx_function_requires(_SameTypeConcept<
4424 typename iterator_traits<_InputIterator1>::value_type,
4425 typename iterator_traits<_InputIterator2>::value_type>)
4426 __glibcxx_function_requires(_LessThanComparableConcept<
4427 typename iterator_traits<_InputIterator1>::value_type>)
4428 __glibcxx_requires_sorted(__first1, __last1);
4429 __glibcxx_requires_sorted(__first2, __last2);
4430
4431 while (__first1 != __last1 && __first2 != __last2)
4432 if (*__first1 < *__first2)
4433 {
4434 *__result = *__first1;
4435 ++__first1;
4436 ++__result;
4437 }
4438 else if (*__first2 < *__first1)
4439 {
4440 *__result = *__first2;
4441 ++__first2;
4442 ++__result;
4443 }
4444 else
4445 {
4446 ++__first1;
4447 ++__first2;
4448 }
4449 return std::copy(__first2, __last2, std::copy(__first1,
4450 __last1, __result));
4451 }
4452
4453 /**
4454 * @brief Return the symmetric difference of two sorted ranges using
4455 * comparison functor.
4456 * @param first1 Start of first range.
4457 * @param last1 End of first range.
4458 * @param first2 Start of second range.
4459 * @param last2 End of second range.
4460 * @param comp The comparison functor.
4461 * @return End of the output range.
4462 * @ingroup setoperations
4463 *
4464 * This operation iterates over both ranges, copying elements present in
4465 * one range but not the other in order to the output range. Iterators
4466 * increment for each range. When the current element of one range is less
4467 * than the other according to @a comp, that element is copied and the
4468 * iterator advances. If an element is contained in both ranges according
4469 * to @a comp, no elements are copied and both ranges advance. The output
4470 * range may not overlap either input range.
4471 */
4472 template<typename _InputIterator1, typename _InputIterator2,
4473 typename _OutputIterator, typename _Compare>
4474 _OutputIterator
4475 set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
4476 _InputIterator2 __first2, _InputIterator2 __last2,
4477 _OutputIterator __result,
4478 _Compare __comp)
4479 {
4480 // concept requirements
4481 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4482 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4483 __glibcxx_function_requires(_SameTypeConcept<
4484 typename iterator_traits<_InputIterator1>::value_type,
4485 typename iterator_traits<_InputIterator2>::value_type>)
4486 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4487 typename iterator_traits<_InputIterator1>::value_type>)
4488 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4489 typename iterator_traits<_InputIterator1>::value_type,
4490 typename iterator_traits<_InputIterator2>::value_type>)
4491 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4492 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4493
4494 while (__first1 != __last1 && __first2 != __last2)
4495 if (__comp(*__first1, *__first2))
4496 {
4497 *__result = *__first1;
4498 ++__first1;
4499 ++__result;
4500 }
4501 else if (__comp(*__first2, *__first1))
4502 {
4503 *__result = *__first2;
4504 ++__first2;
4505 ++__result;
4506 }
4507 else
4508 {
4509 ++__first1;
4510 ++__first2;
4511 }
4512 return std::copy(__first2, __last2, std::copy(__first1,
4513 __last1, __result));
4514 }
4515
4516 // min_element and max_element, with and without an explicitly supplied
4517 // comparison function.
4518
4519 /**
4520 * @brief Return the maximum element in a range.
4521 * @param first Start of range.
4522 * @param last End of range.
4523 * @return Iterator referencing the first instance of the largest value.
4524 */
4525 template<typename _ForwardIterator>
4526 _ForwardIterator
4527 max_element(_ForwardIterator __first, _ForwardIterator __last)
4528 {
4529 // concept requirements
4530 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4531 __glibcxx_function_requires(_LessThanComparableConcept<
4532 typename iterator_traits<_ForwardIterator>::value_type>)
4533 __glibcxx_requires_valid_range(__first, __last);
4534
4535 if (__first == __last)
4536 return __first;
4537 _ForwardIterator __result = __first;
4538 while (++__first != __last)
4539 if (*__result < *__first)
4540 __result = __first;
4541 return __result;
4542 }
4543
4544 /**
4545 * @brief Return the maximum element in a range using comparison functor.
4546 * @param first Start of range.
4547 * @param last End of range.
4548 * @param comp Comparison functor.
4549 * @return Iterator referencing the first instance of the largest value
4550 * according to comp.
4551 */
4552 template<typename _ForwardIterator, typename _Compare>
4553 _ForwardIterator
4554 max_element(_ForwardIterator __first, _ForwardIterator __last,
4555 _Compare __comp)
4556 {
4557 // concept requirements
4558 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4559 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4560 typename iterator_traits<_ForwardIterator>::value_type,
4561 typename iterator_traits<_ForwardIterator>::value_type>)
4562 __glibcxx_requires_valid_range(__first, __last);
4563
4564 if (__first == __last) return __first;
4565 _ForwardIterator __result = __first;
4566 while (++__first != __last)
4567 if (__comp(*__result, *__first)) __result = __first;
4568 return __result;
4569 }
4570
4571 /**
4572 * @brief Return the minimum element in a range.
4573 * @param first Start of range.
4574 * @param last End of range.
4575 * @return Iterator referencing the first instance of the smallest value.
4576 */
4577 template<typename _ForwardIterator>
4578 _ForwardIterator
4579 min_element(_ForwardIterator __first, _ForwardIterator __last)
4580 {
4581 // concept requirements
4582 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4583 __glibcxx_function_requires(_LessThanComparableConcept<
4584 typename iterator_traits<_ForwardIterator>::value_type>)
4585 __glibcxx_requires_valid_range(__first, __last);
4586
4587 if (__first == __last)
4588 return __first;
4589 _ForwardIterator __result = __first;
4590 while (++__first != __last)
4591 if (*__first < *__result)
4592 __result = __first;
4593 return __result;
4594 }
4595
4596 /**
4597 * @brief Return the minimum element in a range using comparison functor.
4598 * @param first Start of range.
4599 * @param last End of range.
4600 * @param comp Comparison functor.
4601 * @return Iterator referencing the first instance of the smallest value
4602 * according to comp.
4603 */
4604 template<typename _ForwardIterator, typename _Compare>
4605 _ForwardIterator
4606 min_element(_ForwardIterator __first, _ForwardIterator __last,
4607 _Compare __comp)
4608 {
4609 // concept requirements
4610 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4611 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4612 typename iterator_traits<_ForwardIterator>::value_type,
4613 typename iterator_traits<_ForwardIterator>::value_type>)
4614 __glibcxx_requires_valid_range(__first, __last);
4615
4616 if (__first == __last)
4617 return __first;
4618 _ForwardIterator __result = __first;
4619 while (++__first != __last)
4620 if (__comp(*__first, *__result))
4621 __result = __first;
4622 return __result;
4623 }
4624
4625 // next_permutation and prev_permutation, with and without an explicitly
4626 // supplied comparison function.
4627
4628 /**
4629 * @brief Permute range into the next "dictionary" ordering.
4630 * @param first Start of range.
4631 * @param last End of range.
4632 * @return False if wrapped to first permutation, true otherwise.
4633 *
4634 * Treats all permutations of the range as a set of "dictionary" sorted
4635 * sequences. Permutes the current sequence into the next one of this set.
4636 * Returns true if there are more sequences to generate. If the sequence
4637 * is the largest of the set, the smallest is generated and false returned.
4638 */
4639 template<typename _BidirectionalIterator>
4640 bool
4641 next_permutation(_BidirectionalIterator __first,
4642 _BidirectionalIterator __last)
4643 {
4644 // concept requirements
4645 __glibcxx_function_requires(_BidirectionalIteratorConcept<
4646 _BidirectionalIterator>)
4647 __glibcxx_function_requires(_LessThanComparableConcept<
4648 typename iterator_traits<_BidirectionalIterator>::value_type>)
4649 __glibcxx_requires_valid_range(__first, __last);
4650
4651 if (__first == __last)
4652 return false;
4653 _BidirectionalIterator __i = __first;
4654 ++__i;
4655 if (__i == __last)
4656 return false;
4657 __i = __last;
4658 --__i;
4659
4660 for(;;)
4661 {
4662 _BidirectionalIterator __ii = __i;
4663 --__i;
4664 if (*__i < *__ii)
4665 {
4666 _BidirectionalIterator __j = __last;
4667 while (!(*__i < *--__j))
4668 {}
4669 std::iter_swap(__i, __j);
4670 std::reverse(__ii, __last);
4671 return true;
4672 }
4673 if (__i == __first)
4674 {
4675 std::reverse(__first, __last);
4676 return false;
4677 }
4678 }
4679 }
4680
4681 /**
4682 * @brief Permute range into the next "dictionary" ordering using
4683 * comparison functor.
4684 * @param first Start of range.
4685 * @param last End of range.
4686 * @param comp
4687 * @return False if wrapped to first permutation, true otherwise.
4688 *
4689 * Treats all permutations of the range [first,last) as a set of
4690 * "dictionary" sorted sequences ordered by @a comp. Permutes the current
4691 * sequence into the next one of this set. Returns true if there are more
4692 * sequences to generate. If the sequence is the largest of the set, the
4693 * smallest is generated and false returned.
4694 */
4695 template<typename _BidirectionalIterator, typename _Compare>
4696 bool
4697 next_permutation(_BidirectionalIterator __first,
4698 _BidirectionalIterator __last, _Compare __comp)
4699 {
4700 // concept requirements
4701 __glibcxx_function_requires(_BidirectionalIteratorConcept<
4702 _BidirectionalIterator>)
4703 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4704 typename iterator_traits<_BidirectionalIterator>::value_type,
4705 typename iterator_traits<_BidirectionalIterator>::value_type>)
4706 __glibcxx_requires_valid_range(__first, __last);
4707
4708 if (__first == __last)
4709 return false;
4710 _BidirectionalIterator __i = __first;
4711 ++__i;
4712 if (__i == __last)
4713 return false;
4714 __i = __last;
4715 --__i;
4716
4717 for(;;)
4718 {
4719 _BidirectionalIterator __ii = __i;
4720 --__i;
4721 if (__comp(*__i, *__ii))
4722 {
4723 _BidirectionalIterator __j = __last;
4724 while (!__comp(*__i, *--__j))
4725 {}
4726 std::iter_swap(__i, __j);
4727 std::reverse(__ii, __last);
4728 return true;
4729 }
4730 if (__i == __first)
4731 {
4732 std::reverse(__first, __last);
4733 return false;
4734 }
4735 }
4736 }
4737
4738 /**
4739 * @brief Permute range into the previous "dictionary" ordering.
4740 * @param first Start of range.
4741 * @param last End of range.
4742 * @return False if wrapped to last permutation, true otherwise.
4743 *
4744 * Treats all permutations of the range as a set of "dictionary" sorted
4745 * sequences. Permutes the current sequence into the previous one of this
4746 * set. Returns true if there are more sequences to generate. If the
4747 * sequence is the smallest of the set, the largest is generated and false
4748 * returned.
4749 */
4750 template<typename _BidirectionalIterator>
4751 bool
4752 prev_permutation(_BidirectionalIterator __first,
4753 _BidirectionalIterator __last)
4754 {
4755 // concept requirements
4756 __glibcxx_function_requires(_BidirectionalIteratorConcept<
4757 _BidirectionalIterator>)
4758 __glibcxx_function_requires(_LessThanComparableConcept<
4759 typename iterator_traits<_BidirectionalIterator>::value_type>)
4760 __glibcxx_requires_valid_range(__first, __last);
4761
4762 if (__first == __last)
4763 return false;
4764 _BidirectionalIterator __i = __first;
4765 ++__i;
4766 if (__i == __last)
4767 return false;
4768 __i = __last;
4769 --__i;
4770
4771 for(;;)
4772 {
4773 _BidirectionalIterator __ii = __i;
4774 --__i;
4775 if (*__ii < *__i)
4776 {
4777 _BidirectionalIterator __j = __last;
4778 while (!(*--__j < *__i))
4779 {}
4780 std::iter_swap(__i, __j);
4781 std::reverse(__ii, __last);
4782 return true;
4783 }
4784 if (__i == __first)
4785 {
4786 std::reverse(__first, __last);
4787 return false;
4788 }
4789 }
4790 }
4791
4792 /**
4793 * @brief Permute range into the previous "dictionary" ordering using
4794 * comparison functor.
4795 * @param first Start of range.
4796 * @param last End of range.
4797 * @param comp
4798 * @return False if wrapped to last permutation, true otherwise.
4799 *
4800 * Treats all permutations of the range [first,last) as a set of
4801 * "dictionary" sorted sequences ordered by @a comp. Permutes the current
4802 * sequence into the previous one of this set. Returns true if there are
4803 * more sequences to generate. If the sequence is the smallest of the set,
4804 * the largest is generated and false returned.
4805 */
4806 template<typename _BidirectionalIterator, typename _Compare>
4807 bool
4808 prev_permutation(_BidirectionalIterator __first,
4809 _BidirectionalIterator __last, _Compare __comp)
4810 {
4811 // concept requirements
4812 __glibcxx_function_requires(_BidirectionalIteratorConcept<
4813 _BidirectionalIterator>)
4814 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4815 typename iterator_traits<_BidirectionalIterator>::value_type,
4816 typename iterator_traits<_BidirectionalIterator>::value_type>)
4817 __glibcxx_requires_valid_range(__first, __last);
4818
4819 if (__first == __last)
4820 return false;
4821 _BidirectionalIterator __i = __first;
4822 ++__i;
4823 if (__i == __last)
4824 return false;
4825 __i = __last;
4826 --__i;
4827
4828 for(;;)
4829 {
4830 _BidirectionalIterator __ii = __i;
4831 --__i;
4832 if (__comp(*__ii, *__i))
4833 {
4834 _BidirectionalIterator __j = __last;
4835 while (!__comp(*--__j, *__i))
4836 {}
4837 std::iter_swap(__i, __j);
4838 std::reverse(__ii, __last);
4839 return true;
4840 }
4841 if (__i == __first)
4842 {
4843 std::reverse(__first, __last);
4844 return false;
4845 }
4846 }
4847 }
4848
4849 // find_first_of, with and without an explicitly supplied comparison function.
4850
4851 /**
4852 * @brief Find element from a set in a sequence.
4853 * @param first1 Start of range to search.
4854 * @param last1 End of range to search.
4855 * @param first2 Start of match candidates.
4856 * @param last2 End of match candidates.
4857 * @return The first iterator @c i in the range
4858 * @p [first1,last1) such that @c *i == @p *(i2) such that i2 is an
4859 * interator in [first2,last2), or @p last1 if no such iterator exists.
4860 *
4861 * Searches the range @p [first1,last1) for an element that is equal to
4862 * some element in the range [first2,last2). If found, returns an iterator
4863 * in the range [first1,last1), otherwise returns @p last1.
4864 */
4865 template<typename _InputIterator, typename _ForwardIterator>
4866 _InputIterator
4867 find_first_of(_InputIterator __first1, _InputIterator __last1,
4868 _ForwardIterator __first2, _ForwardIterator __last2)
4869 {
4870 // concept requirements
4871 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4872 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4873 __glibcxx_function_requires(_EqualOpConcept<
4874 typename iterator_traits<_InputIterator>::value_type,
4875 typename iterator_traits<_ForwardIterator>::value_type>)
4876 __glibcxx_requires_valid_range(__first1, __last1);
4877 __glibcxx_requires_valid_range(__first2, __last2);
4878
4879 for ( ; __first1 != __last1; ++__first1)
4880 for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter)
4881 if (*__first1 == *__iter)
4882 return __first1;
4883 return __last1;
4884 }
4885
4886 /**
4887 * @brief Find element from a set in a sequence using a predicate.
4888 * @param first1 Start of range to search.
4889 * @param last1 End of range to search.
4890 * @param first2 Start of match candidates.
4891 * @param last2 End of match candidates.
4892 * @param comp Predicate to use.
4893 * @return The first iterator @c i in the range
4894 * @p [first1,last1) such that @c comp(*i, @p *(i2)) is true and i2 is an
4895 * interator in [first2,last2), or @p last1 if no such iterator exists.
4896 *
4897 * Searches the range @p [first1,last1) for an element that is equal to
4898 * some element in the range [first2,last2). If found, returns an iterator in
4899 * the range [first1,last1), otherwise returns @p last1.
4900 */
4901 template<typename _InputIterator, typename _ForwardIterator,
4902 typename _BinaryPredicate>
4903 _InputIterator
4904 find_first_of(_InputIterator __first1, _InputIterator __last1,
4905 _ForwardIterator __first2, _ForwardIterator __last2,
4906 _BinaryPredicate __comp)
4907 {
4908 // concept requirements
4909 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4910 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4911 __glibcxx_function_requires(_EqualOpConcept<
4912 typename iterator_traits<_InputIterator>::value_type,
4913 typename iterator_traits<_ForwardIterator>::value_type>)
4914 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4915 typename iterator_traits<_InputIterator>::value_type,
4916 typename iterator_traits<_ForwardIterator>::value_type>)
4917 __glibcxx_requires_valid_range(__first1, __last1);
4918 __glibcxx_requires_valid_range(__first2, __last2);
4919
4920 for ( ; __first1 != __last1; ++__first1)
4921 for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter)
4922 if (__comp(*__first1, *__iter))
4923 return __first1;
4924 return __last1;
4925 }
4926
4927
4928 // find_end, with and without an explicitly supplied comparison function.
4929 // Search [first2, last2) as a subsequence in [first1, last1), and return
4930 // the *last* possible match. Note that find_end for bidirectional iterators
4931 // is much faster than for forward iterators.
4932
4933 // find_end for forward iterators.
4934 template<typename _ForwardIterator1, typename _ForwardIterator2>
4935 _ForwardIterator1
4936 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4937 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
4938 forward_iterator_tag, forward_iterator_tag)
4939 {
4940 if (__first2 == __last2)
4941 return __last1;
4942 else
4943 {
4944 _ForwardIterator1 __result = __last1;
4945 while (1)
4946 {
4947 _ForwardIterator1 __new_result
4948 = std::search(__first1, __last1, __first2, __last2);
4949 if (__new_result == __last1)
4950 return __result;
4951 else
4952 {
4953 __result = __new_result;
4954 __first1 = __new_result;
4955 ++__first1;
4956 }
4957 }
4958 }
4959 }
4960
4961 template<typename _ForwardIterator1, typename _ForwardIterator2,
4962 typename _BinaryPredicate>
4963 _ForwardIterator1
4964 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4965 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
4966 forward_iterator_tag, forward_iterator_tag,
4967 _BinaryPredicate __comp)
4968 {
4969 if (__first2 == __last2)
4970 return __last1;
4971 else
4972 {
4973 _ForwardIterator1 __result = __last1;
4974 while (1)
4975 {
4976 _ForwardIterator1 __new_result
4977 = std::search(__first1, __last1, __first2, __last2, __comp);
4978 if (__new_result == __last1)
4979 return __result;
4980 else
4981 {
4982 __result = __new_result;
4983 __first1 = __new_result;
4984 ++__first1;
4985 }
4986 }
4987 }
4988 }
4989
4990 // find_end for bidirectional iterators. Requires partial specialization.
4991 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2>
4992 _BidirectionalIterator1
4993 __find_end(_BidirectionalIterator1 __first1,
4994 _BidirectionalIterator1 __last1,
4995 _BidirectionalIterator2 __first2,
4996 _BidirectionalIterator2 __last2,
4997 bidirectional_iterator_tag, bidirectional_iterator_tag)
4998 {
4999 // concept requirements
5000 __glibcxx_function_requires(_BidirectionalIteratorConcept<
5001 _BidirectionalIterator1>)
5002 __glibcxx_function_requires(_BidirectionalIteratorConcept<
5003 _BidirectionalIterator2>)
5004
5005 typedef reverse_iterator<_BidirectionalIterator1> _RevIterator1;
5006 typedef reverse_iterator<_BidirectionalIterator2> _RevIterator2;
5007
5008 _RevIterator1 __rlast1(__first1);
5009 _RevIterator2 __rlast2(__first2);
5010 _RevIterator1 __rresult = std::search(_RevIterator1(__last1), __rlast1,
5011 _RevIterator2(__last2), __rlast2);
5012
5013 if (__rresult == __rlast1)
5014 return __last1;
5015 else
5016 {
5017 _BidirectionalIterator1 __result = __rresult.base();
5018 std::advance(__result, -std::distance(__first2, __last2));
5019 return __result;
5020 }
5021 }
5022
5023 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
5024 typename _BinaryPredicate>
5025 _BidirectionalIterator1
5026 __find_end(_BidirectionalIterator1 __first1,
5027 _BidirectionalIterator1 __last1,
5028 _BidirectionalIterator2 __first2,
5029 _BidirectionalIterator2 __last2,
5030 bidirectional_iterator_tag, bidirectional_iterator_tag,
5031 _BinaryPredicate __comp)
5032 {
5033 // concept requirements
5034 __glibcxx_function_requires(_BidirectionalIteratorConcept<
5035 _BidirectionalIterator1>)
5036 __glibcxx_function_requires(_BidirectionalIteratorConcept<
5037 _BidirectionalIterator2>)
5038
5039 typedef reverse_iterator<_BidirectionalIterator1> _RevIterator1;
5040 typedef reverse_iterator<_BidirectionalIterator2> _RevIterator2;
5041
5042 _RevIterator1 __rlast1(__first1);
5043 _RevIterator2 __rlast2(__first2);
5044 _RevIterator1 __rresult = std::search(_RevIterator1(__last1), __rlast1,
5045 _RevIterator2(__last2), __rlast2,
5046 __comp);
5047
5048 if (__rresult == __rlast1)
5049 return __last1;
5050 else
5051 {
5052 _BidirectionalIterator1 __result = __rresult.base();
5053 std::advance(__result, -std::distance(__first2, __last2));
5054 return __result;
5055 }
5056 }
5057
5058 // Dispatching functions for find_end.
5059
5060 /**
5061 * @brief Find last matching subsequence in a sequence.
5062 * @param first1 Start of range to search.
5063 * @param last1 End of range to search.
5064 * @param first2 Start of sequence to match.
5065 * @param last2 End of sequence to match.
5066 * @return The last iterator @c i in the range
5067 * @p [first1,last1-(last2-first2)) such that @c *(i+N) == @p *(first2+N)
5068 * for each @c N in the range @p [0,last2-first2), or @p last1 if no
5069 * such iterator exists.
5070 *
5071 * Searches the range @p [first1,last1) for a sub-sequence that compares
5072 * equal value-by-value with the sequence given by @p [first2,last2) and
5073 * returns an iterator to the first element of the sub-sequence, or
5074 * @p last1 if the sub-sequence is not found. The sub-sequence will be the
5075 * last such subsequence contained in [first,last1).
5076 *
5077 * Because the sub-sequence must lie completely within the range
5078 * @p [first1,last1) it must start at a position less than
5079 * @p last1-(last2-first2) where @p last2-first2 is the length of the
5080 * sub-sequence.
5081 * This means that the returned iterator @c i will be in the range
5082 * @p [first1,last1-(last2-first2))
5083 */
5084 template<typename _ForwardIterator1, typename _ForwardIterator2>
5085 inline _ForwardIterator1
5086 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
5087 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
5088 {
5089 // concept requirements
5090 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
5091 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
5092 __glibcxx_function_requires(_EqualOpConcept<
5093 typename iterator_traits<_ForwardIterator1>::value_type,
5094 typename iterator_traits<_ForwardIterator2>::value_type>)
5095 __glibcxx_requires_valid_range(__first1, __last1);
5096 __glibcxx_requires_valid_range(__first2, __last2);
5097
5098 return std::__find_end(__first1, __last1, __first2, __last2,
5099 std::__iterator_category(__first1),
5100 std::__iterator_category(__first2));
5101 }
5102
5103 /**
5104 * @brief Find last matching subsequence in a sequence using a predicate.
5105 * @param first1 Start of range to search.
5106 * @param last1 End of range to search.
5107 * @param first2 Start of sequence to match.
5108 * @param last2 End of sequence to match.
5109 * @param comp The predicate to use.
5110 * @return The last iterator @c i in the range
5111 * @p [first1,last1-(last2-first2)) such that @c predicate(*(i+N), @p
5112 * (first2+N)) is true for each @c N in the range @p [0,last2-first2), or
5113 * @p last1 if no such iterator exists.
5114 *
5115 * Searches the range @p [first1,last1) for a sub-sequence that compares
5116 * equal value-by-value with the sequence given by @p [first2,last2) using
5117 * comp as a predicate and returns an iterator to the first element of the
5118 * sub-sequence, or @p last1 if the sub-sequence is not found. The
5119 * sub-sequence will be the last such subsequence contained in
5120 * [first,last1).
5121 *
5122 * Because the sub-sequence must lie completely within the range
5123 * @p [first1,last1) it must start at a position less than
5124 * @p last1-(last2-first2) where @p last2-first2 is the length of the
5125 * sub-sequence.
5126 * This means that the returned iterator @c i will be in the range
5127 * @p [first1,last1-(last2-first2))
5128 */
5129 template<typename _ForwardIterator1, typename _ForwardIterator2,
5130 typename _BinaryPredicate>
5131 inline _ForwardIterator1
5132 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
5133 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
5134 _BinaryPredicate __comp)
5135 {
5136 // concept requirements
5137 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
5138 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
5139 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
5140 typename iterator_traits<_ForwardIterator1>::value_type,
5141 typename iterator_traits<_ForwardIterator2>::value_type>)
5142 __glibcxx_requires_valid_range(__first1, __last1);
5143 __glibcxx_requires_valid_range(__first2, __last2);
5144
5145 return std::__find_end(__first1, __last1, __first2, __last2,
5146 std::__iterator_category(__first1),
5147 std::__iterator_category(__first2),
5148 __comp);
5149 }
5150
5151 } // namespace std
5152
5153 #endif /* _ALGO_H */