projects / gcc.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
All files: Update FSF address.
[gcc.git] / libstdc++-v3 / include / bits / stl_algo.h
1 // Algorithm implementation -*- C++ -*-
2
3 // Copyright (C) 2001, 2002, 2003, 2004, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
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(_EqualOpConcept<
417 typename iterator_traits<_InputIterator>::value_type, _Tp>)
418 __glibcxx_requires_valid_range(__first, __last);
419 typename iterator_traits<_InputIterator>::difference_type __n = 0;
420 for ( ; __first != __last; ++__first)
421 if (*__first == __value)
422 ++__n;
423 return __n;
424 }
425
426 /**
427 * @brief Count the elements of a sequence for which a predicate is true.
428 * @param first An input iterator.
429 * @param last An input iterator.
430 * @param pred A predicate.
431 * @return The number of iterators @c i in the range @p [first,last)
432 * for which @p pred(*i) is true.
433 */
434 template<typename _InputIterator, typename _Predicate>
435 typename iterator_traits<_InputIterator>::difference_type
436 count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
437 {
438 // concept requirements
439 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
440 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
441 typename iterator_traits<_InputIterator>::value_type>)
442 __glibcxx_requires_valid_range(__first, __last);
443 typename iterator_traits<_InputIterator>::difference_type __n = 0;
444 for ( ; __first != __last; ++__first)
445 if (__pred(*__first))
446 ++__n;
447 return __n;
448 }
449
450 /**
451 * @brief Search a sequence for a matching sub-sequence.
452 * @param first1 A forward iterator.
453 * @param last1 A forward iterator.
454 * @param first2 A forward iterator.
455 * @param last2 A forward iterator.
456 * @return The first iterator @c i in the range
457 * @p [first1,last1-(last2-first2)) such that @c *(i+N) == @p *(first2+N)
458 * for each @c N in the range @p [0,last2-first2), or @p last1 if no
459 * such iterator exists.
460 *
461 * Searches the range @p [first1,last1) for a sub-sequence that compares
462 * equal value-by-value with the sequence given by @p [first2,last2) and
463 * returns an iterator to the first element of the sub-sequence, or
464 * @p last1 if the sub-sequence is not found.
465 *
466 * Because the sub-sequence must lie completely within the range
467 * @p [first1,last1) it must start at a position less than
468 * @p last1-(last2-first2) where @p last2-first2 is the length of the
469 * sub-sequence.
470 * This means that the returned iterator @c i will be in the range
471 * @p [first1,last1-(last2-first2))
472 */
473 template<typename _ForwardIterator1, typename _ForwardIterator2>
474 _ForwardIterator1
475 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
476 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
477 {
478 // concept requirements
479 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
480 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
481 __glibcxx_function_requires(_EqualOpConcept<
482 typename iterator_traits<_ForwardIterator1>::value_type,
483 typename iterator_traits<_ForwardIterator2>::value_type>)
484 __glibcxx_requires_valid_range(__first1, __last1);
485 __glibcxx_requires_valid_range(__first2, __last2);
486 // Test for empty ranges
487 if (__first1 == __last1 || __first2 == __last2)
488 return __first1;
489
490 // Test for a pattern of length 1.
491 _ForwardIterator2 __tmp(__first2);
492 ++__tmp;
493 if (__tmp == __last2)
494 return std::find(__first1, __last1, *__first2);
495
496 // General case.
497 _ForwardIterator2 __p1, __p;
498 __p1 = __first2; ++__p1;
499 _ForwardIterator1 __current = __first1;
500
501 while (__first1 != __last1)
502 {
503 __first1 = std::find(__first1, __last1, *__first2);
504 if (__first1 == __last1)
505 return __last1;
506
507 __p = __p1;
508 __current = __first1;
509 if (++__current == __last1)
510 return __last1;
511
512 while (*__current == *__p)
513 {
514 if (++__p == __last2)
515 return __first1;
516 if (++__current == __last1)
517 return __last1;
518 }
519 ++__first1;
520 }
521 return __first1;
522 }
523
524 /**
525 * @brief Search a sequence for a matching sub-sequence using a predicate.
526 * @param first1 A forward iterator.
527 * @param last1 A forward iterator.
528 * @param first2 A forward iterator.
529 * @param last2 A forward iterator.
530 * @param predicate A binary predicate.
531 * @return The first iterator @c i in the range
532 * @p [first1,last1-(last2-first2)) such that
533 * @p predicate(*(i+N),*(first2+N)) is true for each @c N in the range
534 * @p [0,last2-first2), or @p last1 if no such iterator exists.
535 *
536 * Searches the range @p [first1,last1) for a sub-sequence that compares
537 * equal value-by-value with the sequence given by @p [first2,last2),
538 * using @p predicate to determine equality, and returns an iterator
539 * to the first element of the sub-sequence, or @p last1 if no such
540 * iterator exists.
541 *
542 * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2)
543 */
544 template<typename _ForwardIterator1, typename _ForwardIterator2,
545 typename _BinaryPredicate>
546 _ForwardIterator1
547 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
548 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
549 _BinaryPredicate __predicate)
550 {
551 // concept requirements
552 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
553 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
554 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
555 typename iterator_traits<_ForwardIterator1>::value_type,
556 typename iterator_traits<_ForwardIterator2>::value_type>)
557 __glibcxx_requires_valid_range(__first1, __last1);
558 __glibcxx_requires_valid_range(__first2, __last2);
559
560 // Test for empty ranges
561 if (__first1 == __last1 || __first2 == __last2)
562 return __first1;
563
564 // Test for a pattern of length 1.
565 _ForwardIterator2 __tmp(__first2);
566 ++__tmp;
567 if (__tmp == __last2)
568 {
569 while (__first1 != __last1 && !__predicate(*__first1, *__first2))
570 ++__first1;
571 return __first1;
572 }
573
574 // General case.
575 _ForwardIterator2 __p1, __p;
576 __p1 = __first2; ++__p1;
577 _ForwardIterator1 __current = __first1;
578
579 while (__first1 != __last1)
580 {
581 while (__first1 != __last1)
582 {
583 if (__predicate(*__first1, *__first2))
584 break;
585 ++__first1;
586 }
587 while (__first1 != __last1 && !__predicate(*__first1, *__first2))
588 ++__first1;
589 if (__first1 == __last1)
590 return __last1;
591
592 __p = __p1;
593 __current = __first1;
594 if (++__current == __last1)
595 return __last1;
596
597 while (__predicate(*__current, *__p))
598 {
599 if (++__p == __last2)
600 return __first1;
601 if (++__current == __last1)
602 return __last1;
603 }
604 ++__first1;
605 }
606 return __first1;
607 }
608
609 /**
610 * @brief Search a sequence for a number of consecutive values.
611 * @param first A forward iterator.
612 * @param last A forward iterator.
613 * @param count The number of consecutive values.
614 * @param val The value to find.
615 * @return The first iterator @c i in the range @p [first,last-count)
616 * such that @c *(i+N) == @p val for each @c N in the range @p [0,count),
617 * or @p last if no such iterator exists.
618 *
619 * Searches the range @p [first,last) for @p count consecutive elements
620 * equal to @p val.
621 */
622 template<typename _ForwardIterator, typename _Integer, typename _Tp>
623 _ForwardIterator
624 search_n(_ForwardIterator __first, _ForwardIterator __last,
625 _Integer __count, const _Tp& __val)
626 {
627 // concept requirements
628 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
629 __glibcxx_function_requires(_EqualOpConcept<
630 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
631 __glibcxx_requires_valid_range(__first, __last);
632
633 if (__count <= 0)
634 return __first;
635 else
636 {
637 __first = std::find(__first, __last, __val);
638 while (__first != __last)
639 {
640 typename iterator_traits<_ForwardIterator>::difference_type
641 __n = __count;
642 _ForwardIterator __i = __first;
643 ++__i;
644 while (__i != __last && __n != 1 && *__i == __val)
645 {
646 ++__i;
647 --__n;
648 }
649 if (__n == 1)
650 return __first;
651 else
652 __first = std::find(__i, __last, __val);
653 }
654 return __last;
655 }
656 }
657
658 /**
659 * @brief Search a sequence for a number of consecutive values using a
660 * predicate.
661 * @param first A forward iterator.
662 * @param last A forward iterator.
663 * @param count The number of consecutive values.
664 * @param val The value to find.
665 * @param binary_pred A binary predicate.
666 * @return The first iterator @c i in the range @p [first,last-count)
667 * such that @p binary_pred(*(i+N),val) is true for each @c N in the
668 * range @p [0,count), or @p last if no such iterator exists.
669 *
670 * Searches the range @p [first,last) for @p count consecutive elements
671 * for which the predicate returns true.
672 */
673 template<typename _ForwardIterator, typename _Integer, typename _Tp,
674 typename _BinaryPredicate>
675 _ForwardIterator
676 search_n(_ForwardIterator __first, _ForwardIterator __last,
677 _Integer __count, const _Tp& __val,
678 _BinaryPredicate __binary_pred)
679 {
680 // concept requirements
681 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
682 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
683 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
684 __glibcxx_requires_valid_range(__first, __last);
685
686 if (__count <= 0)
687 return __first;
688 else
689 {
690 while (__first != __last)
691 {
692 if (__binary_pred(*__first, __val))
693 break;
694 ++__first;
695 }
696 while (__first != __last)
697 {
698 typename iterator_traits<_ForwardIterator>::difference_type
699 __n = __count;
700 _ForwardIterator __i = __first;
701 ++__i;
702 while (__i != __last && __n != 1 && __binary_pred(*__i, __val))
703 {
704 ++__i;
705 --__n;
706 }
707 if (__n == 1)
708 return __first;
709 else
710 {
711 while (__i != __last)
712 {
713 if (__binary_pred(*__i, __val))
714 break;
715 ++__i;
716 }
717 __first = __i;
718 }
719 }
720 return __last;
721 }
722 }
723
724 /**
725 * @brief Swap the elements of two sequences.
726 * @param first1 A forward iterator.
727 * @param last1 A forward iterator.
728 * @param first2 A forward iterator.
729 * @return An iterator equal to @p first2+(last1-first1).
730 *
731 * Swaps each element in the range @p [first1,last1) with the
732 * corresponding element in the range @p [first2,(last1-first1)).
733 * The ranges must not overlap.
734 */
735 template<typename _ForwardIterator1, typename _ForwardIterator2>
736 _ForwardIterator2
737 swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
738 _ForwardIterator2 __first2)
739 {
740 // concept requirements
741 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
742 _ForwardIterator1>)
743 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
744 _ForwardIterator2>)
745 __glibcxx_function_requires(_ConvertibleConcept<
746 typename iterator_traits<_ForwardIterator1>::value_type,
747 typename iterator_traits<_ForwardIterator2>::value_type>)
748 __glibcxx_function_requires(_ConvertibleConcept<
749 typename iterator_traits<_ForwardIterator2>::value_type,
750 typename iterator_traits<_ForwardIterator1>::value_type>)
751 __glibcxx_requires_valid_range(__first1, __last1);
752
753 for ( ; __first1 != __last1; ++__first1, ++__first2)
754 std::iter_swap(__first1, __first2);
755 return __first2;
756 }
757
758 /**
759 * @brief Perform an operation on a sequence.
760 * @param first An input iterator.
761 * @param last An input iterator.
762 * @param result An output iterator.
763 * @param unary_op A unary operator.
764 * @return An output iterator equal to @p result+(last-first).
765 *
766 * Applies the operator to each element in the input range and assigns
767 * the results to successive elements of the output sequence.
768 * Evaluates @p *(result+N)=unary_op(*(first+N)) for each @c N in the
769 * range @p [0,last-first).
770 *
771 * @p unary_op must not alter its argument.
772 */
773 template<typename _InputIterator, typename _OutputIterator,
774 typename _UnaryOperation>
775 _OutputIterator
776 transform(_InputIterator __first, _InputIterator __last,
777 _OutputIterator __result, _UnaryOperation __unary_op)
778 {
779 // concept requirements
780 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
781 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
782 // "the type returned by a _UnaryOperation"
783 __typeof__(__unary_op(*__first))>)
784 __glibcxx_requires_valid_range(__first, __last);
785
786 for ( ; __first != __last; ++__first, ++__result)
787 *__result = __unary_op(*__first);
788 return __result;
789 }
790
791 /**
792 * @brief Perform an operation on corresponding elements of two sequences.
793 * @param first1 An input iterator.
794 * @param last1 An input iterator.
795 * @param first2 An input iterator.
796 * @param result An output iterator.
797 * @param binary_op A binary operator.
798 * @return An output iterator equal to @p result+(last-first).
799 *
800 * Applies the operator to the corresponding elements in the two
801 * input ranges and assigns the results to successive elements of the
802 * output sequence.
803 * Evaluates @p *(result+N)=binary_op(*(first1+N),*(first2+N)) for each
804 * @c N in the range @p [0,last1-first1).
805 *
806 * @p binary_op must not alter either of its arguments.
807 */
808 template<typename _InputIterator1, typename _InputIterator2,
809 typename _OutputIterator, typename _BinaryOperation>
810 _OutputIterator
811 transform(_InputIterator1 __first1, _InputIterator1 __last1,
812 _InputIterator2 __first2, _OutputIterator __result,
813 _BinaryOperation __binary_op)
814 {
815 // concept requirements
816 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
817 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
818 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
819 // "the type returned by a _BinaryOperation"
820 __typeof__(__binary_op(*__first1,*__first2))>)
821 __glibcxx_requires_valid_range(__first1, __last1);
822
823 for ( ; __first1 != __last1; ++__first1, ++__first2, ++__result)
824 *__result = __binary_op(*__first1, *__first2);
825 return __result;
826 }
827
828 /**
829 * @brief Replace each occurrence of one value in a sequence with another
830 * value.
831 * @param first A forward iterator.
832 * @param last A forward iterator.
833 * @param old_value The value to be replaced.
834 * @param new_value The replacement value.
835 * @return replace() returns no value.
836 *
837 * For each iterator @c i in the range @p [first,last) if @c *i ==
838 * @p old_value then the assignment @c *i = @p new_value is performed.
839 */
840 template<typename _ForwardIterator, typename _Tp>
841 void
842 replace(_ForwardIterator __first, _ForwardIterator __last,
843 const _Tp& __old_value, const _Tp& __new_value)
844 {
845 // concept requirements
846 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
847 _ForwardIterator>)
848 __glibcxx_function_requires(_EqualOpConcept<
849 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
850 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
851 typename iterator_traits<_ForwardIterator>::value_type>)
852 __glibcxx_requires_valid_range(__first, __last);
853
854 for ( ; __first != __last; ++__first)
855 if (*__first == __old_value)
856 *__first = __new_value;
857 }
858
859 /**
860 * @brief Replace each value in a sequence for which a predicate returns
861 * true with another value.
862 * @param first A forward iterator.
863 * @param last A forward iterator.
864 * @param pred A predicate.
865 * @param new_value The replacement value.
866 * @return replace_if() returns no value.
867 *
868 * For each iterator @c i in the range @p [first,last) if @p pred(*i)
869 * is true then the assignment @c *i = @p new_value is performed.
870 */
871 template<typename _ForwardIterator, typename _Predicate, typename _Tp>
872 void
873 replace_if(_ForwardIterator __first, _ForwardIterator __last,
874 _Predicate __pred, const _Tp& __new_value)
875 {
876 // concept requirements
877 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
878 _ForwardIterator>)
879 __glibcxx_function_requires(_ConvertibleConcept<_Tp,
880 typename iterator_traits<_ForwardIterator>::value_type>)
881 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
882 typename iterator_traits<_ForwardIterator>::value_type>)
883 __glibcxx_requires_valid_range(__first, __last);
884
885 for ( ; __first != __last; ++__first)
886 if (__pred(*__first))
887 *__first = __new_value;
888 }
889
890 /**
891 * @brief Copy a sequence, replacing each element of one value with another
892 * value.
893 * @param first An input iterator.
894 * @param last An input iterator.
895 * @param result An output iterator.
896 * @param old_value The value to be replaced.
897 * @param new_value The replacement value.
898 * @return The end of the output sequence, @p result+(last-first).
899 *
900 * Copies each element in the input range @p [first,last) to the
901 * output range @p [result,result+(last-first)) replacing elements
902 * equal to @p old_value with @p new_value.
903 */
904 template<typename _InputIterator, typename _OutputIterator, typename _Tp>
905 _OutputIterator
906 replace_copy(_InputIterator __first, _InputIterator __last,
907 _OutputIterator __result,
908 const _Tp& __old_value, const _Tp& __new_value)
909 {
910 // concept requirements
911 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
912 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
913 typename iterator_traits<_InputIterator>::value_type>)
914 __glibcxx_function_requires(_EqualOpConcept<
915 typename iterator_traits<_InputIterator>::value_type, _Tp>)
916 __glibcxx_requires_valid_range(__first, __last);
917
918 for ( ; __first != __last; ++__first, ++__result)
919 if (*__first == __old_value)
920 *__result = __new_value;
921 else
922 *__result = *__first;
923 return __result;
924 }
925
926 /**
927 * @brief Copy a sequence, replacing each value for which a predicate
928 * returns true with another value.
929 * @param first An input iterator.
930 * @param last An input iterator.
931 * @param result An output iterator.
932 * @param pred A predicate.
933 * @param new_value The replacement value.
934 * @return The end of the output sequence, @p result+(last-first).
935 *
936 * Copies each element in the range @p [first,last) to the range
937 * @p [result,result+(last-first)) replacing elements for which
938 * @p pred returns true with @p new_value.
939 */
940 template<typename _InputIterator, typename _OutputIterator,
941 typename _Predicate, typename _Tp>
942 _OutputIterator
943 replace_copy_if(_InputIterator __first, _InputIterator __last,
944 _OutputIterator __result,
945 _Predicate __pred, const _Tp& __new_value)
946 {
947 // concept requirements
948 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
949 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
950 typename iterator_traits<_InputIterator>::value_type>)
951 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
952 typename iterator_traits<_InputIterator>::value_type>)
953 __glibcxx_requires_valid_range(__first, __last);
954
955 for ( ; __first != __last; ++__first, ++__result)
956 if (__pred(*__first))
957 *__result = __new_value;
958 else
959 *__result = *__first;
960 return __result;
961 }
962
963 /**
964 * @brief Assign the result of a function object to each value in a
965 * sequence.
966 * @param first A forward iterator.
967 * @param last A forward iterator.
968 * @param gen A function object taking no arguments.
969 * @return generate() returns no value.
970 *
971 * Performs the assignment @c *i = @p gen() for each @c i in the range
972 * @p [first,last).
973 */
974 template<typename _ForwardIterator, typename _Generator>
975 void
976 generate(_ForwardIterator __first, _ForwardIterator __last,
977 _Generator __gen)
978 {
979 // concept requirements
980 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
981 __glibcxx_function_requires(_GeneratorConcept<_Generator,
982 typename iterator_traits<_ForwardIterator>::value_type>)
983 __glibcxx_requires_valid_range(__first, __last);
984
985 for ( ; __first != __last; ++__first)
986 *__first = __gen();
987 }
988
989 /**
990 * @brief Assign the result of a function object to each value in a
991 * sequence.
992 * @param first A forward iterator.
993 * @param n The length of the sequence.
994 * @param gen A function object taking no arguments.
995 * @return The end of the sequence, @p first+n
996 *
997 * Performs the assignment @c *i = @p gen() for each @c i in the range
998 * @p [first,first+n).
999 */
1000 template<typename _OutputIterator, typename _Size, typename _Generator>
1001 _OutputIterator
1002 generate_n(_OutputIterator __first, _Size __n, _Generator __gen)
1003 {
1004 // concept requirements
1005 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1006 // "the type returned by a _Generator"
1007 __typeof__(__gen())>)
1008
1009 for ( ; __n > 0; --__n, ++__first)
1010 *__first = __gen();
1011 return __first;
1012 }
1013
1014 /**
1015 * @brief Copy a sequence, removing elements of a given value.
1016 * @param first An input iterator.
1017 * @param last An input iterator.
1018 * @param result An output iterator.
1019 * @param value The value to be removed.
1020 * @return An iterator designating the end of the resulting sequence.
1021 *
1022 * Copies each element in the range @p [first,last) not equal to @p value
1023 * to the range beginning at @p result.
1024 * remove_copy() is stable, so the relative order of elements that are
1025 * copied is unchanged.
1026 */
1027 template<typename _InputIterator, typename _OutputIterator, typename _Tp>
1028 _OutputIterator
1029 remove_copy(_InputIterator __first, _InputIterator __last,
1030 _OutputIterator __result, const _Tp& __value)
1031 {
1032 // concept requirements
1033 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1034 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1035 typename iterator_traits<_InputIterator>::value_type>)
1036 __glibcxx_function_requires(_EqualOpConcept<
1037 typename iterator_traits<_InputIterator>::value_type, _Tp>)
1038 __glibcxx_requires_valid_range(__first, __last);
1039
1040 for ( ; __first != __last; ++__first)
1041 if (!(*__first == __value))
1042 {
1043 *__result = *__first;
1044 ++__result;
1045 }
1046 return __result;
1047 }
1048
1049 /**
1050 * @brief Copy a sequence, removing elements for which a predicate is true.
1051 * @param first An input iterator.
1052 * @param last An input iterator.
1053 * @param result An output iterator.
1054 * @param pred A predicate.
1055 * @return An iterator designating the end of the resulting sequence.
1056 *
1057 * Copies each element in the range @p [first,last) for which
1058 * @p pred returns true to the range beginning at @p result.
1059 *
1060 * remove_copy_if() is stable, so the relative order of elements that are
1061 * copied is unchanged.
1062 */
1063 template<typename _InputIterator, typename _OutputIterator,
1064 typename _Predicate>
1065 _OutputIterator
1066 remove_copy_if(_InputIterator __first, _InputIterator __last,
1067 _OutputIterator __result, _Predicate __pred)
1068 {
1069 // concept requirements
1070 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1071 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1072 typename iterator_traits<_InputIterator>::value_type>)
1073 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1074 typename iterator_traits<_InputIterator>::value_type>)
1075 __glibcxx_requires_valid_range(__first, __last);
1076
1077 for ( ; __first != __last; ++__first)
1078 if (!__pred(*__first))
1079 {
1080 *__result = *__first;
1081 ++__result;
1082 }
1083 return __result;
1084 }
1085
1086 /**
1087 * @brief Remove elements from a sequence.
1088 * @param first An input iterator.
1089 * @param last An input iterator.
1090 * @param value The value to be removed.
1091 * @return An iterator designating the end of the resulting sequence.
1092 *
1093 * All elements equal to @p value are removed from the range
1094 * @p [first,last).
1095 *
1096 * remove() is stable, so the relative order of elements that are
1097 * not removed is unchanged.
1098 *
1099 * Elements between the end of the resulting sequence and @p last
1100 * are still present, but their value is unspecified.
1101 */
1102 template<typename _ForwardIterator, typename _Tp>
1103 _ForwardIterator
1104 remove(_ForwardIterator __first, _ForwardIterator __last,
1105 const _Tp& __value)
1106 {
1107 // concept requirements
1108 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1109 _ForwardIterator>)
1110 __glibcxx_function_requires(_EqualOpConcept<
1111 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
1112 __glibcxx_requires_valid_range(__first, __last);
1113
1114 __first = std::find(__first, __last, __value);
1115 _ForwardIterator __i = __first;
1116 return __first == __last ? __first
1117 : std::remove_copy(++__i, __last,
1118 __first, __value);
1119 }
1120
1121 /**
1122 * @brief Remove elements from a sequence using a predicate.
1123 * @param first A forward iterator.
1124 * @param last A forward iterator.
1125 * @param pred A predicate.
1126 * @return An iterator designating the end of the resulting sequence.
1127 *
1128 * All elements for which @p pred returns true are removed from the range
1129 * @p [first,last).
1130 *
1131 * remove_if() is stable, so the relative order of elements that are
1132 * not removed is unchanged.
1133 *
1134 * Elements between the end of the resulting sequence and @p last
1135 * are still present, but their value is unspecified.
1136 */
1137 template<typename _ForwardIterator, typename _Predicate>
1138 _ForwardIterator
1139 remove_if(_ForwardIterator __first, _ForwardIterator __last,
1140 _Predicate __pred)
1141 {
1142 // concept requirements
1143 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1144 _ForwardIterator>)
1145 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1146 typename iterator_traits<_ForwardIterator>::value_type>)
1147 __glibcxx_requires_valid_range(__first, __last);
1148
1149 __first = std::find_if(__first, __last, __pred);
1150 _ForwardIterator __i = __first;
1151 return __first == __last ? __first
1152 : std::remove_copy_if(++__i, __last,
1153 __first, __pred);
1154 }
1155
1156 /**
1157 * @if maint
1158 * This is an uglified unique_copy(_InputIterator, _InputIterator,
1159 * _OutputIterator)
1160 * overloaded for output iterators.
1161 * @endif
1162 */
1163 template<typename _InputIterator, typename _OutputIterator>
1164 _OutputIterator
1165 __unique_copy(_InputIterator __first, _InputIterator __last,
1166 _OutputIterator __result,
1167 output_iterator_tag)
1168 {
1169 // concept requirements -- taken care of in dispatching function
1170 typename iterator_traits<_InputIterator>::value_type __value = *__first;
1171 *__result = __value;
1172 while (++__first != __last)
1173 if (!(__value == *__first))
1174 {
1175 __value = *__first;
1176 *++__result = __value;
1177 }
1178 return ++__result;
1179 }
1180
1181 /**
1182 * @if maint
1183 * This is an uglified unique_copy(_InputIterator, _InputIterator,
1184 * _OutputIterator)
1185 * overloaded for forward iterators.
1186 * @endif
1187 */
1188 template<typename _InputIterator, typename _ForwardIterator>
1189 _ForwardIterator
1190 __unique_copy(_InputIterator __first, _InputIterator __last,
1191 _ForwardIterator __result,
1192 forward_iterator_tag)
1193 {
1194 // concept requirements -- taken care of in dispatching function
1195 *__result = *__first;
1196 while (++__first != __last)
1197 if (!(*__result == *__first))
1198 *++__result = *__first;
1199 return ++__result;
1200 }
1201
1202 /**
1203 * @if maint
1204 * This is an uglified
1205 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1206 * _BinaryPredicate)
1207 * overloaded for output iterators.
1208 * @endif
1209 */
1210 template<typename _InputIterator, typename _OutputIterator,
1211 typename _BinaryPredicate>
1212 _OutputIterator
1213 __unique_copy(_InputIterator __first, _InputIterator __last,
1214 _OutputIterator __result,
1215 _BinaryPredicate __binary_pred,
1216 output_iterator_tag)
1217 {
1218 // concept requirements -- iterators already checked
1219 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1220 typename iterator_traits<_InputIterator>::value_type,
1221 typename iterator_traits<_InputIterator>::value_type>)
1222
1223 typename iterator_traits<_InputIterator>::value_type __value = *__first;
1224 *__result = __value;
1225 while (++__first != __last)
1226 if (!__binary_pred(__value, *__first))
1227 {
1228 __value = *__first;
1229 *++__result = __value;
1230 }
1231 return ++__result;
1232 }
1233
1234 /**
1235 * @if maint
1236 * This is an uglified
1237 * unique_copy(_InputIterator, _InputIterator, _OutputIterator,
1238 * _BinaryPredicate)
1239 * overloaded for forward iterators.
1240 * @endif
1241 */
1242 template<typename _InputIterator, typename _ForwardIterator,
1243 typename _BinaryPredicate>
1244 _ForwardIterator
1245 __unique_copy(_InputIterator __first, _InputIterator __last,
1246 _ForwardIterator __result,
1247 _BinaryPredicate __binary_pred,
1248 forward_iterator_tag)
1249 {
1250 // concept requirements -- iterators already checked
1251 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1252 typename iterator_traits<_ForwardIterator>::value_type,
1253 typename iterator_traits<_InputIterator>::value_type>)
1254
1255 *__result = *__first;
1256 while (++__first != __last)
1257 if (!__binary_pred(*__result, *__first)) *++__result = *__first;
1258 return ++__result;
1259 }
1260
1261 /**
1262 * @brief Copy a sequence, removing consecutive duplicate values.
1263 * @param first An input iterator.
1264 * @param last An input iterator.
1265 * @param result An output iterator.
1266 * @return An iterator designating the end of the resulting sequence.
1267 *
1268 * Copies each element in the range @p [first,last) to the range
1269 * beginning at @p result, except that only the first element is copied
1270 * from groups of consecutive elements that compare equal.
1271 * unique_copy() is stable, so the relative order of elements that are
1272 * copied is unchanged.
1273 */
1274 template<typename _InputIterator, typename _OutputIterator>
1275 inline _OutputIterator
1276 unique_copy(_InputIterator __first, _InputIterator __last,
1277 _OutputIterator __result)
1278 {
1279 // concept requirements
1280 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1281 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1282 typename iterator_traits<_InputIterator>::value_type>)
1283 __glibcxx_function_requires(_EqualityComparableConcept<
1284 typename iterator_traits<_InputIterator>::value_type>)
1285 __glibcxx_requires_valid_range(__first, __last);
1286
1287 typedef typename iterator_traits<_OutputIterator>::iterator_category
1288 _IterType;
1289
1290 if (__first == __last) return __result;
1291 return std::__unique_copy(__first, __last, __result, _IterType());
1292 }
1293
1294 /**
1295 * @brief Copy a sequence, removing consecutive values using a predicate.
1296 * @param first An input iterator.
1297 * @param last An input iterator.
1298 * @param result An output iterator.
1299 * @param binary_pred A binary predicate.
1300 * @return An iterator designating the end of the resulting sequence.
1301 *
1302 * Copies each element in the range @p [first,last) to the range
1303 * beginning at @p result, except that only the first element is copied
1304 * from groups of consecutive elements for which @p binary_pred returns
1305 * true.
1306 * unique_copy() is stable, so the relative order of elements that are
1307 * copied is unchanged.
1308 */
1309 template<typename _InputIterator, typename _OutputIterator,
1310 typename _BinaryPredicate>
1311 inline _OutputIterator
1312 unique_copy(_InputIterator __first, _InputIterator __last,
1313 _OutputIterator __result,
1314 _BinaryPredicate __binary_pred)
1315 {
1316 // concept requirements -- predicates checked later
1317 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
1318 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1319 typename iterator_traits<_InputIterator>::value_type>)
1320 __glibcxx_requires_valid_range(__first, __last);
1321
1322 typedef typename iterator_traits<_OutputIterator>::iterator_category
1323 _IterType;
1324
1325 if (__first == __last) return __result;
1326 return std::__unique_copy(__first, __last, __result,
1327 __binary_pred, _IterType());
1328 }
1329
1330 /**
1331 * @brief Remove consecutive duplicate values from a sequence.
1332 * @param first A forward iterator.
1333 * @param last A forward iterator.
1334 * @return An iterator designating the end of the resulting sequence.
1335 *
1336 * Removes all but the first element from each group of consecutive
1337 * values that compare equal.
1338 * unique() is stable, so the relative order of elements that are
1339 * not removed is unchanged.
1340 * Elements between the end of the resulting sequence and @p last
1341 * are still present, but their value is unspecified.
1342 */
1343 template<typename _ForwardIterator>
1344 _ForwardIterator
1345 unique(_ForwardIterator __first, _ForwardIterator __last)
1346 {
1347 // concept requirements
1348 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1349 _ForwardIterator>)
1350 __glibcxx_function_requires(_EqualityComparableConcept<
1351 typename iterator_traits<_ForwardIterator>::value_type>)
1352 __glibcxx_requires_valid_range(__first, __last);
1353
1354 // Skip the beginning, if already unique.
1355 __first = std::adjacent_find(__first, __last);
1356 if (__first == __last)
1357 return __last;
1358
1359 // Do the real copy work.
1360 _ForwardIterator __dest = __first;
1361 ++__first;
1362 while (++__first != __last)
1363 if (!(*__dest == *__first))
1364 *++__dest = *__first;
1365 return ++__dest;
1366 }
1367
1368 /**
1369 * @brief Remove consecutive values from a sequence using a predicate.
1370 * @param first A forward iterator.
1371 * @param last A forward iterator.
1372 * @param binary_pred A binary predicate.
1373 * @return An iterator designating the end of the resulting sequence.
1374 *
1375 * Removes all but the first element from each group of consecutive
1376 * values for which @p binary_pred returns true.
1377 * unique() is stable, so the relative order of elements that are
1378 * not removed is unchanged.
1379 * Elements between the end of the resulting sequence and @p last
1380 * are still present, but their value is unspecified.
1381 */
1382 template<typename _ForwardIterator, typename _BinaryPredicate>
1383 _ForwardIterator
1384 unique(_ForwardIterator __first, _ForwardIterator __last,
1385 _BinaryPredicate __binary_pred)
1386 {
1387 // concept requirements
1388 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1389 _ForwardIterator>)
1390 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
1391 typename iterator_traits<_ForwardIterator>::value_type,
1392 typename iterator_traits<_ForwardIterator>::value_type>)
1393 __glibcxx_requires_valid_range(__first, __last);
1394
1395 // Skip the beginning, if already unique.
1396 __first = std::adjacent_find(__first, __last, __binary_pred);
1397 if (__first == __last)
1398 return __last;
1399
1400 // Do the real copy work.
1401 _ForwardIterator __dest = __first;
1402 ++__first;
1403 while (++__first != __last)
1404 if (!__binary_pred(*__dest, *__first))
1405 *++__dest = *__first;
1406 return ++__dest;
1407 }
1408
1409 /**
1410 * @if maint
1411 * This is an uglified reverse(_BidirectionalIterator,
1412 * _BidirectionalIterator)
1413 * overloaded for bidirectional iterators.
1414 * @endif
1415 */
1416 template<typename _BidirectionalIterator>
1417 void
1418 __reverse(_BidirectionalIterator __first, _BidirectionalIterator __last,
1419 bidirectional_iterator_tag)
1420 {
1421 while (true)
1422 if (__first == __last || __first == --__last)
1423 return;
1424 else
1425 {
1426 std::iter_swap(__first, __last);
1427 ++__first;
1428 }
1429 }
1430
1431 /**
1432 * @if maint
1433 * This is an uglified reverse(_BidirectionalIterator,
1434 * _BidirectionalIterator)
1435 * overloaded for random access iterators.
1436 * @endif
1437 */
1438 template<typename _RandomAccessIterator>
1439 void
1440 __reverse(_RandomAccessIterator __first, _RandomAccessIterator __last,
1441 random_access_iterator_tag)
1442 {
1443 if (__first == __last)
1444 return;
1445 --__last;
1446 while (__first < __last)
1447 {
1448 std::iter_swap(__first, __last);
1449 ++__first;
1450 --__last;
1451 }
1452 }
1453
1454 /**
1455 * @brief Reverse a sequence.
1456 * @param first A bidirectional iterator.
1457 * @param last A bidirectional iterator.
1458 * @return reverse() returns no value.
1459 *
1460 * Reverses the order of the elements in the range @p [first,last),
1461 * so that the first element becomes the last etc.
1462 * For every @c i such that @p 0<=i<=(last-first)/2), @p reverse()
1463 * swaps @p *(first+i) and @p *(last-(i+1))
1464 */
1465 template<typename _BidirectionalIterator>
1466 inline void
1467 reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
1468 {
1469 // concept requirements
1470 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
1471 _BidirectionalIterator>)
1472 __glibcxx_requires_valid_range(__first, __last);
1473 std::__reverse(__first, __last, std::__iterator_category(__first));
1474 }
1475
1476 /**
1477 * @brief Copy a sequence, reversing its elements.
1478 * @param first A bidirectional iterator.
1479 * @param last A bidirectional iterator.
1480 * @param result An output iterator.
1481 * @return An iterator designating the end of the resulting sequence.
1482 *
1483 * Copies the elements in the range @p [first,last) to the range
1484 * @p [result,result+(last-first)) such that the order of the
1485 * elements is reversed.
1486 * For every @c i such that @p 0<=i<=(last-first), @p reverse_copy()
1487 * performs the assignment @p *(result+(last-first)-i) = *(first+i).
1488 * The ranges @p [first,last) and @p [result,result+(last-first))
1489 * must not overlap.
1490 */
1491 template<typename _BidirectionalIterator, typename _OutputIterator>
1492 _OutputIterator
1493 reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last,
1494 _OutputIterator __result)
1495 {
1496 // concept requirements
1497 __glibcxx_function_requires(_BidirectionalIteratorConcept<
1498 _BidirectionalIterator>)
1499 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1500 typename iterator_traits<_BidirectionalIterator>::value_type>)
1501 __glibcxx_requires_valid_range(__first, __last);
1502
1503 while (__first != __last)
1504 {
1505 --__last;
1506 *__result = *__last;
1507 ++__result;
1508 }
1509 return __result;
1510 }
1511
1512
1513 /**
1514 * @if maint
1515 * This is a helper function for the rotate algorithm specialized on RAIs.
1516 * It returns the greatest common divisor of two integer values.
1517 * @endif
1518 */
1519 template<typename _EuclideanRingElement>
1520 _EuclideanRingElement
1521 __gcd(_EuclideanRingElement __m, _EuclideanRingElement __n)
1522 {
1523 while (__n != 0)
1524 {
1525 _EuclideanRingElement __t = __m % __n;
1526 __m = __n;
1527 __n = __t;
1528 }
1529 return __m;
1530 }
1531
1532 /**
1533 * @if maint
1534 * This is a helper function for the rotate algorithm.
1535 * @endif
1536 */
1537 template<typename _ForwardIterator>
1538 void
1539 __rotate(_ForwardIterator __first,
1540 _ForwardIterator __middle,
1541 _ForwardIterator __last,
1542 forward_iterator_tag)
1543 {
1544 if (__first == __middle || __last == __middle)
1545 return;
1546
1547 _ForwardIterator __first2 = __middle;
1548 do
1549 {
1550 swap(*__first, *__first2);
1551 ++__first;
1552 ++__first2;
1553 if (__first == __middle)
1554 __middle = __first2;
1555 }
1556 while (__first2 != __last);
1557
1558 __first2 = __middle;
1559
1560 while (__first2 != __last)
1561 {
1562 swap(*__first, *__first2);
1563 ++__first;
1564 ++__first2;
1565 if (__first == __middle)
1566 __middle = __first2;
1567 else if (__first2 == __last)
1568 __first2 = __middle;
1569 }
1570 }
1571
1572 /**
1573 * @if maint
1574 * This is a helper function for the rotate algorithm.
1575 * @endif
1576 */
1577 template<typename _BidirectionalIterator>
1578 void
1579 __rotate(_BidirectionalIterator __first,
1580 _BidirectionalIterator __middle,
1581 _BidirectionalIterator __last,
1582 bidirectional_iterator_tag)
1583 {
1584 // concept requirements
1585 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
1586 _BidirectionalIterator>)
1587
1588 if (__first == __middle || __last == __middle)
1589 return;
1590
1591 std::__reverse(__first, __middle, bidirectional_iterator_tag());
1592 std::__reverse(__middle, __last, bidirectional_iterator_tag());
1593
1594 while (__first != __middle && __middle != __last)
1595 {
1596 swap(*__first, *--__last);
1597 ++__first;
1598 }
1599
1600 if (__first == __middle)
1601 std::__reverse(__middle, __last, bidirectional_iterator_tag());
1602 else
1603 std::__reverse(__first, __middle, bidirectional_iterator_tag());
1604 }
1605
1606 /**
1607 * @if maint
1608 * This is a helper function for the rotate algorithm.
1609 * @endif
1610 */
1611 template<typename _RandomAccessIterator>
1612 void
1613 __rotate(_RandomAccessIterator __first,
1614 _RandomAccessIterator __middle,
1615 _RandomAccessIterator __last,
1616 random_access_iterator_tag)
1617 {
1618 // concept requirements
1619 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1620 _RandomAccessIterator>)
1621
1622 if (__first == __middle || __last == __middle)
1623 return;
1624
1625 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
1626 _Distance;
1627 typedef typename iterator_traits<_RandomAccessIterator>::value_type
1628 _ValueType;
1629
1630 const _Distance __n = __last - __first;
1631 const _Distance __k = __middle - __first;
1632 const _Distance __l = __n - __k;
1633
1634 if (__k == __l)
1635 {
1636 std::swap_ranges(__first, __middle, __middle);
1637 return;
1638 }
1639
1640 const _Distance __d = __gcd(__n, __k);
1641
1642 for (_Distance __i = 0; __i < __d; __i++)
1643 {
1644 _ValueType __tmp = *__first;
1645 _RandomAccessIterator __p = __first;
1646
1647 if (__k < __l)
1648 {
1649 for (_Distance __j = 0; __j < __l / __d; __j++)
1650 {
1651 if (__p > __first + __l)
1652 {
1653 *__p = *(__p - __l);
1654 __p -= __l;
1655 }
1656
1657 *__p = *(__p + __k);
1658 __p += __k;
1659 }
1660 }
1661 else
1662 {
1663 for (_Distance __j = 0; __j < __k / __d - 1; __j ++)
1664 {
1665 if (__p < __last - __k)
1666 {
1667 *__p = *(__p + __k);
1668 __p += __k;
1669 }
1670 *__p = * (__p - __l);
1671 __p -= __l;
1672 }
1673 }
1674
1675 *__p = __tmp;
1676 ++__first;
1677 }
1678 }
1679
1680 /**
1681 * @brief Rotate the elements of a sequence.
1682 * @param first A forward iterator.
1683 * @param middle A forward iterator.
1684 * @param last A forward iterator.
1685 * @return Nothing.
1686 *
1687 * Rotates the elements of the range @p [first,last) by @p (middle-first)
1688 * positions so that the element at @p middle is moved to @p first, the
1689 * element at @p middle+1 is moved to @first+1 and so on for each element
1690 * in the range @p [first,last).
1691 *
1692 * This effectively swaps the ranges @p [first,middle) and
1693 * @p [middle,last).
1694 *
1695 * Performs @p *(first+(n+(last-middle))%(last-first))=*(first+n) for
1696 * each @p n in the range @p [0,last-first).
1697 */
1698 template<typename _ForwardIterator>
1699 inline void
1700 rotate(_ForwardIterator __first, _ForwardIterator __middle,
1701 _ForwardIterator __last)
1702 {
1703 // concept requirements
1704 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1705 _ForwardIterator>)
1706 __glibcxx_requires_valid_range(__first, __middle);
1707 __glibcxx_requires_valid_range(__middle, __last);
1708
1709 typedef typename iterator_traits<_ForwardIterator>::iterator_category
1710 _IterType;
1711 std::__rotate(__first, __middle, __last, _IterType());
1712 }
1713
1714 /**
1715 * @brief Copy a sequence, rotating its elements.
1716 * @param first A forward iterator.
1717 * @param middle A forward iterator.
1718 * @param last A forward iterator.
1719 * @param result An output iterator.
1720 * @return An iterator designating the end of the resulting sequence.
1721 *
1722 * Copies the elements of the range @p [first,last) to the range
1723 * beginning at @result, rotating the copied elements by @p (middle-first)
1724 * positions so that the element at @p middle is moved to @p result, the
1725 * element at @p middle+1 is moved to @result+1 and so on for each element
1726 * in the range @p [first,last).
1727 *
1728 * Performs @p *(result+(n+(last-middle))%(last-first))=*(first+n) for
1729 * each @p n in the range @p [0,last-first).
1730 */
1731 template<typename _ForwardIterator, typename _OutputIterator>
1732 _OutputIterator
1733 rotate_copy(_ForwardIterator __first, _ForwardIterator __middle,
1734 _ForwardIterator __last, _OutputIterator __result)
1735 {
1736 // concept requirements
1737 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1738 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
1739 typename iterator_traits<_ForwardIterator>::value_type>)
1740 __glibcxx_requires_valid_range(__first, __middle);
1741 __glibcxx_requires_valid_range(__middle, __last);
1742
1743 return std::copy(__first, __middle,
1744 std::copy(__middle, __last, __result));
1745 }
1746
1747 /**
1748 * @brief Randomly shuffle the elements of a sequence.
1749 * @param first A forward iterator.
1750 * @param last A forward iterator.
1751 * @return Nothing.
1752 *
1753 * Reorder the elements in the range @p [first,last) using a random
1754 * distribution, so that every possible ordering of the sequence is
1755 * equally likely.
1756 */
1757 template<typename _RandomAccessIterator>
1758 inline void
1759 random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
1760 {
1761 // concept requirements
1762 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1763 _RandomAccessIterator>)
1764 __glibcxx_requires_valid_range(__first, __last);
1765
1766 if (__first != __last)
1767 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
1768 std::iter_swap(__i, __first + (std::rand() % ((__i - __first) + 1)));
1769 }
1770
1771 /**
1772 * @brief Shuffle the elements of a sequence using a random number
1773 * generator.
1774 * @param first A forward iterator.
1775 * @param last A forward iterator.
1776 * @param rand The RNG functor or function.
1777 * @return Nothing.
1778 *
1779 * Reorders the elements in the range @p [first,last) using @p rand to
1780 * provide a random distribution. Calling @p rand(N) for a positive
1781 * integer @p N should return a randomly chosen integer from the
1782 * range [0,N).
1783 */
1784 template<typename _RandomAccessIterator, typename _RandomNumberGenerator>
1785 void
1786 random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
1787 _RandomNumberGenerator& __rand)
1788 {
1789 // concept requirements
1790 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
1791 _RandomAccessIterator>)
1792 __glibcxx_requires_valid_range(__first, __last);
1793
1794 if (__first == __last)
1795 return;
1796 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
1797 std::iter_swap(__i, __first + __rand((__i - __first) + 1));
1798 }
1799
1800
1801 /**
1802 * @if maint
1803 * This is a helper function...
1804 * @endif
1805 */
1806 template<typename _ForwardIterator, typename _Predicate>
1807 _ForwardIterator
1808 __partition(_ForwardIterator __first, _ForwardIterator __last,
1809 _Predicate __pred,
1810 forward_iterator_tag)
1811 {
1812 if (__first == __last)
1813 return __first;
1814
1815 while (__pred(*__first))
1816 if (++__first == __last)
1817 return __first;
1818
1819 _ForwardIterator __next = __first;
1820
1821 while (++__next != __last)
1822 if (__pred(*__next))
1823 {
1824 swap(*__first, *__next);
1825 ++__first;
1826 }
1827
1828 return __first;
1829 }
1830
1831 /**
1832 * @if maint
1833 * This is a helper function...
1834 * @endif
1835 */
1836 template<typename _BidirectionalIterator, typename _Predicate>
1837 _BidirectionalIterator
1838 __partition(_BidirectionalIterator __first, _BidirectionalIterator __last,
1839 _Predicate __pred,
1840 bidirectional_iterator_tag)
1841 {
1842 while (true)
1843 {
1844 while (true)
1845 if (__first == __last)
1846 return __first;
1847 else if (__pred(*__first))
1848 ++__first;
1849 else
1850 break;
1851 --__last;
1852 while (true)
1853 if (__first == __last)
1854 return __first;
1855 else if (!__pred(*__last))
1856 --__last;
1857 else
1858 break;
1859 std::iter_swap(__first, __last);
1860 ++__first;
1861 }
1862 }
1863
1864 /**
1865 * @brief Move elements for which a predicate is true to the beginning
1866 * of a sequence.
1867 * @param first A forward iterator.
1868 * @param last A forward iterator.
1869 * @param pred A predicate functor.
1870 * @return An iterator @p middle such that @p pred(i) is true for each
1871 * iterator @p i in the range @p [first,middle) and false for each @p i
1872 * in the range @p [middle,last).
1873 *
1874 * @p pred must not modify its operand. @p partition() does not preserve
1875 * the relative ordering of elements in each group, use
1876 * @p stable_partition() if this is needed.
1877 */
1878 template<typename _ForwardIterator, typename _Predicate>
1879 inline _ForwardIterator
1880 partition(_ForwardIterator __first, _ForwardIterator __last,
1881 _Predicate __pred)
1882 {
1883 // concept requirements
1884 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1885 _ForwardIterator>)
1886 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1887 typename iterator_traits<_ForwardIterator>::value_type>)
1888 __glibcxx_requires_valid_range(__first, __last);
1889
1890 return std::__partition(__first, __last, __pred,
1891 std::__iterator_category(__first));
1892 }
1893
1894
1895 /**
1896 * @if maint
1897 * This is a helper function...
1898 * @endif
1899 */
1900 template<typename _ForwardIterator, typename _Predicate, typename _Distance>
1901 _ForwardIterator
1902 __inplace_stable_partition(_ForwardIterator __first,
1903 _ForwardIterator __last,
1904 _Predicate __pred, _Distance __len)
1905 {
1906 if (__len == 1)
1907 return __pred(*__first) ? __last : __first;
1908 _ForwardIterator __middle = __first;
1909 std::advance(__middle, __len / 2);
1910 _ForwardIterator __begin = std::__inplace_stable_partition(__first,
1911 __middle,
1912 __pred,
1913 __len / 2);
1914 _ForwardIterator __end = std::__inplace_stable_partition(__middle, __last,
1915 __pred,
1916 __len
1917 - __len / 2);
1918 std::rotate(__begin, __middle, __end);
1919 std::advance(__begin, std::distance(__middle, __end));
1920 return __begin;
1921 }
1922
1923 /**
1924 * @if maint
1925 * This is a helper function...
1926 * @endif
1927 */
1928 template<typename _ForwardIterator, typename _Pointer, typename _Predicate,
1929 typename _Distance>
1930 _ForwardIterator
1931 __stable_partition_adaptive(_ForwardIterator __first,
1932 _ForwardIterator __last,
1933 _Predicate __pred, _Distance __len,
1934 _Pointer __buffer,
1935 _Distance __buffer_size)
1936 {
1937 if (__len <= __buffer_size)
1938 {
1939 _ForwardIterator __result1 = __first;
1940 _Pointer __result2 = __buffer;
1941 for ( ; __first != __last ; ++__first)
1942 if (__pred(*__first))
1943 {
1944 *__result1 = *__first;
1945 ++__result1;
1946 }
1947 else
1948 {
1949 *__result2 = *__first;
1950 ++__result2;
1951 }
1952 std::copy(__buffer, __result2, __result1);
1953 return __result1;
1954 }
1955 else
1956 {
1957 _ForwardIterator __middle = __first;
1958 std::advance(__middle, __len / 2);
1959 _ForwardIterator __begin =
1960 std::__stable_partition_adaptive(__first, __middle, __pred,
1961 __len / 2, __buffer,
1962 __buffer_size);
1963 _ForwardIterator __end =
1964 std::__stable_partition_adaptive(__middle, __last, __pred,
1965 __len - __len / 2,
1966 __buffer, __buffer_size);
1967 std::rotate(__begin, __middle, __end);
1968 std::advance(__begin, std::distance(__middle, __end));
1969 return __begin;
1970 }
1971 }
1972
1973 /**
1974 * @brief Move elements for which a predicate is true to the beginning
1975 * of a sequence, preserving relative ordering.
1976 * @param first A forward iterator.
1977 * @param last A forward iterator.
1978 * @param pred A predicate functor.
1979 * @return An iterator @p middle such that @p pred(i) is true for each
1980 * iterator @p i in the range @p [first,middle) and false for each @p i
1981 * in the range @p [middle,last).
1982 *
1983 * Performs the same function as @p partition() with the additional
1984 * guarantee that the relative ordering of elements in each group is
1985 * preserved, so any two elements @p x and @p y in the range
1986 * @p [first,last) such that @p pred(x)==pred(y) will have the same
1987 * relative ordering after calling @p stable_partition().
1988 */
1989 template<typename _ForwardIterator, typename _Predicate>
1990 _ForwardIterator
1991 stable_partition(_ForwardIterator __first, _ForwardIterator __last,
1992 _Predicate __pred)
1993 {
1994 // concept requirements
1995 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1996 _ForwardIterator>)
1997 __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
1998 typename iterator_traits<_ForwardIterator>::value_type>)
1999 __glibcxx_requires_valid_range(__first, __last);
2000
2001 if (__first == __last)
2002 return __first;
2003 else
2004 {
2005 typedef typename iterator_traits<_ForwardIterator>::value_type
2006 _ValueType;
2007 typedef typename iterator_traits<_ForwardIterator>::difference_type
2008 _DistanceType;
2009
2010 _Temporary_buffer<_ForwardIterator, _ValueType> __buf(__first,
2011 __last);
2012 if (__buf.size() > 0)
2013 return
2014 std::__stable_partition_adaptive(__first, __last, __pred,
2015 _DistanceType(__buf.requested_size()),
2016 __buf.begin(), __buf.size());
2017 else
2018 return
2019 std::__inplace_stable_partition(__first, __last, __pred,
2020 _DistanceType(__buf.requested_size()));
2021 }
2022 }
2023
2024 /**
2025 * @if maint
2026 * This is a helper function...
2027 * @endif
2028 */
2029 template<typename _RandomAccessIterator, typename _Tp>
2030 _RandomAccessIterator
2031 __unguarded_partition(_RandomAccessIterator __first,
2032 _RandomAccessIterator __last, _Tp __pivot)
2033 {
2034 while (true)
2035 {
2036 while (*__first < __pivot)
2037 ++__first;
2038 --__last;
2039 while (__pivot < *__last)
2040 --__last;
2041 if (!(__first < __last))
2042 return __first;
2043 std::iter_swap(__first, __last);
2044 ++__first;
2045 }
2046 }
2047
2048 /**
2049 * @if maint
2050 * This is a helper function...
2051 * @endif
2052 */
2053 template<typename _RandomAccessIterator, typename _Tp, typename _Compare>
2054 _RandomAccessIterator
2055 __unguarded_partition(_RandomAccessIterator __first,
2056 _RandomAccessIterator __last,
2057 _Tp __pivot, _Compare __comp)
2058 {
2059 while (true)
2060 {
2061 while (__comp(*__first, __pivot))
2062 ++__first;
2063 --__last;
2064 while (__comp(__pivot, *__last))
2065 --__last;
2066 if (!(__first < __last))
2067 return __first;
2068 std::iter_swap(__first, __last);
2069 ++__first;
2070 }
2071 }
2072
2073 /**
2074 * @if maint
2075 * @doctodo
2076 * This controls some aspect of the sort routines.
2077 * @endif
2078 */
2079 enum { _S_threshold = 16 };
2080
2081 /**
2082 * @if maint
2083 * This is a helper function for the sort routine.
2084 * @endif
2085 */
2086 template<typename _RandomAccessIterator, typename _Tp>
2087 void
2088 __unguarded_linear_insert(_RandomAccessIterator __last, _Tp __val)
2089 {
2090 _RandomAccessIterator __next = __last;
2091 --__next;
2092 while (__val < *__next)
2093 {
2094 *__last = *__next;
2095 __last = __next;
2096 --__next;
2097 }
2098 *__last = __val;
2099 }
2100
2101 /**
2102 * @if maint
2103 * This is a helper function for the sort routine.
2104 * @endif
2105 */
2106 template<typename _RandomAccessIterator, typename _Tp, typename _Compare>
2107 void
2108 __unguarded_linear_insert(_RandomAccessIterator __last, _Tp __val,
2109 _Compare __comp)
2110 {
2111 _RandomAccessIterator __next = __last;
2112 --__next;
2113 while (__comp(__val, *__next))
2114 {
2115 *__last = *__next;
2116 __last = __next;
2117 --__next;
2118 }
2119 *__last = __val;
2120 }
2121
2122 /**
2123 * @if maint
2124 * This is a helper function for the sort routine.
2125 * @endif
2126 */
2127 template<typename _RandomAccessIterator>
2128 void
2129 __insertion_sort(_RandomAccessIterator __first,
2130 _RandomAccessIterator __last)
2131 {
2132 if (__first == __last)
2133 return;
2134
2135 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
2136 {
2137 typename iterator_traits<_RandomAccessIterator>::value_type
2138 __val = *__i;
2139 if (__val < *__first)
2140 {
2141 std::copy_backward(__first, __i, __i + 1);
2142 *__first = __val;
2143 }
2144 else
2145 std::__unguarded_linear_insert(__i, __val);
2146 }
2147 }
2148
2149 /**
2150 * @if maint
2151 * This is a helper function for the sort routine.
2152 * @endif
2153 */
2154 template<typename _RandomAccessIterator, typename _Compare>
2155 void
2156 __insertion_sort(_RandomAccessIterator __first,
2157 _RandomAccessIterator __last, _Compare __comp)
2158 {
2159 if (__first == __last) return;
2160
2161 for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i)
2162 {
2163 typename iterator_traits<_RandomAccessIterator>::value_type
2164 __val = *__i;
2165 if (__comp(__val, *__first))
2166 {
2167 std::copy_backward(__first, __i, __i + 1);
2168 *__first = __val;
2169 }
2170 else
2171 std::__unguarded_linear_insert(__i, __val, __comp);
2172 }
2173 }
2174
2175 /**
2176 * @if maint
2177 * This is a helper function for the sort routine.
2178 * @endif
2179 */
2180 template<typename _RandomAccessIterator>
2181 inline void
2182 __unguarded_insertion_sort(_RandomAccessIterator __first,
2183 _RandomAccessIterator __last)
2184 {
2185 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2186 _ValueType;
2187
2188 for (_RandomAccessIterator __i = __first; __i != __last; ++__i)
2189 std::__unguarded_linear_insert(__i, _ValueType(*__i));
2190 }
2191
2192 /**
2193 * @if maint
2194 * This is a helper function for the sort routine.
2195 * @endif
2196 */
2197 template<typename _RandomAccessIterator, typename _Compare>
2198 inline void
2199 __unguarded_insertion_sort(_RandomAccessIterator __first,
2200 _RandomAccessIterator __last, _Compare __comp)
2201 {
2202 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2203 _ValueType;
2204
2205 for (_RandomAccessIterator __i = __first; __i != __last; ++__i)
2206 std::__unguarded_linear_insert(__i, _ValueType(*__i), __comp);
2207 }
2208
2209 /**
2210 * @if maint
2211 * This is a helper function for the sort routine.
2212 * @endif
2213 */
2214 template<typename _RandomAccessIterator>
2215 void
2216 __final_insertion_sort(_RandomAccessIterator __first,
2217 _RandomAccessIterator __last)
2218 {
2219 if (__last - __first > int(_S_threshold))
2220 {
2221 std::__insertion_sort(__first, __first + int(_S_threshold));
2222 std::__unguarded_insertion_sort(__first + int(_S_threshold), __last);
2223 }
2224 else
2225 std::__insertion_sort(__first, __last);
2226 }
2227
2228 /**
2229 * @if maint
2230 * This is a helper function for the sort routine.
2231 * @endif
2232 */
2233 template<typename _RandomAccessIterator, typename _Compare>
2234 void
2235 __final_insertion_sort(_RandomAccessIterator __first,
2236 _RandomAccessIterator __last, _Compare __comp)
2237 {
2238 if (__last - __first > int(_S_threshold))
2239 {
2240 std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
2241 std::__unguarded_insertion_sort(__first + int(_S_threshold), __last,
2242 __comp);
2243 }
2244 else
2245 std::__insertion_sort(__first, __last, __comp);
2246 }
2247
2248 /**
2249 * @if maint
2250 * This is a helper function for the sort routine.
2251 * @endif
2252 */
2253 template<typename _Size>
2254 inline _Size
2255 __lg(_Size __n)
2256 {
2257 _Size __k;
2258 for (__k = 0; __n != 1; __n >>= 1)
2259 ++__k;
2260 return __k;
2261 }
2262
2263 /**
2264 * @brief Sort the smallest elements of a sequence.
2265 * @param first An iterator.
2266 * @param middle Another iterator.
2267 * @param last Another iterator.
2268 * @return Nothing.
2269 *
2270 * Sorts the smallest @p (middle-first) elements in the range
2271 * @p [first,last) and moves them to the range @p [first,middle). The
2272 * order of the remaining elements in the range @p [middle,last) is
2273 * undefined.
2274 * After the sort if @p i and @j are iterators in the range
2275 * @p [first,middle) such that @i precedes @j and @k is an iterator in
2276 * the range @p [middle,last) then @p *j<*i and @p *k<*i are both false.
2277 */
2278 template<typename _RandomAccessIterator>
2279 void
2280 partial_sort(_RandomAccessIterator __first,
2281 _RandomAccessIterator __middle,
2282 _RandomAccessIterator __last)
2283 {
2284 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2285 _ValueType;
2286
2287 // concept requirements
2288 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2289 _RandomAccessIterator>)
2290 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
2291 __glibcxx_requires_valid_range(__first, __middle);
2292 __glibcxx_requires_valid_range(__middle, __last);
2293
2294 std::make_heap(__first, __middle);
2295 for (_RandomAccessIterator __i = __middle; __i < __last; ++__i)
2296 if (*__i < *__first)
2297 std::__pop_heap(__first, __middle, __i, _ValueType(*__i));
2298 std::sort_heap(__first, __middle);
2299 }
2300
2301 /**
2302 * @brief Sort the smallest elements of a sequence using a predicate
2303 * for comparison.
2304 * @param first An iterator.
2305 * @param middle Another iterator.
2306 * @param last Another iterator.
2307 * @param comp A comparison functor.
2308 * @return Nothing.
2309 *
2310 * Sorts the smallest @p (middle-first) elements in the range
2311 * @p [first,last) and moves them to the range @p [first,middle). The
2312 * order of the remaining elements in the range @p [middle,last) is
2313 * undefined.
2314 * After the sort if @p i and @j are iterators in the range
2315 * @p [first,middle) such that @i precedes @j and @k is an iterator in
2316 * the range @p [middle,last) then @p *comp(j,*i) and @p comp(*k,*i)
2317 * are both false.
2318 */
2319 template<typename _RandomAccessIterator, typename _Compare>
2320 void
2321 partial_sort(_RandomAccessIterator __first,
2322 _RandomAccessIterator __middle,
2323 _RandomAccessIterator __last,
2324 _Compare __comp)
2325 {
2326 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2327 _ValueType;
2328
2329 // concept requirements
2330 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2331 _RandomAccessIterator>)
2332 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2333 _ValueType, _ValueType>)
2334 __glibcxx_requires_valid_range(__first, __middle);
2335 __glibcxx_requires_valid_range(__middle, __last);
2336
2337 std::make_heap(__first, __middle, __comp);
2338 for (_RandomAccessIterator __i = __middle; __i < __last; ++__i)
2339 if (__comp(*__i, *__first))
2340 std::__pop_heap(__first, __middle, __i, _ValueType(*__i), __comp);
2341 std::sort_heap(__first, __middle, __comp);
2342 }
2343
2344 /**
2345 * @brief Copy the smallest elements of a sequence.
2346 * @param first An iterator.
2347 * @param last Another iterator.
2348 * @param result_first A random-access iterator.
2349 * @param result_last Another random-access iterator.
2350 * @return An iterator indicating the end of the resulting sequence.
2351 *
2352 * Copies and sorts the smallest N values from the range @p [first,last)
2353 * to the range beginning at @p result_first, where the number of
2354 * elements to be copied, @p N, is the smaller of @p (last-first) and
2355 * @p (result_last-result_first).
2356 * After the sort if @p i and @j are iterators in the range
2357 * @p [result_first,result_first+N) such that @i precedes @j then
2358 * @p *j<*i is false.
2359 * The value returned is @p result_first+N.
2360 */
2361 template<typename _InputIterator, typename _RandomAccessIterator>
2362 _RandomAccessIterator
2363 partial_sort_copy(_InputIterator __first, _InputIterator __last,
2364 _RandomAccessIterator __result_first,
2365 _RandomAccessIterator __result_last)
2366 {
2367 typedef typename iterator_traits<_InputIterator>::value_type
2368 _InputValueType;
2369 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2370 _OutputValueType;
2371 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
2372 _DistanceType;
2373
2374 // concept requirements
2375 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
2376 __glibcxx_function_requires(_ConvertibleConcept<_InputValueType,
2377 _OutputValueType>)
2378 __glibcxx_function_requires(_LessThanComparableConcept<_OutputValueType>)
2379 __glibcxx_function_requires(_LessThanComparableConcept<_InputValueType>)
2380 __glibcxx_requires_valid_range(__first, __last);
2381 __glibcxx_requires_valid_range(__result_first, __result_last);
2382
2383 if (__result_first == __result_last)
2384 return __result_last;
2385 _RandomAccessIterator __result_real_last = __result_first;
2386 while(__first != __last && __result_real_last != __result_last)
2387 {
2388 *__result_real_last = *__first;
2389 ++__result_real_last;
2390 ++__first;
2391 }
2392 std::make_heap(__result_first, __result_real_last);
2393 while (__first != __last)
2394 {
2395 if (*__first < *__result_first)
2396 std::__adjust_heap(__result_first, _DistanceType(0),
2397 _DistanceType(__result_real_last
2398 - __result_first),
2399 _InputValueType(*__first));
2400 ++__first;
2401 }
2402 std::sort_heap(__result_first, __result_real_last);
2403 return __result_real_last;
2404 }
2405
2406 /**
2407 * @brief Copy the smallest elements of a sequence using a predicate for
2408 * comparison.
2409 * @param first An input iterator.
2410 * @param last Another input iterator.
2411 * @param result_first A random-access iterator.
2412 * @param result_last Another random-access iterator.
2413 * @param comp A comparison functor.
2414 * @return An iterator indicating the end of the resulting sequence.
2415 *
2416 * Copies and sorts the smallest N values from the range @p [first,last)
2417 * to the range beginning at @p result_first, where the number of
2418 * elements to be copied, @p N, is the smaller of @p (last-first) and
2419 * @p (result_last-result_first).
2420 * After the sort if @p i and @j are iterators in the range
2421 * @p [result_first,result_first+N) such that @i precedes @j then
2422 * @p comp(*j,*i) is false.
2423 * The value returned is @p result_first+N.
2424 */
2425 template<typename _InputIterator, typename _RandomAccessIterator, typename _Compare>
2426 _RandomAccessIterator
2427 partial_sort_copy(_InputIterator __first, _InputIterator __last,
2428 _RandomAccessIterator __result_first,
2429 _RandomAccessIterator __result_last,
2430 _Compare __comp)
2431 {
2432 typedef typename iterator_traits<_InputIterator>::value_type
2433 _InputValueType;
2434 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2435 _OutputValueType;
2436 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
2437 _DistanceType;
2438
2439 // concept requirements
2440 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
2441 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2442 _RandomAccessIterator>)
2443 __glibcxx_function_requires(_ConvertibleConcept<_InputValueType,
2444 _OutputValueType>)
2445 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2446 _OutputValueType, _OutputValueType>)
2447 __glibcxx_requires_valid_range(__first, __last);
2448 __glibcxx_requires_valid_range(__result_first, __result_last);
2449
2450 if (__result_first == __result_last)
2451 return __result_last;
2452 _RandomAccessIterator __result_real_last = __result_first;
2453 while(__first != __last && __result_real_last != __result_last)
2454 {
2455 *__result_real_last = *__first;
2456 ++__result_real_last;
2457 ++__first;
2458 }
2459 std::make_heap(__result_first, __result_real_last, __comp);
2460 while (__first != __last)
2461 {
2462 if (__comp(*__first, *__result_first))
2463 std::__adjust_heap(__result_first, _DistanceType(0),
2464 _DistanceType(__result_real_last
2465 - __result_first),
2466 _InputValueType(*__first),
2467 __comp);
2468 ++__first;
2469 }
2470 std::sort_heap(__result_first, __result_real_last, __comp);
2471 return __result_real_last;
2472 }
2473
2474 /**
2475 * @if maint
2476 * This is a helper function for the sort routine.
2477 * @endif
2478 */
2479 template<typename _RandomAccessIterator, typename _Size>
2480 void
2481 __introsort_loop(_RandomAccessIterator __first,
2482 _RandomAccessIterator __last,
2483 _Size __depth_limit)
2484 {
2485 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2486 _ValueType;
2487
2488 while (__last - __first > int(_S_threshold))
2489 {
2490 if (__depth_limit == 0)
2491 {
2492 std::partial_sort(__first, __last, __last);
2493 return;
2494 }
2495 --__depth_limit;
2496 _RandomAccessIterator __cut =
2497 std::__unguarded_partition(__first, __last,
2498 _ValueType(std::__median(*__first,
2499 *(__first
2500 + (__last
2501 - __first)
2502 / 2),
2503 *(__last
2504 - 1))));
2505 std::__introsort_loop(__cut, __last, __depth_limit);
2506 __last = __cut;
2507 }
2508 }
2509
2510 /**
2511 * @if maint
2512 * This is a helper function for the sort routine.
2513 * @endif
2514 */
2515 template<typename _RandomAccessIterator, typename _Size, typename _Compare>
2516 void
2517 __introsort_loop(_RandomAccessIterator __first,
2518 _RandomAccessIterator __last,
2519 _Size __depth_limit, _Compare __comp)
2520 {
2521 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2522 _ValueType;
2523
2524 while (__last - __first > int(_S_threshold))
2525 {
2526 if (__depth_limit == 0)
2527 {
2528 std::partial_sort(__first, __last, __last, __comp);
2529 return;
2530 }
2531 --__depth_limit;
2532 _RandomAccessIterator __cut =
2533 std::__unguarded_partition(__first, __last,
2534 _ValueType(std::__median(*__first,
2535 *(__first
2536 + (__last
2537 - __first)
2538 / 2),
2539 *(__last - 1),
2540 __comp)),
2541 __comp);
2542 std::__introsort_loop(__cut, __last, __depth_limit, __comp);
2543 __last = __cut;
2544 }
2545 }
2546
2547 /**
2548 * @brief Sort the elements of a sequence.
2549 * @param first An iterator.
2550 * @param last Another iterator.
2551 * @return Nothing.
2552 *
2553 * Sorts the elements in the range @p [first,last) in ascending order,
2554 * such that @p *(i+1)<*i is false for each iterator @p i in the range
2555 * @p [first,last-1).
2556 *
2557 * The relative ordering of equivalent elements is not preserved, use
2558 * @p stable_sort() if this is needed.
2559 */
2560 template<typename _RandomAccessIterator>
2561 inline void
2562 sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
2563 {
2564 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2565 _ValueType;
2566
2567 // concept requirements
2568 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2569 _RandomAccessIterator>)
2570 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
2571 __glibcxx_requires_valid_range(__first, __last);
2572
2573 if (__first != __last)
2574 {
2575 std::__introsort_loop(__first, __last, __lg(__last - __first) * 2);
2576 std::__final_insertion_sort(__first, __last);
2577 }
2578 }
2579
2580 /**
2581 * @brief Sort the elements of a sequence using a predicate for comparison.
2582 * @param first An iterator.
2583 * @param last Another iterator.
2584 * @param comp A comparison functor.
2585 * @return Nothing.
2586 *
2587 * Sorts the elements in the range @p [first,last) in ascending order,
2588 * such that @p comp(*(i+1),*i) is false for every iterator @p i in the
2589 * range @p [first,last-1).
2590 *
2591 * The relative ordering of equivalent elements is not preserved, use
2592 * @p stable_sort() if this is needed.
2593 */
2594 template<typename _RandomAccessIterator, typename _Compare>
2595 inline void
2596 sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
2597 _Compare __comp)
2598 {
2599 typedef typename iterator_traits<_RandomAccessIterator>::value_type
2600 _ValueType;
2601
2602 // concept requirements
2603 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
2604 _RandomAccessIterator>)
2605 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _ValueType,
2606 _ValueType>)
2607 __glibcxx_requires_valid_range(__first, __last);
2608
2609 if (__first != __last)
2610 {
2611 std::__introsort_loop(__first, __last, __lg(__last - __first) * 2,
2612 __comp);
2613 std::__final_insertion_sort(__first, __last, __comp);
2614 }
2615 }
2616
2617 /**
2618 * @brief Finds the first position in which @a val could be inserted
2619 * without changing the ordering.
2620 * @param first An iterator.
2621 * @param last Another iterator.
2622 * @param val The search term.
2623 * @return An iterator pointing to the first element "not less than" @a val,
2624 * or end() if every element is less than @a val.
2625 * @ingroup binarysearch
2626 */
2627 template<typename _ForwardIterator, typename _Tp>
2628 _ForwardIterator
2629 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
2630 const _Tp& __val)
2631 {
2632 typedef typename iterator_traits<_ForwardIterator>::value_type
2633 _ValueType;
2634 typedef typename iterator_traits<_ForwardIterator>::difference_type
2635 _DistanceType;
2636
2637 // concept requirements
2638 // Note that these are slightly stricter than those of the 4-argument
2639 // version, defined next. The difference is in the strictness of the
2640 // comparison operations... so for looser checking, define your own
2641 // comparison function, as was intended.
2642 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2643 __glibcxx_function_requires(_SameTypeConcept<_Tp, _ValueType>)
2644 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
2645 __glibcxx_requires_partitioned(__first, __last, __val);
2646
2647 _DistanceType __len = std::distance(__first, __last);
2648 _DistanceType __half;
2649 _ForwardIterator __middle;
2650
2651 while (__len > 0)
2652 {
2653 __half = __len >> 1;
2654 __middle = __first;
2655 std::advance(__middle, __half);
2656 if (*__middle < __val)
2657 {
2658 __first = __middle;
2659 ++__first;
2660 __len = __len - __half - 1;
2661 }
2662 else
2663 __len = __half;
2664 }
2665 return __first;
2666 }
2667
2668 /**
2669 * @brief Finds the first position in which @a val could be inserted
2670 * without changing the ordering.
2671 * @param first An iterator.
2672 * @param last Another iterator.
2673 * @param val The search term.
2674 * @param comp A functor to use for comparisons.
2675 * @return An iterator pointing to the first element "not less than" @a val,
2676 * or end() if every element is less than @a val.
2677 * @ingroup binarysearch
2678 *
2679 * The comparison function should have the same effects on ordering as
2680 * the function used for the initial sort.
2681 */
2682 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2683 _ForwardIterator
2684 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
2685 const _Tp& __val, _Compare __comp)
2686 {
2687 typedef typename iterator_traits<_ForwardIterator>::value_type
2688 _ValueType;
2689 typedef typename iterator_traits<_ForwardIterator>::difference_type
2690 _DistanceType;
2691
2692 // concept requirements
2693 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2694 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2695 _ValueType, _Tp>)
2696 __glibcxx_requires_partitioned_pred(__first, __last, __val, __comp);
2697
2698 _DistanceType __len = std::distance(__first, __last);
2699 _DistanceType __half;
2700 _ForwardIterator __middle;
2701
2702 while (__len > 0)
2703 {
2704 __half = __len >> 1;
2705 __middle = __first;
2706 std::advance(__middle, __half);
2707 if (__comp(*__middle, __val))
2708 {
2709 __first = __middle;
2710 ++__first;
2711 __len = __len - __half - 1;
2712 }
2713 else
2714 __len = __half;
2715 }
2716 return __first;
2717 }
2718
2719 /**
2720 * @brief Finds the last position in which @a val could be inserted
2721 * without changing the ordering.
2722 * @param first An iterator.
2723 * @param last Another iterator.
2724 * @param val The search term.
2725 * @return An iterator pointing to the first element greater than @a val,
2726 * or end() if no elements are greater than @a val.
2727 * @ingroup binarysearch
2728 */
2729 template<typename _ForwardIterator, typename _Tp>
2730 _ForwardIterator
2731 upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2732 const _Tp& __val)
2733 {
2734 typedef typename iterator_traits<_ForwardIterator>::value_type
2735 _ValueType;
2736 typedef typename iterator_traits<_ForwardIterator>::difference_type
2737 _DistanceType;
2738
2739 // concept requirements
2740 // See comments on lower_bound.
2741 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2742 __glibcxx_function_requires(_SameTypeConcept<_Tp, _ValueType>)
2743 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
2744 __glibcxx_requires_partitioned(__first, __last, __val);
2745
2746 _DistanceType __len = std::distance(__first, __last);
2747 _DistanceType __half;
2748 _ForwardIterator __middle;
2749
2750 while (__len > 0)
2751 {
2752 __half = __len >> 1;
2753 __middle = __first;
2754 std::advance(__middle, __half);
2755 if (__val < *__middle)
2756 __len = __half;
2757 else
2758 {
2759 __first = __middle;
2760 ++__first;
2761 __len = __len - __half - 1;
2762 }
2763 }
2764 return __first;
2765 }
2766
2767 /**
2768 * @brief Finds the last position in which @a val could be inserted
2769 * without changing the ordering.
2770 * @param first An iterator.
2771 * @param last Another iterator.
2772 * @param val The search term.
2773 * @param comp A functor to use for comparisons.
2774 * @return An iterator pointing to the first element greater than @a val,
2775 * or end() if no elements are greater than @a val.
2776 * @ingroup binarysearch
2777 *
2778 * The comparison function should have the same effects on ordering as
2779 * the function used for the initial sort.
2780 */
2781 template<typename _ForwardIterator, typename _Tp, typename _Compare>
2782 _ForwardIterator
2783 upper_bound(_ForwardIterator __first, _ForwardIterator __last,
2784 const _Tp& __val, _Compare __comp)
2785 {
2786 typedef typename iterator_traits<_ForwardIterator>::value_type
2787 _ValueType;
2788 typedef typename iterator_traits<_ForwardIterator>::difference_type
2789 _DistanceType;
2790
2791 // concept requirements
2792 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
2793 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
2794 _Tp, _ValueType>)
2795 __glibcxx_requires_partitioned_pred(__first, __last, __val, __comp);
2796
2797 _DistanceType __len = std::distance(__first, __last);
2798 _DistanceType __half;
2799 _ForwardIterator __middle;
2800
2801 while (__len > 0)
2802 {
2803 __half = __len >> 1;
2804 __middle = __first;
2805 std::advance(__middle, __half);
2806 if (__comp(__val, *__middle))
2807 __len = __half;
2808 else
2809 {
2810 __first = __middle;
2811 ++__first;
2812 __len = __len - __half - 1;
2813 }
2814 }
2815 return __first;
2816 }
2817
2818 /**
2819 * @if maint
2820 * This is a helper function for the merge routines.
2821 * @endif
2822 */
2823 template<typename _BidirectionalIterator, typename _Distance>
2824 void
2825 __merge_without_buffer(_BidirectionalIterator __first,
2826 _BidirectionalIterator __middle,
2827 _BidirectionalIterator __last,
2828 _Distance __len1, _Distance __len2)
2829 {
2830 if (__len1 == 0 || __len2 == 0)
2831 return;
2832 if (__len1 + __len2 == 2)
2833 {
2834 if (*__middle < *__first)
2835 std::iter_swap(__first, __middle);
2836 return;
2837 }
2838 _BidirectionalIterator __first_cut = __first;
2839 _BidirectionalIterator __second_cut = __middle;
2840 _Distance __len11 = 0;
2841 _Distance __len22 = 0;
2842 if (__len1 > __len2)
2843 {
2844 __len11 = __len1 / 2;
2845 std::advance(__first_cut, __len11);
2846 __second_cut = std::lower_bound(__middle, __last, *__first_cut);
2847 __len22 = std::distance(__middle, __second_cut);
2848 }
2849 else
2850 {
2851 __len22 = __len2 / 2;
2852 std::advance(__second_cut, __len22);
2853 __first_cut = std::upper_bound(__first, __middle, *__second_cut);
2854 __len11 = std::distance(__first, __first_cut);
2855 }
2856 std::rotate(__first_cut, __middle, __second_cut);
2857 _BidirectionalIterator __new_middle = __first_cut;
2858 std::advance(__new_middle, std::distance(__middle, __second_cut));
2859 std::__merge_without_buffer(__first, __first_cut, __new_middle,
2860 __len11, __len22);
2861 std::__merge_without_buffer(__new_middle, __second_cut, __last,
2862 __len1 - __len11, __len2 - __len22);
2863 }
2864
2865 /**
2866 * @if maint
2867 * This is a helper function for the merge routines.
2868 * @endif
2869 */
2870 template<typename _BidirectionalIterator, typename _Distance,
2871 typename _Compare>
2872 void
2873 __merge_without_buffer(_BidirectionalIterator __first,
2874 _BidirectionalIterator __middle,
2875 _BidirectionalIterator __last,
2876 _Distance __len1, _Distance __len2,
2877 _Compare __comp)
2878 {
2879 if (__len1 == 0 || __len2 == 0)
2880 return;
2881 if (__len1 + __len2 == 2)
2882 {
2883 if (__comp(*__middle, *__first))
2884 std::iter_swap(__first, __middle);
2885 return;
2886 }
2887 _BidirectionalIterator __first_cut = __first;
2888 _BidirectionalIterator __second_cut = __middle;
2889 _Distance __len11 = 0;
2890 _Distance __len22 = 0;
2891 if (__len1 > __len2)
2892 {
2893 __len11 = __len1 / 2;
2894 std::advance(__first_cut, __len11);
2895 __second_cut = std::lower_bound(__middle, __last, *__first_cut,
2896 __comp);
2897 __len22 = std::distance(__middle, __second_cut);
2898 }
2899 else
2900 {
2901 __len22 = __len2 / 2;
2902 std::advance(__second_cut, __len22);
2903 __first_cut = std::upper_bound(__first, __middle, *__second_cut,
2904 __comp);
2905 __len11 = std::distance(__first, __first_cut);
2906 }
2907 std::rotate(__first_cut, __middle, __second_cut);
2908 _BidirectionalIterator __new_middle = __first_cut;
2909 std::advance(__new_middle, std::distance(__middle, __second_cut));
2910 std::__merge_without_buffer(__first, __first_cut, __new_middle,
2911 __len11, __len22, __comp);
2912 std::__merge_without_buffer(__new_middle, __second_cut, __last,
2913 __len1 - __len11, __len2 - __len22, __comp);
2914 }
2915
2916 /**
2917 * @if maint
2918 * This is a helper function for the stable sorting routines.
2919 * @endif
2920 */
2921 template<typename _RandomAccessIterator>
2922 void
2923 __inplace_stable_sort(_RandomAccessIterator __first,
2924 _RandomAccessIterator __last)
2925 {
2926 if (__last - __first < 15)
2927 {
2928 std::__insertion_sort(__first, __last);
2929 return;
2930 }
2931 _RandomAccessIterator __middle = __first + (__last - __first) / 2;
2932 std::__inplace_stable_sort(__first, __middle);
2933 std::__inplace_stable_sort(__middle, __last);
2934 std::__merge_without_buffer(__first, __middle, __last,
2935 __middle - __first,
2936 __last - __middle);
2937 }
2938
2939 /**
2940 * @if maint
2941 * This is a helper function for the stable sorting routines.
2942 * @endif
2943 */
2944 template<typename _RandomAccessIterator, typename _Compare>
2945 void
2946 __inplace_stable_sort(_RandomAccessIterator __first,
2947 _RandomAccessIterator __last, _Compare __comp)
2948 {
2949 if (__last - __first < 15)
2950 {
2951 std::__insertion_sort(__first, __last, __comp);
2952 return;
2953 }
2954 _RandomAccessIterator __middle = __first + (__last - __first) / 2;
2955 std::__inplace_stable_sort(__first, __middle, __comp);
2956 std::__inplace_stable_sort(__middle, __last, __comp);
2957 std::__merge_without_buffer(__first, __middle, __last,
2958 __middle - __first,
2959 __last - __middle,
2960 __comp);
2961 }
2962
2963 /**
2964 * @brief Merges two sorted ranges.
2965 * @param first1 An iterator.
2966 * @param first2 Another iterator.
2967 * @param last1 Another iterator.
2968 * @param last2 Another iterator.
2969 * @param result An iterator pointing to the end of the merged range.
2970 * @return An iterator pointing to the first element "not less than" @a val.
2971 *
2972 * Merges the ranges [first1,last1) and [first2,last2) into the sorted range
2973 * [result, result + (last1-first1) + (last2-first2)). Both input ranges
2974 * must be sorted, and the output range must not overlap with either of
2975 * the input ranges. The sort is @e stable, that is, for equivalent
2976 * elements in the two ranges, elements from the first range will always
2977 * come before elements from the second.
2978 */
2979 template<typename _InputIterator1, typename _InputIterator2,
2980 typename _OutputIterator>
2981 _OutputIterator
2982 merge(_InputIterator1 __first1, _InputIterator1 __last1,
2983 _InputIterator2 __first2, _InputIterator2 __last2,
2984 _OutputIterator __result)
2985 {
2986 // concept requirements
2987 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2988 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2989 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
2990 typename iterator_traits<_InputIterator1>::value_type>)
2991 __glibcxx_function_requires(_SameTypeConcept<
2992 typename iterator_traits<_InputIterator1>::value_type,
2993 typename iterator_traits<_InputIterator2>::value_type>)
2994 __glibcxx_function_requires(_LessThanComparableConcept<
2995 typename iterator_traits<_InputIterator1>::value_type>)
2996 __glibcxx_requires_sorted(__first1, __last1);
2997 __glibcxx_requires_sorted(__first2, __last2);
2998
2999 while (__first1 != __last1 && __first2 != __last2)
3000 {
3001 if (*__first2 < *__first1)
3002 {
3003 *__result = *__first2;
3004 ++__first2;
3005 }
3006 else
3007 {
3008 *__result = *__first1;
3009 ++__first1;
3010 }
3011 ++__result;
3012 }
3013 return std::copy(__first2, __last2, std::copy(__first1, __last1,
3014 __result));
3015 }
3016
3017 /**
3018 * @brief Merges two sorted ranges.
3019 * @param first1 An iterator.
3020 * @param first2 Another iterator.
3021 * @param last1 Another iterator.
3022 * @param last2 Another iterator.
3023 * @param result An iterator pointing to the end of the merged range.
3024 * @param comp A functor to use for comparisons.
3025 * @return An iterator pointing to the first element "not less than" @a val.
3026 *
3027 * Merges the ranges [first1,last1) and [first2,last2) into the sorted range
3028 * [result, result + (last1-first1) + (last2-first2)). Both input ranges
3029 * must be sorted, and the output range must not overlap with either of
3030 * the input ranges. The sort is @e stable, that is, for equivalent
3031 * elements in the two ranges, elements from the first range will always
3032 * come before elements from the second.
3033 *
3034 * The comparison function should have the same effects on ordering as
3035 * the function used for the initial sort.
3036 */
3037 template<typename _InputIterator1, typename _InputIterator2,
3038 typename _OutputIterator, typename _Compare>
3039 _OutputIterator
3040 merge(_InputIterator1 __first1, _InputIterator1 __last1,
3041 _InputIterator2 __first2, _InputIterator2 __last2,
3042 _OutputIterator __result, _Compare __comp)
3043 {
3044 // concept requirements
3045 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
3046 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
3047 __glibcxx_function_requires(_SameTypeConcept<
3048 typename iterator_traits<_InputIterator1>::value_type,
3049 typename iterator_traits<_InputIterator2>::value_type>)
3050 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
3051 typename iterator_traits<_InputIterator1>::value_type>)
3052 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3053 typename iterator_traits<_InputIterator1>::value_type,
3054 typename iterator_traits<_InputIterator2>::value_type>)
3055 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
3056 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
3057
3058 while (__first1 != __last1 && __first2 != __last2)
3059 {
3060 if (__comp(*__first2, *__first1))
3061 {
3062 *__result = *__first2;
3063 ++__first2;
3064 }
3065 else
3066 {
3067 *__result = *__first1;
3068 ++__first1;
3069 }
3070 ++__result;
3071 }
3072 return std::copy(__first2, __last2, std::copy(__first1, __last1,
3073 __result));
3074 }
3075
3076 template<typename _RandomAccessIterator1, typename _RandomAccessIterator2,
3077 typename _Distance>
3078 void
3079 __merge_sort_loop(_RandomAccessIterator1 __first,
3080 _RandomAccessIterator1 __last,
3081 _RandomAccessIterator2 __result,
3082 _Distance __step_size)
3083 {
3084 const _Distance __two_step = 2 * __step_size;
3085
3086 while (__last - __first >= __two_step)
3087 {
3088 __result = std::merge(__first, __first + __step_size,
3089 __first + __step_size, __first + __two_step,
3090 __result);
3091 __first += __two_step;
3092 }
3093
3094 __step_size = std::min(_Distance(__last - __first), __step_size);
3095 std::merge(__first, __first + __step_size, __first + __step_size, __last,
3096 __result);
3097 }
3098
3099 template<typename _RandomAccessIterator1, typename _RandomAccessIterator2,
3100 typename _Distance, typename _Compare>
3101 void
3102 __merge_sort_loop(_RandomAccessIterator1 __first,
3103 _RandomAccessIterator1 __last,
3104 _RandomAccessIterator2 __result, _Distance __step_size,
3105 _Compare __comp)
3106 {
3107 const _Distance __two_step = 2 * __step_size;
3108
3109 while (__last - __first >= __two_step)
3110 {
3111 __result = std::merge(__first, __first + __step_size,
3112 __first + __step_size, __first + __two_step,
3113 __result,
3114 __comp);
3115 __first += __two_step;
3116 }
3117 __step_size = std::min(_Distance(__last - __first), __step_size);
3118
3119 std::merge(__first, __first + __step_size,
3120 __first + __step_size, __last,
3121 __result,
3122 __comp);
3123 }
3124
3125 enum { _S_chunk_size = 7 };
3126
3127 template<typename _RandomAccessIterator, typename _Distance>
3128 void
3129 __chunk_insertion_sort(_RandomAccessIterator __first,
3130 _RandomAccessIterator __last,
3131 _Distance __chunk_size)
3132 {
3133 while (__last - __first >= __chunk_size)
3134 {
3135 std::__insertion_sort(__first, __first + __chunk_size);
3136 __first += __chunk_size;
3137 }
3138 std::__insertion_sort(__first, __last);
3139 }
3140
3141 template<typename _RandomAccessIterator, typename _Distance, typename _Compare>
3142 void
3143 __chunk_insertion_sort(_RandomAccessIterator __first,
3144 _RandomAccessIterator __last,
3145 _Distance __chunk_size, _Compare __comp)
3146 {
3147 while (__last - __first >= __chunk_size)
3148 {
3149 std::__insertion_sort(__first, __first + __chunk_size, __comp);
3150 __first += __chunk_size;
3151 }
3152 std::__insertion_sort(__first, __last, __comp);
3153 }
3154
3155 template<typename _RandomAccessIterator, typename _Pointer>
3156 void
3157 __merge_sort_with_buffer(_RandomAccessIterator __first,
3158 _RandomAccessIterator __last,
3159 _Pointer __buffer)
3160 {
3161 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3162 _Distance;
3163
3164 const _Distance __len = __last - __first;
3165 const _Pointer __buffer_last = __buffer + __len;
3166
3167 _Distance __step_size = _S_chunk_size;
3168 std::__chunk_insertion_sort(__first, __last, __step_size);
3169
3170 while (__step_size < __len)
3171 {
3172 std::__merge_sort_loop(__first, __last, __buffer, __step_size);
3173 __step_size *= 2;
3174 std::__merge_sort_loop(__buffer, __buffer_last, __first, __step_size);
3175 __step_size *= 2;
3176 }
3177 }
3178
3179 template<typename _RandomAccessIterator, typename _Pointer, typename _Compare>
3180 void
3181 __merge_sort_with_buffer(_RandomAccessIterator __first,
3182 _RandomAccessIterator __last,
3183 _Pointer __buffer, _Compare __comp)
3184 {
3185 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3186 _Distance;
3187
3188 const _Distance __len = __last - __first;
3189 const _Pointer __buffer_last = __buffer + __len;
3190
3191 _Distance __step_size = _S_chunk_size;
3192 std::__chunk_insertion_sort(__first, __last, __step_size, __comp);
3193
3194 while (__step_size < __len)
3195 {
3196 std::__merge_sort_loop(__first, __last, __buffer,
3197 __step_size, __comp);
3198 __step_size *= 2;
3199 std::__merge_sort_loop(__buffer, __buffer_last, __first,
3200 __step_size, __comp);
3201 __step_size *= 2;
3202 }
3203 }
3204
3205 /**
3206 * @if maint
3207 * This is a helper function for the merge routines.
3208 * @endif
3209 */
3210 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
3211 typename _BidirectionalIterator3>
3212 _BidirectionalIterator3
3213 __merge_backward(_BidirectionalIterator1 __first1,
3214 _BidirectionalIterator1 __last1,
3215 _BidirectionalIterator2 __first2,
3216 _BidirectionalIterator2 __last2,
3217 _BidirectionalIterator3 __result)
3218 {
3219 if (__first1 == __last1)
3220 return std::copy_backward(__first2, __last2, __result);
3221 if (__first2 == __last2)
3222 return std::copy_backward(__first1, __last1, __result);
3223 --__last1;
3224 --__last2;
3225 while (true)
3226 {
3227 if (*__last2 < *__last1)
3228 {
3229 *--__result = *__last1;
3230 if (__first1 == __last1)
3231 return std::copy_backward(__first2, ++__last2, __result);
3232 --__last1;
3233 }
3234 else
3235 {
3236 *--__result = *__last2;
3237 if (__first2 == __last2)
3238 return std::copy_backward(__first1, ++__last1, __result);
3239 --__last2;
3240 }
3241 }
3242 }
3243
3244 /**
3245 * @if maint
3246 * This is a helper function for the merge routines.
3247 * @endif
3248 */
3249 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
3250 typename _BidirectionalIterator3, typename _Compare>
3251 _BidirectionalIterator3
3252 __merge_backward(_BidirectionalIterator1 __first1,
3253 _BidirectionalIterator1 __last1,
3254 _BidirectionalIterator2 __first2,
3255 _BidirectionalIterator2 __last2,
3256 _BidirectionalIterator3 __result,
3257 _Compare __comp)
3258 {
3259 if (__first1 == __last1)
3260 return std::copy_backward(__first2, __last2, __result);
3261 if (__first2 == __last2)
3262 return std::copy_backward(__first1, __last1, __result);
3263 --__last1;
3264 --__last2;
3265 while (true)
3266 {
3267 if (__comp(*__last2, *__last1))
3268 {
3269 *--__result = *__last1;
3270 if (__first1 == __last1)
3271 return std::copy_backward(__first2, ++__last2, __result);
3272 --__last1;
3273 }
3274 else
3275 {
3276 *--__result = *__last2;
3277 if (__first2 == __last2)
3278 return std::copy_backward(__first1, ++__last1, __result);
3279 --__last2;
3280 }
3281 }
3282 }
3283
3284 /**
3285 * @if maint
3286 * This is a helper function for the merge routines.
3287 * @endif
3288 */
3289 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
3290 typename _Distance>
3291 _BidirectionalIterator1
3292 __rotate_adaptive(_BidirectionalIterator1 __first,
3293 _BidirectionalIterator1 __middle,
3294 _BidirectionalIterator1 __last,
3295 _Distance __len1, _Distance __len2,
3296 _BidirectionalIterator2 __buffer,
3297 _Distance __buffer_size)
3298 {
3299 _BidirectionalIterator2 __buffer_end;
3300 if (__len1 > __len2 && __len2 <= __buffer_size)
3301 {
3302 __buffer_end = std::copy(__middle, __last, __buffer);
3303 std::copy_backward(__first, __middle, __last);
3304 return std::copy(__buffer, __buffer_end, __first);
3305 }
3306 else if (__len1 <= __buffer_size)
3307 {
3308 __buffer_end = std::copy(__first, __middle, __buffer);
3309 std::copy(__middle, __last, __first);
3310 return std::copy_backward(__buffer, __buffer_end, __last);
3311 }
3312 else
3313 {
3314 std::rotate(__first, __middle, __last);
3315 std::advance(__first, std::distance(__middle, __last));
3316 return __first;
3317 }
3318 }
3319
3320 /**
3321 * @if maint
3322 * This is a helper function for the merge routines.
3323 * @endif
3324 */
3325 template<typename _BidirectionalIterator, typename _Distance,
3326 typename _Pointer>
3327 void
3328 __merge_adaptive(_BidirectionalIterator __first,
3329 _BidirectionalIterator __middle,
3330 _BidirectionalIterator __last,
3331 _Distance __len1, _Distance __len2,
3332 _Pointer __buffer, _Distance __buffer_size)
3333 {
3334 if (__len1 <= __len2 && __len1 <= __buffer_size)
3335 {
3336 _Pointer __buffer_end = std::copy(__first, __middle, __buffer);
3337 std::merge(__buffer, __buffer_end, __middle, __last, __first);
3338 }
3339 else if (__len2 <= __buffer_size)
3340 {
3341 _Pointer __buffer_end = std::copy(__middle, __last, __buffer);
3342 std::__merge_backward(__first, __middle, __buffer,
3343 __buffer_end, __last);
3344 }
3345 else
3346 {
3347 _BidirectionalIterator __first_cut = __first;
3348 _BidirectionalIterator __second_cut = __middle;
3349 _Distance __len11 = 0;
3350 _Distance __len22 = 0;
3351 if (__len1 > __len2)
3352 {
3353 __len11 = __len1 / 2;
3354 std::advance(__first_cut, __len11);
3355 __second_cut = std::lower_bound(__middle, __last,
3356 *__first_cut);
3357 __len22 = std::distance(__middle, __second_cut);
3358 }
3359 else
3360 {
3361 __len22 = __len2 / 2;
3362 std::advance(__second_cut, __len22);
3363 __first_cut = std::upper_bound(__first, __middle,
3364 *__second_cut);
3365 __len11 = std::distance(__first, __first_cut);
3366 }
3367 _BidirectionalIterator __new_middle =
3368 std::__rotate_adaptive(__first_cut, __middle, __second_cut,
3369 __len1 - __len11, __len22, __buffer,
3370 __buffer_size);
3371 std::__merge_adaptive(__first, __first_cut, __new_middle, __len11,
3372 __len22, __buffer, __buffer_size);
3373 std::__merge_adaptive(__new_middle, __second_cut, __last,
3374 __len1 - __len11,
3375 __len2 - __len22, __buffer, __buffer_size);
3376 }
3377 }
3378
3379 /**
3380 * @if maint
3381 * This is a helper function for the merge routines.
3382 * @endif
3383 */
3384 template<typename _BidirectionalIterator, typename _Distance, typename _Pointer,
3385 typename _Compare>
3386 void
3387 __merge_adaptive(_BidirectionalIterator __first,
3388 _BidirectionalIterator __middle,
3389 _BidirectionalIterator __last,
3390 _Distance __len1, _Distance __len2,
3391 _Pointer __buffer, _Distance __buffer_size,
3392 _Compare __comp)
3393 {
3394 if (__len1 <= __len2 && __len1 <= __buffer_size)
3395 {
3396 _Pointer __buffer_end = std::copy(__first, __middle, __buffer);
3397 std::merge(__buffer, __buffer_end, __middle, __last, __first, __comp);
3398 }
3399 else if (__len2 <= __buffer_size)
3400 {
3401 _Pointer __buffer_end = std::copy(__middle, __last, __buffer);
3402 std::__merge_backward(__first, __middle, __buffer, __buffer_end,
3403 __last, __comp);
3404 }
3405 else
3406 {
3407 _BidirectionalIterator __first_cut = __first;
3408 _BidirectionalIterator __second_cut = __middle;
3409 _Distance __len11 = 0;
3410 _Distance __len22 = 0;
3411 if (__len1 > __len2)
3412 {
3413 __len11 = __len1 / 2;
3414 std::advance(__first_cut, __len11);
3415 __second_cut = std::lower_bound(__middle, __last, *__first_cut,
3416 __comp);
3417 __len22 = std::distance(__middle, __second_cut);
3418 }
3419 else
3420 {
3421 __len22 = __len2 / 2;
3422 std::advance(__second_cut, __len22);
3423 __first_cut = std::upper_bound(__first, __middle, *__second_cut,
3424 __comp);
3425 __len11 = std::distance(__first, __first_cut);
3426 }
3427 _BidirectionalIterator __new_middle =
3428 std::__rotate_adaptive(__first_cut, __middle, __second_cut,
3429 __len1 - __len11, __len22, __buffer,
3430 __buffer_size);
3431 std::__merge_adaptive(__first, __first_cut, __new_middle, __len11,
3432 __len22, __buffer, __buffer_size, __comp);
3433 std::__merge_adaptive(__new_middle, __second_cut, __last,
3434 __len1 - __len11,
3435 __len2 - __len22, __buffer,
3436 __buffer_size, __comp);
3437 }
3438 }
3439
3440 /**
3441 * @brief Merges two sorted ranges in place.
3442 * @param first An iterator.
3443 * @param middle Another iterator.
3444 * @param last Another iterator.
3445 * @return Nothing.
3446 *
3447 * Merges two sorted and consecutive ranges, [first,middle) and
3448 * [middle,last), and puts the result in [first,last). The output will
3449 * be sorted. The sort is @e stable, that is, for equivalent
3450 * elements in the two ranges, elements from the first range will always
3451 * come before elements from the second.
3452 *
3453 * If enough additional memory is available, this takes (last-first)-1
3454 * comparisons. Otherwise an NlogN algorithm is used, where N is
3455 * distance(first,last).
3456 */
3457 template<typename _BidirectionalIterator>
3458 void
3459 inplace_merge(_BidirectionalIterator __first,
3460 _BidirectionalIterator __middle,
3461 _BidirectionalIterator __last)
3462 {
3463 typedef typename iterator_traits<_BidirectionalIterator>::value_type
3464 _ValueType;
3465 typedef typename iterator_traits<_BidirectionalIterator>::difference_type
3466 _DistanceType;
3467
3468 // concept requirements
3469 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
3470 _BidirectionalIterator>)
3471 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
3472 __glibcxx_requires_sorted(__first, __middle);
3473 __glibcxx_requires_sorted(__middle, __last);
3474
3475 if (__first == __middle || __middle == __last)
3476 return;
3477
3478 _DistanceType __len1 = std::distance(__first, __middle);
3479 _DistanceType __len2 = std::distance(__middle, __last);
3480
3481 _Temporary_buffer<_BidirectionalIterator, _ValueType> __buf(__first,
3482 __last);
3483 if (__buf.begin() == 0)
3484 std::__merge_without_buffer(__first, __middle, __last, __len1, __len2);
3485 else
3486 std::__merge_adaptive(__first, __middle, __last, __len1, __len2,
3487 __buf.begin(), _DistanceType(__buf.size()));
3488 }
3489
3490 /**
3491 * @brief Merges two sorted ranges in place.
3492 * @param first An iterator.
3493 * @param middle Another iterator.
3494 * @param last Another iterator.
3495 * @param comp A functor to use for comparisons.
3496 * @return Nothing.
3497 *
3498 * Merges two sorted and consecutive ranges, [first,middle) and
3499 * [middle,last), and puts the result in [first,last). The output will
3500 * be sorted. The sort is @e stable, that is, for equivalent
3501 * elements in the two ranges, elements from the first range will always
3502 * come before elements from the second.
3503 *
3504 * If enough additional memory is available, this takes (last-first)-1
3505 * comparisons. Otherwise an NlogN algorithm is used, where N is
3506 * distance(first,last).
3507 *
3508 * The comparison function should have the same effects on ordering as
3509 * the function used for the initial sort.
3510 */
3511 template<typename _BidirectionalIterator, typename _Compare>
3512 void
3513 inplace_merge(_BidirectionalIterator __first,
3514 _BidirectionalIterator __middle,
3515 _BidirectionalIterator __last,
3516 _Compare __comp)
3517 {
3518 typedef typename iterator_traits<_BidirectionalIterator>::value_type
3519 _ValueType;
3520 typedef typename iterator_traits<_BidirectionalIterator>::difference_type
3521 _DistanceType;
3522
3523 // concept requirements
3524 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
3525 _BidirectionalIterator>)
3526 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3527 _ValueType, _ValueType>)
3528 __glibcxx_requires_sorted_pred(__first, __middle, __comp);
3529 __glibcxx_requires_sorted_pred(__middle, __last, __comp);
3530
3531 if (__first == __middle || __middle == __last)
3532 return;
3533
3534 const _DistanceType __len1 = std::distance(__first, __middle);
3535 const _DistanceType __len2 = std::distance(__middle, __last);
3536
3537 _Temporary_buffer<_BidirectionalIterator, _ValueType> __buf(__first,
3538 __last);
3539 if (__buf.begin() == 0)
3540 std::__merge_without_buffer(__first, __middle, __last, __len1,
3541 __len2, __comp);
3542 else
3543 std::__merge_adaptive(__first, __middle, __last, __len1, __len2,
3544 __buf.begin(), _DistanceType(__buf.size()),
3545 __comp);
3546 }
3547
3548 template<typename _RandomAccessIterator, typename _Pointer,
3549 typename _Distance>
3550 void
3551 __stable_sort_adaptive(_RandomAccessIterator __first,
3552 _RandomAccessIterator __last,
3553 _Pointer __buffer, _Distance __buffer_size)
3554 {
3555 const _Distance __len = (__last - __first + 1) / 2;
3556 const _RandomAccessIterator __middle = __first + __len;
3557 if (__len > __buffer_size)
3558 {
3559 std::__stable_sort_adaptive(__first, __middle,
3560 __buffer, __buffer_size);
3561 std::__stable_sort_adaptive(__middle, __last,
3562 __buffer, __buffer_size);
3563 }
3564 else
3565 {
3566 std::__merge_sort_with_buffer(__first, __middle, __buffer);
3567 std::__merge_sort_with_buffer(__middle, __last, __buffer);
3568 }
3569 std::__merge_adaptive(__first, __middle, __last,
3570 _Distance(__middle - __first),
3571 _Distance(__last - __middle),
3572 __buffer, __buffer_size);
3573 }
3574
3575 template<typename _RandomAccessIterator, typename _Pointer,
3576 typename _Distance, typename _Compare>
3577 void
3578 __stable_sort_adaptive(_RandomAccessIterator __first,
3579 _RandomAccessIterator __last,
3580 _Pointer __buffer, _Distance __buffer_size,
3581 _Compare __comp)
3582 {
3583 const _Distance __len = (__last - __first + 1) / 2;
3584 const _RandomAccessIterator __middle = __first + __len;
3585 if (__len > __buffer_size)
3586 {
3587 std::__stable_sort_adaptive(__first, __middle, __buffer,
3588 __buffer_size, __comp);
3589 std::__stable_sort_adaptive(__middle, __last, __buffer,
3590 __buffer_size, __comp);
3591 }
3592 else
3593 {
3594 std::__merge_sort_with_buffer(__first, __middle, __buffer, __comp);
3595 std::__merge_sort_with_buffer(__middle, __last, __buffer, __comp);
3596 }
3597 std::__merge_adaptive(__first, __middle, __last,
3598 _Distance(__middle - __first),
3599 _Distance(__last - __middle),
3600 __buffer, __buffer_size,
3601 __comp);
3602 }
3603
3604 /**
3605 * @brief Sort the elements of a sequence, preserving the relative order
3606 * of equivalent elements.
3607 * @param first An iterator.
3608 * @param last Another iterator.
3609 * @return Nothing.
3610 *
3611 * Sorts the elements in the range @p [first,last) in ascending order,
3612 * such that @p *(i+1)<*i is false for each iterator @p i in the range
3613 * @p [first,last-1).
3614 *
3615 * The relative ordering of equivalent elements is preserved, so any two
3616 * elements @p x and @p y in the range @p [first,last) such that
3617 * @p x<y is false and @p y<x is false will have the same relative
3618 * ordering after calling @p stable_sort().
3619 */
3620 template<typename _RandomAccessIterator>
3621 inline void
3622 stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
3623 {
3624 typedef typename iterator_traits<_RandomAccessIterator>::value_type
3625 _ValueType;
3626 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3627 _DistanceType;
3628
3629 // concept requirements
3630 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3631 _RandomAccessIterator>)
3632 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
3633 __glibcxx_requires_valid_range(__first, __last);
3634
3635 _Temporary_buffer<_RandomAccessIterator, _ValueType>
3636 buf(__first, __last);
3637 if (buf.begin() == 0)
3638 std::__inplace_stable_sort(__first, __last);
3639 else
3640 std::__stable_sort_adaptive(__first, __last, buf.begin(),
3641 _DistanceType(buf.size()));
3642 }
3643
3644 /**
3645 * @brief Sort the elements of a sequence using a predicate for comparison,
3646 * preserving the relative order of equivalent elements.
3647 * @param first An iterator.
3648 * @param last Another iterator.
3649 * @param comp A comparison functor.
3650 * @return Nothing.
3651 *
3652 * Sorts the elements in the range @p [first,last) in ascending order,
3653 * such that @p comp(*(i+1),*i) is false for each iterator @p i in the
3654 * range @p [first,last-1).
3655 *
3656 * The relative ordering of equivalent elements is preserved, so any two
3657 * elements @p x and @p y in the range @p [first,last) such that
3658 * @p comp(x,y) is false and @p comp(y,x) is false will have the same
3659 * relative ordering after calling @p stable_sort().
3660 */
3661 template<typename _RandomAccessIterator, typename _Compare>
3662 inline void
3663 stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
3664 _Compare __comp)
3665 {
3666 typedef typename iterator_traits<_RandomAccessIterator>::value_type
3667 _ValueType;
3668 typedef typename iterator_traits<_RandomAccessIterator>::difference_type
3669 _DistanceType;
3670
3671 // concept requirements
3672 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3673 _RandomAccessIterator>)
3674 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3675 _ValueType,
3676 _ValueType>)
3677 __glibcxx_requires_valid_range(__first, __last);
3678
3679 _Temporary_buffer<_RandomAccessIterator, _ValueType> buf(__first, __last);
3680 if (buf.begin() == 0)
3681 std::__inplace_stable_sort(__first, __last, __comp);
3682 else
3683 std::__stable_sort_adaptive(__first, __last, buf.begin(),
3684 _DistanceType(buf.size()), __comp);
3685 }
3686
3687 /**
3688 * @brief Sort a sequence just enough to find a particular position.
3689 * @param first An iterator.
3690 * @param nth Another iterator.
3691 * @param last Another iterator.
3692 * @return Nothing.
3693 *
3694 * Rearranges the elements in the range @p [first,last) so that @p *nth
3695 * is the same element that would have been in that position had the
3696 * whole sequence been sorted.
3697 * whole sequence been sorted. The elements either side of @p *nth are
3698 * not completely sorted, but for any iterator @i in the range
3699 * @p [first,nth) and any iterator @j in the range @p [nth,last) it
3700 * holds that @p *j<*i is false.
3701 */
3702 template<typename _RandomAccessIterator>
3703 void
3704 nth_element(_RandomAccessIterator __first,
3705 _RandomAccessIterator __nth,
3706 _RandomAccessIterator __last)
3707 {
3708 typedef typename iterator_traits<_RandomAccessIterator>::value_type
3709 _ValueType;
3710
3711 // concept requirements
3712 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3713 _RandomAccessIterator>)
3714 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
3715 __glibcxx_requires_valid_range(__first, __nth);
3716 __glibcxx_requires_valid_range(__nth, __last);
3717
3718 while (__last - __first > 3)
3719 {
3720 _RandomAccessIterator __cut =
3721 std::__unguarded_partition(__first, __last,
3722 _ValueType(std::__median(*__first,
3723 *(__first
3724 + (__last
3725 - __first)
3726 / 2),
3727 *(__last
3728 - 1))));
3729 if (__cut <= __nth)
3730 __first = __cut;
3731 else
3732 __last = __cut;
3733 }
3734 std::__insertion_sort(__first, __last);
3735 }
3736
3737 /**
3738 * @brief Sort a sequence just enough to find a particular position
3739 * using a predicate for comparison.
3740 * @param first An iterator.
3741 * @param nth Another iterator.
3742 * @param last Another iterator.
3743 * @param comp A comparison functor.
3744 * @return Nothing.
3745 *
3746 * Rearranges the elements in the range @p [first,last) so that @p *nth
3747 * is the same element that would have been in that position had the
3748 * whole sequence been sorted. The elements either side of @p *nth are
3749 * not completely sorted, but for any iterator @i in the range
3750 * @p [first,nth) and any iterator @j in the range @p [nth,last) it
3751 * holds that @p comp(*j,*i) is false.
3752 */
3753 template<typename _RandomAccessIterator, typename _Compare>
3754 void
3755 nth_element(_RandomAccessIterator __first,
3756 _RandomAccessIterator __nth,
3757 _RandomAccessIterator __last,
3758 _Compare __comp)
3759 {
3760 typedef typename iterator_traits<_RandomAccessIterator>::value_type
3761 _ValueType;
3762
3763 // concept requirements
3764 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
3765 _RandomAccessIterator>)
3766 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3767 _ValueType, _ValueType>)
3768 __glibcxx_requires_valid_range(__first, __nth);
3769 __glibcxx_requires_valid_range(__nth, __last);
3770
3771 while (__last - __first > 3)
3772 {
3773 _RandomAccessIterator __cut =
3774 std::__unguarded_partition(__first, __last,
3775 _ValueType(std::__median(*__first,
3776 *(__first
3777 + (__last
3778 - __first)
3779 / 2),
3780 *(__last - 1),
3781 __comp)), __comp);
3782 if (__cut <= __nth)
3783 __first = __cut;
3784 else
3785 __last = __cut;
3786 }
3787 std::__insertion_sort(__first, __last, __comp);
3788 }
3789
3790 /**
3791 * @brief Finds the largest subrange in which @a val could be inserted
3792 * at any place in it without changing the ordering.
3793 * @param first An iterator.
3794 * @param last Another iterator.
3795 * @param val The search term.
3796 * @return An pair of iterators defining the subrange.
3797 * @ingroup binarysearch
3798 *
3799 * This is equivalent to
3800 * @code
3801 * std::make_pair(lower_bound(first, last, val),
3802 * upper_bound(first, last, val))
3803 * @endcode
3804 * but does not actually call those functions.
3805 */
3806 template<typename _ForwardIterator, typename _Tp>
3807 pair<_ForwardIterator, _ForwardIterator>
3808 equal_range(_ForwardIterator __first, _ForwardIterator __last,
3809 const _Tp& __val)
3810 {
3811 typedef typename iterator_traits<_ForwardIterator>::value_type
3812 _ValueType;
3813 typedef typename iterator_traits<_ForwardIterator>::difference_type
3814 _DistanceType;
3815
3816 // concept requirements
3817 // See comments on lower_bound.
3818 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3819 __glibcxx_function_requires(_SameTypeConcept<_Tp, _ValueType>)
3820 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
3821 __glibcxx_requires_partitioned(__first, __last, __val);
3822
3823 _DistanceType __len = std::distance(__first, __last);
3824 _DistanceType __half;
3825 _ForwardIterator __middle, __left, __right;
3826
3827 while (__len > 0)
3828 {
3829 __half = __len >> 1;
3830 __middle = __first;
3831 std::advance(__middle, __half);
3832 if (*__middle < __val)
3833 {
3834 __first = __middle;
3835 ++__first;
3836 __len = __len - __half - 1;
3837 }
3838 else if (__val < *__middle)
3839 __len = __half;
3840 else
3841 {
3842 __left = std::lower_bound(__first, __middle, __val);
3843 std::advance(__first, __len);
3844 __right = std::upper_bound(++__middle, __first, __val);
3845 return pair<_ForwardIterator, _ForwardIterator>(__left, __right);
3846 }
3847 }
3848 return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
3849 }
3850
3851 /**
3852 * @brief Finds the largest subrange in which @a val could be inserted
3853 * at any place in it without changing the ordering.
3854 * @param first An iterator.
3855 * @param last Another iterator.
3856 * @param val The search term.
3857 * @param comp A functor to use for comparisons.
3858 * @return An pair of iterators defining the subrange.
3859 * @ingroup binarysearch
3860 *
3861 * This is equivalent to
3862 * @code
3863 * std::make_pair(lower_bound(first, last, val, comp),
3864 * upper_bound(first, last, val, comp))
3865 * @endcode
3866 * but does not actually call those functions.
3867 */
3868 template<typename _ForwardIterator, typename _Tp, typename _Compare>
3869 pair<_ForwardIterator, _ForwardIterator>
3870 equal_range(_ForwardIterator __first, _ForwardIterator __last,
3871 const _Tp& __val,
3872 _Compare __comp)
3873 {
3874 typedef typename iterator_traits<_ForwardIterator>::value_type
3875 _ValueType;
3876 typedef typename iterator_traits<_ForwardIterator>::difference_type
3877 _DistanceType;
3878
3879 // concept requirements
3880 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3881 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3882 _ValueType, _Tp>)
3883 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3884 _Tp, _ValueType>)
3885 __glibcxx_requires_partitioned_pred(__first, __last, __val, __comp);
3886
3887 _DistanceType __len = std::distance(__first, __last);
3888 _DistanceType __half;
3889 _ForwardIterator __middle, __left, __right;
3890
3891 while (__len > 0)
3892 {
3893 __half = __len >> 1;
3894 __middle = __first;
3895 std::advance(__middle, __half);
3896 if (__comp(*__middle, __val))
3897 {
3898 __first = __middle;
3899 ++__first;
3900 __len = __len - __half - 1;
3901 }
3902 else if (__comp(__val, *__middle))
3903 __len = __half;
3904 else
3905 {
3906 __left = std::lower_bound(__first, __middle, __val, __comp);
3907 std::advance(__first, __len);
3908 __right = std::upper_bound(++__middle, __first, __val, __comp);
3909 return pair<_ForwardIterator, _ForwardIterator>(__left, __right);
3910 }
3911 }
3912 return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
3913 }
3914
3915 /**
3916 * @brief Determines whether an element exists in a range.
3917 * @param first An iterator.
3918 * @param last Another iterator.
3919 * @param val The search term.
3920 * @return True if @a val (or its equivelent) is in [@a first,@a last ].
3921 * @ingroup binarysearch
3922 *
3923 * Note that this does not actually return an iterator to @a val. For
3924 * that, use std::find or a container's specialized find member functions.
3925 */
3926 template<typename _ForwardIterator, typename _Tp>
3927 bool
3928 binary_search(_ForwardIterator __first, _ForwardIterator __last,
3929 const _Tp& __val)
3930 {
3931 // concept requirements
3932 // See comments on lower_bound.
3933 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3934 __glibcxx_function_requires(_SameTypeConcept<_Tp,
3935 typename iterator_traits<_ForwardIterator>::value_type>)
3936 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
3937 __glibcxx_requires_partitioned(__first, __last, __val);
3938
3939 _ForwardIterator __i = std::lower_bound(__first, __last, __val);
3940 return __i != __last && !(__val < *__i);
3941 }
3942
3943 /**
3944 * @brief Determines whether an element exists in a range.
3945 * @param first An iterator.
3946 * @param last Another iterator.
3947 * @param val The search term.
3948 * @param comp A functor to use for comparisons.
3949 * @return True if @a val (or its equivelent) is in [@a first,@a last ].
3950 * @ingroup binarysearch
3951 *
3952 * Note that this does not actually return an iterator to @a val. For
3953 * that, use std::find or a container's specialized find member functions.
3954 *
3955 * The comparison function should have the same effects on ordering as
3956 * the function used for the initial sort.
3957 */
3958 template<typename _ForwardIterator, typename _Tp, typename _Compare>
3959 bool
3960 binary_search(_ForwardIterator __first, _ForwardIterator __last,
3961 const _Tp& __val, _Compare __comp)
3962 {
3963 // concept requirements
3964 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
3965 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
3966 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
3967 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _Tp,
3968 typename iterator_traits<_ForwardIterator>::value_type>)
3969 __glibcxx_requires_partitioned_pred(__first, __last, __val, __comp);
3970
3971 _ForwardIterator __i = std::lower_bound(__first, __last, __val, __comp);
3972 return __i != __last && !__comp(__val, *__i);
3973 }
3974
3975 // Set algorithms: includes, set_union, set_intersection, set_difference,
3976 // set_symmetric_difference. All of these algorithms have the precondition
3977 // that their input ranges are sorted and the postcondition that their output
3978 // ranges are sorted.
3979
3980 /**
3981 * @brief Determines whether all elements of a sequence exists in a range.
3982 * @param first1 Start of search range.
3983 * @param last1 End of search range.
3984 * @param first2 Start of sequence
3985 * @param last2 End of sequence.
3986 * @return True if each element in [first2,last2) is contained in order
3987 * within [first1,last1). False otherwise.
3988 * @ingroup setoperations
3989 *
3990 * This operation expects both [first1,last1) and [first2,last2) to be
3991 * sorted. Searches for the presence of each element in [first2,last2)
3992 * within [first1,last1). The iterators over each range only move forward,
3993 * so this is a linear algorithm. If an element in [first2,last2) is not
3994 * found before the search iterator reaches @a last2, false is returned.
3995 */
3996 template<typename _InputIterator1, typename _InputIterator2>
3997 bool
3998 includes(_InputIterator1 __first1, _InputIterator1 __last1,
3999 _InputIterator2 __first2, _InputIterator2 __last2)
4000 {
4001 // concept requirements
4002 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4003 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4004 __glibcxx_function_requires(_SameTypeConcept<
4005 typename iterator_traits<_InputIterator1>::value_type,
4006 typename iterator_traits<_InputIterator2>::value_type>)
4007 __glibcxx_function_requires(_LessThanComparableConcept<
4008 typename iterator_traits<_InputIterator1>::value_type>)
4009 __glibcxx_requires_sorted(__first1, __last1);
4010 __glibcxx_requires_sorted(__first2, __last2);
4011
4012 while (__first1 != __last1 && __first2 != __last2)
4013 if (*__first2 < *__first1)
4014 return false;
4015 else if(*__first1 < *__first2)
4016 ++__first1;
4017 else
4018 ++__first1, ++__first2;
4019
4020 return __first2 == __last2;
4021 }
4022
4023 /**
4024 * @brief Determines whether all elements of a sequence exists in a range
4025 * using comparison.
4026 * @param first1 Start of search range.
4027 * @param last1 End of search range.
4028 * @param first2 Start of sequence
4029 * @param last2 End of sequence.
4030 * @param comp Comparison function to use.
4031 * @return True if each element in [first2,last2) is contained in order
4032 * within [first1,last1) according to comp. False otherwise.
4033 * @ingroup setoperations
4034 *
4035 * This operation expects both [first1,last1) and [first2,last2) to be
4036 * sorted. Searches for the presence of each element in [first2,last2)
4037 * within [first1,last1), using comp to decide. The iterators over each
4038 * range only move forward, so this is a linear algorithm. If an element
4039 * in [first2,last2) is not found before the search iterator reaches @a
4040 * last2, false is returned.
4041 */
4042 template<typename _InputIterator1, typename _InputIterator2,
4043 typename _Compare>
4044 bool
4045 includes(_InputIterator1 __first1, _InputIterator1 __last1,
4046 _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
4047 {
4048 // concept requirements
4049 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4050 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4051 __glibcxx_function_requires(_SameTypeConcept<
4052 typename iterator_traits<_InputIterator1>::value_type,
4053 typename iterator_traits<_InputIterator2>::value_type>)
4054 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4055 typename iterator_traits<_InputIterator1>::value_type,
4056 typename iterator_traits<_InputIterator2>::value_type>)
4057 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4058 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4059
4060 while (__first1 != __last1 && __first2 != __last2)
4061 if (__comp(*__first2, *__first1))
4062 return false;
4063 else if(__comp(*__first1, *__first2))
4064 ++__first1;
4065 else
4066 ++__first1, ++__first2;
4067
4068 return __first2 == __last2;
4069 }
4070
4071 /**
4072 * @brief Return the union of two sorted ranges.
4073 * @param first1 Start of first range.
4074 * @param last1 End of first range.
4075 * @param first2 Start of second range.
4076 * @param last2 End of second range.
4077 * @return End of the output range.
4078 * @ingroup setoperations
4079 *
4080 * This operation iterates over both ranges, copying elements present in
4081 * each range in order to the output range. Iterators increment for each
4082 * range. When the current element of one range is less than the other,
4083 * that element is copied and the iterator advanced. If an element is
4084 * contained in both ranges, the element from the first range is copied and
4085 * both ranges advance. The output range may not overlap either input
4086 * range.
4087 */
4088 template<typename _InputIterator1, typename _InputIterator2,
4089 typename _OutputIterator>
4090 _OutputIterator
4091 set_union(_InputIterator1 __first1, _InputIterator1 __last1,
4092 _InputIterator2 __first2, _InputIterator2 __last2,
4093 _OutputIterator __result)
4094 {
4095 // concept requirements
4096 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4097 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4098 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4099 typename iterator_traits<_InputIterator1>::value_type>)
4100 __glibcxx_function_requires(_SameTypeConcept<
4101 typename iterator_traits<_InputIterator1>::value_type,
4102 typename iterator_traits<_InputIterator2>::value_type>)
4103 __glibcxx_function_requires(_LessThanComparableConcept<
4104 typename iterator_traits<_InputIterator1>::value_type>)
4105 __glibcxx_requires_sorted(__first1, __last1);
4106 __glibcxx_requires_sorted(__first2, __last2);
4107
4108 while (__first1 != __last1 && __first2 != __last2)
4109 {
4110 if (*__first1 < *__first2)
4111 {
4112 *__result = *__first1;
4113 ++__first1;
4114 }
4115 else if (*__first2 < *__first1)
4116 {
4117 *__result = *__first2;
4118 ++__first2;
4119 }
4120 else
4121 {
4122 *__result = *__first1;
4123 ++__first1;
4124 ++__first2;
4125 }
4126 ++__result;
4127 }
4128 return std::copy(__first2, __last2, std::copy(__first1, __last1,
4129 __result));
4130 }
4131
4132 /**
4133 * @brief Return the union of two sorted ranges using a comparison functor.
4134 * @param first1 Start of first range.
4135 * @param last1 End of first range.
4136 * @param first2 Start of second range.
4137 * @param last2 End of second range.
4138 * @param comp The comparison functor.
4139 * @return End of the output range.
4140 * @ingroup setoperations
4141 *
4142 * This operation iterates over both ranges, copying elements present in
4143 * each range in order to the output range. Iterators increment for each
4144 * range. When the current element of one range is less than the other
4145 * according to @a comp, that element is copied and the iterator advanced.
4146 * If an equivalent element according to @a comp is contained in both
4147 * ranges, the element from the first range is copied and both ranges
4148 * advance. The output range may not overlap either input range.
4149 */
4150 template<typename _InputIterator1, typename _InputIterator2,
4151 typename _OutputIterator, typename _Compare>
4152 _OutputIterator
4153 set_union(_InputIterator1 __first1, _InputIterator1 __last1,
4154 _InputIterator2 __first2, _InputIterator2 __last2,
4155 _OutputIterator __result, _Compare __comp)
4156 {
4157 // concept requirements
4158 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4159 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4160 __glibcxx_function_requires(_SameTypeConcept<
4161 typename iterator_traits<_InputIterator1>::value_type,
4162 typename iterator_traits<_InputIterator2>::value_type>)
4163 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4164 typename iterator_traits<_InputIterator1>::value_type>)
4165 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4166 typename iterator_traits<_InputIterator1>::value_type,
4167 typename iterator_traits<_InputIterator2>::value_type>)
4168 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4169 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4170
4171 while (__first1 != __last1 && __first2 != __last2)
4172 {
4173 if (__comp(*__first1, *__first2))
4174 {
4175 *__result = *__first1;
4176 ++__first1;
4177 }
4178 else if (__comp(*__first2, *__first1))
4179 {
4180 *__result = *__first2;
4181 ++__first2;
4182 }
4183 else
4184 {
4185 *__result = *__first1;
4186 ++__first1;
4187 ++__first2;
4188 }
4189 ++__result;
4190 }
4191 return std::copy(__first2, __last2, std::copy(__first1, __last1,
4192 __result));
4193 }
4194
4195 /**
4196 * @brief Return the intersection of two sorted ranges.
4197 * @param first1 Start of first range.
4198 * @param last1 End of first range.
4199 * @param first2 Start of second range.
4200 * @param last2 End of second range.
4201 * @return End of the output range.
4202 * @ingroup setoperations
4203 *
4204 * This operation iterates over both ranges, copying elements present in
4205 * both ranges in order to the output range. Iterators increment for each
4206 * range. When the current element of one range is less than the other,
4207 * that iterator advances. If an element is contained in both ranges, the
4208 * element from the first range is copied and both ranges advance. The
4209 * output range may not overlap either input range.
4210 */
4211 template<typename _InputIterator1, typename _InputIterator2,
4212 typename _OutputIterator>
4213 _OutputIterator
4214 set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
4215 _InputIterator2 __first2, _InputIterator2 __last2,
4216 _OutputIterator __result)
4217 {
4218 // concept requirements
4219 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4220 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4221 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4222 typename iterator_traits<_InputIterator1>::value_type>)
4223 __glibcxx_function_requires(_SameTypeConcept<
4224 typename iterator_traits<_InputIterator1>::value_type,
4225 typename iterator_traits<_InputIterator2>::value_type>)
4226 __glibcxx_function_requires(_LessThanComparableConcept<
4227 typename iterator_traits<_InputIterator1>::value_type>)
4228 __glibcxx_requires_sorted(__first1, __last1);
4229 __glibcxx_requires_sorted(__first2, __last2);
4230
4231 while (__first1 != __last1 && __first2 != __last2)
4232 if (*__first1 < *__first2)
4233 ++__first1;
4234 else if (*__first2 < *__first1)
4235 ++__first2;
4236 else
4237 {
4238 *__result = *__first1;
4239 ++__first1;
4240 ++__first2;
4241 ++__result;
4242 }
4243 return __result;
4244 }
4245
4246 /**
4247 * @brief Return the intersection of two sorted ranges using comparison
4248 * functor.
4249 * @param first1 Start of first range.
4250 * @param last1 End of first range.
4251 * @param first2 Start of second range.
4252 * @param last2 End of second range.
4253 * @param comp The comparison functor.
4254 * @return End of the output range.
4255 * @ingroup setoperations
4256 *
4257 * This operation iterates over both ranges, copying elements present in
4258 * both ranges in order to the output range. Iterators increment for each
4259 * range. When the current element of one range is less than the other
4260 * according to @a comp, that iterator advances. If an element is
4261 * contained in both ranges according to @a comp, the element from the
4262 * first range is copied and both ranges advance. The output range may not
4263 * overlap either input range.
4264 */
4265 template<typename _InputIterator1, typename _InputIterator2,
4266 typename _OutputIterator, typename _Compare>
4267 _OutputIterator
4268 set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
4269 _InputIterator2 __first2, _InputIterator2 __last2,
4270 _OutputIterator __result, _Compare __comp)
4271 {
4272 // concept requirements
4273 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4274 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4275 __glibcxx_function_requires(_SameTypeConcept<
4276 typename iterator_traits<_InputIterator1>::value_type,
4277 typename iterator_traits<_InputIterator2>::value_type>)
4278 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4279 typename iterator_traits<_InputIterator1>::value_type>)
4280 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4281 typename iterator_traits<_InputIterator1>::value_type,
4282 typename iterator_traits<_InputIterator2>::value_type>)
4283 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4284 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4285
4286 while (__first1 != __last1 && __first2 != __last2)
4287 if (__comp(*__first1, *__first2))
4288 ++__first1;
4289 else if (__comp(*__first2, *__first1))
4290 ++__first2;
4291 else
4292 {
4293 *__result = *__first1;
4294 ++__first1;
4295 ++__first2;
4296 ++__result;
4297 }
4298 return __result;
4299 }
4300
4301 /**
4302 * @brief Return the difference of two sorted ranges.
4303 * @param first1 Start of first range.
4304 * @param last1 End of first range.
4305 * @param first2 Start of second range.
4306 * @param last2 End of second range.
4307 * @return End of the output range.
4308 * @ingroup setoperations
4309 *
4310 * This operation iterates over both ranges, copying elements present in
4311 * the first range but not the second in order to the output range.
4312 * Iterators increment for each range. When the current element of the
4313 * first range is less than the second, that element is copied and the
4314 * iterator advances. If the current element of the second range is less,
4315 * the iterator advances, but no element is copied. If an element is
4316 * contained in both ranges, no elements are copied and both ranges
4317 * advance. The output range may not overlap either input range.
4318 */
4319 template<typename _InputIterator1, typename _InputIterator2,
4320 typename _OutputIterator>
4321 _OutputIterator
4322 set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
4323 _InputIterator2 __first2, _InputIterator2 __last2,
4324 _OutputIterator __result)
4325 {
4326 // concept requirements
4327 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4328 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4329 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4330 typename iterator_traits<_InputIterator1>::value_type>)
4331 __glibcxx_function_requires(_SameTypeConcept<
4332 typename iterator_traits<_InputIterator1>::value_type,
4333 typename iterator_traits<_InputIterator2>::value_type>)
4334 __glibcxx_function_requires(_LessThanComparableConcept<
4335 typename iterator_traits<_InputIterator1>::value_type>)
4336 __glibcxx_requires_sorted(__first1, __last1);
4337 __glibcxx_requires_sorted(__first2, __last2);
4338
4339 while (__first1 != __last1 && __first2 != __last2)
4340 if (*__first1 < *__first2)
4341 {
4342 *__result = *__first1;
4343 ++__first1;
4344 ++__result;
4345 }
4346 else if (*__first2 < *__first1)
4347 ++__first2;
4348 else
4349 {
4350 ++__first1;
4351 ++__first2;
4352 }
4353 return std::copy(__first1, __last1, __result);
4354 }
4355
4356 /**
4357 * @brief Return the difference of two sorted ranges using comparison
4358 * functor.
4359 * @param first1 Start of first range.
4360 * @param last1 End of first range.
4361 * @param first2 Start of second range.
4362 * @param last2 End of second range.
4363 * @param comp The comparison functor.
4364 * @return End of the output range.
4365 * @ingroup setoperations
4366 *
4367 * This operation iterates over both ranges, copying elements present in
4368 * the first range but not the second in order to the output range.
4369 * Iterators increment for each range. When the current element of the
4370 * first range is less than the second according to @a comp, that element
4371 * is copied and the iterator advances. If the current element of the
4372 * second range is less, no element is copied and the iterator advances.
4373 * If an element is contained in both ranges according to @a comp, no
4374 * elements are copied and both ranges advance. The output range may not
4375 * overlap either input range.
4376 */
4377 template<typename _InputIterator1, typename _InputIterator2,
4378 typename _OutputIterator, typename _Compare>
4379 _OutputIterator
4380 set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
4381 _InputIterator2 __first2, _InputIterator2 __last2,
4382 _OutputIterator __result, _Compare __comp)
4383 {
4384 // concept requirements
4385 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4386 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4387 __glibcxx_function_requires(_SameTypeConcept<
4388 typename iterator_traits<_InputIterator1>::value_type,
4389 typename iterator_traits<_InputIterator2>::value_type>)
4390 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4391 typename iterator_traits<_InputIterator1>::value_type>)
4392 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4393 typename iterator_traits<_InputIterator1>::value_type,
4394 typename iterator_traits<_InputIterator2>::value_type>)
4395 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4396 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4397
4398 while (__first1 != __last1 && __first2 != __last2)
4399 if (__comp(*__first1, *__first2))
4400 {
4401 *__result = *__first1;
4402 ++__first1;
4403 ++__result;
4404 }
4405 else if (__comp(*__first2, *__first1))
4406 ++__first2;
4407 else
4408 {
4409 ++__first1;
4410 ++__first2;
4411 }
4412 return std::copy(__first1, __last1, __result);
4413 }
4414
4415 /**
4416 * @brief Return the symmetric difference of two sorted ranges.
4417 * @param first1 Start of first range.
4418 * @param last1 End of first range.
4419 * @param first2 Start of second range.
4420 * @param last2 End of second range.
4421 * @return End of the output range.
4422 * @ingroup setoperations
4423 *
4424 * This operation iterates over both ranges, copying elements present in
4425 * one range but not the other in order to the output range. Iterators
4426 * increment for each range. When the current element of one range is less
4427 * than the other, that element is copied and the iterator advances. If an
4428 * element is contained in both ranges, no elements are copied and both
4429 * ranges advance. The output range may not overlap either input range.
4430 */
4431 template<typename _InputIterator1, typename _InputIterator2,
4432 typename _OutputIterator>
4433 _OutputIterator
4434 set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
4435 _InputIterator2 __first2, _InputIterator2 __last2,
4436 _OutputIterator __result)
4437 {
4438 // concept requirements
4439 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4440 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4441 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4442 typename iterator_traits<_InputIterator1>::value_type>)
4443 __glibcxx_function_requires(_SameTypeConcept<
4444 typename iterator_traits<_InputIterator1>::value_type,
4445 typename iterator_traits<_InputIterator2>::value_type>)
4446 __glibcxx_function_requires(_LessThanComparableConcept<
4447 typename iterator_traits<_InputIterator1>::value_type>)
4448 __glibcxx_requires_sorted(__first1, __last1);
4449 __glibcxx_requires_sorted(__first2, __last2);
4450
4451 while (__first1 != __last1 && __first2 != __last2)
4452 if (*__first1 < *__first2)
4453 {
4454 *__result = *__first1;
4455 ++__first1;
4456 ++__result;
4457 }
4458 else if (*__first2 < *__first1)
4459 {
4460 *__result = *__first2;
4461 ++__first2;
4462 ++__result;
4463 }
4464 else
4465 {
4466 ++__first1;
4467 ++__first2;
4468 }
4469 return std::copy(__first2, __last2, std::copy(__first1,
4470 __last1, __result));
4471 }
4472
4473 /**
4474 * @brief Return the symmetric difference of two sorted ranges using
4475 * comparison functor.
4476 * @param first1 Start of first range.
4477 * @param last1 End of first range.
4478 * @param first2 Start of second range.
4479 * @param last2 End of second range.
4480 * @param comp The comparison functor.
4481 * @return End of the output range.
4482 * @ingroup setoperations
4483 *
4484 * This operation iterates over both ranges, copying elements present in
4485 * one range but not the other in order to the output range. Iterators
4486 * increment for each range. When the current element of one range is less
4487 * than the other according to @a comp, that element is copied and the
4488 * iterator advances. If an element is contained in both ranges according
4489 * to @a comp, no elements are copied and both ranges advance. The output
4490 * range may not overlap either input range.
4491 */
4492 template<typename _InputIterator1, typename _InputIterator2,
4493 typename _OutputIterator, typename _Compare>
4494 _OutputIterator
4495 set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
4496 _InputIterator2 __first2, _InputIterator2 __last2,
4497 _OutputIterator __result,
4498 _Compare __comp)
4499 {
4500 // concept requirements
4501 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
4502 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
4503 __glibcxx_function_requires(_SameTypeConcept<
4504 typename iterator_traits<_InputIterator1>::value_type,
4505 typename iterator_traits<_InputIterator2>::value_type>)
4506 __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
4507 typename iterator_traits<_InputIterator1>::value_type>)
4508 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4509 typename iterator_traits<_InputIterator1>::value_type,
4510 typename iterator_traits<_InputIterator2>::value_type>)
4511 __glibcxx_requires_sorted_pred(__first1, __last1, __comp);
4512 __glibcxx_requires_sorted_pred(__first2, __last2, __comp);
4513
4514 while (__first1 != __last1 && __first2 != __last2)
4515 if (__comp(*__first1, *__first2))
4516 {
4517 *__result = *__first1;
4518 ++__first1;
4519 ++__result;
4520 }
4521 else if (__comp(*__first2, *__first1))
4522 {
4523 *__result = *__first2;
4524 ++__first2;
4525 ++__result;
4526 }
4527 else
4528 {
4529 ++__first1;
4530 ++__first2;
4531 }
4532 return std::copy(__first2, __last2, std::copy(__first1,
4533 __last1, __result));
4534 }
4535
4536 // min_element and max_element, with and without an explicitly supplied
4537 // comparison function.
4538
4539 /**
4540 * @brief Return the maximum element in a range.
4541 * @param first Start of range.
4542 * @param last End of range.
4543 * @return Iterator referencing the first instance of the largest value.
4544 */
4545 template<typename _ForwardIterator>
4546 _ForwardIterator
4547 max_element(_ForwardIterator __first, _ForwardIterator __last)
4548 {
4549 // concept requirements
4550 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4551 __glibcxx_function_requires(_LessThanComparableConcept<
4552 typename iterator_traits<_ForwardIterator>::value_type>)
4553 __glibcxx_requires_valid_range(__first, __last);
4554
4555 if (__first == __last)
4556 return __first;
4557 _ForwardIterator __result = __first;
4558 while (++__first != __last)
4559 if (*__result < *__first)
4560 __result = __first;
4561 return __result;
4562 }
4563
4564 /**
4565 * @brief Return the maximum element in a range using comparison functor.
4566 * @param first Start of range.
4567 * @param last End of range.
4568 * @param comp Comparison functor.
4569 * @return Iterator referencing the first instance of the largest value
4570 * according to comp.
4571 */
4572 template<typename _ForwardIterator, typename _Compare>
4573 _ForwardIterator
4574 max_element(_ForwardIterator __first, _ForwardIterator __last,
4575 _Compare __comp)
4576 {
4577 // concept requirements
4578 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4579 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4580 typename iterator_traits<_ForwardIterator>::value_type,
4581 typename iterator_traits<_ForwardIterator>::value_type>)
4582 __glibcxx_requires_valid_range(__first, __last);
4583
4584 if (__first == __last) return __first;
4585 _ForwardIterator __result = __first;
4586 while (++__first != __last)
4587 if (__comp(*__result, *__first)) __result = __first;
4588 return __result;
4589 }
4590
4591 /**
4592 * @brief Return the minimum element in a range.
4593 * @param first Start of range.
4594 * @param last End of range.
4595 * @return Iterator referencing the first instance of the smallest value.
4596 */
4597 template<typename _ForwardIterator>
4598 _ForwardIterator
4599 min_element(_ForwardIterator __first, _ForwardIterator __last)
4600 {
4601 // concept requirements
4602 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4603 __glibcxx_function_requires(_LessThanComparableConcept<
4604 typename iterator_traits<_ForwardIterator>::value_type>)
4605 __glibcxx_requires_valid_range(__first, __last);
4606
4607 if (__first == __last)
4608 return __first;
4609 _ForwardIterator __result = __first;
4610 while (++__first != __last)
4611 if (*__first < *__result)
4612 __result = __first;
4613 return __result;
4614 }
4615
4616 /**
4617 * @brief Return the minimum element in a range using comparison functor.
4618 * @param first Start of range.
4619 * @param last End of range.
4620 * @param comp Comparison functor.
4621 * @return Iterator referencing the first instance of the smallest value
4622 * according to comp.
4623 */
4624 template<typename _ForwardIterator, typename _Compare>
4625 _ForwardIterator
4626 min_element(_ForwardIterator __first, _ForwardIterator __last,
4627 _Compare __comp)
4628 {
4629 // concept requirements
4630 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4631 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4632 typename iterator_traits<_ForwardIterator>::value_type,
4633 typename iterator_traits<_ForwardIterator>::value_type>)
4634 __glibcxx_requires_valid_range(__first, __last);
4635
4636 if (__first == __last)
4637 return __first;
4638 _ForwardIterator __result = __first;
4639 while (++__first != __last)
4640 if (__comp(*__first, *__result))
4641 __result = __first;
4642 return __result;
4643 }
4644
4645 // next_permutation and prev_permutation, with and without an explicitly
4646 // supplied comparison function.
4647
4648 /**
4649 * @brief Permute range into the next "dictionary" ordering.
4650 * @param first Start of range.
4651 * @param last End of range.
4652 * @return False if wrapped to first permutation, true otherwise.
4653 *
4654 * Treats all permutations of the range as a set of "dictionary" sorted
4655 * sequences. Permutes the current sequence into the next one of this set.
4656 * Returns true if there are more sequences to generate. If the sequence
4657 * is the largest of the set, the smallest is generated and false returned.
4658 */
4659 template<typename _BidirectionalIterator>
4660 bool
4661 next_permutation(_BidirectionalIterator __first,
4662 _BidirectionalIterator __last)
4663 {
4664 // concept requirements
4665 __glibcxx_function_requires(_BidirectionalIteratorConcept<
4666 _BidirectionalIterator>)
4667 __glibcxx_function_requires(_LessThanComparableConcept<
4668 typename iterator_traits<_BidirectionalIterator>::value_type>)
4669 __glibcxx_requires_valid_range(__first, __last);
4670
4671 if (__first == __last)
4672 return false;
4673 _BidirectionalIterator __i = __first;
4674 ++__i;
4675 if (__i == __last)
4676 return false;
4677 __i = __last;
4678 --__i;
4679
4680 for(;;)
4681 {
4682 _BidirectionalIterator __ii = __i;
4683 --__i;
4684 if (*__i < *__ii)
4685 {
4686 _BidirectionalIterator __j = __last;
4687 while (!(*__i < *--__j))
4688 {}
4689 std::iter_swap(__i, __j);
4690 std::reverse(__ii, __last);
4691 return true;
4692 }
4693 if (__i == __first)
4694 {
4695 std::reverse(__first, __last);
4696 return false;
4697 }
4698 }
4699 }
4700
4701 /**
4702 * @brief Permute range into the next "dictionary" ordering using
4703 * comparison functor.
4704 * @param first Start of range.
4705 * @param last End of range.
4706 * @param comp
4707 * @return False if wrapped to first permutation, true otherwise.
4708 *
4709 * Treats all permutations of the range [first,last) as a set of
4710 * "dictionary" sorted sequences ordered by @a comp. Permutes the current
4711 * sequence into the next one of this set. Returns true if there are more
4712 * sequences to generate. If the sequence is the largest of the set, the
4713 * smallest is generated and false returned.
4714 */
4715 template<typename _BidirectionalIterator, typename _Compare>
4716 bool
4717 next_permutation(_BidirectionalIterator __first,
4718 _BidirectionalIterator __last, _Compare __comp)
4719 {
4720 // concept requirements
4721 __glibcxx_function_requires(_BidirectionalIteratorConcept<
4722 _BidirectionalIterator>)
4723 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4724 typename iterator_traits<_BidirectionalIterator>::value_type,
4725 typename iterator_traits<_BidirectionalIterator>::value_type>)
4726 __glibcxx_requires_valid_range(__first, __last);
4727
4728 if (__first == __last)
4729 return false;
4730 _BidirectionalIterator __i = __first;
4731 ++__i;
4732 if (__i == __last)
4733 return false;
4734 __i = __last;
4735 --__i;
4736
4737 for(;;)
4738 {
4739 _BidirectionalIterator __ii = __i;
4740 --__i;
4741 if (__comp(*__i, *__ii))
4742 {
4743 _BidirectionalIterator __j = __last;
4744 while (!__comp(*__i, *--__j))
4745 {}
4746 std::iter_swap(__i, __j);
4747 std::reverse(__ii, __last);
4748 return true;
4749 }
4750 if (__i == __first)
4751 {
4752 std::reverse(__first, __last);
4753 return false;
4754 }
4755 }
4756 }
4757
4758 /**
4759 * @brief Permute range into the previous "dictionary" ordering.
4760 * @param first Start of range.
4761 * @param last End of range.
4762 * @return False if wrapped to last permutation, true otherwise.
4763 *
4764 * Treats all permutations of the range as a set of "dictionary" sorted
4765 * sequences. Permutes the current sequence into the previous one of this
4766 * set. Returns true if there are more sequences to generate. If the
4767 * sequence is the smallest of the set, the largest is generated and false
4768 * returned.
4769 */
4770 template<typename _BidirectionalIterator>
4771 bool
4772 prev_permutation(_BidirectionalIterator __first,
4773 _BidirectionalIterator __last)
4774 {
4775 // concept requirements
4776 __glibcxx_function_requires(_BidirectionalIteratorConcept<
4777 _BidirectionalIterator>)
4778 __glibcxx_function_requires(_LessThanComparableConcept<
4779 typename iterator_traits<_BidirectionalIterator>::value_type>)
4780 __glibcxx_requires_valid_range(__first, __last);
4781
4782 if (__first == __last)
4783 return false;
4784 _BidirectionalIterator __i = __first;
4785 ++__i;
4786 if (__i == __last)
4787 return false;
4788 __i = __last;
4789 --__i;
4790
4791 for(;;)
4792 {
4793 _BidirectionalIterator __ii = __i;
4794 --__i;
4795 if (*__ii < *__i)
4796 {
4797 _BidirectionalIterator __j = __last;
4798 while (!(*--__j < *__i))
4799 {}
4800 std::iter_swap(__i, __j);
4801 std::reverse(__ii, __last);
4802 return true;
4803 }
4804 if (__i == __first)
4805 {
4806 std::reverse(__first, __last);
4807 return false;
4808 }
4809 }
4810 }
4811
4812 /**
4813 * @brief Permute range into the previous "dictionary" ordering using
4814 * comparison functor.
4815 * @param first Start of range.
4816 * @param last End of range.
4817 * @param comp
4818 * @return False if wrapped to last permutation, true otherwise.
4819 *
4820 * Treats all permutations of the range [first,last) as a set of
4821 * "dictionary" sorted sequences ordered by @a comp. Permutes the current
4822 * sequence into the previous one of this set. Returns true if there are
4823 * more sequences to generate. If the sequence is the smallest of the set,
4824 * the largest is generated and false returned.
4825 */
4826 template<typename _BidirectionalIterator, typename _Compare>
4827 bool
4828 prev_permutation(_BidirectionalIterator __first,
4829 _BidirectionalIterator __last, _Compare __comp)
4830 {
4831 // concept requirements
4832 __glibcxx_function_requires(_BidirectionalIteratorConcept<
4833 _BidirectionalIterator>)
4834 __glibcxx_function_requires(_BinaryPredicateConcept<_Compare,
4835 typename iterator_traits<_BidirectionalIterator>::value_type,
4836 typename iterator_traits<_BidirectionalIterator>::value_type>)
4837 __glibcxx_requires_valid_range(__first, __last);
4838
4839 if (__first == __last)
4840 return false;
4841 _BidirectionalIterator __i = __first;
4842 ++__i;
4843 if (__i == __last)
4844 return false;
4845 __i = __last;
4846 --__i;
4847
4848 for(;;)
4849 {
4850 _BidirectionalIterator __ii = __i;
4851 --__i;
4852 if (__comp(*__ii, *__i))
4853 {
4854 _BidirectionalIterator __j = __last;
4855 while (!__comp(*--__j, *__i))
4856 {}
4857 std::iter_swap(__i, __j);
4858 std::reverse(__ii, __last);
4859 return true;
4860 }
4861 if (__i == __first)
4862 {
4863 std::reverse(__first, __last);
4864 return false;
4865 }
4866 }
4867 }
4868
4869 // find_first_of, with and without an explicitly supplied comparison function.
4870
4871 /**
4872 * @brief Find element from a set in a sequence.
4873 * @param first1 Start of range to search.
4874 * @param last1 End of range to search.
4875 * @param first2 Start of match candidates.
4876 * @param last2 End of match candidates.
4877 * @return The first iterator @c i in the range
4878 * @p [first1,last1) such that @c *i == @p *(i2) such that i2 is an
4879 * interator in [first2,last2), or @p last1 if no such iterator exists.
4880 *
4881 * Searches the range @p [first1,last1) for an element that is equal to
4882 * some element in the range [first2,last2). If found, returns an iterator
4883 * in the range [first1,last1), otherwise returns @p last1.
4884 */
4885 template<typename _InputIterator, typename _ForwardIterator>
4886 _InputIterator
4887 find_first_of(_InputIterator __first1, _InputIterator __last1,
4888 _ForwardIterator __first2, _ForwardIterator __last2)
4889 {
4890 // concept requirements
4891 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4892 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4893 __glibcxx_function_requires(_EqualOpConcept<
4894 typename iterator_traits<_InputIterator>::value_type,
4895 typename iterator_traits<_ForwardIterator>::value_type>)
4896 __glibcxx_requires_valid_range(__first1, __last1);
4897 __glibcxx_requires_valid_range(__first2, __last2);
4898
4899 for ( ; __first1 != __last1; ++__first1)
4900 for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter)
4901 if (*__first1 == *__iter)
4902 return __first1;
4903 return __last1;
4904 }
4905
4906 /**
4907 * @brief Find element from a set in a sequence using a predicate.
4908 * @param first1 Start of range to search.
4909 * @param last1 End of range to search.
4910 * @param first2 Start of match candidates.
4911 * @param last2 End of match candidates.
4912 * @param comp Predicate to use.
4913 * @return The first iterator @c i in the range
4914 * @p [first1,last1) such that @c comp(*i, @p *(i2)) is true and i2 is an
4915 * interator in [first2,last2), or @p last1 if no such iterator exists.
4916 *
4917 * Searches the range @p [first1,last1) for an element that is equal to
4918 * some element in the range [first2,last2). If found, returns an iterator in
4919 * the range [first1,last1), otherwise returns @p last1.
4920 */
4921 template<typename _InputIterator, typename _ForwardIterator,
4922 typename _BinaryPredicate>
4923 _InputIterator
4924 find_first_of(_InputIterator __first1, _InputIterator __last1,
4925 _ForwardIterator __first2, _ForwardIterator __last2,
4926 _BinaryPredicate __comp)
4927 {
4928 // concept requirements
4929 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
4930 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
4931 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
4932 typename iterator_traits<_InputIterator>::value_type,
4933 typename iterator_traits<_ForwardIterator>::value_type>)
4934 __glibcxx_requires_valid_range(__first1, __last1);
4935 __glibcxx_requires_valid_range(__first2, __last2);
4936
4937 for ( ; __first1 != __last1; ++__first1)
4938 for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter)
4939 if (__comp(*__first1, *__iter))
4940 return __first1;
4941 return __last1;
4942 }
4943
4944
4945 // find_end, with and without an explicitly supplied comparison function.
4946 // Search [first2, last2) as a subsequence in [first1, last1), and return
4947 // the *last* possible match. Note that find_end for bidirectional iterators
4948 // is much faster than for forward iterators.
4949
4950 // find_end for forward iterators.
4951 template<typename _ForwardIterator1, typename _ForwardIterator2>
4952 _ForwardIterator1
4953 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4954 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
4955 forward_iterator_tag, forward_iterator_tag)
4956 {
4957 if (__first2 == __last2)
4958 return __last1;
4959 else
4960 {
4961 _ForwardIterator1 __result = __last1;
4962 while (1)
4963 {
4964 _ForwardIterator1 __new_result
4965 = std::search(__first1, __last1, __first2, __last2);
4966 if (__new_result == __last1)
4967 return __result;
4968 else
4969 {
4970 __result = __new_result;
4971 __first1 = __new_result;
4972 ++__first1;
4973 }
4974 }
4975 }
4976 }
4977
4978 template<typename _ForwardIterator1, typename _ForwardIterator2,
4979 typename _BinaryPredicate>
4980 _ForwardIterator1
4981 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
4982 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
4983 forward_iterator_tag, forward_iterator_tag,
4984 _BinaryPredicate __comp)
4985 {
4986 if (__first2 == __last2)
4987 return __last1;
4988 else
4989 {
4990 _ForwardIterator1 __result = __last1;
4991 while (1)
4992 {
4993 _ForwardIterator1 __new_result
4994 = std::search(__first1, __last1, __first2, __last2, __comp);
4995 if (__new_result == __last1)
4996 return __result;
4997 else
4998 {
4999 __result = __new_result;
5000 __first1 = __new_result;
5001 ++__first1;
5002 }
5003 }
5004 }
5005 }
5006
5007 // find_end for bidirectional iterators. Requires partial specialization.
5008 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2>
5009 _BidirectionalIterator1
5010 __find_end(_BidirectionalIterator1 __first1,
5011 _BidirectionalIterator1 __last1,
5012 _BidirectionalIterator2 __first2,
5013 _BidirectionalIterator2 __last2,
5014 bidirectional_iterator_tag, bidirectional_iterator_tag)
5015 {
5016 // concept requirements
5017 __glibcxx_function_requires(_BidirectionalIteratorConcept<
5018 _BidirectionalIterator1>)
5019 __glibcxx_function_requires(_BidirectionalIteratorConcept<
5020 _BidirectionalIterator2>)
5021
5022 typedef reverse_iterator<_BidirectionalIterator1> _RevIterator1;
5023 typedef reverse_iterator<_BidirectionalIterator2> _RevIterator2;
5024
5025 _RevIterator1 __rlast1(__first1);
5026 _RevIterator2 __rlast2(__first2);
5027 _RevIterator1 __rresult = std::search(_RevIterator1(__last1), __rlast1,
5028 _RevIterator2(__last2), __rlast2);
5029
5030 if (__rresult == __rlast1)
5031 return __last1;
5032 else
5033 {
5034 _BidirectionalIterator1 __result = __rresult.base();
5035 std::advance(__result, -std::distance(__first2, __last2));
5036 return __result;
5037 }
5038 }
5039
5040 template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
5041 typename _BinaryPredicate>
5042 _BidirectionalIterator1
5043 __find_end(_BidirectionalIterator1 __first1,
5044 _BidirectionalIterator1 __last1,
5045 _BidirectionalIterator2 __first2,
5046 _BidirectionalIterator2 __last2,
5047 bidirectional_iterator_tag, bidirectional_iterator_tag,
5048 _BinaryPredicate __comp)
5049 {
5050 // concept requirements
5051 __glibcxx_function_requires(_BidirectionalIteratorConcept<
5052 _BidirectionalIterator1>)
5053 __glibcxx_function_requires(_BidirectionalIteratorConcept<
5054 _BidirectionalIterator2>)
5055
5056 typedef reverse_iterator<_BidirectionalIterator1> _RevIterator1;
5057 typedef reverse_iterator<_BidirectionalIterator2> _RevIterator2;
5058
5059 _RevIterator1 __rlast1(__first1);
5060 _RevIterator2 __rlast2(__first2);
5061 _RevIterator1 __rresult = std::search(_RevIterator1(__last1), __rlast1,
5062 _RevIterator2(__last2), __rlast2,
5063 __comp);
5064
5065 if (__rresult == __rlast1)
5066 return __last1;
5067 else
5068 {
5069 _BidirectionalIterator1 __result = __rresult.base();
5070 std::advance(__result, -std::distance(__first2, __last2));
5071 return __result;
5072 }
5073 }
5074
5075 // Dispatching functions for find_end.
5076
5077 /**
5078 * @brief Find last matching subsequence in a sequence.
5079 * @param first1 Start of range to search.
5080 * @param last1 End of range to search.
5081 * @param first2 Start of sequence to match.
5082 * @param last2 End of sequence to match.
5083 * @return The last iterator @c i in the range
5084 * @p [first1,last1-(last2-first2)) such that @c *(i+N) == @p *(first2+N)
5085 * for each @c N in the range @p [0,last2-first2), or @p last1 if no
5086 * such iterator exists.
5087 *
5088 * Searches the range @p [first1,last1) for a sub-sequence that compares
5089 * equal value-by-value with the sequence given by @p [first2,last2) and
5090 * returns an iterator to the first element of the sub-sequence, or
5091 * @p last1 if the sub-sequence is not found. The sub-sequence will be the
5092 * last such subsequence contained in [first,last1).
5093 *
5094 * Because the sub-sequence must lie completely within the range
5095 * @p [first1,last1) it must start at a position less than
5096 * @p last1-(last2-first2) where @p last2-first2 is the length of the
5097 * sub-sequence.
5098 * This means that the returned iterator @c i will be in the range
5099 * @p [first1,last1-(last2-first2))
5100 */
5101 template<typename _ForwardIterator1, typename _ForwardIterator2>
5102 inline _ForwardIterator1
5103 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
5104 _ForwardIterator2 __first2, _ForwardIterator2 __last2)
5105 {
5106 // concept requirements
5107 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
5108 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
5109 __glibcxx_function_requires(_EqualOpConcept<
5110 typename iterator_traits<_ForwardIterator1>::value_type,
5111 typename iterator_traits<_ForwardIterator2>::value_type>)
5112 __glibcxx_requires_valid_range(__first1, __last1);
5113 __glibcxx_requires_valid_range(__first2, __last2);
5114
5115 return std::__find_end(__first1, __last1, __first2, __last2,
5116 std::__iterator_category(__first1),
5117 std::__iterator_category(__first2));
5118 }
5119
5120 /**
5121 * @brief Find last matching subsequence in a sequence using a predicate.
5122 * @param first1 Start of range to search.
5123 * @param last1 End of range to search.
5124 * @param first2 Start of sequence to match.
5125 * @param last2 End of sequence to match.
5126 * @param comp The predicate to use.
5127 * @return The last iterator @c i in the range
5128 * @p [first1,last1-(last2-first2)) such that @c predicate(*(i+N), @p
5129 * (first2+N)) is true for each @c N in the range @p [0,last2-first2), or
5130 * @p last1 if no such iterator exists.
5131 *
5132 * Searches the range @p [first1,last1) for a sub-sequence that compares
5133 * equal value-by-value with the sequence given by @p [first2,last2) using
5134 * comp as a predicate and returns an iterator to the first element of the
5135 * sub-sequence, or @p last1 if the sub-sequence is not found. The
5136 * sub-sequence will be the last such subsequence contained in
5137 * [first,last1).
5138 *
5139 * Because the sub-sequence must lie completely within the range
5140 * @p [first1,last1) it must start at a position less than
5141 * @p last1-(last2-first2) where @p last2-first2 is the length of the
5142 * sub-sequence.
5143 * This means that the returned iterator @c i will be in the range
5144 * @p [first1,last1-(last2-first2))
5145 */
5146 template<typename _ForwardIterator1, typename _ForwardIterator2,
5147 typename _BinaryPredicate>
5148 inline _ForwardIterator1
5149 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
5150 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
5151 _BinaryPredicate __comp)
5152 {
5153 // concept requirements
5154 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
5155 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
5156 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
5157 typename iterator_traits<_ForwardIterator1>::value_type,
5158 typename iterator_traits<_ForwardIterator2>::value_type>)
5159 __glibcxx_requires_valid_range(__first1, __last1);
5160 __glibcxx_requires_valid_range(__first2, __last2);
5161
5162 return std::__find_end(__first1, __last1, __first2, __last2,
5163 std::__iterator_category(__first1),
5164 std::__iterator_category(__first2),
5165 __comp);
5166 }
5167
5168 } // namespace std
5169
5170 #endif /* _ALGO_H */