1// Core algorithmic facilities -*- C++ -*-
2
3// Copyright (C) 2001-2017 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996-1998
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_algobase.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{algorithm}
54 */
55
56#ifndef _STL_ALGOBASE_H
57#define _STL_ALGOBASE_H 1
58
59#include <bits/c++config.h>
60#include <bits/functexcept.h>
61#include <bits/cpp_type_traits.h>
62#include <ext/type_traits.h>
63#include <ext/numeric_traits.h>
64#include <bits/stl_pair.h>
65#include <bits/stl_iterator_base_types.h>
66#include <bits/stl_iterator_base_funcs.h>
67#include <bits/stl_iterator.h>
68#include <bits/concept_check.h>
69#include <debug/debug.h>
70#include <bits/move.h> // For std::swap
71#include <bits/predefined_ops.h>
72
73namespace std _GLIBCXX_VISIBILITY(default)
74{
75_GLIBCXX_BEGIN_NAMESPACE_VERSION
76
77#if __cplusplus < 201103L
78 // See http://gcc.gnu.org/ml/libstdc++/2004-08/msg00167.html: in a
79 // nutshell, we are partially implementing the resolution of DR 187,
80 // when it's safe, i.e., the value_types are equal.
81 template<bool _BoolType>
82 struct __iter_swap
83 {
84 template<typename _ForwardIterator1, typename _ForwardIterator2>
85 static void
86 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
87 {
88 typedef typename iterator_traits<_ForwardIterator1>::value_type
89 _ValueType1;
90 _ValueType1 __tmp = *__a;
91 *__a = *__b;
92 *__b = __tmp;
93 }
94 };
95
96 template<>
97 struct __iter_swap<true>
98 {
99 template<typename _ForwardIterator1, typename _ForwardIterator2>
100 static void
101 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
102 {
103 swap(*__a, *__b);
104 }
105 };
106#endif
107
108 /**
109 * @brief Swaps the contents of two iterators.
110 * @ingroup mutating_algorithms
111 * @param __a An iterator.
112 * @param __b Another iterator.
113 * @return Nothing.
114 *
115 * This function swaps the values pointed to by two iterators, not the
116 * iterators themselves.
117 */
118 template<typename _ForwardIterator1, typename _ForwardIterator2>
119 inline void
120 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
121 {
122 // concept requirements
123 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
124 _ForwardIterator1>)
125 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
126 _ForwardIterator2>)
127
128#if __cplusplus < 201103L
129 typedef typename iterator_traits<_ForwardIterator1>::value_type
130 _ValueType1;
131 typedef typename iterator_traits<_ForwardIterator2>::value_type
132 _ValueType2;
133
134 __glibcxx_function_requires(_ConvertibleConcept<_ValueType1,
135 _ValueType2>)
136 __glibcxx_function_requires(_ConvertibleConcept<_ValueType2,
137 _ValueType1>)
138
139 typedef typename iterator_traits<_ForwardIterator1>::reference
140 _ReferenceType1;
141 typedef typename iterator_traits<_ForwardIterator2>::reference
142 _ReferenceType2;
143 std::__iter_swap<__are_same<_ValueType1, _ValueType2>::__value
144 && __are_same<_ValueType1&, _ReferenceType1>::__value
145 && __are_same<_ValueType2&, _ReferenceType2>::__value>::
146 iter_swap(__a, __b);
147#else
148 swap(*__a, *__b);
149#endif
150 }
151
152 /**
153 * @brief Swap the elements of two sequences.
154 * @ingroup mutating_algorithms
155 * @param __first1 A forward iterator.
156 * @param __last1 A forward iterator.
157 * @param __first2 A forward iterator.
158 * @return An iterator equal to @p first2+(last1-first1).
159 *
160 * Swaps each element in the range @p [first1,last1) with the
161 * corresponding element in the range @p [first2,(last1-first1)).
162 * The ranges must not overlap.
163 */
164 template<typename _ForwardIterator1, typename _ForwardIterator2>
165 _ForwardIterator2
166 swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
167 _ForwardIterator2 __first2)
168 {
169 // concept requirements
170 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
171 _ForwardIterator1>)
172 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
173 _ForwardIterator2>)
174 __glibcxx_requires_valid_range(__first1, __last1);
175
176 for (; __first1 != __last1; ++__first1, (void)++__first2)
177 std::iter_swap(__first1, __first2);
178 return __first2;
179 }
180
181 /**
182 * @brief This does what you think it does.
183 * @ingroup sorting_algorithms
184 * @param __a A thing of arbitrary type.
185 * @param __b Another thing of arbitrary type.
186 * @return The lesser of the parameters.
187 *
188 * This is the simple classic generic implementation. It will work on
189 * temporary expressions, since they are only evaluated once, unlike a
190 * preprocessor macro.
191 */
192 template<typename _Tp>
193 _GLIBCXX14_CONSTEXPR
194 inline const _Tp&
195 min(const _Tp& __a, const _Tp& __b)
196 {
197 // concept requirements
198 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
199 //return __b < __a ? __b : __a;
200 if (__b < __a)
201 return __b;
202 return __a;
203 }
204
205 /**
206 * @brief This does what you think it does.
207 * @ingroup sorting_algorithms
208 * @param __a A thing of arbitrary type.
209 * @param __b Another thing of arbitrary type.
210 * @return The greater of the parameters.
211 *
212 * This is the simple classic generic implementation. It will work on
213 * temporary expressions, since they are only evaluated once, unlike a
214 * preprocessor macro.
215 */
216 template<typename _Tp>
217 _GLIBCXX14_CONSTEXPR
218 inline const _Tp&
219 max(const _Tp& __a, const _Tp& __b)
220 {
221 // concept requirements
222 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
223 //return __a < __b ? __b : __a;
224 if (__a < __b)
225 return __b;
226 return __a;
227 }
228
229 /**
230 * @brief This does what you think it does.
231 * @ingroup sorting_algorithms
232 * @param __a A thing of arbitrary type.
233 * @param __b Another thing of arbitrary type.
234 * @param __comp A @link comparison_functors comparison functor@endlink.
235 * @return The lesser of the parameters.
236 *
237 * This will work on temporary expressions, since they are only evaluated
238 * once, unlike a preprocessor macro.
239 */
240 template<typename _Tp, typename _Compare>
241 _GLIBCXX14_CONSTEXPR
242 inline const _Tp&
243 min(const _Tp& __a, const _Tp& __b, _Compare __comp)
244 {
245 //return __comp(__b, __a) ? __b : __a;
246 if (__comp(__b, __a))
247 return __b;
248 return __a;
249 }
250
251 /**
252 * @brief This does what you think it does.
253 * @ingroup sorting_algorithms
254 * @param __a A thing of arbitrary type.
255 * @param __b Another thing of arbitrary type.
256 * @param __comp A @link comparison_functors comparison functor@endlink.
257 * @return The greater of the parameters.
258 *
259 * This will work on temporary expressions, since they are only evaluated
260 * once, unlike a preprocessor macro.
261 */
262 template<typename _Tp, typename _Compare>
263 _GLIBCXX14_CONSTEXPR
264 inline const _Tp&
265 max(const _Tp& __a, const _Tp& __b, _Compare __comp)
266 {
267 //return __comp(__a, __b) ? __b : __a;
268 if (__comp(__a, __b))
269 return __b;
270 return __a;
271 }
272
273 // Fallback implementation of the function in bits/stl_iterator.h used to
274 // remove the __normal_iterator wrapper. See copy, fill, ...
275 template<typename _Iterator>
276 inline _Iterator
277 __niter_base(_Iterator __it)
278 { return __it; }
279
280 // All of these auxiliary structs serve two purposes. (1) Replace
281 // calls to copy with memmove whenever possible. (Memmove, not memcpy,
282 // because the input and output ranges are permitted to overlap.)
283 // (2) If we're using random access iterators, then write the loop as
284 // a for loop with an explicit count.
285
286 template<bool, bool, typename>
287 struct __copy_move
288 {
289 template<typename _II, typename _OI>
290 static _OI
291 __copy_m(_II __first, _II __last, _OI __result)
292 {
293 for (; __first != __last; ++__result, (void)++__first)
294 *__result = *__first;
295 return __result;
296 }
297 };
298
299#if __cplusplus >= 201103L
300 template<typename _Category>
301 struct __copy_move<true, false, _Category>
302 {
303 template<typename _II, typename _OI>
304 static _OI
305 __copy_m(_II __first, _II __last, _OI __result)
306 {
307 for (; __first != __last; ++__result, (void)++__first)
308 *__result = std::move(*__first);
309 return __result;
310 }
311 };
312#endif
313
314 template<>
315 struct __copy_move<false, false, random_access_iterator_tag>
316 {
317 template<typename _II, typename _OI>
318 static _OI
319 __copy_m(_II __first, _II __last, _OI __result)
320 {
321 typedef typename iterator_traits<_II>::difference_type _Distance;
322 for(_Distance __n = __last - __first; __n > 0; --__n)
323 {
324 *__result = *__first;
325 ++__first;
326 ++__result;
327 }
328 return __result;
329 }
330 };
331
332#if __cplusplus >= 201103L
333 template<>
334 struct __copy_move<true, false, random_access_iterator_tag>
335 {
336 template<typename _II, typename _OI>
337 static _OI
338 __copy_m(_II __first, _II __last, _OI __result)
339 {
340 typedef typename iterator_traits<_II>::difference_type _Distance;
341 for(_Distance __n = __last - __first; __n > 0; --__n)
342 {
343 *__result = std::move(*__first);
344 ++__first;
345 ++__result;
346 }
347 return __result;
348 }
349 };
350#endif
351
352 template<bool _IsMove>
353 struct __copy_move<_IsMove, true, random_access_iterator_tag>
354 {
355 template<typename _Tp>
356 static _Tp*
357 __copy_m(const _Tp* __first, const _Tp* __last, _Tp* __result)
358 {
359#if __cplusplus >= 201103L
360 using __assignable = conditional<_IsMove,
361 is_move_assignable<_Tp>,
362 is_copy_assignable<_Tp>>;
363 // trivial types can have deleted assignment
364 static_assert( __assignable::type::value, "type is not assignable" );
365#endif
366 const ptrdiff_t _Num = __last - __first;
367 if (_Num)
368 __builtin_memmove(__result, __first, sizeof(_Tp) * _Num);
369 return __result + _Num;
370 }
371 };
372
373 template<bool _IsMove, typename _II, typename _OI>
374 inline _OI
375 __copy_move_a(_II __first, _II __last, _OI __result)
376 {
377 typedef typename iterator_traits<_II>::value_type _ValueTypeI;
378 typedef typename iterator_traits<_OI>::value_type _ValueTypeO;
379 typedef typename iterator_traits<_II>::iterator_category _Category;
380 const bool __simple = (__is_trivial(_ValueTypeI)
381 && __is_pointer<_II>::__value
382 && __is_pointer<_OI>::__value
383 && __are_same<_ValueTypeI, _ValueTypeO>::__value);
384
385 return std::__copy_move<_IsMove, __simple,
386 _Category>::__copy_m(__first, __last, __result);
387 }
388
389 // Helpers for streambuf iterators (either istream or ostream).
390 // NB: avoid including <iosfwd>, relatively large.
391 template<typename _CharT>
392 struct char_traits;
393
394 template<typename _CharT, typename _Traits>
395 class istreambuf_iterator;
396
397 template<typename _CharT, typename _Traits>
398 class ostreambuf_iterator;
399
400 template<bool _IsMove, typename _CharT>
401 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
402 ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
403 __copy_move_a2(_CharT*, _CharT*,
404 ostreambuf_iterator<_CharT, char_traits<_CharT> >);
405
406 template<bool _IsMove, typename _CharT>
407 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
408 ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
409 __copy_move_a2(const _CharT*, const _CharT*,
410 ostreambuf_iterator<_CharT, char_traits<_CharT> >);
411
412 template<bool _IsMove, typename _CharT>
413 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
414 _CharT*>::__type
415 __copy_move_a2(istreambuf_iterator<_CharT, char_traits<_CharT> >,
416 istreambuf_iterator<_CharT, char_traits<_CharT> >, _CharT*);
417
418 template<bool _IsMove, typename _II, typename _OI>
419 inline _OI
420 __copy_move_a2(_II __first, _II __last, _OI __result)
421 {
422 return _OI(std::__copy_move_a<_IsMove>(std::__niter_base(__first),
423 std::__niter_base(__last),
424 std::__niter_base(__result)));
425 }
426
427 /**
428 * @brief Copies the range [first,last) into result.
429 * @ingroup mutating_algorithms
430 * @param __first An input iterator.
431 * @param __last An input iterator.
432 * @param __result An output iterator.
433 * @return result + (first - last)
434 *
435 * This inline function will boil down to a call to @c memmove whenever
436 * possible. Failing that, if random access iterators are passed, then the
437 * loop count will be known (and therefore a candidate for compiler
438 * optimizations such as unrolling). Result may not be contained within
439 * [first,last); the copy_backward function should be used instead.
440 *
441 * Note that the end of the output range is permitted to be contained
442 * within [first,last).
443 */
444 template<typename _II, typename _OI>
445 inline _OI
446 copy(_II __first, _II __last, _OI __result)
447 {
448 // concept requirements
449 __glibcxx_function_requires(_InputIteratorConcept<_II>)
450 __glibcxx_function_requires(_OutputIteratorConcept<_OI,
451 typename iterator_traits<_II>::value_type>)
452 __glibcxx_requires_valid_range(__first, __last);
453
454 return (std::__copy_move_a2<__is_move_iterator<_II>::__value>
455 (std::__miter_base(__first), std::__miter_base(__last),
456 __result));
457 }
458
459#if __cplusplus >= 201103L
460 /**
461 * @brief Moves the range [first,last) into result.
462 * @ingroup mutating_algorithms
463 * @param __first An input iterator.
464 * @param __last An input iterator.
465 * @param __result An output iterator.
466 * @return result + (first - last)
467 *
468 * This inline function will boil down to a call to @c memmove whenever
469 * possible. Failing that, if random access iterators are passed, then the
470 * loop count will be known (and therefore a candidate for compiler
471 * optimizations such as unrolling). Result may not be contained within
472 * [first,last); the move_backward function should be used instead.
473 *
474 * Note that the end of the output range is permitted to be contained
475 * within [first,last).
476 */
477 template<typename _II, typename _OI>
478 inline _OI
479 move(_II __first, _II __last, _OI __result)
480 {
481 // concept requirements
482 __glibcxx_function_requires(_InputIteratorConcept<_II>)
483 __glibcxx_function_requires(_OutputIteratorConcept<_OI,
484 typename iterator_traits<_II>::value_type>)
485 __glibcxx_requires_valid_range(__first, __last);
486
487 return std::__copy_move_a2<true>(std::__miter_base(__first),
488 std::__miter_base(__last), __result);
489 }
490
491#define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::move(_Tp, _Up, _Vp)
492#else
493#define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::copy(_Tp, _Up, _Vp)
494#endif
495
496 template<bool, bool, typename>
497 struct __copy_move_backward
498 {
499 template<typename _BI1, typename _BI2>
500 static _BI2
501 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
502 {
503 while (__first != __last)
504 *--__result = *--__last;
505 return __result;
506 }
507 };
508
509#if __cplusplus >= 201103L
510 template<typename _Category>
511 struct __copy_move_backward<true, false, _Category>
512 {
513 template<typename _BI1, typename _BI2>
514 static _BI2
515 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
516 {
517 while (__first != __last)
518 *--__result = std::move(*--__last);
519 return __result;
520 }
521 };
522#endif
523
524 template<>
525 struct __copy_move_backward<false, false, random_access_iterator_tag>
526 {
527 template<typename _BI1, typename _BI2>
528 static _BI2
529 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
530 {
531 typename iterator_traits<_BI1>::difference_type __n;
532 for (__n = __last - __first; __n > 0; --__n)
533 *--__result = *--__last;
534 return __result;
535 }
536 };
537
538#if __cplusplus >= 201103L
539 template<>
540 struct __copy_move_backward<true, false, random_access_iterator_tag>
541 {
542 template<typename _BI1, typename _BI2>
543 static _BI2
544 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
545 {
546 typename iterator_traits<_BI1>::difference_type __n;
547 for (__n = __last - __first; __n > 0; --__n)
548 *--__result = std::move(*--__last);
549 return __result;
550 }
551 };
552#endif
553
554 template<bool _IsMove>
555 struct __copy_move_backward<_IsMove, true, random_access_iterator_tag>
556 {
557 template<typename _Tp>
558 static _Tp*
559 __copy_move_b(const _Tp* __first, const _Tp* __last, _Tp* __result)
560 {
561#if __cplusplus >= 201103L
562 using __assignable = conditional<_IsMove,
563 is_move_assignable<_Tp>,
564 is_copy_assignable<_Tp>>;
565 // trivial types can have deleted assignment
566 static_assert( __assignable::type::value, "type is not assignable" );
567#endif
568 const ptrdiff_t _Num = __last - __first;
569 if (_Num)
570 __builtin_memmove(__result - _Num, __first, sizeof(_Tp) * _Num);
571 return __result - _Num;
572 }
573 };
574
575 template<bool _IsMove, typename _BI1, typename _BI2>
576 inline _BI2
577 __copy_move_backward_a(_BI1 __first, _BI1 __last, _BI2 __result)
578 {
579 typedef typename iterator_traits<_BI1>::value_type _ValueType1;
580 typedef typename iterator_traits<_BI2>::value_type _ValueType2;
581 typedef typename iterator_traits<_BI1>::iterator_category _Category;
582 const bool __simple = (__is_trivial(_ValueType1)
583 && __is_pointer<_BI1>::__value
584 && __is_pointer<_BI2>::__value
585 && __are_same<_ValueType1, _ValueType2>::__value);
586
587 return std::__copy_move_backward<_IsMove, __simple,
588 _Category>::__copy_move_b(__first,
589 __last,
590 __result);
591 }
592
593 template<bool _IsMove, typename _BI1, typename _BI2>
594 inline _BI2
595 __copy_move_backward_a2(_BI1 __first, _BI1 __last, _BI2 __result)
596 {
597 return _BI2(std::__copy_move_backward_a<_IsMove>
598 (std::__niter_base(__first), std::__niter_base(__last),
599 std::__niter_base(__result)));
600 }
601
602 /**
603 * @brief Copies the range [first,last) into result.
604 * @ingroup mutating_algorithms
605 * @param __first A bidirectional iterator.
606 * @param __last A bidirectional iterator.
607 * @param __result A bidirectional iterator.
608 * @return result - (first - last)
609 *
610 * The function has the same effect as copy, but starts at the end of the
611 * range and works its way to the start, returning the start of the result.
612 * This inline function will boil down to a call to @c memmove whenever
613 * possible. Failing that, if random access iterators are passed, then the
614 * loop count will be known (and therefore a candidate for compiler
615 * optimizations such as unrolling).
616 *
617 * Result may not be in the range (first,last]. Use copy instead. Note
618 * that the start of the output range may overlap [first,last).
619 */
620 template<typename _BI1, typename _BI2>
621 inline _BI2
622 copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
623 {
624 // concept requirements
625 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
626 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
627 __glibcxx_function_requires(_ConvertibleConcept<
628 typename iterator_traits<_BI1>::value_type,
629 typename iterator_traits<_BI2>::value_type>)
630 __glibcxx_requires_valid_range(__first, __last);
631
632 return (std::__copy_move_backward_a2<__is_move_iterator<_BI1>::__value>
633 (std::__miter_base(__first), std::__miter_base(__last),
634 __result));
635 }
636
637#if __cplusplus >= 201103L
638 /**
639 * @brief Moves the range [first,last) into result.
640 * @ingroup mutating_algorithms
641 * @param __first A bidirectional iterator.
642 * @param __last A bidirectional iterator.
643 * @param __result A bidirectional iterator.
644 * @return result - (first - last)
645 *
646 * The function has the same effect as move, but starts at the end of the
647 * range and works its way to the start, returning the start of the result.
648 * This inline function will boil down to a call to @c memmove whenever
649 * possible. Failing that, if random access iterators are passed, then the
650 * loop count will be known (and therefore a candidate for compiler
651 * optimizations such as unrolling).
652 *
653 * Result may not be in the range (first,last]. Use move instead. Note
654 * that the start of the output range may overlap [first,last).
655 */
656 template<typename _BI1, typename _BI2>
657 inline _BI2
658 move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
659 {
660 // concept requirements
661 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
662 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
663 __glibcxx_function_requires(_ConvertibleConcept<
664 typename iterator_traits<_BI1>::value_type,
665 typename iterator_traits<_BI2>::value_type>)
666 __glibcxx_requires_valid_range(__first, __last);
667
668 return std::__copy_move_backward_a2<true>(std::__miter_base(__first),
669 std::__miter_base(__last),
670 __result);
671 }
672
673#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::move_backward(_Tp, _Up, _Vp)
674#else
675#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::copy_backward(_Tp, _Up, _Vp)
676#endif
677
678 template<typename _ForwardIterator, typename _Tp>
679 inline typename
680 __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, void>::__type
681 __fill_a(_ForwardIterator __first, _ForwardIterator __last,
682 const _Tp& __value)
683 {
684 for (; __first != __last; ++__first)
685 *__first = __value;
686 }
687
688 template<typename _ForwardIterator, typename _Tp>
689 inline typename
690 __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, void>::__type
691 __fill_a(_ForwardIterator __first, _ForwardIterator __last,
692 const _Tp& __value)
693 {
694 const _Tp __tmp = __value;
695 for (; __first != __last; ++__first)
696 *__first = __tmp;
697 }
698
699 // Specialization: for char types we can use memset.
700 template<typename _Tp>
701 inline typename
702 __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, void>::__type
703 __fill_a(_Tp* __first, _Tp* __last, const _Tp& __c)
704 {
705 const _Tp __tmp = __c;
706 if (const size_t __len = __last - __first)
707 __builtin_memset(__first, static_cast<unsigned char>(__tmp), __len);
708 }
709
710 /**
711 * @brief Fills the range [first,last) with copies of value.
712 * @ingroup mutating_algorithms
713 * @param __first A forward iterator.
714 * @param __last A forward iterator.
715 * @param __value A reference-to-const of arbitrary type.
716 * @return Nothing.
717 *
718 * This function fills a range with copies of the same value. For char
719 * types filling contiguous areas of memory, this becomes an inline call
720 * to @c memset or @c wmemset.
721 */
722 template<typename _ForwardIterator, typename _Tp>
723 inline void
724 fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
725 {
726 // concept requirements
727 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
728 _ForwardIterator>)
729 __glibcxx_requires_valid_range(__first, __last);
730
731 std::__fill_a(std::__niter_base(__first), std::__niter_base(__last),
732 __value);
733 }
734
735 template<typename _OutputIterator, typename _Size, typename _Tp>
736 inline typename
737 __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, _OutputIterator>::__type
738 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
739 {
740 for (__decltype(__n + 0) __niter = __n;
741 __niter > 0; --__niter, (void) ++__first)
742 *__first = __value;
743 return __first;
744 }
745
746 template<typename _OutputIterator, typename _Size, typename _Tp>
747 inline typename
748 __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, _OutputIterator>::__type
749 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
750 {
751 const _Tp __tmp = __value;
752 for (__decltype(__n + 0) __niter = __n;
753 __niter > 0; --__niter, (void) ++__first)
754 *__first = __tmp;
755 return __first;
756 }
757
758 template<typename _Size, typename _Tp>
759 inline typename
760 __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, _Tp*>::__type
761 __fill_n_a(_Tp* __first, _Size __n, const _Tp& __c)
762 {
763 std::__fill_a(__first, __first + __n, __c);
764 return __first + __n;
765 }
766
767 /**
768 * @brief Fills the range [first,first+n) with copies of value.
769 * @ingroup mutating_algorithms
770 * @param __first An output iterator.
771 * @param __n The count of copies to perform.
772 * @param __value A reference-to-const of arbitrary type.
773 * @return The iterator at first+n.
774 *
775 * This function fills a range with copies of the same value. For char
776 * types filling contiguous areas of memory, this becomes an inline call
777 * to @c memset or @ wmemset.
778 *
779 * _GLIBCXX_RESOLVE_LIB_DEFECTS
780 * DR 865. More algorithms that throw away information
781 */
782 template<typename _OI, typename _Size, typename _Tp>
783 inline _OI
784 fill_n(_OI __first, _Size __n, const _Tp& __value)
785 {
786 // concept requirements
787 __glibcxx_function_requires(_OutputIteratorConcept<_OI, _Tp>)
788
789 return _OI(std::__fill_n_a(std::__niter_base(__first), __n, __value));
790 }
791
792 template<bool _BoolType>
793 struct __equal
794 {
795 template<typename _II1, typename _II2>
796 static bool
797 equal(_II1 __first1, _II1 __last1, _II2 __first2)
798 {
799 for (; __first1 != __last1; ++__first1, (void) ++__first2)
800 if (!(*__first1 == *__first2))
801 return false;
802 return true;
803 }
804 };
805
806 template<>
807 struct __equal<true>
808 {
809 template<typename _Tp>
810 static bool
811 equal(const _Tp* __first1, const _Tp* __last1, const _Tp* __first2)
812 {
813 if (const size_t __len = (__last1 - __first1))
814 return !__builtin_memcmp(__first1, __first2, sizeof(_Tp) * __len);
815 return true;
816 }
817 };
818
819 template<typename _II1, typename _II2>
820 inline bool
821 __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)
822 {
823 typedef typename iterator_traits<_II1>::value_type _ValueType1;
824 typedef typename iterator_traits<_II2>::value_type _ValueType2;
825 const bool __simple = ((__is_integer<_ValueType1>::__value
826 || __is_pointer<_ValueType1>::__value)
827 && __is_pointer<_II1>::__value
828 && __is_pointer<_II2>::__value
829 && __are_same<_ValueType1, _ValueType2>::__value);
830
831 return std::__equal<__simple>::equal(__first1, __last1, __first2);
832 }
833
834 template<typename, typename>
835 struct __lc_rai
836 {
837 template<typename _II1, typename _II2>
838 static _II1
839 __newlast1(_II1, _II1 __last1, _II2, _II2)
840 { return __last1; }
841
842 template<typename _II>
843 static bool
844 __cnd2(_II __first, _II __last)
845 { return __first != __last; }
846 };
847
848 template<>
849 struct __lc_rai<random_access_iterator_tag, random_access_iterator_tag>
850 {
851 template<typename _RAI1, typename _RAI2>
852 static _RAI1
853 __newlast1(_RAI1 __first1, _RAI1 __last1,
854 _RAI2 __first2, _RAI2 __last2)
855 {
856 const typename iterator_traits<_RAI1>::difference_type
857 __diff1 = __last1 - __first1;
858 const typename iterator_traits<_RAI2>::difference_type
859 __diff2 = __last2 - __first2;
860 return __diff2 < __diff1 ? __first1 + __diff2 : __last1;
861 }
862
863 template<typename _RAI>
864 static bool
865 __cnd2(_RAI, _RAI)
866 { return true; }
867 };
868
869 template<typename _II1, typename _II2, typename _Compare>
870 bool
871 __lexicographical_compare_impl(_II1 __first1, _II1 __last1,
872 _II2 __first2, _II2 __last2,
873 _Compare __comp)
874 {
875 typedef typename iterator_traits<_II1>::iterator_category _Category1;
876 typedef typename iterator_traits<_II2>::iterator_category _Category2;
877 typedef std::__lc_rai<_Category1, _Category2> __rai_type;
878
879 __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
880 for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
881 ++__first1, (void)++__first2)
882 {
883 if (__comp(__first1, __first2))
884 return true;
885 if (__comp(__first2, __first1))
886 return false;
887 }
888 return __first1 == __last1 && __first2 != __last2;
889 }
890
891 template<bool _BoolType>
892 struct __lexicographical_compare
893 {
894 template<typename _II1, typename _II2>
895 static bool __lc(_II1, _II1, _II2, _II2);
896 };
897
898 template<bool _BoolType>
899 template<typename _II1, typename _II2>
900 bool
901 __lexicographical_compare<_BoolType>::
902 __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
903 {
904 return std::__lexicographical_compare_impl(__first1, __last1,
905 __first2, __last2,
906 __gnu_cxx::__ops::__iter_less_iter());
907 }
908
909 template<>
910 struct __lexicographical_compare<true>
911 {
912 template<typename _Tp, typename _Up>
913 static bool
914 __lc(const _Tp* __first1, const _Tp* __last1,
915 const _Up* __first2, const _Up* __last2)
916 {
917 const size_t __len1 = __last1 - __first1;
918 const size_t __len2 = __last2 - __first2;
919 if (const size_t __len = std::min(__len1, __len2))
920 if (int __result = __builtin_memcmp(__first1, __first2, __len))
921 return __result < 0;
922 return __len1 < __len2;
923 }
924 };
925
926 template<typename _II1, typename _II2>
927 inline bool
928 __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
929 _II2 __first2, _II2 __last2)
930 {
931 typedef typename iterator_traits<_II1>::value_type _ValueType1;
932 typedef typename iterator_traits<_II2>::value_type _ValueType2;
933 const bool __simple =
934 (__is_byte<_ValueType1>::__value && __is_byte<_ValueType2>::__value
935 && !__gnu_cxx::__numeric_traits<_ValueType1>::__is_signed
936 && !__gnu_cxx::__numeric_traits<_ValueType2>::__is_signed
937 && __is_pointer<_II1>::__value
938 && __is_pointer<_II2>::__value);
939
940 return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
941 __first2, __last2);
942 }
943
944 template<typename _ForwardIterator, typename _Tp, typename _Compare>
945 _ForwardIterator
946 __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
947 const _Tp& __val, _Compare __comp)
948 {
949 typedef typename iterator_traits<_ForwardIterator>::difference_type
950 _DistanceType;
951
952 _DistanceType __len = std::distance(__first, __last);
953
954 while (__len > 0)
955 {
956 _DistanceType __half = __len >> 1;
957 _ForwardIterator __middle = __first;
958 std::advance(__middle, __half);
959 if (__comp(__middle, __val))
960 {
961 __first = __middle;
962 ++__first;
963 __len = __len - __half - 1;
964 }
965 else
966 __len = __half;
967 }
968 return __first;
969 }
970
971 /**
972 * @brief Finds the first position in which @a val could be inserted
973 * without changing the ordering.
974 * @param __first An iterator.
975 * @param __last Another iterator.
976 * @param __val The search term.
977 * @return An iterator pointing to the first element <em>not less
978 * than</em> @a val, or end() if every element is less than
979 * @a val.
980 * @ingroup binary_search_algorithms
981 */
982 template<typename _ForwardIterator, typename _Tp>
983 inline _ForwardIterator
984 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
985 const _Tp& __val)
986 {
987 // concept requirements
988 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
989 __glibcxx_function_requires(_LessThanOpConcept<
990 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
991 __glibcxx_requires_partitioned_lower(__first, __last, __val);
992
993 return std::__lower_bound(__first, __last, __val,
994 __gnu_cxx::__ops::__iter_less_val());
995 }
996
997 /// This is a helper function for the sort routines and for random.tcc.
998 // Precondition: __n > 0.
999 inline _GLIBCXX_CONSTEXPR int
1000 __lg(int __n)
1001 { return sizeof(int) * __CHAR_BIT__ - 1 - __builtin_clz(__n); }
1002
1003 inline _GLIBCXX_CONSTEXPR unsigned
1004 __lg(unsigned __n)
1005 { return sizeof(int) * __CHAR_BIT__ - 1 - __builtin_clz(__n); }
1006
1007 inline _GLIBCXX_CONSTEXPR long
1008 __lg(long __n)
1009 { return sizeof(long) * __CHAR_BIT__ - 1 - __builtin_clzl(__n); }
1010
1011 inline _GLIBCXX_CONSTEXPR unsigned long
1012 __lg(unsigned long __n)
1013 { return sizeof(long) * __CHAR_BIT__ - 1 - __builtin_clzl(__n); }
1014
1015 inline _GLIBCXX_CONSTEXPR long long
1016 __lg(long long __n)
1017 { return sizeof(long long) * __CHAR_BIT__ - 1 - __builtin_clzll(__n); }
1018
1019 inline _GLIBCXX_CONSTEXPR unsigned long long
1020 __lg(unsigned long long __n)
1021 { return sizeof(long long) * __CHAR_BIT__ - 1 - __builtin_clzll(__n); }
1022
1023_GLIBCXX_BEGIN_NAMESPACE_ALGO
1024
1025 /**
1026 * @brief Tests a range for element-wise equality.
1027 * @ingroup non_mutating_algorithms
1028 * @param __first1 An input iterator.
1029 * @param __last1 An input iterator.
1030 * @param __first2 An input iterator.
1031 * @return A boolean true or false.
1032 *
1033 * This compares the elements of two ranges using @c == and returns true or
1034 * false depending on whether all of the corresponding elements of the
1035 * ranges are equal.
1036 */
1037 template<typename _II1, typename _II2>
1038 inline bool
1039 equal(_II1 __first1, _II1 __last1, _II2 __first2)
1040 {
1041 // concept requirements
1042 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1043 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1044 __glibcxx_function_requires(_EqualOpConcept<
1045 typename iterator_traits<_II1>::value_type,
1046 typename iterator_traits<_II2>::value_type>)
1047 __glibcxx_requires_valid_range(__first1, __last1);
1048
1049 return std::__equal_aux(std::__niter_base(__first1),
1050 std::__niter_base(__last1),
1051 std::__niter_base(__first2));
1052 }
1053
1054 /**
1055 * @brief Tests a range for element-wise equality.
1056 * @ingroup non_mutating_algorithms
1057 * @param __first1 An input iterator.
1058 * @param __last1 An input iterator.
1059 * @param __first2 An input iterator.
1060 * @param __binary_pred A binary predicate @link functors
1061 * functor@endlink.
1062 * @return A boolean true or false.
1063 *
1064 * This compares the elements of two ranges using the binary_pred
1065 * parameter, and returns true or
1066 * false depending on whether all of the corresponding elements of the
1067 * ranges are equal.
1068 */
1069 template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1070 inline bool
1071 equal(_IIter1 __first1, _IIter1 __last1,
1072 _IIter2 __first2, _BinaryPredicate __binary_pred)
1073 {
1074 // concept requirements
1075 __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1076 __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1077 __glibcxx_requires_valid_range(__first1, __last1);
1078
1079 for (; __first1 != __last1; ++__first1, (void)++__first2)
1080 if (!bool(__binary_pred(*__first1, *__first2)))
1081 return false;
1082 return true;
1083 }
1084
1085#if __cplusplus >= 201103L
1086 // 4-iterator version of std::equal<It1, It2> for use in C++11.
1087 template<typename _II1, typename _II2>
1088 inline bool
1089 __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1090 {
1091 using _RATag = random_access_iterator_tag;
1092 using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1093 using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1094 using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1095 if (_RAIters())
1096 {
1097 auto __d1 = std::distance(__first1, __last1);
1098 auto __d2 = std::distance(__first2, __last2);
1099 if (__d1 != __d2)
1100 return false;
1101 return _GLIBCXX_STD_A::equal(__first1, __last1, __first2);
1102 }
1103
1104 for (; __first1 != __last1 && __first2 != __last2;
1105 ++__first1, (void)++__first2)
1106 if (!(*__first1 == *__first2))
1107 return false;
1108 return __first1 == __last1 && __first2 == __last2;
1109 }
1110
1111 // 4-iterator version of std::equal<It1, It2, BinaryPred> for use in C++11.
1112 template<typename _II1, typename _II2, typename _BinaryPredicate>
1113 inline bool
1114 __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2,
1115 _BinaryPredicate __binary_pred)
1116 {
1117 using _RATag = random_access_iterator_tag;
1118 using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1119 using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1120 using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1121 if (_RAIters())
1122 {
1123 auto __d1 = std::distance(__first1, __last1);
1124 auto __d2 = std::distance(__first2, __last2);
1125 if (__d1 != __d2)
1126 return false;
1127 return _GLIBCXX_STD_A::equal(__first1, __last1, __first2,
1128 __binary_pred);
1129 }
1130
1131 for (; __first1 != __last1 && __first2 != __last2;
1132 ++__first1, (void)++__first2)
1133 if (!bool(__binary_pred(*__first1, *__first2)))
1134 return false;
1135 return __first1 == __last1 && __first2 == __last2;
1136 }
1137#endif // C++11
1138
1139#if __cplusplus > 201103L
1140
1141#define __cpp_lib_robust_nonmodifying_seq_ops 201304
1142
1143 /**
1144 * @brief Tests a range for element-wise equality.
1145 * @ingroup non_mutating_algorithms
1146 * @param __first1 An input iterator.
1147 * @param __last1 An input iterator.
1148 * @param __first2 An input iterator.
1149 * @param __last2 An input iterator.
1150 * @return A boolean true or false.
1151 *
1152 * This compares the elements of two ranges using @c == and returns true or
1153 * false depending on whether all of the corresponding elements of the
1154 * ranges are equal.
1155 */
1156 template<typename _II1, typename _II2>
1157 inline bool
1158 equal(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1159 {
1160 // concept requirements
1161 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1162 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1163 __glibcxx_function_requires(_EqualOpConcept<
1164 typename iterator_traits<_II1>::value_type,
1165 typename iterator_traits<_II2>::value_type>)
1166 __glibcxx_requires_valid_range(__first1, __last1);
1167 __glibcxx_requires_valid_range(__first2, __last2);
1168
1169 return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2);
1170 }
1171
1172 /**
1173 * @brief Tests a range for element-wise equality.
1174 * @ingroup non_mutating_algorithms
1175 * @param __first1 An input iterator.
1176 * @param __last1 An input iterator.
1177 * @param __first2 An input iterator.
1178 * @param __last2 An input iterator.
1179 * @param __binary_pred A binary predicate @link functors
1180 * functor@endlink.
1181 * @return A boolean true or false.
1182 *
1183 * This compares the elements of two ranges using the binary_pred
1184 * parameter, and returns true or
1185 * false depending on whether all of the corresponding elements of the
1186 * ranges are equal.
1187 */
1188 template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1189 inline bool
1190 equal(_IIter1 __first1, _IIter1 __last1,
1191 _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
1192 {
1193 // concept requirements
1194 __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1195 __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1196 __glibcxx_requires_valid_range(__first1, __last1);
1197 __glibcxx_requires_valid_range(__first2, __last2);
1198
1199 return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2,
1200 __binary_pred);
1201 }
1202#endif // C++14
1203
1204 /**
1205 * @brief Performs @b dictionary comparison on ranges.
1206 * @ingroup sorting_algorithms
1207 * @param __first1 An input iterator.
1208 * @param __last1 An input iterator.
1209 * @param __first2 An input iterator.
1210 * @param __last2 An input iterator.
1211 * @return A boolean true or false.
1212 *
1213 * <em>Returns true if the sequence of elements defined by the range
1214 * [first1,last1) is lexicographically less than the sequence of elements
1215 * defined by the range [first2,last2). Returns false otherwise.</em>
1216 * (Quoted from [25.3.8]/1.) If the iterators are all character pointers,
1217 * then this is an inline call to @c memcmp.
1218 */
1219 template<typename _II1, typename _II2>
1220 inline bool
1221 lexicographical_compare(_II1 __first1, _II1 __last1,
1222 _II2 __first2, _II2 __last2)
1223 {
1224#ifdef _GLIBCXX_CONCEPT_CHECKS
1225 // concept requirements
1226 typedef typename iterator_traits<_II1>::value_type _ValueType1;
1227 typedef typename iterator_traits<_II2>::value_type _ValueType2;
1228#endif
1229 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1230 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1231 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
1232 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
1233 __glibcxx_requires_valid_range(__first1, __last1);
1234 __glibcxx_requires_valid_range(__first2, __last2);
1235
1236 return std::__lexicographical_compare_aux(std::__niter_base(__first1),
1237 std::__niter_base(__last1),
1238 std::__niter_base(__first2),
1239 std::__niter_base(__last2));
1240 }
1241
1242 /**
1243 * @brief Performs @b dictionary comparison on ranges.
1244 * @ingroup sorting_algorithms
1245 * @param __first1 An input iterator.
1246 * @param __last1 An input iterator.
1247 * @param __first2 An input iterator.
1248 * @param __last2 An input iterator.
1249 * @param __comp A @link comparison_functors comparison functor@endlink.
1250 * @return A boolean true or false.
1251 *
1252 * The same as the four-parameter @c lexicographical_compare, but uses the
1253 * comp parameter instead of @c <.
1254 */
1255 template<typename _II1, typename _II2, typename _Compare>
1256 inline bool
1257 lexicographical_compare(_II1 __first1, _II1 __last1,
1258 _II2 __first2, _II2 __last2, _Compare __comp)
1259 {
1260 // concept requirements
1261 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1262 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1263 __glibcxx_requires_valid_range(__first1, __last1);
1264 __glibcxx_requires_valid_range(__first2, __last2);
1265
1266 return std::__lexicographical_compare_impl
1267 (__first1, __last1, __first2, __last2,
1268 __gnu_cxx::__ops::__iter_comp_iter(__comp));
1269 }
1270
1271 template<typename _InputIterator1, typename _InputIterator2,
1272 typename _BinaryPredicate>
1273 pair<_InputIterator1, _InputIterator2>
1274 __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1275 _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1276 {
1277 while (__first1 != __last1 && __binary_pred(__first1, __first2))
1278 {
1279 ++__first1;
1280 ++__first2;
1281 }
1282 return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
1283 }
1284
1285 /**
1286 * @brief Finds the places in ranges which don't match.
1287 * @ingroup non_mutating_algorithms
1288 * @param __first1 An input iterator.
1289 * @param __last1 An input iterator.
1290 * @param __first2 An input iterator.
1291 * @return A pair of iterators pointing to the first mismatch.
1292 *
1293 * This compares the elements of two ranges using @c == and returns a pair
1294 * of iterators. The first iterator points into the first range, the
1295 * second iterator points into the second range, and the elements pointed
1296 * to by the iterators are not equal.
1297 */
1298 template<typename _InputIterator1, typename _InputIterator2>
1299 inline pair<_InputIterator1, _InputIterator2>
1300 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1301 _InputIterator2 __first2)
1302 {
1303 // concept requirements
1304 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1305 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1306 __glibcxx_function_requires(_EqualOpConcept<
1307 typename iterator_traits<_InputIterator1>::value_type,
1308 typename iterator_traits<_InputIterator2>::value_type>)
1309 __glibcxx_requires_valid_range(__first1, __last1);
1310
1311 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1312 __gnu_cxx::__ops::__iter_equal_to_iter());
1313 }
1314
1315 /**
1316 * @brief Finds the places in ranges which don't match.
1317 * @ingroup non_mutating_algorithms
1318 * @param __first1 An input iterator.
1319 * @param __last1 An input iterator.
1320 * @param __first2 An input iterator.
1321 * @param __binary_pred A binary predicate @link functors
1322 * functor@endlink.
1323 * @return A pair of iterators pointing to the first mismatch.
1324 *
1325 * This compares the elements of two ranges using the binary_pred
1326 * parameter, and returns a pair
1327 * of iterators. The first iterator points into the first range, the
1328 * second iterator points into the second range, and the elements pointed
1329 * to by the iterators are not equal.
1330 */
1331 template<typename _InputIterator1, typename _InputIterator2,
1332 typename _BinaryPredicate>
1333 inline pair<_InputIterator1, _InputIterator2>
1334 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1335 _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1336 {
1337 // concept requirements
1338 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1339 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1340 __glibcxx_requires_valid_range(__first1, __last1);
1341
1342 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1343 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
1344 }
1345
1346#if __cplusplus > 201103L
1347
1348 template<typename _InputIterator1, typename _InputIterator2,
1349 typename _BinaryPredicate>
1350 pair<_InputIterator1, _InputIterator2>
1351 __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1352 _InputIterator2 __first2, _InputIterator2 __last2,
1353 _BinaryPredicate __binary_pred)
1354 {
1355 while (__first1 != __last1 && __first2 != __last2
1356 && __binary_pred(__first1, __first2))
1357 {
1358 ++__first1;
1359 ++__first2;
1360 }
1361 return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
1362 }
1363
1364 /**
1365 * @brief Finds the places in ranges which don't match.
1366 * @ingroup non_mutating_algorithms
1367 * @param __first1 An input iterator.
1368 * @param __last1 An input iterator.
1369 * @param __first2 An input iterator.
1370 * @param __last2 An input iterator.
1371 * @return A pair of iterators pointing to the first mismatch.
1372 *
1373 * This compares the elements of two ranges using @c == and returns a pair
1374 * of iterators. The first iterator points into the first range, the
1375 * second iterator points into the second range, and the elements pointed
1376 * to by the iterators are not equal.
1377 */
1378 template<typename _InputIterator1, typename _InputIterator2>
1379 inline pair<_InputIterator1, _InputIterator2>
1380 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1381 _InputIterator2 __first2, _InputIterator2 __last2)
1382 {
1383 // concept requirements
1384 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1385 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1386 __glibcxx_function_requires(_EqualOpConcept<
1387 typename iterator_traits<_InputIterator1>::value_type,
1388 typename iterator_traits<_InputIterator2>::value_type>)
1389 __glibcxx_requires_valid_range(__first1, __last1);
1390 __glibcxx_requires_valid_range(__first2, __last2);
1391
1392 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
1393 __gnu_cxx::__ops::__iter_equal_to_iter());
1394 }
1395
1396 /**
1397 * @brief Finds the places in ranges which don't match.
1398 * @ingroup non_mutating_algorithms
1399 * @param __first1 An input iterator.
1400 * @param __last1 An input iterator.
1401 * @param __first2 An input iterator.
1402 * @param __last2 An input iterator.
1403 * @param __binary_pred A binary predicate @link functors
1404 * functor@endlink.
1405 * @return A pair of iterators pointing to the first mismatch.
1406 *
1407 * This compares the elements of two ranges using the binary_pred
1408 * parameter, and returns a pair
1409 * of iterators. The first iterator points into the first range, the
1410 * second iterator points into the second range, and the elements pointed
1411 * to by the iterators are not equal.
1412 */
1413 template<typename _InputIterator1, typename _InputIterator2,
1414 typename _BinaryPredicate>
1415 inline pair<_InputIterator1, _InputIterator2>
1416 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1417 _InputIterator2 __first2, _InputIterator2 __last2,
1418 _BinaryPredicate __binary_pred)
1419 {
1420 // concept requirements
1421 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1422 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1423 __glibcxx_requires_valid_range(__first1, __last1);
1424 __glibcxx_requires_valid_range(__first2, __last2);
1425
1426 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
1427 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
1428 }
1429#endif
1430
1431_GLIBCXX_END_NAMESPACE_ALGO
1432_GLIBCXX_END_NAMESPACE_VERSION
1433} // namespace std
1434
1435// NB: This file is included within many other C++ includes, as a way
1436// of getting the base algorithms. So, make sure that parallel bits
1437// come in too if requested.
1438#ifdef _GLIBCXX_PARALLEL
1439# include <parallel/algobase.h>
1440#endif
1441
1442#endif
1443