1 // Core algorithmic facilities -*- C++ -*-
2
3 // Copyright (C) 2001-2019 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 #if __cplusplus >= 201103L
73 # include <type_traits>
74 #endif
75
_GLIBCXX_VISIBILITY(default)76 namespace std _GLIBCXX_VISIBILITY(default)
77 {
78 _GLIBCXX_BEGIN_NAMESPACE_VERSION
79
80 #if __cplusplus < 201103L
81 // See http://gcc.gnu.org/ml/libstdc++/2004-08/msg00167.html: in a
82 // nutshell, we are partially implementing the resolution of DR 187,
83 // when it's safe, i.e., the value_types are equal.
84 template<bool _BoolType>
85 struct __iter_swap
86 {
87 template<typename _ForwardIterator1, typename _ForwardIterator2>
88 static void
89 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
90 {
91 typedef typename iterator_traits<_ForwardIterator1>::value_type
92 _ValueType1;
93 _ValueType1 __tmp = *__a;
94 *__a = *__b;
95 *__b = __tmp;
96 }
97 };
98
99 template<>
100 struct __iter_swap<true>
101 {
102 template<typename _ForwardIterator1, typename _ForwardIterator2>
103 static void
104 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
105 {
106 swap(*__a, *__b);
107 }
108 };
109 #endif
110
111 /**
112 * @brief Swaps the contents of two iterators.
113 * @ingroup mutating_algorithms
114 * @param __a An iterator.
115 * @param __b Another iterator.
116 * @return Nothing.
117 *
118 * This function swaps the values pointed to by two iterators, not the
119 * iterators themselves.
120 */
121 template<typename _ForwardIterator1, typename _ForwardIterator2>
122 inline void
123 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
124 {
125 // concept requirements
126 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
127 _ForwardIterator1>)
128 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
129 _ForwardIterator2>)
130
131 #if __cplusplus < 201103L
132 typedef typename iterator_traits<_ForwardIterator1>::value_type
133 _ValueType1;
134 typedef typename iterator_traits<_ForwardIterator2>::value_type
135 _ValueType2;
136
137 __glibcxx_function_requires(_ConvertibleConcept<_ValueType1,
138 _ValueType2>)
139 __glibcxx_function_requires(_ConvertibleConcept<_ValueType2,
140 _ValueType1>)
141
142 typedef typename iterator_traits<_ForwardIterator1>::reference
143 _ReferenceType1;
144 typedef typename iterator_traits<_ForwardIterator2>::reference
145 _ReferenceType2;
146 std::__iter_swap<__are_same<_ValueType1, _ValueType2>::__value
147 && __are_same<_ValueType1&, _ReferenceType1>::__value
148 && __are_same<_ValueType2&, _ReferenceType2>::__value>::
149 iter_swap(__a, __b);
150 #else
151 swap(*__a, *__b);
152 #endif
153 }
154
155 /**
156 * @brief Swap the elements of two sequences.
157 * @ingroup mutating_algorithms
158 * @param __first1 A forward iterator.
159 * @param __last1 A forward iterator.
160 * @param __first2 A forward iterator.
161 * @return An iterator equal to @p first2+(last1-first1).
162 *
163 * Swaps each element in the range @p [first1,last1) with the
164 * corresponding element in the range @p [first2,(last1-first1)).
165 * The ranges must not overlap.
166 */
167 template<typename _ForwardIterator1, typename _ForwardIterator2>
168 _ForwardIterator2
169 swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
170 _ForwardIterator2 __first2)
171 {
172 // concept requirements
173 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
174 _ForwardIterator1>)
175 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
176 _ForwardIterator2>)
177 __glibcxx_requires_valid_range(__first1, __last1);
178
179 for (; __first1 != __last1; ++__first1, (void)++__first2)
180 std::iter_swap(__first1, __first2);
181 return __first2;
182 }
183
184 /**
185 * @brief This does what you think it does.
186 * @ingroup sorting_algorithms
187 * @param __a A thing of arbitrary type.
188 * @param __b Another thing of arbitrary type.
189 * @return The lesser of the parameters.
190 *
191 * This is the simple classic generic implementation. It will work on
192 * temporary expressions, since they are only evaluated once, unlike a
193 * preprocessor macro.
194 */
195 template<typename _Tp>
196 _GLIBCXX14_CONSTEXPR
197 inline const _Tp&
198 min(const _Tp& __a, const _Tp& __b)
199 {
200 // concept requirements
201 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
202 //return __b < __a ? __b : __a;
203 if (__b < __a)
204 return __b;
205 return __a;
206 }
207
208 /**
209 * @brief This does what you think it does.
210 * @ingroup sorting_algorithms
211 * @param __a A thing of arbitrary type.
212 * @param __b Another thing of arbitrary type.
213 * @return The greater of the parameters.
214 *
215 * This is the simple classic generic implementation. It will work on
216 * temporary expressions, since they are only evaluated once, unlike a
217 * preprocessor macro.
218 */
219 template<typename _Tp>
220 _GLIBCXX14_CONSTEXPR
221 inline const _Tp&
222 max(const _Tp& __a, const _Tp& __b)
223 {
224 // concept requirements
225 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
226 //return __a < __b ? __b : __a;
227 if (__a < __b)
228 return __b;
229 return __a;
230 }
231
232 /**
233 * @brief This does what you think it does.
234 * @ingroup sorting_algorithms
235 * @param __a A thing of arbitrary type.
236 * @param __b Another thing of arbitrary type.
237 * @param __comp A @link comparison_functors comparison functor@endlink.
238 * @return The lesser of the parameters.
239 *
240 * This will work on temporary expressions, since they are only evaluated
241 * once, unlike a preprocessor macro.
242 */
243 template<typename _Tp, typename _Compare>
244 _GLIBCXX14_CONSTEXPR
245 inline const _Tp&
246 min(const _Tp& __a, const _Tp& __b, _Compare __comp)
247 {
248 //return __comp(__b, __a) ? __b : __a;
249 if (__comp(__b, __a))
250 return __b;
251 return __a;
252 }
253
254 /**
255 * @brief This does what you think it does.
256 * @ingroup sorting_algorithms
257 * @param __a A thing of arbitrary type.
258 * @param __b Another thing of arbitrary type.
259 * @param __comp A @link comparison_functors comparison functor@endlink.
260 * @return The greater of the parameters.
261 *
262 * This will work on temporary expressions, since they are only evaluated
263 * once, unlike a preprocessor macro.
264 */
265 template<typename _Tp, typename _Compare>
266 _GLIBCXX14_CONSTEXPR
267 inline const _Tp&
268 max(const _Tp& __a, const _Tp& __b, _Compare __comp)
269 {
270 //return __comp(__a, __b) ? __b : __a;
271 if (__comp(__a, __b))
272 return __b;
273 return __a;
274 }
275
276 // Fallback implementation of the function in bits/stl_iterator.h used to
277 // remove the __normal_iterator wrapper. See copy, fill, ...
278 template<typename _Iterator>
279 inline _Iterator
280 __niter_base(_Iterator __it)
281 _GLIBCXX_NOEXCEPT_IF(std::is_nothrow_copy_constructible<_Iterator>::value)
282 { return __it; }
283
284 // Reverse the __niter_base transformation to get a
285 // __normal_iterator back again (this assumes that __normal_iterator
286 // is only used to wrap random access iterators, like pointers).
287 template<typename _From, typename _To>
288 inline _From
289 __niter_wrap(_From __from, _To __res)
290 { return __from + (__res - std::__niter_base(__from)); }
291
292 // No need to wrap, iterator already has the right type.
293 template<typename _Iterator>
294 inline _Iterator
295 __niter_wrap(const _Iterator&, _Iterator __res)
296 { return __res; }
297
298 // All of these auxiliary structs serve two purposes. (1) Replace
299 // calls to copy with memmove whenever possible. (Memmove, not memcpy,
300 // because the input and output ranges are permitted to overlap.)
301 // (2) If we're using random access iterators, then write the loop as
302 // a for loop with an explicit count.
303
304 template<bool _IsMove, bool _IsSimple, typename _Category>
305 struct __copy_move
306 {
307 template<typename _II, typename _OI>
308 static _OI
309 __copy_m(_II __first, _II __last, _OI __result)
310 {
311 for (; __first != __last; ++__result, (void)++__first)
312 *__result = *__first;
313 return __result;
314 }
315 };
316
317 #if __cplusplus >= 201103L
318 template<typename _Category>
319 struct __copy_move<true, false, _Category>
320 {
321 template<typename _II, typename _OI>
322 static _OI
323 __copy_m(_II __first, _II __last, _OI __result)
324 {
325 for (; __first != __last; ++__result, (void)++__first)
326 *__result = std::move(*__first);
327 return __result;
328 }
329 };
330 #endif
331
332 template<>
333 struct __copy_move<false, false, random_access_iterator_tag>
334 {
335 template<typename _II, typename _OI>
336 static _OI
337 __copy_m(_II __first, _II __last, _OI __result)
338 {
339 typedef typename iterator_traits<_II>::difference_type _Distance;
340 for(_Distance __n = __last - __first; __n > 0; --__n)
341 {
342 *__result = *__first;
343 ++__first;
344 ++__result;
345 }
346 return __result;
347 }
348 };
349
350 #if __cplusplus >= 201103L
351 template<>
352 struct __copy_move<true, false, random_access_iterator_tag>
353 {
354 template<typename _II, typename _OI>
355 static _OI
356 __copy_m(_II __first, _II __last, _OI __result)
357 {
358 typedef typename iterator_traits<_II>::difference_type _Distance;
359 for(_Distance __n = __last - __first; __n > 0; --__n)
360 {
361 *__result = std::move(*__first);
362 ++__first;
363 ++__result;
364 }
365 return __result;
366 }
367 };
368 #endif
369
370 template<bool _IsMove>
371 struct __copy_move<_IsMove, true, random_access_iterator_tag>
372 {
373 template<typename _Tp>
374 static _Tp*
375 __copy_m(const _Tp* __first, const _Tp* __last, _Tp* __result)
376 {
377 #if __cplusplus >= 201103L
378 using __assignable = conditional<_IsMove,
379 is_move_assignable<_Tp>,
380 is_copy_assignable<_Tp>>;
381 // trivial types can have deleted assignment
382 static_assert( __assignable::type::value, "type is not assignable" );
383 #endif
384 const ptrdiff_t _Num = __last - __first;
385 if (_Num)
386 __builtin_memmove(__result, __first, sizeof(_Tp) * _Num);
387 return __result + _Num;
388 }
389 };
390
391 template<bool _IsMove, typename _II, typename _OI>
392 inline _OI
393 __copy_move_a(_II __first, _II __last, _OI __result)
394 {
395 typedef typename iterator_traits<_II>::value_type _ValueTypeI;
396 typedef typename iterator_traits<_OI>::value_type _ValueTypeO;
397 typedef typename iterator_traits<_II>::iterator_category _Category;
398 const bool __simple = (__is_trivially_copyable(_ValueTypeI)
399 && __is_pointer<_II>::__value
400 && __is_pointer<_OI>::__value
401 && __are_same<_ValueTypeI, _ValueTypeO>::__value);
402
403 return std::__copy_move<_IsMove, __simple,
404 _Category>::__copy_m(__first, __last, __result);
405 }
406
407 // Helpers for streambuf iterators (either istream or ostream).
408 // NB: avoid including <iosfwd>, relatively large.
409 template<typename _CharT>
410 struct char_traits;
411
412 template<typename _CharT, typename _Traits>
413 class istreambuf_iterator;
414
415 template<typename _CharT, typename _Traits>
416 class ostreambuf_iterator;
417
418 template<bool _IsMove, typename _CharT>
419 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
420 ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
421 __copy_move_a2(_CharT*, _CharT*,
422 ostreambuf_iterator<_CharT, char_traits<_CharT> >);
423
424 template<bool _IsMove, typename _CharT>
425 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
426 ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
427 __copy_move_a2(const _CharT*, const _CharT*,
428 ostreambuf_iterator<_CharT, char_traits<_CharT> >);
429
430 template<bool _IsMove, typename _CharT>
431 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
432 _CharT*>::__type
433 __copy_move_a2(istreambuf_iterator<_CharT, char_traits<_CharT> >,
434 istreambuf_iterator<_CharT, char_traits<_CharT> >, _CharT*);
435
436 template<bool _IsMove, typename _II, typename _OI>
437 inline _OI
438 __copy_move_a2(_II __first, _II __last, _OI __result)
439 {
440 return std::__niter_wrap(__result,
441 std::__copy_move_a<_IsMove>(std::__niter_base(__first),
442 std::__niter_base(__last),
443 std::__niter_base(__result)));
444 }
445
446 /**
447 * @brief Copies the range [first,last) into result.
448 * @ingroup mutating_algorithms
449 * @param __first An input iterator.
450 * @param __last An input iterator.
451 * @param __result An output iterator.
452 * @return result + (last - first)
453 *
454 * This inline function will boil down to a call to @c memmove whenever
455 * possible. Failing that, if random access iterators are passed, then the
456 * loop count will be known (and therefore a candidate for compiler
457 * optimizations such as unrolling). Result may not be contained within
458 * [first,last); the copy_backward function should be used instead.
459 *
460 * Note that the end of the output range is permitted to be contained
461 * within [first,last).
462 */
463 template<typename _II, typename _OI>
464 inline _OI
465 copy(_II __first, _II __last, _OI __result)
466 {
467 // concept requirements
468 __glibcxx_function_requires(_InputIteratorConcept<_II>)
469 __glibcxx_function_requires(_OutputIteratorConcept<_OI,
470 typename iterator_traits<_II>::value_type>)
471 __glibcxx_requires_can_increment_range(__first, __last, __result);
472
473 return std::__copy_move_a2<__is_move_iterator<_II>::__value>
474 (std::__miter_base(__first), std::__miter_base(__last), __result);
475 }
476
477 #if __cplusplus >= 201103L
478 /**
479 * @brief Moves the range [first,last) into result.
480 * @ingroup mutating_algorithms
481 * @param __first An input iterator.
482 * @param __last An input iterator.
483 * @param __result An output iterator.
484 * @return result + (last - first)
485 *
486 * This inline function will boil down to a call to @c memmove whenever
487 * possible. Failing that, if random access iterators are passed, then the
488 * loop count will be known (and therefore a candidate for compiler
489 * optimizations such as unrolling). Result may not be contained within
490 * [first,last); the move_backward function should be used instead.
491 *
492 * Note that the end of the output range is permitted to be contained
493 * within [first,last).
494 */
495 template<typename _II, typename _OI>
496 inline _OI
497 move(_II __first, _II __last, _OI __result)
498 {
499 // concept requirements
500 __glibcxx_function_requires(_InputIteratorConcept<_II>)
501 __glibcxx_function_requires(_OutputIteratorConcept<_OI,
502 typename iterator_traits<_II>::value_type>)
503 __glibcxx_requires_can_increment_range(__first, __last, __result);
504
505 return std::__copy_move_a2<true>(std::__miter_base(__first),
506 std::__miter_base(__last), __result);
507 }
508
509 #define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::move(_Tp, _Up, _Vp)
510 #else
511 #define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::copy(_Tp, _Up, _Vp)
512 #endif
513
514 template<bool, bool, typename>
515 struct __copy_move_backward
516 {
517 template<typename _BI1, typename _BI2>
518 static _BI2
519 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
520 {
521 while (__first != __last)
522 *--__result = *--__last;
523 return __result;
524 }
525 };
526
527 #if __cplusplus >= 201103L
528 template<typename _Category>
529 struct __copy_move_backward<true, false, _Category>
530 {
531 template<typename _BI1, typename _BI2>
532 static _BI2
533 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
534 {
535 while (__first != __last)
536 *--__result = std::move(*--__last);
537 return __result;
538 }
539 };
540 #endif
541
542 template<>
543 struct __copy_move_backward<false, false, random_access_iterator_tag>
544 {
545 template<typename _BI1, typename _BI2>
546 static _BI2
547 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
548 {
549 typename iterator_traits<_BI1>::difference_type __n;
550 for (__n = __last - __first; __n > 0; --__n)
551 *--__result = *--__last;
552 return __result;
553 }
554 };
555
556 #if __cplusplus >= 201103L
557 template<>
558 struct __copy_move_backward<true, false, random_access_iterator_tag>
559 {
560 template<typename _BI1, typename _BI2>
561 static _BI2
562 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
563 {
564 typename iterator_traits<_BI1>::difference_type __n;
565 for (__n = __last - __first; __n > 0; --__n)
566 *--__result = std::move(*--__last);
567 return __result;
568 }
569 };
570 #endif
571
572 template<bool _IsMove>
573 struct __copy_move_backward<_IsMove, true, random_access_iterator_tag>
574 {
575 template<typename _Tp>
576 static _Tp*
577 __copy_move_b(const _Tp* __first, const _Tp* __last, _Tp* __result)
578 {
579 #if __cplusplus >= 201103L
580 using __assignable = conditional<_IsMove,
581 is_move_assignable<_Tp>,
582 is_copy_assignable<_Tp>>;
583 // trivial types can have deleted assignment
584 static_assert( __assignable::type::value, "type is not assignable" );
585 #endif
586 const ptrdiff_t _Num = __last - __first;
587 if (_Num)
588 __builtin_memmove(__result - _Num, __first, sizeof(_Tp) * _Num);
589 return __result - _Num;
590 }
591 };
592
593 template<bool _IsMove, typename _BI1, typename _BI2>
594 inline _BI2
595 __copy_move_backward_a(_BI1 __first, _BI1 __last, _BI2 __result)
596 {
597 typedef typename iterator_traits<_BI1>::value_type _ValueType1;
598 typedef typename iterator_traits<_BI2>::value_type _ValueType2;
599 typedef typename iterator_traits<_BI1>::iterator_category _Category;
600 const bool __simple = (__is_trivially_copyable(_ValueType1)
601 && __is_pointer<_BI1>::__value
602 && __is_pointer<_BI2>::__value
603 && __are_same<_ValueType1, _ValueType2>::__value);
604
605 return std::__copy_move_backward<_IsMove, __simple,
606 _Category>::__copy_move_b(__first,
607 __last,
608 __result);
609 }
610
611 template<bool _IsMove, typename _BI1, typename _BI2>
612 inline _BI2
613 __copy_move_backward_a2(_BI1 __first, _BI1 __last, _BI2 __result)
614 {
615 return std::__niter_wrap(__result,
616 std::__copy_move_backward_a<_IsMove>
617 (std::__niter_base(__first), std::__niter_base(__last),
618 std::__niter_base(__result)));
619 }
620
621 /**
622 * @brief Copies the range [first,last) into result.
623 * @ingroup mutating_algorithms
624 * @param __first A bidirectional iterator.
625 * @param __last A bidirectional iterator.
626 * @param __result A bidirectional iterator.
627 * @return result - (last - first)
628 *
629 * The function has the same effect as copy, but starts at the end of the
630 * range and works its way to the start, returning the start of the result.
631 * This inline function will boil down to a call to @c memmove whenever
632 * possible. Failing that, if random access iterators are passed, then the
633 * loop count will be known (and therefore a candidate for compiler
634 * optimizations such as unrolling).
635 *
636 * Result may not be in the range (first,last]. Use copy instead. Note
637 * that the start of the output range may overlap [first,last).
638 */
639 template<typename _BI1, typename _BI2>
640 inline _BI2
641 copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
642 {
643 // concept requirements
644 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
645 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
646 __glibcxx_function_requires(_ConvertibleConcept<
647 typename iterator_traits<_BI1>::value_type,
648 typename iterator_traits<_BI2>::value_type>)
649 __glibcxx_requires_can_decrement_range(__first, __last, __result);
650
651 return std::__copy_move_backward_a2<__is_move_iterator<_BI1>::__value>
652 (std::__miter_base(__first), std::__miter_base(__last), __result);
653 }
654
655 #if __cplusplus >= 201103L
656 /**
657 * @brief Moves the range [first,last) into result.
658 * @ingroup mutating_algorithms
659 * @param __first A bidirectional iterator.
660 * @param __last A bidirectional iterator.
661 * @param __result A bidirectional iterator.
662 * @return result - (last - first)
663 *
664 * The function has the same effect as move, but starts at the end of the
665 * range and works its way to the start, returning the start of the result.
666 * This inline function will boil down to a call to @c memmove whenever
667 * possible. Failing that, if random access iterators are passed, then the
668 * loop count will be known (and therefore a candidate for compiler
669 * optimizations such as unrolling).
670 *
671 * Result may not be in the range (first,last]. Use move instead. Note
672 * that the start of the output range may overlap [first,last).
673 */
674 template<typename _BI1, typename _BI2>
675 inline _BI2
676 move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
677 {
678 // concept requirements
679 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
680 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
681 __glibcxx_function_requires(_ConvertibleConcept<
682 typename iterator_traits<_BI1>::value_type,
683 typename iterator_traits<_BI2>::value_type>)
684 __glibcxx_requires_can_decrement_range(__first, __last, __result);
685
686 return std::__copy_move_backward_a2<true>(std::__miter_base(__first),
687 std::__miter_base(__last),
688 __result);
689 }
690
691 #define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::move_backward(_Tp, _Up, _Vp)
692 #else
693 #define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::copy_backward(_Tp, _Up, _Vp)
694 #endif
695
696 template<typename _ForwardIterator, typename _Tp>
697 inline typename
698 __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, void>::__type
699 __fill_a(_ForwardIterator __first, _ForwardIterator __last,
700 const _Tp& __value)
701 {
702 for (; __first != __last; ++__first)
703 *__first = __value;
704 }
705
706 template<typename _ForwardIterator, typename _Tp>
707 inline typename
708 __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, void>::__type
709 __fill_a(_ForwardIterator __first, _ForwardIterator __last,
710 const _Tp& __value)
711 {
712 const _Tp __tmp = __value;
713 for (; __first != __last; ++__first)
714 *__first = __tmp;
715 }
716
717 // Specialization: for char types we can use memset.
718 template<typename _Tp>
719 inline typename
720 __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, void>::__type
721 __fill_a(_Tp* __first, _Tp* __last, const _Tp& __c)
722 {
723 const _Tp __tmp = __c;
724 if (const size_t __len = __last - __first)
725 __builtin_memset(__first, static_cast<unsigned char>(__tmp), __len);
726 }
727
728 /**
729 * @brief Fills the range [first,last) with copies of value.
730 * @ingroup mutating_algorithms
731 * @param __first A forward iterator.
732 * @param __last A forward iterator.
733 * @param __value A reference-to-const of arbitrary type.
734 * @return Nothing.
735 *
736 * This function fills a range with copies of the same value. For char
737 * types filling contiguous areas of memory, this becomes an inline call
738 * to @c memset or @c wmemset.
739 */
740 template<typename _ForwardIterator, typename _Tp>
741 inline void
742 fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
743 {
744 // concept requirements
745 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
746 _ForwardIterator>)
747 __glibcxx_requires_valid_range(__first, __last);
748
749 std::__fill_a(std::__niter_base(__first), std::__niter_base(__last),
750 __value);
751 }
752
753 template<typename _OutputIterator, typename _Size, typename _Tp>
754 inline typename
755 __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, _OutputIterator>::__type
756 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
757 {
758 for (__decltype(__n + 0) __niter = __n;
759 __niter > 0; --__niter, (void) ++__first)
760 *__first = __value;
761 return __first;
762 }
763
764 template<typename _OutputIterator, typename _Size, typename _Tp>
765 inline typename
766 __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, _OutputIterator>::__type
767 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
768 {
769 const _Tp __tmp = __value;
770 for (__decltype(__n + 0) __niter = __n;
771 __niter > 0; --__niter, (void) ++__first)
772 *__first = __tmp;
773 return __first;
774 }
775
776 template<typename _Size, typename _Tp>
777 inline typename
778 __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, _Tp*>::__type
779 __fill_n_a(_Tp* __first, _Size __n, const _Tp& __c)
780 {
781 std::__fill_a(__first, __first + __n, __c);
782 return __first + __n;
783 }
784
785 /**
786 * @brief Fills the range [first,first+n) with copies of value.
787 * @ingroup mutating_algorithms
788 * @param __first An output iterator.
789 * @param __n The count of copies to perform.
790 * @param __value A reference-to-const of arbitrary type.
791 * @return The iterator at first+n.
792 *
793 * This function fills a range with copies of the same value. For char
794 * types filling contiguous areas of memory, this becomes an inline call
795 * to @c memset or @ wmemset.
796 *
797 * _GLIBCXX_RESOLVE_LIB_DEFECTS
798 * DR 865. More algorithms that throw away information
799 */
800 template<typename _OI, typename _Size, typename _Tp>
801 inline _OI
802 fill_n(_OI __first, _Size __n, const _Tp& __value)
803 {
804 // concept requirements
805 __glibcxx_function_requires(_OutputIteratorConcept<_OI, _Tp>)
806 __glibcxx_requires_can_increment(__first, __n);
807
808 return std::__niter_wrap(__first,
809 std::__fill_n_a(std::__niter_base(__first), __n, __value));
810 }
811
812 template<bool _BoolType>
813 struct __equal
814 {
815 template<typename _II1, typename _II2>
816 static bool
817 equal(_II1 __first1, _II1 __last1, _II2 __first2)
818 {
819 for (; __first1 != __last1; ++__first1, (void) ++__first2)
820 if (!(*__first1 == *__first2))
821 return false;
822 return true;
823 }
824 };
825
826 template<>
827 struct __equal<true>
828 {
829 template<typename _Tp>
830 static bool
831 equal(const _Tp* __first1, const _Tp* __last1, const _Tp* __first2)
832 {
833 if (const size_t __len = (__last1 - __first1))
834 return !__builtin_memcmp(__first1, __first2, sizeof(_Tp) * __len);
835 return true;
836 }
837 };
838
839 template<typename _II1, typename _II2>
840 inline bool
841 __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)
842 {
843 typedef typename iterator_traits<_II1>::value_type _ValueType1;
844 typedef typename iterator_traits<_II2>::value_type _ValueType2;
845 const bool __simple = ((__is_integer<_ValueType1>::__value
846 || __is_pointer<_ValueType1>::__value)
847 && __is_pointer<_II1>::__value
848 && __is_pointer<_II2>::__value
849 && __are_same<_ValueType1, _ValueType2>::__value);
850
851 return std::__equal<__simple>::equal(__first1, __last1, __first2);
852 }
853
854 template<typename, typename>
855 struct __lc_rai
856 {
857 template<typename _II1, typename _II2>
858 static _II1
859 __newlast1(_II1, _II1 __last1, _II2, _II2)
860 { return __last1; }
861
862 template<typename _II>
863 static bool
864 __cnd2(_II __first, _II __last)
865 { return __first != __last; }
866 };
867
868 template<>
869 struct __lc_rai<random_access_iterator_tag, random_access_iterator_tag>
870 {
871 template<typename _RAI1, typename _RAI2>
872 static _RAI1
873 __newlast1(_RAI1 __first1, _RAI1 __last1,
874 _RAI2 __first2, _RAI2 __last2)
875 {
876 const typename iterator_traits<_RAI1>::difference_type
877 __diff1 = __last1 - __first1;
878 const typename iterator_traits<_RAI2>::difference_type
879 __diff2 = __last2 - __first2;
880 return __diff2 < __diff1 ? __first1 + __diff2 : __last1;
881 }
882
883 template<typename _RAI>
884 static bool
885 __cnd2(_RAI, _RAI)
886 { return true; }
887 };
888
889 template<typename _II1, typename _II2, typename _Compare>
890 bool
891 __lexicographical_compare_impl(_II1 __first1, _II1 __last1,
892 _II2 __first2, _II2 __last2,
893 _Compare __comp)
894 {
895 typedef typename iterator_traits<_II1>::iterator_category _Category1;
896 typedef typename iterator_traits<_II2>::iterator_category _Category2;
897 typedef std::__lc_rai<_Category1, _Category2> __rai_type;
898
899 __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
900 for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
901 ++__first1, (void)++__first2)
902 {
903 if (__comp(__first1, __first2))
904 return true;
905 if (__comp(__first2, __first1))
906 return false;
907 }
908 return __first1 == __last1 && __first2 != __last2;
909 }
910
911 template<bool _BoolType>
912 struct __lexicographical_compare
913 {
914 template<typename _II1, typename _II2>
915 static bool __lc(_II1, _II1, _II2, _II2);
916 };
917
918 template<bool _BoolType>
919 template<typename _II1, typename _II2>
920 bool
921 __lexicographical_compare<_BoolType>::
922 __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
923 {
924 return std::__lexicographical_compare_impl(__first1, __last1,
925 __first2, __last2,
926 __gnu_cxx::__ops::__iter_less_iter());
927 }
928
929 template<>
930 struct __lexicographical_compare<true>
931 {
932 template<typename _Tp, typename _Up>
933 static bool
934 __lc(const _Tp* __first1, const _Tp* __last1,
935 const _Up* __first2, const _Up* __last2)
936 {
937 const size_t __len1 = __last1 - __first1;
938 const size_t __len2 = __last2 - __first2;
939 if (const size_t __len = std::min(__len1, __len2))
940 if (int __result = __builtin_memcmp(__first1, __first2, __len))
941 return __result < 0;
942 return __len1 < __len2;
943 }
944 };
945
946 template<typename _II1, typename _II2>
947 inline bool
948 __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
949 _II2 __first2, _II2 __last2)
950 {
951 typedef typename iterator_traits<_II1>::value_type _ValueType1;
952 typedef typename iterator_traits<_II2>::value_type _ValueType2;
953 const bool __simple =
954 (__is_byte<_ValueType1>::__value && __is_byte<_ValueType2>::__value
955 && !__gnu_cxx::__numeric_traits<_ValueType1>::__is_signed
956 && !__gnu_cxx::__numeric_traits<_ValueType2>::__is_signed
957 && __is_pointer<_II1>::__value
958 && __is_pointer<_II2>::__value);
959
960 return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
961 __first2, __last2);
962 }
963
964 template<typename _ForwardIterator, typename _Tp, typename _Compare>
965 _ForwardIterator
966 __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
967 const _Tp& __val, _Compare __comp)
968 {
969 typedef typename iterator_traits<_ForwardIterator>::difference_type
970 _DistanceType;
971
972 _DistanceType __len = std::distance(__first, __last);
973
974 while (__len > 0)
975 {
976 _DistanceType __half = __len >> 1;
977 _ForwardIterator __middle = __first;
978 std::advance(__middle, __half);
979 if (__comp(__middle, __val))
980 {
981 __first = __middle;
982 ++__first;
983 __len = __len - __half - 1;
984 }
985 else
986 __len = __half;
987 }
988 return __first;
989 }
990
991 /**
992 * @brief Finds the first position in which @a val could be inserted
993 * without changing the ordering.
994 * @param __first An iterator.
995 * @param __last Another iterator.
996 * @param __val The search term.
997 * @return An iterator pointing to the first element <em>not less
998 * than</em> @a val, or end() if every element is less than
999 * @a val.
1000 * @ingroup binary_search_algorithms
1001 */
1002 template<typename _ForwardIterator, typename _Tp>
1003 inline _ForwardIterator
1004 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1005 const _Tp& __val)
1006 {
1007 // concept requirements
1008 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1009 __glibcxx_function_requires(_LessThanOpConcept<
1010 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
1011 __glibcxx_requires_partitioned_lower(__first, __last, __val);
1012
1013 return std::__lower_bound(__first, __last, __val,
1014 __gnu_cxx::__ops::__iter_less_val());
1015 }
1016
1017 /// This is a helper function for the sort routines and for random.tcc.
1018 // Precondition: __n > 0.
1019 inline _GLIBCXX_CONSTEXPR int
1020 __lg(int __n)
1021 { return (int)sizeof(int) * __CHAR_BIT__ - 1 - __builtin_clz(__n); }
1022
1023 inline _GLIBCXX_CONSTEXPR unsigned
1024 __lg(unsigned __n)
1025 { return (int)sizeof(int) * __CHAR_BIT__ - 1 - __builtin_clz(__n); }
1026
1027 inline _GLIBCXX_CONSTEXPR long
1028 __lg(long __n)
1029 { return (int)sizeof(long) * __CHAR_BIT__ - 1 - __builtin_clzl(__n); }
1030
1031 inline _GLIBCXX_CONSTEXPR unsigned long
1032 __lg(unsigned long __n)
1033 { return (int)sizeof(long) * __CHAR_BIT__ - 1 - __builtin_clzl(__n); }
1034
1035 inline _GLIBCXX_CONSTEXPR long long
1036 __lg(long long __n)
1037 { return (int)sizeof(long long) * __CHAR_BIT__ - 1 - __builtin_clzll(__n); }
1038
1039 inline _GLIBCXX_CONSTEXPR unsigned long long
1040 __lg(unsigned long long __n)
1041 { return (int)sizeof(long long) * __CHAR_BIT__ - 1 - __builtin_clzll(__n); }
1042
1043 _GLIBCXX_BEGIN_NAMESPACE_ALGO
1044
1045 /**
1046 * @brief Tests a range for element-wise equality.
1047 * @ingroup non_mutating_algorithms
1048 * @param __first1 An input iterator.
1049 * @param __last1 An input iterator.
1050 * @param __first2 An input iterator.
1051 * @return A boolean true or false.
1052 *
1053 * This compares the elements of two ranges using @c == and returns true or
1054 * false depending on whether all of the corresponding elements of the
1055 * ranges are equal.
1056 */
1057 template<typename _II1, typename _II2>
1058 inline bool
1059 equal(_II1 __first1, _II1 __last1, _II2 __first2)
1060 {
1061 // concept requirements
1062 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1063 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1064 __glibcxx_function_requires(_EqualOpConcept<
1065 typename iterator_traits<_II1>::value_type,
1066 typename iterator_traits<_II2>::value_type>)
1067 __glibcxx_requires_can_increment_range(__first1, __last1, __first2);
1068
1069 return std::__equal_aux(std::__niter_base(__first1),
1070 std::__niter_base(__last1),
1071 std::__niter_base(__first2));
1072 }
1073
1074 /**
1075 * @brief Tests a range for element-wise equality.
1076 * @ingroup non_mutating_algorithms
1077 * @param __first1 An input iterator.
1078 * @param __last1 An input iterator.
1079 * @param __first2 An input iterator.
1080 * @param __binary_pred A binary predicate @link functors
1081 * functor@endlink.
1082 * @return A boolean true or false.
1083 *
1084 * This compares the elements of two ranges using the binary_pred
1085 * parameter, and returns true or
1086 * false depending on whether all of the corresponding elements of the
1087 * ranges are equal.
1088 */
1089 template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1090 inline bool
1091 equal(_IIter1 __first1, _IIter1 __last1,
1092 _IIter2 __first2, _BinaryPredicate __binary_pred)
1093 {
1094 // concept requirements
1095 __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1096 __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1097 __glibcxx_requires_valid_range(__first1, __last1);
1098
1099 for (; __first1 != __last1; ++__first1, (void)++__first2)
1100 if (!bool(__binary_pred(*__first1, *__first2)))
1101 return false;
1102 return true;
1103 }
1104
1105 #if __cplusplus >= 201103L
1106 // 4-iterator version of std::equal<It1, It2> for use in C++11.
1107 template<typename _II1, typename _II2>
1108 inline bool
1109 __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1110 {
1111 using _RATag = random_access_iterator_tag;
1112 using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1113 using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1114 using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1115 if (_RAIters())
1116 {
1117 auto __d1 = std::distance(__first1, __last1);
1118 auto __d2 = std::distance(__first2, __last2);
1119 if (__d1 != __d2)
1120 return false;
1121 return _GLIBCXX_STD_A::equal(__first1, __last1, __first2);
1122 }
1123
1124 for (; __first1 != __last1 && __first2 != __last2;
1125 ++__first1, (void)++__first2)
1126 if (!(*__first1 == *__first2))
1127 return false;
1128 return __first1 == __last1 && __first2 == __last2;
1129 }
1130
1131 // 4-iterator version of std::equal<It1, It2, BinaryPred> for use in C++11.
1132 template<typename _II1, typename _II2, typename _BinaryPredicate>
1133 inline bool
1134 __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2,
1135 _BinaryPredicate __binary_pred)
1136 {
1137 using _RATag = random_access_iterator_tag;
1138 using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1139 using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1140 using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1141 if (_RAIters())
1142 {
1143 auto __d1 = std::distance(__first1, __last1);
1144 auto __d2 = std::distance(__first2, __last2);
1145 if (__d1 != __d2)
1146 return false;
1147 return _GLIBCXX_STD_A::equal(__first1, __last1, __first2,
1148 __binary_pred);
1149 }
1150
1151 for (; __first1 != __last1 && __first2 != __last2;
1152 ++__first1, (void)++__first2)
1153 if (!bool(__binary_pred(*__first1, *__first2)))
1154 return false;
1155 return __first1 == __last1 && __first2 == __last2;
1156 }
1157 #endif // C++11
1158
1159 #if __cplusplus > 201103L
1160
1161 #define __cpp_lib_robust_nonmodifying_seq_ops 201304
1162
1163 /**
1164 * @brief Tests a range for element-wise equality.
1165 * @ingroup non_mutating_algorithms
1166 * @param __first1 An input iterator.
1167 * @param __last1 An input iterator.
1168 * @param __first2 An input iterator.
1169 * @param __last2 An input iterator.
1170 * @return A boolean true or false.
1171 *
1172 * This compares the elements of two ranges using @c == and returns true or
1173 * false depending on whether all of the corresponding elements of the
1174 * ranges are equal.
1175 */
1176 template<typename _II1, typename _II2>
1177 inline bool
1178 equal(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1179 {
1180 // concept requirements
1181 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1182 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1183 __glibcxx_function_requires(_EqualOpConcept<
1184 typename iterator_traits<_II1>::value_type,
1185 typename iterator_traits<_II2>::value_type>)
1186 __glibcxx_requires_valid_range(__first1, __last1);
1187 __glibcxx_requires_valid_range(__first2, __last2);
1188
1189 return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2);
1190 }
1191
1192 /**
1193 * @brief Tests a range for element-wise equality.
1194 * @ingroup non_mutating_algorithms
1195 * @param __first1 An input iterator.
1196 * @param __last1 An input iterator.
1197 * @param __first2 An input iterator.
1198 * @param __last2 An input iterator.
1199 * @param __binary_pred A binary predicate @link functors
1200 * functor@endlink.
1201 * @return A boolean true or false.
1202 *
1203 * This compares the elements of two ranges using the binary_pred
1204 * parameter, and returns true or
1205 * false depending on whether all of the corresponding elements of the
1206 * ranges are equal.
1207 */
1208 template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1209 inline bool
1210 equal(_IIter1 __first1, _IIter1 __last1,
1211 _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
1212 {
1213 // concept requirements
1214 __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1215 __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1216 __glibcxx_requires_valid_range(__first1, __last1);
1217 __glibcxx_requires_valid_range(__first2, __last2);
1218
1219 return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2,
1220 __binary_pred);
1221 }
1222 #endif // C++14
1223
1224 /**
1225 * @brief Performs @b dictionary comparison on ranges.
1226 * @ingroup sorting_algorithms
1227 * @param __first1 An input iterator.
1228 * @param __last1 An input iterator.
1229 * @param __first2 An input iterator.
1230 * @param __last2 An input iterator.
1231 * @return A boolean true or false.
1232 *
1233 * <em>Returns true if the sequence of elements defined by the range
1234 * [first1,last1) is lexicographically less than the sequence of elements
1235 * defined by the range [first2,last2). Returns false otherwise.</em>
1236 * (Quoted from [25.3.8]/1.) If the iterators are all character pointers,
1237 * then this is an inline call to @c memcmp.
1238 */
1239 template<typename _II1, typename _II2>
1240 inline bool
1241 lexicographical_compare(_II1 __first1, _II1 __last1,
1242 _II2 __first2, _II2 __last2)
1243 {
1244 #ifdef _GLIBCXX_CONCEPT_CHECKS
1245 // concept requirements
1246 typedef typename iterator_traits<_II1>::value_type _ValueType1;
1247 typedef typename iterator_traits<_II2>::value_type _ValueType2;
1248 #endif
1249 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1250 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1251 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
1252 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
1253 __glibcxx_requires_valid_range(__first1, __last1);
1254 __glibcxx_requires_valid_range(__first2, __last2);
1255
1256 return std::__lexicographical_compare_aux(std::__niter_base(__first1),
1257 std::__niter_base(__last1),
1258 std::__niter_base(__first2),
1259 std::__niter_base(__last2));
1260 }
1261
1262 /**
1263 * @brief Performs @b dictionary comparison on ranges.
1264 * @ingroup sorting_algorithms
1265 * @param __first1 An input iterator.
1266 * @param __last1 An input iterator.
1267 * @param __first2 An input iterator.
1268 * @param __last2 An input iterator.
1269 * @param __comp A @link comparison_functors comparison functor@endlink.
1270 * @return A boolean true or false.
1271 *
1272 * The same as the four-parameter @c lexicographical_compare, but uses the
1273 * comp parameter instead of @c <.
1274 */
1275 template<typename _II1, typename _II2, typename _Compare>
1276 inline bool
1277 lexicographical_compare(_II1 __first1, _II1 __last1,
1278 _II2 __first2, _II2 __last2, _Compare __comp)
1279 {
1280 // concept requirements
1281 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1282 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1283 __glibcxx_requires_valid_range(__first1, __last1);
1284 __glibcxx_requires_valid_range(__first2, __last2);
1285
1286 return std::__lexicographical_compare_impl
1287 (__first1, __last1, __first2, __last2,
1288 __gnu_cxx::__ops::__iter_comp_iter(__comp));
1289 }
1290
1291 template<typename _InputIterator1, typename _InputIterator2,
1292 typename _BinaryPredicate>
1293 pair<_InputIterator1, _InputIterator2>
1294 __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1295 _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1296 {
1297 while (__first1 != __last1 && __binary_pred(__first1, __first2))
1298 {
1299 ++__first1;
1300 ++__first2;
1301 }
1302 return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
1303 }
1304
1305 /**
1306 * @brief Finds the places in ranges which don't match.
1307 * @ingroup non_mutating_algorithms
1308 * @param __first1 An input iterator.
1309 * @param __last1 An input iterator.
1310 * @param __first2 An input iterator.
1311 * @return A pair of iterators pointing to the first mismatch.
1312 *
1313 * This compares the elements of two ranges using @c == and returns a pair
1314 * of iterators. The first iterator points into the first range, the
1315 * second iterator points into the second range, and the elements pointed
1316 * to by the iterators are not equal.
1317 */
1318 template<typename _InputIterator1, typename _InputIterator2>
1319 inline pair<_InputIterator1, _InputIterator2>
1320 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1321 _InputIterator2 __first2)
1322 {
1323 // concept requirements
1324 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1325 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1326 __glibcxx_function_requires(_EqualOpConcept<
1327 typename iterator_traits<_InputIterator1>::value_type,
1328 typename iterator_traits<_InputIterator2>::value_type>)
1329 __glibcxx_requires_valid_range(__first1, __last1);
1330
1331 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1332 __gnu_cxx::__ops::__iter_equal_to_iter());
1333 }
1334
1335 /**
1336 * @brief Finds the places in ranges which don't match.
1337 * @ingroup non_mutating_algorithms
1338 * @param __first1 An input iterator.
1339 * @param __last1 An input iterator.
1340 * @param __first2 An input iterator.
1341 * @param __binary_pred A binary predicate @link functors
1342 * functor@endlink.
1343 * @return A pair of iterators pointing to the first mismatch.
1344 *
1345 * This compares the elements of two ranges using the binary_pred
1346 * parameter, and returns a pair
1347 * of iterators. The first iterator points into the first range, the
1348 * second iterator points into the second range, and the elements pointed
1349 * to by the iterators are not equal.
1350 */
1351 template<typename _InputIterator1, typename _InputIterator2,
1352 typename _BinaryPredicate>
1353 inline pair<_InputIterator1, _InputIterator2>
1354 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1355 _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1356 {
1357 // concept requirements
1358 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1359 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1360 __glibcxx_requires_valid_range(__first1, __last1);
1361
1362 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1363 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
1364 }
1365
1366 #if __cplusplus > 201103L
1367
1368 template<typename _InputIterator1, typename _InputIterator2,
1369 typename _BinaryPredicate>
1370 pair<_InputIterator1, _InputIterator2>
1371 __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1372 _InputIterator2 __first2, _InputIterator2 __last2,
1373 _BinaryPredicate __binary_pred)
1374 {
1375 while (__first1 != __last1 && __first2 != __last2
1376 && __binary_pred(__first1, __first2))
1377 {
1378 ++__first1;
1379 ++__first2;
1380 }
1381 return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
1382 }
1383
1384 /**
1385 * @brief Finds the places in ranges which don't match.
1386 * @ingroup non_mutating_algorithms
1387 * @param __first1 An input iterator.
1388 * @param __last1 An input iterator.
1389 * @param __first2 An input iterator.
1390 * @param __last2 An input iterator.
1391 * @return A pair of iterators pointing to the first mismatch.
1392 *
1393 * This compares the elements of two ranges using @c == and returns a pair
1394 * of iterators. The first iterator points into the first range, the
1395 * second iterator points into the second range, and the elements pointed
1396 * to by the iterators are not equal.
1397 */
1398 template<typename _InputIterator1, typename _InputIterator2>
1399 inline pair<_InputIterator1, _InputIterator2>
1400 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1401 _InputIterator2 __first2, _InputIterator2 __last2)
1402 {
1403 // concept requirements
1404 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1405 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1406 __glibcxx_function_requires(_EqualOpConcept<
1407 typename iterator_traits<_InputIterator1>::value_type,
1408 typename iterator_traits<_InputIterator2>::value_type>)
1409 __glibcxx_requires_valid_range(__first1, __last1);
1410 __glibcxx_requires_valid_range(__first2, __last2);
1411
1412 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
1413 __gnu_cxx::__ops::__iter_equal_to_iter());
1414 }
1415
1416 /**
1417 * @brief Finds the places in ranges which don't match.
1418 * @ingroup non_mutating_algorithms
1419 * @param __first1 An input iterator.
1420 * @param __last1 An input iterator.
1421 * @param __first2 An input iterator.
1422 * @param __last2 An input iterator.
1423 * @param __binary_pred A binary predicate @link functors
1424 * functor@endlink.
1425 * @return A pair of iterators pointing to the first mismatch.
1426 *
1427 * This compares the elements of two ranges using the binary_pred
1428 * parameter, and returns a pair
1429 * of iterators. The first iterator points into the first range, the
1430 * second iterator points into the second range, and the elements pointed
1431 * to by the iterators are not equal.
1432 */
1433 template<typename _InputIterator1, typename _InputIterator2,
1434 typename _BinaryPredicate>
1435 inline pair<_InputIterator1, _InputIterator2>
1436 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1437 _InputIterator2 __first2, _InputIterator2 __last2,
1438 _BinaryPredicate __binary_pred)
1439 {
1440 // concept requirements
1441 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1442 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1443 __glibcxx_requires_valid_range(__first1, __last1);
1444 __glibcxx_requires_valid_range(__first2, __last2);
1445
1446 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
1447 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
1448 }
1449 #endif
1450
1451 _GLIBCXX_END_NAMESPACE_ALGO
1452 _GLIBCXX_END_NAMESPACE_VERSION
1453 } // namespace std
1454
1455 // NB: This file is included within many other C++ includes, as a way
1456 // of getting the base algorithms. So, make sure that parallel bits
1457 // come in too if requested.
1458 #ifdef _GLIBCXX_PARALLEL
1459 # include <parallel/algobase.h>
1460 #endif
1461
1462 #endif
1463