1// Core algorithmic facilities -*- C++ -*-
2
3// Copyright (C) 2001-2024 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#if __cplusplus >= 201402L
76# include <bit> // std::__bit_width
77#endif
78#if __cplusplus >= 202002L
79# include <compare>
80#endif
81
82namespace std _GLIBCXX_VISIBILITY(default)
83{
84_GLIBCXX_BEGIN_NAMESPACE_VERSION
85
86 /*
87 * A constexpr wrapper for __builtin_memcmp.
88 * @param __num The number of elements of type _Tp (not bytes).
89 */
90 template<typename _Tp, typename _Up>
91 _GLIBCXX14_CONSTEXPR
92 inline int
93 __memcmp(const _Tp* __first1, const _Up* __first2, size_t __num)
94 {
95#if __cplusplus >= 201103L
96 static_assert(sizeof(_Tp) == sizeof(_Up), "can be compared with memcmp");
97#endif
98#ifdef __cpp_lib_is_constant_evaluated
99 if (std::is_constant_evaluated())
100 {
101 for(; __num > 0; ++__first1, ++__first2, --__num)
102 if (*__first1 != *__first2)
103 return *__first1 < *__first2 ? -1 : 1;
104 return 0;
105 }
106 else
107#endif
108 return __builtin_memcmp(__first1, __first2, sizeof(_Tp) * __num);
109 }
110
111#if __cplusplus < 201103L
112 // See http://gcc.gnu.org/ml/libstdc++/2004-08/msg00167.html: in a
113 // nutshell, we are partially implementing the resolution of DR 187,
114 // when it's safe, i.e., the value_types are equal.
115 template<bool _BoolType>
116 struct __iter_swap
117 {
118 template<typename _ForwardIterator1, typename _ForwardIterator2>
119 static void
120 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
121 {
122 typedef typename iterator_traits<_ForwardIterator1>::value_type
123 _ValueType1;
124 _ValueType1 __tmp = *__a;
125 *__a = *__b;
126 *__b = __tmp;
127 }
128 };
129
130 template<>
131 struct __iter_swap<true>
132 {
133 template<typename _ForwardIterator1, typename _ForwardIterator2>
134 static void
135 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
136 {
137 swap(*__a, *__b);
138 }
139 };
140#endif // C++03
141
142 /**
143 * @brief Swaps the contents of two iterators.
144 * @ingroup mutating_algorithms
145 * @param __a An iterator.
146 * @param __b Another iterator.
147 * @return Nothing.
148 *
149 * This function swaps the values pointed to by two iterators, not the
150 * iterators themselves.
151 */
152 template<typename _ForwardIterator1, typename _ForwardIterator2>
153 _GLIBCXX20_CONSTEXPR
154 inline void
155 iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
156 {
157 // concept requirements
158 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
159 _ForwardIterator1>)
160 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
161 _ForwardIterator2>)
162
163#if __cplusplus < 201103L
164 typedef typename iterator_traits<_ForwardIterator1>::value_type
165 _ValueType1;
166 typedef typename iterator_traits<_ForwardIterator2>::value_type
167 _ValueType2;
168
169 __glibcxx_function_requires(_ConvertibleConcept<_ValueType1,
170 _ValueType2>)
171 __glibcxx_function_requires(_ConvertibleConcept<_ValueType2,
172 _ValueType1>)
173
174 typedef typename iterator_traits<_ForwardIterator1>::reference
175 _ReferenceType1;
176 typedef typename iterator_traits<_ForwardIterator2>::reference
177 _ReferenceType2;
178 std::__iter_swap<__are_same<_ValueType1, _ValueType2>::__value
179 && __are_same<_ValueType1&, _ReferenceType1>::__value
180 && __are_same<_ValueType2&, _ReferenceType2>::__value>::
181 iter_swap(__a, __b);
182#else
183 // _GLIBCXX_RESOLVE_LIB_DEFECTS
184 // 187. iter_swap underspecified
185 swap(*__a, *__b);
186#endif
187 }
188
189 /**
190 * @brief Swap the elements of two sequences.
191 * @ingroup mutating_algorithms
192 * @param __first1 A forward iterator.
193 * @param __last1 A forward iterator.
194 * @param __first2 A forward iterator.
195 * @return An iterator equal to @p first2+(last1-first1).
196 *
197 * Swaps each element in the range @p [first1,last1) with the
198 * corresponding element in the range @p [first2,(last1-first1)).
199 * The ranges must not overlap.
200 */
201 template<typename _ForwardIterator1, typename _ForwardIterator2>
202 _GLIBCXX20_CONSTEXPR
203 _ForwardIterator2
204 swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
205 _ForwardIterator2 __first2)
206 {
207 // concept requirements
208 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
209 _ForwardIterator1>)
210 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
211 _ForwardIterator2>)
212 __glibcxx_requires_valid_range(__first1, __last1);
213
214 for (; __first1 != __last1; ++__first1, (void)++__first2)
215 std::iter_swap(__first1, __first2);
216 return __first2;
217 }
218
219 /**
220 * @brief This does what you think it does.
221 * @ingroup sorting_algorithms
222 * @param __a A thing of arbitrary type.
223 * @param __b Another thing of arbitrary type.
224 * @return The lesser of the parameters.
225 *
226 * This is the simple classic generic implementation. It will work on
227 * temporary expressions, since they are only evaluated once, unlike a
228 * preprocessor macro.
229 */
230 template<typename _Tp>
231 _GLIBCXX_NODISCARD _GLIBCXX14_CONSTEXPR
232 inline const _Tp&
233 min(const _Tp& __a, const _Tp& __b)
234 {
235 // concept requirements
236 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
237 //return __b < __a ? __b : __a;
238 if (__b < __a)
239 return __b;
240 return __a;
241 }
242
243 /**
244 * @brief This does what you think it does.
245 * @ingroup sorting_algorithms
246 * @param __a A thing of arbitrary type.
247 * @param __b Another thing of arbitrary type.
248 * @return The greater of the parameters.
249 *
250 * This is the simple classic generic implementation. It will work on
251 * temporary expressions, since they are only evaluated once, unlike a
252 * preprocessor macro.
253 */
254 template<typename _Tp>
255 _GLIBCXX_NODISCARD _GLIBCXX14_CONSTEXPR
256 inline const _Tp&
257 max(const _Tp& __a, const _Tp& __b)
258 {
259 // concept requirements
260 __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
261 //return __a < __b ? __b : __a;
262 if (__a < __b)
263 return __b;
264 return __a;
265 }
266
267 /**
268 * @brief This does what you think it does.
269 * @ingroup sorting_algorithms
270 * @param __a A thing of arbitrary type.
271 * @param __b Another thing of arbitrary type.
272 * @param __comp A @link comparison_functors comparison functor@endlink.
273 * @return The lesser of the parameters.
274 *
275 * This will work on temporary expressions, since they are only evaluated
276 * once, unlike a preprocessor macro.
277 */
278 template<typename _Tp, typename _Compare>
279 _GLIBCXX_NODISCARD _GLIBCXX14_CONSTEXPR
280 inline const _Tp&
281 min(const _Tp& __a, const _Tp& __b, _Compare __comp)
282 {
283 //return __comp(__b, __a) ? __b : __a;
284 if (__comp(__b, __a))
285 return __b;
286 return __a;
287 }
288
289 /**
290 * @brief This does what you think it does.
291 * @ingroup sorting_algorithms
292 * @param __a A thing of arbitrary type.
293 * @param __b Another thing of arbitrary type.
294 * @param __comp A @link comparison_functors comparison functor@endlink.
295 * @return The greater of the parameters.
296 *
297 * This will work on temporary expressions, since they are only evaluated
298 * once, unlike a preprocessor macro.
299 */
300 template<typename _Tp, typename _Compare>
301 _GLIBCXX_NODISCARD _GLIBCXX14_CONSTEXPR
302 inline const _Tp&
303 max(const _Tp& __a, const _Tp& __b, _Compare __comp)
304 {
305 //return __comp(__a, __b) ? __b : __a;
306 if (__comp(__a, __b))
307 return __b;
308 return __a;
309 }
310
311 // Fallback implementation of the function in bits/stl_iterator.h used to
312 // remove the __normal_iterator wrapper. See copy, fill, ...
313 template<typename _Iterator>
314 _GLIBCXX20_CONSTEXPR
315 inline _Iterator
316 __niter_base(_Iterator __it)
317 _GLIBCXX_NOEXCEPT_IF(std::is_nothrow_copy_constructible<_Iterator>::value)
318 { return __it; }
319
320#if __cplusplus < 201103L
321 template<typename _Ite, typename _Seq>
322 _Ite
323 __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
324 std::random_access_iterator_tag>&);
325
326 template<typename _Ite, typename _Cont, typename _Seq>
327 _Ite
328 __niter_base(const ::__gnu_debug::_Safe_iterator<
329 ::__gnu_cxx::__normal_iterator<_Ite, _Cont>, _Seq,
330 std::random_access_iterator_tag>&);
331#else
332 template<typename _Ite, typename _Seq>
333 _GLIBCXX20_CONSTEXPR
334 decltype(std::__niter_base(std::declval<_Ite>()))
335 __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
336 std::random_access_iterator_tag>&)
337 noexcept(std::is_nothrow_copy_constructible<_Ite>::value);
338#endif
339
340 // Reverse the __niter_base transformation to get a
341 // __normal_iterator back again (this assumes that __normal_iterator
342 // is only used to wrap random access iterators, like pointers).
343 template<typename _From, typename _To>
344 _GLIBCXX20_CONSTEXPR
345 inline _From
346 __niter_wrap(_From __from, _To __res)
347 { return __from + (std::__niter_base(__res) - std::__niter_base(__from)); }
348
349 // No need to wrap, iterator already has the right type.
350 template<typename _Iterator>
351 _GLIBCXX20_CONSTEXPR
352 inline _Iterator
353 __niter_wrap(const _Iterator&, _Iterator __res)
354 { return __res; }
355
356 // All of these auxiliary structs serve two purposes. (1) Replace
357 // calls to copy with memmove whenever possible. (Memmove, not memcpy,
358 // because the input and output ranges are permitted to overlap.)
359 // (2) If we're using random access iterators, then write the loop as
360 // a for loop with an explicit count.
361
362 template<bool _IsMove, bool _IsSimple, typename _Category>
363 struct __copy_move
364 {
365 template<typename _II, typename _OI>
366 _GLIBCXX20_CONSTEXPR
367 static _OI
368 __copy_m(_II __first, _II __last, _OI __result)
369 {
370 for (; __first != __last; ++__result, (void)++__first)
371 *__result = *__first;
372 return __result;
373 }
374 };
375
376#if __cplusplus >= 201103L
377 template<typename _Category>
378 struct __copy_move<true, false, _Category>
379 {
380 template<typename _II, typename _OI>
381 _GLIBCXX20_CONSTEXPR
382 static _OI
383 __copy_m(_II __first, _II __last, _OI __result)
384 {
385 for (; __first != __last; ++__result, (void)++__first)
386 *__result = std::move(*__first);
387 return __result;
388 }
389 };
390#endif
391
392 template<>
393 struct __copy_move<false, false, random_access_iterator_tag>
394 {
395 template<typename _II, typename _OI>
396 _GLIBCXX20_CONSTEXPR
397 static _OI
398 __copy_m(_II __first, _II __last, _OI __result)
399 {
400 typedef typename iterator_traits<_II>::difference_type _Distance;
401 for(_Distance __n = __last - __first; __n > 0; --__n)
402 {
403 *__result = *__first;
404 ++__first;
405 ++__result;
406 }
407 return __result;
408 }
409
410 template<typename _Tp, typename _Up>
411 static void
412 __assign_one(_Tp* __to, _Up* __from)
413 { *__to = *__from; }
414 };
415
416#if __cplusplus >= 201103L
417 template<>
418 struct __copy_move<true, false, random_access_iterator_tag>
419 {
420 template<typename _II, typename _OI>
421 _GLIBCXX20_CONSTEXPR
422 static _OI
423 __copy_m(_II __first, _II __last, _OI __result)
424 {
425 typedef typename iterator_traits<_II>::difference_type _Distance;
426 for(_Distance __n = __last - __first; __n > 0; --__n)
427 {
428 *__result = std::move(*__first);
429 ++__first;
430 ++__result;
431 }
432 return __result;
433 }
434
435 template<typename _Tp, typename _Up>
436 static void
437 __assign_one(_Tp* __to, _Up* __from)
438 { *__to = std::move(*__from); }
439 };
440#endif
441
442 template<bool _IsMove>
443 struct __copy_move<_IsMove, true, random_access_iterator_tag>
444 {
445 template<typename _Tp, typename _Up>
446 _GLIBCXX20_CONSTEXPR
447 static _Up*
448 __copy_m(_Tp* __first, _Tp* __last, _Up* __result)
449 {
450 const ptrdiff_t _Num = __last - __first;
451 if (__builtin_expect(_Num > 1, true))
452 __builtin_memmove(__result, __first, sizeof(_Tp) * _Num);
453 else if (_Num == 1)
454 std::__copy_move<_IsMove, false, random_access_iterator_tag>::
455 __assign_one(__result, __first);
456 return __result + _Num;
457 }
458 };
459
460_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
461
462 template<typename _Tp, typename _Ref, typename _Ptr>
463 struct _Deque_iterator;
464
465 struct _Bit_iterator;
466
467_GLIBCXX_END_NAMESPACE_CONTAINER
468
469#if _GLIBCXX_HOSTED
470 // Helpers for streambuf iterators (either istream or ostream).
471 // NB: avoid including <iosfwd>, relatively large.
472 template<typename _CharT>
473 struct char_traits;
474
475 template<typename _CharT, typename _Traits>
476 class istreambuf_iterator;
477
478 template<typename _CharT, typename _Traits>
479 class ostreambuf_iterator;
480
481 template<bool _IsMove, typename _CharT>
482 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
483 ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
484 __copy_move_a2(_CharT*, _CharT*,
485 ostreambuf_iterator<_CharT, char_traits<_CharT> >);
486
487 template<bool _IsMove, typename _CharT>
488 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
489 ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
490 __copy_move_a2(const _CharT*, const _CharT*,
491 ostreambuf_iterator<_CharT, char_traits<_CharT> >);
492
493 template<bool _IsMove, typename _CharT>
494 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
495 _CharT*>::__type
496 __copy_move_a2(istreambuf_iterator<_CharT, char_traits<_CharT> >,
497 istreambuf_iterator<_CharT, char_traits<_CharT> >, _CharT*);
498
499 template<bool _IsMove, typename _CharT>
500 typename __gnu_cxx::__enable_if<
501 __is_char<_CharT>::__value,
502 _GLIBCXX_STD_C::_Deque_iterator<_CharT, _CharT&, _CharT*> >::__type
503 __copy_move_a2(
504 istreambuf_iterator<_CharT, char_traits<_CharT> >,
505 istreambuf_iterator<_CharT, char_traits<_CharT> >,
506 _GLIBCXX_STD_C::_Deque_iterator<_CharT, _CharT&, _CharT*>);
507#endif // HOSTED
508
509 template<bool _IsMove, typename _II, typename _OI>
510 _GLIBCXX20_CONSTEXPR
511 inline _OI
512 __copy_move_a2(_II __first, _II __last, _OI __result)
513 {
514 typedef typename iterator_traits<_II>::iterator_category _Category;
515#ifdef __cpp_lib_is_constant_evaluated
516 if (std::is_constant_evaluated())
517 return std::__copy_move<_IsMove, false, _Category>::
518 __copy_m(__first, __last, __result);
519#endif
520 return std::__copy_move<_IsMove, __memcpyable<_OI, _II>::__value,
521 _Category>::__copy_m(__first, __last, __result);
522 }
523
524 template<bool _IsMove,
525 typename _Tp, typename _Ref, typename _Ptr, typename _OI>
526 _OI
527 __copy_move_a1(_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
528 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
529 _OI);
530
531 template<bool _IsMove,
532 typename _ITp, typename _IRef, typename _IPtr, typename _OTp>
533 _GLIBCXX_STD_C::_Deque_iterator<_OTp, _OTp&, _OTp*>
534 __copy_move_a1(_GLIBCXX_STD_C::_Deque_iterator<_ITp, _IRef, _IPtr>,
535 _GLIBCXX_STD_C::_Deque_iterator<_ITp, _IRef, _IPtr>,
536 _GLIBCXX_STD_C::_Deque_iterator<_OTp, _OTp&, _OTp*>);
537
538 template<bool _IsMove, typename _II, typename _Tp>
539 typename __gnu_cxx::__enable_if<
540 __is_random_access_iter<_II>::__value,
541 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*> >::__type
542 __copy_move_a1(_II, _II, _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>);
543
544 template<bool _IsMove, typename _II, typename _OI>
545 _GLIBCXX20_CONSTEXPR
546 inline _OI
547 __copy_move_a1(_II __first, _II __last, _OI __result)
548 { return std::__copy_move_a2<_IsMove>(__first, __last, __result); }
549
550 template<bool _IsMove, typename _II, typename _OI>
551 _GLIBCXX20_CONSTEXPR
552 inline _OI
553 __copy_move_a(_II __first, _II __last, _OI __result)
554 {
555 return std::__niter_wrap(__result,
556 std::__copy_move_a1<_IsMove>(std::__niter_base(__first),
557 std::__niter_base(__last),
558 std::__niter_base(__result)));
559 }
560
561 template<bool _IsMove,
562 typename _Ite, typename _Seq, typename _Cat, typename _OI>
563 _GLIBCXX20_CONSTEXPR
564 _OI
565 __copy_move_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
566 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
567 _OI);
568
569 template<bool _IsMove,
570 typename _II, typename _Ite, typename _Seq, typename _Cat>
571 _GLIBCXX20_CONSTEXPR
572 __gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
573 __copy_move_a(_II, _II,
574 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&);
575
576 template<bool _IsMove,
577 typename _IIte, typename _ISeq, typename _ICat,
578 typename _OIte, typename _OSeq, typename _OCat>
579 _GLIBCXX20_CONSTEXPR
580 ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>
581 __copy_move_a(const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>&,
582 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>&,
583 const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>&);
584
585 template<typename _InputIterator, typename _Size, typename _OutputIterator>
586 _GLIBCXX20_CONSTEXPR
587 _OutputIterator
588 __copy_n_a(_InputIterator __first, _Size __n, _OutputIterator __result,
589 bool)
590 {
591 if (__n > 0)
592 {
593 while (true)
594 {
595 *__result = *__first;
596 ++__result;
597 if (--__n > 0)
598 ++__first;
599 else
600 break;
601 }
602 }
603 return __result;
604 }
605
606#if _GLIBCXX_HOSTED
607 template<typename _CharT, typename _Size>
608 typename __gnu_cxx::__enable_if<
609 __is_char<_CharT>::__value, _CharT*>::__type
610 __copy_n_a(istreambuf_iterator<_CharT, char_traits<_CharT> >,
611 _Size, _CharT*, bool);
612
613 template<typename _CharT, typename _Size>
614 typename __gnu_cxx::__enable_if<
615 __is_char<_CharT>::__value,
616 _GLIBCXX_STD_C::_Deque_iterator<_CharT, _CharT&, _CharT*> >::__type
617 __copy_n_a(istreambuf_iterator<_CharT, char_traits<_CharT> >, _Size,
618 _GLIBCXX_STD_C::_Deque_iterator<_CharT, _CharT&, _CharT*>,
619 bool);
620#endif
621
622 /**
623 * @brief Copies the range [first,last) into result.
624 * @ingroup mutating_algorithms
625 * @param __first An input iterator.
626 * @param __last An input iterator.
627 * @param __result An output iterator.
628 * @return result + (last - first)
629 *
630 * This inline function will boil down to a call to @c memmove whenever
631 * possible. Failing that, if random access iterators are passed, then the
632 * loop count will be known (and therefore a candidate for compiler
633 * optimizations such as unrolling). Result may not be contained within
634 * [first,last); the copy_backward function should be used instead.
635 *
636 * Note that the end of the output range is permitted to be contained
637 * within [first,last).
638 */
639 template<typename _II, typename _OI>
640 _GLIBCXX20_CONSTEXPR
641 inline _OI
642 copy(_II __first, _II __last, _OI __result)
643 {
644 // concept requirements
645 __glibcxx_function_requires(_InputIteratorConcept<_II>)
646 __glibcxx_function_requires(_OutputIteratorConcept<_OI,
647 typename iterator_traits<_II>::reference>)
648 __glibcxx_requires_can_increment_range(__first, __last, __result);
649
650 return std::__copy_move_a<__is_move_iterator<_II>::__value>
651 (std::__miter_base(__first), std::__miter_base(__last), __result);
652 }
653
654#if __cplusplus >= 201103L
655 /**
656 * @brief Moves the range [first,last) into result.
657 * @ingroup mutating_algorithms
658 * @param __first An input iterator.
659 * @param __last An input iterator.
660 * @param __result An output iterator.
661 * @return result + (last - first)
662 *
663 * This inline function will boil down to a call to @c memmove whenever
664 * possible. Failing that, if random access iterators are passed, then the
665 * loop count will be known (and therefore a candidate for compiler
666 * optimizations such as unrolling). Result may not be contained within
667 * [first,last); the move_backward function should be used instead.
668 *
669 * Note that the end of the output range is permitted to be contained
670 * within [first,last).
671 */
672 template<typename _II, typename _OI>
673 _GLIBCXX20_CONSTEXPR
674 inline _OI
675 move(_II __first, _II __last, _OI __result)
676 {
677 // concept requirements
678 __glibcxx_function_requires(_InputIteratorConcept<_II>)
679 __glibcxx_function_requires(_OutputIteratorConcept<_OI,
680 typename iterator_traits<_II>::value_type&&>)
681 __glibcxx_requires_can_increment_range(__first, __last, __result);
682
683 return std::__copy_move_a<true>(std::__miter_base(__first),
684 std::__miter_base(__last), __result);
685 }
686
687#define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::move(_Tp, _Up, _Vp)
688#else
689#define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::copy(_Tp, _Up, _Vp)
690#endif
691
692 template<bool _IsMove, bool _IsSimple, typename _Category>
693 struct __copy_move_backward
694 {
695 template<typename _BI1, typename _BI2>
696 _GLIBCXX20_CONSTEXPR
697 static _BI2
698 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
699 {
700 while (__first != __last)
701 *--__result = *--__last;
702 return __result;
703 }
704 };
705
706#if __cplusplus >= 201103L
707 template<typename _Category>
708 struct __copy_move_backward<true, false, _Category>
709 {
710 template<typename _BI1, typename _BI2>
711 _GLIBCXX20_CONSTEXPR
712 static _BI2
713 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
714 {
715 while (__first != __last)
716 *--__result = std::move(*--__last);
717 return __result;
718 }
719 };
720#endif
721
722 template<>
723 struct __copy_move_backward<false, false, random_access_iterator_tag>
724 {
725 template<typename _BI1, typename _BI2>
726 _GLIBCXX20_CONSTEXPR
727 static _BI2
728 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
729 {
730 typename iterator_traits<_BI1>::difference_type
731 __n = __last - __first;
732 for (; __n > 0; --__n)
733 *--__result = *--__last;
734 return __result;
735 }
736 };
737
738#if __cplusplus >= 201103L
739 template<>
740 struct __copy_move_backward<true, false, random_access_iterator_tag>
741 {
742 template<typename _BI1, typename _BI2>
743 _GLIBCXX20_CONSTEXPR
744 static _BI2
745 __copy_move_b(_BI1 __first, _BI1 __last, _BI2 __result)
746 {
747 typename iterator_traits<_BI1>::difference_type
748 __n = __last - __first;
749 for (; __n > 0; --__n)
750 *--__result = std::move(*--__last);
751 return __result;
752 }
753 };
754#endif
755
756 template<bool _IsMove>
757 struct __copy_move_backward<_IsMove, true, random_access_iterator_tag>
758 {
759 template<typename _Tp, typename _Up>
760 _GLIBCXX20_CONSTEXPR
761 static _Up*
762 __copy_move_b(_Tp* __first, _Tp* __last, _Up* __result)
763 {
764 const ptrdiff_t _Num = __last - __first;
765 if (__builtin_expect(_Num > 1, true))
766 __builtin_memmove(__result - _Num, __first, sizeof(_Tp) * _Num);
767 else if (_Num == 1)
768 std::__copy_move<_IsMove, false, random_access_iterator_tag>::
769 __assign_one(__result - 1, __first);
770 return __result - _Num;
771 }
772 };
773
774 template<bool _IsMove, typename _BI1, typename _BI2>
775 _GLIBCXX20_CONSTEXPR
776 inline _BI2
777 __copy_move_backward_a2(_BI1 __first, _BI1 __last, _BI2 __result)
778 {
779 typedef typename iterator_traits<_BI1>::iterator_category _Category;
780#ifdef __cpp_lib_is_constant_evaluated
781 if (std::is_constant_evaluated())
782 return std::__copy_move_backward<_IsMove, false, _Category>::
783 __copy_move_b(__first, __last, __result);
784#endif
785 return std::__copy_move_backward<_IsMove,
786 __memcpyable<_BI2, _BI1>::__value,
787 _Category>::__copy_move_b(__first,
788 __last,
789 __result);
790 }
791
792 template<bool _IsMove, typename _BI1, typename _BI2>
793 _GLIBCXX20_CONSTEXPR
794 inline _BI2
795 __copy_move_backward_a1(_BI1 __first, _BI1 __last, _BI2 __result)
796 { return std::__copy_move_backward_a2<_IsMove>(__first, __last, __result); }
797
798 template<bool _IsMove,
799 typename _Tp, typename _Ref, typename _Ptr, typename _OI>
800 _OI
801 __copy_move_backward_a1(_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
802 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
803 _OI);
804
805 template<bool _IsMove,
806 typename _ITp, typename _IRef, typename _IPtr, typename _OTp>
807 _GLIBCXX_STD_C::_Deque_iterator<_OTp, _OTp&, _OTp*>
808 __copy_move_backward_a1(
809 _GLIBCXX_STD_C::_Deque_iterator<_ITp, _IRef, _IPtr>,
810 _GLIBCXX_STD_C::_Deque_iterator<_ITp, _IRef, _IPtr>,
811 _GLIBCXX_STD_C::_Deque_iterator<_OTp, _OTp&, _OTp*>);
812
813 template<bool _IsMove, typename _II, typename _Tp>
814 typename __gnu_cxx::__enable_if<
815 __is_random_access_iter<_II>::__value,
816 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*> >::__type
817 __copy_move_backward_a1(_II, _II,
818 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>);
819
820 template<bool _IsMove, typename _II, typename _OI>
821 _GLIBCXX20_CONSTEXPR
822 inline _OI
823 __copy_move_backward_a(_II __first, _II __last, _OI __result)
824 {
825 return std::__niter_wrap(__result,
826 std::__copy_move_backward_a1<_IsMove>
827 (std::__niter_base(__first), std::__niter_base(__last),
828 std::__niter_base(__result)));
829 }
830
831 template<bool _IsMove,
832 typename _Ite, typename _Seq, typename _Cat, typename _OI>
833 _GLIBCXX20_CONSTEXPR
834 _OI
835 __copy_move_backward_a(
836 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
837 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
838 _OI);
839
840 template<bool _IsMove,
841 typename _II, typename _Ite, typename _Seq, typename _Cat>
842 _GLIBCXX20_CONSTEXPR
843 __gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
844 __copy_move_backward_a(_II, _II,
845 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&);
846
847 template<bool _IsMove,
848 typename _IIte, typename _ISeq, typename _ICat,
849 typename _OIte, typename _OSeq, typename _OCat>
850 _GLIBCXX20_CONSTEXPR
851 ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>
852 __copy_move_backward_a(
853 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>&,
854 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>&,
855 const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>&);
856
857 /**
858 * @brief Copies the range [first,last) into result.
859 * @ingroup mutating_algorithms
860 * @param __first A bidirectional iterator.
861 * @param __last A bidirectional iterator.
862 * @param __result A bidirectional iterator.
863 * @return result - (last - first)
864 *
865 * The function has the same effect as copy, but starts at the end of the
866 * range and works its way to the start, returning the start of the result.
867 * This inline function will boil down to a call to @c memmove whenever
868 * possible. Failing that, if random access iterators are passed, then the
869 * loop count will be known (and therefore a candidate for compiler
870 * optimizations such as unrolling).
871 *
872 * Result may not be in the range (first,last]. Use copy instead. Note
873 * that the start of the output range may overlap [first,last).
874 */
875 template<typename _BI1, typename _BI2>
876 _GLIBCXX20_CONSTEXPR
877 inline _BI2
878 copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
879 {
880 // concept requirements
881 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
882 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
883 __glibcxx_function_requires(_OutputIteratorConcept<_BI2,
884 typename iterator_traits<_BI1>::reference>)
885 __glibcxx_requires_can_decrement_range(__first, __last, __result);
886
887 return std::__copy_move_backward_a<__is_move_iterator<_BI1>::__value>
888 (std::__miter_base(__first), std::__miter_base(__last), __result);
889 }
890
891#if __cplusplus >= 201103L
892 /**
893 * @brief Moves the range [first,last) into result.
894 * @ingroup mutating_algorithms
895 * @param __first A bidirectional iterator.
896 * @param __last A bidirectional iterator.
897 * @param __result A bidirectional iterator.
898 * @return result - (last - first)
899 *
900 * The function has the same effect as move, but starts at the end of the
901 * range and works its way to the start, returning the start of the result.
902 * This inline function will boil down to a call to @c memmove whenever
903 * possible. Failing that, if random access iterators are passed, then the
904 * loop count will be known (and therefore a candidate for compiler
905 * optimizations such as unrolling).
906 *
907 * Result may not be in the range (first,last]. Use move instead. Note
908 * that the start of the output range may overlap [first,last).
909 */
910 template<typename _BI1, typename _BI2>
911 _GLIBCXX20_CONSTEXPR
912 inline _BI2
913 move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
914 {
915 // concept requirements
916 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
917 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
918 __glibcxx_function_requires(_OutputIteratorConcept<_BI2,
919 typename iterator_traits<_BI1>::value_type&&>)
920 __glibcxx_requires_can_decrement_range(__first, __last, __result);
921
922 return std::__copy_move_backward_a<true>(std::__miter_base(__first),
923 std::__miter_base(__last),
924 __result);
925 }
926
927#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::move_backward(_Tp, _Up, _Vp)
928#else
929#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::copy_backward(_Tp, _Up, _Vp)
930#endif
931
932 template<typename _ForwardIterator, typename _Tp>
933 _GLIBCXX20_CONSTEXPR
934 inline typename
935 __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, void>::__type
936 __fill_a1(_ForwardIterator __first, _ForwardIterator __last,
937 const _Tp& __value)
938 {
939 for (; __first != __last; ++__first)
940 *__first = __value;
941 }
942
943 template<typename _ForwardIterator, typename _Tp>
944 _GLIBCXX20_CONSTEXPR
945 inline typename
946 __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, void>::__type
947 __fill_a1(_ForwardIterator __first, _ForwardIterator __last,
948 const _Tp& __value)
949 {
950 const _Tp __tmp = __value;
951 for (; __first != __last; ++__first)
952 *__first = __tmp;
953 }
954
955 // Specialization: for char types we can use memset.
956 template<typename _Tp>
957 _GLIBCXX20_CONSTEXPR
958 inline typename
959 __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, void>::__type
960 __fill_a1(_Tp* __first, _Tp* __last, const _Tp& __c)
961 {
962 const _Tp __tmp = __c;
963#if __cpp_lib_is_constant_evaluated
964 if (std::is_constant_evaluated())
965 {
966 for (; __first != __last; ++__first)
967 *__first = __tmp;
968 return;
969 }
970#endif
971 if (const size_t __len = __last - __first)
972 __builtin_memset(__first, static_cast<unsigned char>(__tmp), __len);
973 }
974
975 template<typename _Ite, typename _Cont, typename _Tp>
976 _GLIBCXX20_CONSTEXPR
977 inline void
978 __fill_a1(::__gnu_cxx::__normal_iterator<_Ite, _Cont> __first,
979 ::__gnu_cxx::__normal_iterator<_Ite, _Cont> __last,
980 const _Tp& __value)
981 { std::__fill_a1(__first.base(), __last.base(), __value); }
982
983 template<typename _Tp, typename _VTp>
984 void
985 __fill_a1(const _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>&,
986 const _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>&,
987 const _VTp&);
988
989 _GLIBCXX20_CONSTEXPR
990 void
991 __fill_a1(_GLIBCXX_STD_C::_Bit_iterator, _GLIBCXX_STD_C::_Bit_iterator,
992 const bool&);
993
994 template<typename _FIte, typename _Tp>
995 _GLIBCXX20_CONSTEXPR
996 inline void
997 __fill_a(_FIte __first, _FIte __last, const _Tp& __value)
998 { std::__fill_a1(__first, __last, __value); }
999
1000 template<typename _Ite, typename _Seq, typename _Cat, typename _Tp>
1001 _GLIBCXX20_CONSTEXPR
1002 void
1003 __fill_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
1004 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
1005 const _Tp&);
1006
1007 /**
1008 * @brief Fills the range [first,last) with copies of value.
1009 * @ingroup mutating_algorithms
1010 * @param __first A forward iterator.
1011 * @param __last A forward iterator.
1012 * @param __value A reference-to-const of arbitrary type.
1013 * @return Nothing.
1014 *
1015 * This function fills a range with copies of the same value. For char
1016 * types filling contiguous areas of memory, this becomes an inline call
1017 * to @c memset or @c wmemset.
1018 */
1019 template<typename _ForwardIterator, typename _Tp>
1020 _GLIBCXX20_CONSTEXPR
1021 inline void
1022 fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
1023 {
1024 // concept requirements
1025 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1026 _ForwardIterator>)
1027 __glibcxx_requires_valid_range(__first, __last);
1028
1029 std::__fill_a(__first, __last, __value);
1030 }
1031
1032 // Used by fill_n, generate_n, etc. to convert _Size to an integral type:
1033 inline _GLIBCXX_CONSTEXPR int
1034 __size_to_integer(int __n) { return __n; }
1035 inline _GLIBCXX_CONSTEXPR unsigned
1036 __size_to_integer(unsigned __n) { return __n; }
1037 inline _GLIBCXX_CONSTEXPR long
1038 __size_to_integer(long __n) { return __n; }
1039 inline _GLIBCXX_CONSTEXPR unsigned long
1040 __size_to_integer(unsigned long __n) { return __n; }
1041 inline _GLIBCXX_CONSTEXPR long long
1042 __size_to_integer(long long __n) { return __n; }
1043 inline _GLIBCXX_CONSTEXPR unsigned long long
1044 __size_to_integer(unsigned long long __n) { return __n; }
1045
1046#if defined(__GLIBCXX_TYPE_INT_N_0)
1047 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_0
1048 __size_to_integer(__GLIBCXX_TYPE_INT_N_0 __n) { return __n; }
1049 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_0
1050 __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_0 __n) { return __n; }
1051#endif
1052#if defined(__GLIBCXX_TYPE_INT_N_1)
1053 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_1
1054 __size_to_integer(__GLIBCXX_TYPE_INT_N_1 __n) { return __n; }
1055 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_1
1056 __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_1 __n) { return __n; }
1057#endif
1058#if defined(__GLIBCXX_TYPE_INT_N_2)
1059 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_2
1060 __size_to_integer(__GLIBCXX_TYPE_INT_N_2 __n) { return __n; }
1061 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_2
1062 __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_2 __n) { return __n; }
1063#endif
1064#if defined(__GLIBCXX_TYPE_INT_N_3)
1065 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_3
1066 __size_to_integer(__GLIBCXX_TYPE_INT_N_3 __n) { return __n; }
1067 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_3
1068 __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_3 __n) { return __n; }
1069#endif
1070
1071 inline _GLIBCXX_CONSTEXPR long long
1072 __size_to_integer(float __n) { return (long long)__n; }
1073 inline _GLIBCXX_CONSTEXPR long long
1074 __size_to_integer(double __n) { return (long long)__n; }
1075 inline _GLIBCXX_CONSTEXPR long long
1076 __size_to_integer(long double __n) { return (long long)__n; }
1077#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
1078 __extension__ inline _GLIBCXX_CONSTEXPR long long
1079 __size_to_integer(__float128 __n) { return (long long)__n; }
1080#endif
1081
1082 template<typename _OutputIterator, typename _Size, typename _Tp>
1083 _GLIBCXX20_CONSTEXPR
1084 inline typename
1085 __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, _OutputIterator>::__type
1086 __fill_n_a1(_OutputIterator __first, _Size __n, const _Tp& __value)
1087 {
1088 for (; __n > 0; --__n, (void) ++__first)
1089 *__first = __value;
1090 return __first;
1091 }
1092
1093 template<typename _OutputIterator, typename _Size, typename _Tp>
1094 _GLIBCXX20_CONSTEXPR
1095 inline typename
1096 __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, _OutputIterator>::__type
1097 __fill_n_a1(_OutputIterator __first, _Size __n, const _Tp& __value)
1098 {
1099 const _Tp __tmp = __value;
1100 for (; __n > 0; --__n, (void) ++__first)
1101 *__first = __tmp;
1102 return __first;
1103 }
1104
1105 template<typename _Ite, typename _Seq, typename _Cat, typename _Size,
1106 typename _Tp>
1107 _GLIBCXX20_CONSTEXPR
1108 ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
1109 __fill_n_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
1110 _Size __n, const _Tp& __value,
1111 std::input_iterator_tag);
1112
1113 template<typename _OutputIterator, typename _Size, typename _Tp>
1114 _GLIBCXX20_CONSTEXPR
1115 inline _OutputIterator
1116 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1117 std::output_iterator_tag)
1118 {
1119#if __cplusplus >= 201103L
1120 static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1121#endif
1122 return __fill_n_a1(__first, __n, __value);
1123 }
1124
1125 template<typename _OutputIterator, typename _Size, typename _Tp>
1126 _GLIBCXX20_CONSTEXPR
1127 inline _OutputIterator
1128 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1129 std::input_iterator_tag)
1130 {
1131#if __cplusplus >= 201103L
1132 static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1133#endif
1134 return __fill_n_a1(__first, __n, __value);
1135 }
1136
1137 template<typename _OutputIterator, typename _Size, typename _Tp>
1138 _GLIBCXX20_CONSTEXPR
1139 inline _OutputIterator
1140 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1141 std::random_access_iterator_tag)
1142 {
1143#if __cplusplus >= 201103L
1144 static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1145#endif
1146 if (__n <= 0)
1147 return __first;
1148
1149 __glibcxx_requires_can_increment(__first, __n);
1150
1151 std::__fill_a(__first, __first + __n, __value);
1152 return __first + __n;
1153 }
1154
1155 /**
1156 * @brief Fills the range [first,first+n) with copies of value.
1157 * @ingroup mutating_algorithms
1158 * @param __first An output iterator.
1159 * @param __n The count of copies to perform.
1160 * @param __value A reference-to-const of arbitrary type.
1161 * @return The iterator at first+n.
1162 *
1163 * This function fills a range with copies of the same value. For char
1164 * types filling contiguous areas of memory, this becomes an inline call
1165 * to @c memset or @c wmemset.
1166 *
1167 * If @p __n is negative, the function does nothing.
1168 */
1169 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1170 // DR 865. More algorithms that throw away information
1171 // DR 426. search_n(), fill_n(), and generate_n() with negative n
1172 template<typename _OI, typename _Size, typename _Tp>
1173 _GLIBCXX20_CONSTEXPR
1174 inline _OI
1175 fill_n(_OI __first, _Size __n, const _Tp& __value)
1176 {
1177 // concept requirements
1178 __glibcxx_function_requires(_OutputIteratorConcept<_OI, const _Tp&>)
1179
1180 return std::__fill_n_a(__first, std::__size_to_integer(__n), __value,
1181 std::__iterator_category(__first));
1182 }
1183
1184 template<bool _BoolType>
1185 struct __equal
1186 {
1187 template<typename _II1, typename _II2>
1188 _GLIBCXX20_CONSTEXPR
1189 static bool
1190 equal(_II1 __first1, _II1 __last1, _II2 __first2)
1191 {
1192 for (; __first1 != __last1; ++__first1, (void) ++__first2)
1193 if (!(*__first1 == *__first2))
1194 return false;
1195 return true;
1196 }
1197 };
1198
1199 template<>
1200 struct __equal<true>
1201 {
1202 template<typename _Tp>
1203 _GLIBCXX20_CONSTEXPR
1204 static bool
1205 equal(const _Tp* __first1, const _Tp* __last1, const _Tp* __first2)
1206 {
1207 if (const size_t __len = (__last1 - __first1))
1208 return !std::__memcmp(__first1, __first2, __len);
1209 return true;
1210 }
1211 };
1212
1213 template<typename _Tp, typename _Ref, typename _Ptr, typename _II>
1214 typename __gnu_cxx::__enable_if<
1215 __is_random_access_iter<_II>::__value, bool>::__type
1216 __equal_aux1(_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
1217 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
1218 _II);
1219
1220 template<typename _Tp1, typename _Ref1, typename _Ptr1,
1221 typename _Tp2, typename _Ref2, typename _Ptr2>
1222 bool
1223 __equal_aux1(_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1224 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1225 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1226
1227 template<typename _II, typename _Tp, typename _Ref, typename _Ptr>
1228 typename __gnu_cxx::__enable_if<
1229 __is_random_access_iter<_II>::__value, bool>::__type
1230 __equal_aux1(_II, _II,
1231 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>);
1232
1233 template<typename _II1, typename _II2>
1234 _GLIBCXX20_CONSTEXPR
1235 inline bool
1236 __equal_aux1(_II1 __first1, _II1 __last1, _II2 __first2)
1237 {
1238 typedef typename iterator_traits<_II1>::value_type _ValueType1;
1239 const bool __simple = ((__is_integer<_ValueType1>::__value
1240 || __is_pointer<_ValueType1>::__value)
1241 && __memcmpable<_II1, _II2>::__value);
1242 return std::__equal<__simple>::equal(__first1, __last1, __first2);
1243 }
1244
1245 template<typename _II1, typename _II2>
1246 _GLIBCXX20_CONSTEXPR
1247 inline bool
1248 __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)
1249 {
1250 return std::__equal_aux1(std::__niter_base(__first1),
1251 std::__niter_base(__last1),
1252 std::__niter_base(__first2));
1253 }
1254
1255 template<typename _II1, typename _Seq1, typename _Cat1, typename _II2>
1256 _GLIBCXX20_CONSTEXPR
1257 bool
1258 __equal_aux(const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1259 const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1260 _II2);
1261
1262 template<typename _II1, typename _II2, typename _Seq2, typename _Cat2>
1263 _GLIBCXX20_CONSTEXPR
1264 bool
1265 __equal_aux(_II1, _II1,
1266 const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>&);
1267
1268 template<typename _II1, typename _Seq1, typename _Cat1,
1269 typename _II2, typename _Seq2, typename _Cat2>
1270 _GLIBCXX20_CONSTEXPR
1271 bool
1272 __equal_aux(const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1273 const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1274 const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>&);
1275
1276 template<typename, typename>
1277 struct __lc_rai
1278 {
1279 template<typename _II1, typename _II2>
1280 _GLIBCXX20_CONSTEXPR
1281 static _II1
1282 __newlast1(_II1, _II1 __last1, _II2, _II2)
1283 { return __last1; }
1284
1285 template<typename _II>
1286 _GLIBCXX20_CONSTEXPR
1287 static bool
1288 __cnd2(_II __first, _II __last)
1289 { return __first != __last; }
1290 };
1291
1292 template<>
1293 struct __lc_rai<random_access_iterator_tag, random_access_iterator_tag>
1294 {
1295 template<typename _RAI1, typename _RAI2>
1296 _GLIBCXX20_CONSTEXPR
1297 static _RAI1
1298 __newlast1(_RAI1 __first1, _RAI1 __last1,
1299 _RAI2 __first2, _RAI2 __last2)
1300 {
1301 const typename iterator_traits<_RAI1>::difference_type
1302 __diff1 = __last1 - __first1;
1303 const typename iterator_traits<_RAI2>::difference_type
1304 __diff2 = __last2 - __first2;
1305 return __diff2 < __diff1 ? __first1 + __diff2 : __last1;
1306 }
1307
1308 template<typename _RAI>
1309 static _GLIBCXX20_CONSTEXPR bool
1310 __cnd2(_RAI, _RAI)
1311 { return true; }
1312 };
1313
1314 template<typename _II1, typename _II2, typename _Compare>
1315 _GLIBCXX20_CONSTEXPR
1316 bool
1317 __lexicographical_compare_impl(_II1 __first1, _II1 __last1,
1318 _II2 __first2, _II2 __last2,
1319 _Compare __comp)
1320 {
1321 typedef typename iterator_traits<_II1>::iterator_category _Category1;
1322 typedef typename iterator_traits<_II2>::iterator_category _Category2;
1323 typedef std::__lc_rai<_Category1, _Category2> __rai_type;
1324
1325 __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
1326 for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
1327 ++__first1, (void)++__first2)
1328 {
1329 if (__comp(__first1, __first2))
1330 return true;
1331 if (__comp(__first2, __first1))
1332 return false;
1333 }
1334 return __first1 == __last1 && __first2 != __last2;
1335 }
1336
1337 template<bool _BoolType>
1338 struct __lexicographical_compare
1339 {
1340 template<typename _II1, typename _II2>
1341 _GLIBCXX20_CONSTEXPR
1342 static bool
1343 __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1344 {
1345 using __gnu_cxx::__ops::__iter_less_iter;
1346 return std::__lexicographical_compare_impl(__first1, __last1,
1347 __first2, __last2,
1348 __iter_less_iter());
1349 }
1350
1351 template<typename _II1, typename _II2>
1352 _GLIBCXX20_CONSTEXPR
1353 static int
1354 __3way(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1355 {
1356 while (__first1 != __last1)
1357 {
1358 if (__first2 == __last2)
1359 return +1;
1360 if (*__first1 < *__first2)
1361 return -1;
1362 if (*__first2 < *__first1)
1363 return +1;
1364 ++__first1;
1365 ++__first2;
1366 }
1367 return int(__first2 == __last2) - 1;
1368 }
1369 };
1370
1371 template<>
1372 struct __lexicographical_compare<true>
1373 {
1374 template<typename _Tp, typename _Up>
1375 _GLIBCXX20_CONSTEXPR
1376 static bool
1377 __lc(const _Tp* __first1, const _Tp* __last1,
1378 const _Up* __first2, const _Up* __last2)
1379 { return __3way(__first1, __last1, __first2, __last2) < 0; }
1380
1381 template<typename _Tp, typename _Up>
1382 _GLIBCXX20_CONSTEXPR
1383 static ptrdiff_t
1384 __3way(const _Tp* __first1, const _Tp* __last1,
1385 const _Up* __first2, const _Up* __last2)
1386 {
1387 const size_t __len1 = __last1 - __first1;
1388 const size_t __len2 = __last2 - __first2;
1389 if (const size_t __len = std::min(a: __len1, b: __len2))
1390 if (int __result = std::__memcmp(__first1, __first2, __len))
1391 return __result;
1392 return ptrdiff_t(__len1 - __len2);
1393 }
1394 };
1395
1396 template<typename _II1, typename _II2>
1397 _GLIBCXX20_CONSTEXPR
1398 inline bool
1399 __lexicographical_compare_aux1(_II1 __first1, _II1 __last1,
1400 _II2 __first2, _II2 __last2)
1401 {
1402 typedef typename iterator_traits<_II1>::value_type _ValueType1;
1403 typedef typename iterator_traits<_II2>::value_type _ValueType2;
1404 const bool __simple =
1405 (__is_memcmp_ordered_with<_ValueType1, _ValueType2>::__value
1406 && __is_pointer<_II1>::__value
1407 && __is_pointer<_II2>::__value
1408#if __cplusplus > 201703L && __glibcxx_concepts
1409 // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
1410 // so __is_byte<T> could be true, but we can't use memcmp with
1411 // volatile data.
1412 && !is_volatile_v<remove_reference_t<iter_reference_t<_II1>>>
1413 && !is_volatile_v<remove_reference_t<iter_reference_t<_II2>>>
1414#endif
1415 );
1416
1417 return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
1418 __first2, __last2);
1419 }
1420
1421 template<typename _Tp1, typename _Ref1, typename _Ptr1,
1422 typename _Tp2>
1423 bool
1424 __lexicographical_compare_aux1(
1425 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1426 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1427 _Tp2*, _Tp2*);
1428
1429 template<typename _Tp1,
1430 typename _Tp2, typename _Ref2, typename _Ptr2>
1431 bool
1432 __lexicographical_compare_aux1(_Tp1*, _Tp1*,
1433 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
1434 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1435
1436 template<typename _Tp1, typename _Ref1, typename _Ptr1,
1437 typename _Tp2, typename _Ref2, typename _Ptr2>
1438 bool
1439 __lexicographical_compare_aux1(
1440 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1441 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1442 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
1443 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1444
1445 template<typename _II1, typename _II2>
1446 _GLIBCXX20_CONSTEXPR
1447 inline bool
1448 __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
1449 _II2 __first2, _II2 __last2)
1450 {
1451 return std::__lexicographical_compare_aux1(std::__niter_base(__first1),
1452 std::__niter_base(__last1),
1453 std::__niter_base(__first2),
1454 std::__niter_base(__last2));
1455 }
1456
1457 template<typename _Iter1, typename _Seq1, typename _Cat1,
1458 typename _II2>
1459 _GLIBCXX20_CONSTEXPR
1460 bool
1461 __lexicographical_compare_aux(
1462 const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1463 const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1464 _II2, _II2);
1465
1466 template<typename _II1,
1467 typename _Iter2, typename _Seq2, typename _Cat2>
1468 _GLIBCXX20_CONSTEXPR
1469 bool
1470 __lexicographical_compare_aux(
1471 _II1, _II1,
1472 const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&,
1473 const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&);
1474
1475 template<typename _Iter1, typename _Seq1, typename _Cat1,
1476 typename _Iter2, typename _Seq2, typename _Cat2>
1477 _GLIBCXX20_CONSTEXPR
1478 bool
1479 __lexicographical_compare_aux(
1480 const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1481 const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1482 const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&,
1483 const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&);
1484
1485 template<typename _ForwardIterator, typename _Tp, typename _Compare>
1486 _GLIBCXX20_CONSTEXPR
1487 _ForwardIterator
1488 __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1489 const _Tp& __val, _Compare __comp)
1490 {
1491 typedef typename iterator_traits<_ForwardIterator>::difference_type
1492 _DistanceType;
1493
1494 _DistanceType __len = std::distance(__first, __last);
1495
1496 while (__len > 0)
1497 {
1498 _DistanceType __half = __len >> 1;
1499 _ForwardIterator __middle = __first;
1500 std::advance(__middle, __half);
1501 if (__comp(__middle, __val))
1502 {
1503 __first = __middle;
1504 ++__first;
1505 __len = __len - __half - 1;
1506 }
1507 else
1508 __len = __half;
1509 }
1510 return __first;
1511 }
1512
1513 /**
1514 * @brief Finds the first position in which @a val could be inserted
1515 * without changing the ordering.
1516 * @param __first An iterator.
1517 * @param __last Another iterator.
1518 * @param __val The search term.
1519 * @return An iterator pointing to the first element <em>not less
1520 * than</em> @a val, or end() if every element is less than
1521 * @a val.
1522 * @ingroup binary_search_algorithms
1523 */
1524 template<typename _ForwardIterator, typename _Tp>
1525 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1526 inline _ForwardIterator
1527 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1528 const _Tp& __val)
1529 {
1530 // concept requirements
1531 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1532 __glibcxx_function_requires(_LessThanOpConcept<
1533 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
1534 __glibcxx_requires_partitioned_lower(__first, __last, __val);
1535
1536 return std::__lower_bound(__first, __last, __val,
1537 __gnu_cxx::__ops::__iter_less_val());
1538 }
1539
1540 /// This is a helper function for the sort routines and for random.tcc.
1541 // Precondition: __n > 0.
1542 template<typename _Tp>
1543 inline _GLIBCXX_CONSTEXPR _Tp
1544 __lg(_Tp __n)
1545 {
1546#if __cplusplus >= 201402L
1547 return std::__bit_width(make_unsigned_t<_Tp>(__n)) - 1;
1548#else
1549 // Use +__n so it promotes to at least int.
1550 return (sizeof(+__n) * __CHAR_BIT__ - 1)
1551 - (sizeof(+__n) == sizeof(long long)
1552 ? __builtin_clzll(+__n)
1553 : (sizeof(+__n) == sizeof(long)
1554 ? __builtin_clzl(+__n)
1555 : __builtin_clz(+__n)));
1556#endif
1557 }
1558
1559_GLIBCXX_BEGIN_NAMESPACE_ALGO
1560
1561 /**
1562 * @brief Tests a range for element-wise equality.
1563 * @ingroup non_mutating_algorithms
1564 * @param __first1 An input iterator.
1565 * @param __last1 An input iterator.
1566 * @param __first2 An input iterator.
1567 * @return A boolean true or false.
1568 *
1569 * This compares the elements of two ranges using @c == and returns true or
1570 * false depending on whether all of the corresponding elements of the
1571 * ranges are equal.
1572 */
1573 template<typename _II1, typename _II2>
1574 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1575 inline bool
1576 equal(_II1 __first1, _II1 __last1, _II2 __first2)
1577 {
1578 // concept requirements
1579 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1580 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1581 __glibcxx_function_requires(_EqualOpConcept<
1582 typename iterator_traits<_II1>::value_type,
1583 typename iterator_traits<_II2>::value_type>)
1584 __glibcxx_requires_can_increment_range(__first1, __last1, __first2);
1585
1586 return std::__equal_aux(__first1, __last1, __first2);
1587 }
1588
1589 /**
1590 * @brief Tests a range for element-wise equality.
1591 * @ingroup non_mutating_algorithms
1592 * @param __first1 An input iterator.
1593 * @param __last1 An input iterator.
1594 * @param __first2 An input iterator.
1595 * @param __binary_pred A binary predicate @link functors
1596 * functor@endlink.
1597 * @return A boolean true or false.
1598 *
1599 * This compares the elements of two ranges using the binary_pred
1600 * parameter, and returns true or
1601 * false depending on whether all of the corresponding elements of the
1602 * ranges are equal.
1603 */
1604 template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1605 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1606 inline bool
1607 equal(_IIter1 __first1, _IIter1 __last1,
1608 _IIter2 __first2, _BinaryPredicate __binary_pred)
1609 {
1610 // concept requirements
1611 __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1612 __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1613 __glibcxx_requires_valid_range(__first1, __last1);
1614
1615 for (; __first1 != __last1; ++__first1, (void)++__first2)
1616 if (!bool(__binary_pred(*__first1, *__first2)))
1617 return false;
1618 return true;
1619 }
1620
1621#if __cplusplus >= 201103L
1622 // 4-iterator version of std::equal<It1, It2> for use in C++11.
1623 template<typename _II1, typename _II2>
1624 _GLIBCXX20_CONSTEXPR
1625 inline bool
1626 __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1627 {
1628 using _RATag = random_access_iterator_tag;
1629 using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1630 using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1631 using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1632 if (_RAIters())
1633 {
1634 auto __d1 = std::distance(__first1, __last1);
1635 auto __d2 = std::distance(__first2, __last2);
1636 if (__d1 != __d2)
1637 return false;
1638 return _GLIBCXX_STD_A::equal(__first1, __last1, __first2);
1639 }
1640
1641 for (; __first1 != __last1 && __first2 != __last2;
1642 ++__first1, (void)++__first2)
1643 if (!(*__first1 == *__first2))
1644 return false;
1645 return __first1 == __last1 && __first2 == __last2;
1646 }
1647
1648 // 4-iterator version of std::equal<It1, It2, BinaryPred> for use in C++11.
1649 template<typename _II1, typename _II2, typename _BinaryPredicate>
1650 _GLIBCXX20_CONSTEXPR
1651 inline bool
1652 __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2,
1653 _BinaryPredicate __binary_pred)
1654 {
1655 using _RATag = random_access_iterator_tag;
1656 using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1657 using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1658 using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1659 if (_RAIters())
1660 {
1661 auto __d1 = std::distance(__first1, __last1);
1662 auto __d2 = std::distance(__first2, __last2);
1663 if (__d1 != __d2)
1664 return false;
1665 return _GLIBCXX_STD_A::equal(__first1, __last1, __first2,
1666 __binary_pred);
1667 }
1668
1669 for (; __first1 != __last1 && __first2 != __last2;
1670 ++__first1, (void)++__first2)
1671 if (!bool(__binary_pred(*__first1, *__first2)))
1672 return false;
1673 return __first1 == __last1 && __first2 == __last2;
1674 }
1675#endif // C++11
1676
1677#ifdef __glibcxx_robust_nonmodifying_seq_ops // C++ >= 14
1678 /**
1679 * @brief Tests a range for element-wise equality.
1680 * @ingroup non_mutating_algorithms
1681 * @param __first1 An input iterator.
1682 * @param __last1 An input iterator.
1683 * @param __first2 An input iterator.
1684 * @param __last2 An input iterator.
1685 * @return A boolean true or false.
1686 *
1687 * This compares the elements of two ranges using @c == and returns true or
1688 * false depending on whether all of the corresponding elements of the
1689 * ranges are equal.
1690 */
1691 template<typename _II1, typename _II2>
1692 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1693 inline bool
1694 equal(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1695 {
1696 // concept requirements
1697 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1698 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1699 __glibcxx_function_requires(_EqualOpConcept<
1700 typename iterator_traits<_II1>::value_type,
1701 typename iterator_traits<_II2>::value_type>)
1702 __glibcxx_requires_valid_range(__first1, __last1);
1703 __glibcxx_requires_valid_range(__first2, __last2);
1704
1705 return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2);
1706 }
1707
1708 /**
1709 * @brief Tests a range for element-wise equality.
1710 * @ingroup non_mutating_algorithms
1711 * @param __first1 An input iterator.
1712 * @param __last1 An input iterator.
1713 * @param __first2 An input iterator.
1714 * @param __last2 An input iterator.
1715 * @param __binary_pred A binary predicate @link functors
1716 * functor@endlink.
1717 * @return A boolean true or false.
1718 *
1719 * This compares the elements of two ranges using the binary_pred
1720 * parameter, and returns true or
1721 * false depending on whether all of the corresponding elements of the
1722 * ranges are equal.
1723 */
1724 template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1725 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1726 inline bool
1727 equal(_IIter1 __first1, _IIter1 __last1,
1728 _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
1729 {
1730 // concept requirements
1731 __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1732 __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1733 __glibcxx_requires_valid_range(__first1, __last1);
1734 __glibcxx_requires_valid_range(__first2, __last2);
1735
1736 return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2,
1737 __binary_pred);
1738 }
1739#endif // __glibcxx_robust_nonmodifying_seq_ops
1740
1741 /**
1742 * @brief Performs @b dictionary comparison on ranges.
1743 * @ingroup sorting_algorithms
1744 * @param __first1 An input iterator.
1745 * @param __last1 An input iterator.
1746 * @param __first2 An input iterator.
1747 * @param __last2 An input iterator.
1748 * @return A boolean true or false.
1749 *
1750 * <em>Returns true if the sequence of elements defined by the range
1751 * [first1,last1) is lexicographically less than the sequence of elements
1752 * defined by the range [first2,last2). Returns false otherwise.</em>
1753 * (Quoted from [25.3.8]/1.) If the iterators are all character pointers,
1754 * then this is an inline call to @c memcmp.
1755 */
1756 template<typename _II1, typename _II2>
1757 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1758 inline bool
1759 lexicographical_compare(_II1 __first1, _II1 __last1,
1760 _II2 __first2, _II2 __last2)
1761 {
1762#ifdef _GLIBCXX_CONCEPT_CHECKS
1763 // concept requirements
1764 typedef typename iterator_traits<_II1>::value_type _ValueType1;
1765 typedef typename iterator_traits<_II2>::value_type _ValueType2;
1766#endif
1767 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1768 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1769 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
1770 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
1771 __glibcxx_requires_valid_range(__first1, __last1);
1772 __glibcxx_requires_valid_range(__first2, __last2);
1773
1774 return std::__lexicographical_compare_aux(__first1, __last1,
1775 __first2, __last2);
1776 }
1777
1778 /**
1779 * @brief Performs @b dictionary comparison on ranges.
1780 * @ingroup sorting_algorithms
1781 * @param __first1 An input iterator.
1782 * @param __last1 An input iterator.
1783 * @param __first2 An input iterator.
1784 * @param __last2 An input iterator.
1785 * @param __comp A @link comparison_functors comparison functor@endlink.
1786 * @return A boolean true or false.
1787 *
1788 * The same as the four-parameter @c lexicographical_compare, but uses the
1789 * comp parameter instead of @c <.
1790 */
1791 template<typename _II1, typename _II2, typename _Compare>
1792 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1793 inline bool
1794 lexicographical_compare(_II1 __first1, _II1 __last1,
1795 _II2 __first2, _II2 __last2, _Compare __comp)
1796 {
1797 // concept requirements
1798 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1799 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1800 __glibcxx_requires_valid_range(__first1, __last1);
1801 __glibcxx_requires_valid_range(__first2, __last2);
1802
1803 return std::__lexicographical_compare_impl
1804 (__first1, __last1, __first2, __last2,
1805 __gnu_cxx::__ops::__iter_comp_iter(__comp));
1806 }
1807
1808#if __cpp_lib_three_way_comparison
1809 // Both iterators refer to contiguous ranges of unsigned narrow characters,
1810 // or std::byte, or big-endian unsigned integers, suitable for comparison
1811 // using memcmp.
1812 template<typename _Iter1, typename _Iter2>
1813 concept __memcmp_ordered_with
1814 = (__is_memcmp_ordered_with<iter_value_t<_Iter1>,
1815 iter_value_t<_Iter2>>::__value)
1816 && contiguous_iterator<_Iter1> && contiguous_iterator<_Iter2>;
1817
1818 // Return a struct with two members, initialized to the smaller of x and y
1819 // (or x if they compare equal) and the result of the comparison x <=> y.
1820 template<typename _Tp>
1821 constexpr auto
1822 __min_cmp(_Tp __x, _Tp __y)
1823 {
1824 struct _Res {
1825 _Tp _M_min;
1826 decltype(__x <=> __y) _M_cmp;
1827 };
1828 auto __c = __x <=> __y;
1829 if (__c > 0)
1830 return _Res{__y, __c};
1831 return _Res{__x, __c};
1832 }
1833
1834 /**
1835 * @brief Performs dictionary comparison on ranges.
1836 * @ingroup sorting_algorithms
1837 * @param __first1 An input iterator.
1838 * @param __last1 An input iterator.
1839 * @param __first2 An input iterator.
1840 * @param __last2 An input iterator.
1841 * @param __comp A @link comparison_functors comparison functor@endlink.
1842 * @return The comparison category that `__comp(*__first1, *__first2)`
1843 * returns.
1844 */
1845 template<typename _InputIter1, typename _InputIter2, typename _Comp>
1846 [[nodiscard]] constexpr auto
1847 lexicographical_compare_three_way(_InputIter1 __first1,
1848 _InputIter1 __last1,
1849 _InputIter2 __first2,
1850 _InputIter2 __last2,
1851 _Comp __comp)
1852 -> decltype(__comp(*__first1, *__first2))
1853 {
1854 // concept requirements
1855 __glibcxx_function_requires(_InputIteratorConcept<_InputIter1>)
1856 __glibcxx_function_requires(_InputIteratorConcept<_InputIter2>)
1857 __glibcxx_requires_valid_range(__first1, __last1);
1858 __glibcxx_requires_valid_range(__first2, __last2);
1859
1860 using _Cat = decltype(__comp(*__first1, *__first2));
1861 static_assert(same_as<common_comparison_category_t<_Cat>, _Cat>);
1862
1863 if (!std::__is_constant_evaluated())
1864 if constexpr (same_as<_Comp, __detail::_Synth3way>
1865 || same_as<_Comp, compare_three_way>)
1866 if constexpr (__memcmp_ordered_with<_InputIter1, _InputIter2>)
1867 {
1868 const auto [__len, __lencmp] = _GLIBCXX_STD_A::
1869 __min_cmp(__last1 - __first1, __last2 - __first2);
1870 if (__len)
1871 {
1872 const auto __blen = __len * sizeof(*__first1);
1873 const auto __c
1874 = __builtin_memcmp(&*__first1, &*__first2, __blen) <=> 0;
1875 if (__c != 0)
1876 return __c;
1877 }
1878 return __lencmp;
1879 }
1880
1881 while (__first1 != __last1)
1882 {
1883 if (__first2 == __last2)
1884 return strong_ordering::greater;
1885 if (auto __cmp = __comp(*__first1, *__first2); __cmp != 0)
1886 return __cmp;
1887 ++__first1;
1888 ++__first2;
1889 }
1890 return (__first2 == __last2) <=> true; // See PR 94006
1891 }
1892
1893 template<typename _InputIter1, typename _InputIter2>
1894 constexpr auto
1895 lexicographical_compare_three_way(_InputIter1 __first1,
1896 _InputIter1 __last1,
1897 _InputIter2 __first2,
1898 _InputIter2 __last2)
1899 {
1900 return _GLIBCXX_STD_A::
1901 lexicographical_compare_three_way(__first1, __last1, __first2, __last2,
1902 compare_three_way{});
1903 }
1904#endif // three_way_comparison
1905
1906 template<typename _InputIterator1, typename _InputIterator2,
1907 typename _BinaryPredicate>
1908 _GLIBCXX20_CONSTEXPR
1909 pair<_InputIterator1, _InputIterator2>
1910 __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1911 _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1912 {
1913 while (__first1 != __last1 && __binary_pred(__first1, __first2))
1914 {
1915 ++__first1;
1916 ++__first2;
1917 }
1918 return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
1919 }
1920
1921 /**
1922 * @brief Finds the places in ranges which don't match.
1923 * @ingroup non_mutating_algorithms
1924 * @param __first1 An input iterator.
1925 * @param __last1 An input iterator.
1926 * @param __first2 An input iterator.
1927 * @return A pair of iterators pointing to the first mismatch.
1928 *
1929 * This compares the elements of two ranges using @c == and returns a pair
1930 * of iterators. The first iterator points into the first range, the
1931 * second iterator points into the second range, and the elements pointed
1932 * to by the iterators are not equal.
1933 */
1934 template<typename _InputIterator1, typename _InputIterator2>
1935 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1936 inline pair<_InputIterator1, _InputIterator2>
1937 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1938 _InputIterator2 __first2)
1939 {
1940 // concept requirements
1941 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1942 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1943 __glibcxx_function_requires(_EqualOpConcept<
1944 typename iterator_traits<_InputIterator1>::value_type,
1945 typename iterator_traits<_InputIterator2>::value_type>)
1946 __glibcxx_requires_valid_range(__first1, __last1);
1947
1948 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1949 __gnu_cxx::__ops::__iter_equal_to_iter());
1950 }
1951
1952 /**
1953 * @brief Finds the places in ranges which don't match.
1954 * @ingroup non_mutating_algorithms
1955 * @param __first1 An input iterator.
1956 * @param __last1 An input iterator.
1957 * @param __first2 An input iterator.
1958 * @param __binary_pred A binary predicate @link functors
1959 * functor@endlink.
1960 * @return A pair of iterators pointing to the first mismatch.
1961 *
1962 * This compares the elements of two ranges using the binary_pred
1963 * parameter, and returns a pair
1964 * of iterators. The first iterator points into the first range, the
1965 * second iterator points into the second range, and the elements pointed
1966 * to by the iterators are not equal.
1967 */
1968 template<typename _InputIterator1, typename _InputIterator2,
1969 typename _BinaryPredicate>
1970 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1971 inline pair<_InputIterator1, _InputIterator2>
1972 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1973 _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1974 {
1975 // concept requirements
1976 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1977 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1978 __glibcxx_requires_valid_range(__first1, __last1);
1979
1980 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1981 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
1982 }
1983
1984#if __glibcxx_robust_nonmodifying_seq_ops // C++ >= 14
1985 template<typename _InputIterator1, typename _InputIterator2,
1986 typename _BinaryPredicate>
1987 _GLIBCXX20_CONSTEXPR
1988 pair<_InputIterator1, _InputIterator2>
1989 __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1990 _InputIterator2 __first2, _InputIterator2 __last2,
1991 _BinaryPredicate __binary_pred)
1992 {
1993 while (__first1 != __last1 && __first2 != __last2
1994 && __binary_pred(__first1, __first2))
1995 {
1996 ++__first1;
1997 ++__first2;
1998 }
1999 return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
2000 }
2001
2002 /**
2003 * @brief Finds the places in ranges which don't match.
2004 * @ingroup non_mutating_algorithms
2005 * @param __first1 An input iterator.
2006 * @param __last1 An input iterator.
2007 * @param __first2 An input iterator.
2008 * @param __last2 An input iterator.
2009 * @return A pair of iterators pointing to the first mismatch.
2010 *
2011 * This compares the elements of two ranges using @c == and returns a pair
2012 * of iterators. The first iterator points into the first range, the
2013 * second iterator points into the second range, and the elements pointed
2014 * to by the iterators are not equal.
2015 */
2016 template<typename _InputIterator1, typename _InputIterator2>
2017 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2018 inline pair<_InputIterator1, _InputIterator2>
2019 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2020 _InputIterator2 __first2, _InputIterator2 __last2)
2021 {
2022 // concept requirements
2023 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2024 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2025 __glibcxx_function_requires(_EqualOpConcept<
2026 typename iterator_traits<_InputIterator1>::value_type,
2027 typename iterator_traits<_InputIterator2>::value_type>)
2028 __glibcxx_requires_valid_range(__first1, __last1);
2029 __glibcxx_requires_valid_range(__first2, __last2);
2030
2031 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
2032 __gnu_cxx::__ops::__iter_equal_to_iter());
2033 }
2034
2035 /**
2036 * @brief Finds the places in ranges which don't match.
2037 * @ingroup non_mutating_algorithms
2038 * @param __first1 An input iterator.
2039 * @param __last1 An input iterator.
2040 * @param __first2 An input iterator.
2041 * @param __last2 An input iterator.
2042 * @param __binary_pred A binary predicate @link functors
2043 * functor@endlink.
2044 * @return A pair of iterators pointing to the first mismatch.
2045 *
2046 * This compares the elements of two ranges using the binary_pred
2047 * parameter, and returns a pair
2048 * of iterators. The first iterator points into the first range, the
2049 * second iterator points into the second range, and the elements pointed
2050 * to by the iterators are not equal.
2051 */
2052 template<typename _InputIterator1, typename _InputIterator2,
2053 typename _BinaryPredicate>
2054 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2055 inline pair<_InputIterator1, _InputIterator2>
2056 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2057 _InputIterator2 __first2, _InputIterator2 __last2,
2058 _BinaryPredicate __binary_pred)
2059 {
2060 // concept requirements
2061 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2062 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2063 __glibcxx_requires_valid_range(__first1, __last1);
2064 __glibcxx_requires_valid_range(__first2, __last2);
2065
2066 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
2067 __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
2068 }
2069#endif
2070
2071_GLIBCXX_END_NAMESPACE_ALGO
2072
2073 /// This is an overload used by find algos for the Input Iterator case.
2074 template<typename _InputIterator, typename _Predicate>
2075 _GLIBCXX20_CONSTEXPR
2076 inline _InputIterator
2077 __find_if(_InputIterator __first, _InputIterator __last,
2078 _Predicate __pred, input_iterator_tag)
2079 {
2080 while (__first != __last && !__pred(__first))
2081 ++__first;
2082 return __first;
2083 }
2084
2085 /// This is an overload used by find algos for the RAI case.
2086 template<typename _RandomAccessIterator, typename _Predicate>
2087 _GLIBCXX20_CONSTEXPR
2088 _RandomAccessIterator
2089 __find_if(_RandomAccessIterator __first, _RandomAccessIterator __last,
2090 _Predicate __pred, random_access_iterator_tag)
2091 {
2092 typename iterator_traits<_RandomAccessIterator>::difference_type
2093 __trip_count = (__last - __first) >> 2;
2094
2095 for (; __trip_count > 0; --__trip_count)
2096 {
2097 if (__pred(__first))
2098 return __first;
2099 ++__first;
2100
2101 if (__pred(__first))
2102 return __first;
2103 ++__first;
2104
2105 if (__pred(__first))
2106 return __first;
2107 ++__first;
2108
2109 if (__pred(__first))
2110 return __first;
2111 ++__first;
2112 }
2113
2114 switch (__last - __first)
2115 {
2116 case 3:
2117 if (__pred(__first))
2118 return __first;
2119 ++__first;
2120 // FALLTHRU
2121 case 2:
2122 if (__pred(__first))
2123 return __first;
2124 ++__first;
2125 // FALLTHRU
2126 case 1:
2127 if (__pred(__first))
2128 return __first;
2129 ++__first;
2130 // FALLTHRU
2131 case 0:
2132 default:
2133 return __last;
2134 }
2135 }
2136
2137 template<typename _Iterator, typename _Predicate>
2138 _GLIBCXX20_CONSTEXPR
2139 inline _Iterator
2140 __find_if(_Iterator __first, _Iterator __last, _Predicate __pred)
2141 {
2142 return __find_if(__first, __last, __pred,
2143 std::__iterator_category(__first));
2144 }
2145
2146 template<typename _InputIterator, typename _Predicate>
2147 _GLIBCXX20_CONSTEXPR
2148 typename iterator_traits<_InputIterator>::difference_type
2149 __count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
2150 {
2151 typename iterator_traits<_InputIterator>::difference_type __n = 0;
2152 for (; __first != __last; ++__first)
2153 if (__pred(__first))
2154 ++__n;
2155 return __n;
2156 }
2157
2158 template<typename _ForwardIterator, typename _Predicate>
2159 _GLIBCXX20_CONSTEXPR
2160 _ForwardIterator
2161 __remove_if(_ForwardIterator __first, _ForwardIterator __last,
2162 _Predicate __pred)
2163 {
2164 __first = std::__find_if(__first, __last, __pred);
2165 if (__first == __last)
2166 return __first;
2167 _ForwardIterator __result = __first;
2168 ++__first;
2169 for (; __first != __last; ++__first)
2170 if (!__pred(__first))
2171 {
2172 *__result = _GLIBCXX_MOVE(*__first);
2173 ++__result;
2174 }
2175 return __result;
2176 }
2177
2178 template<typename _ForwardIterator1, typename _ForwardIterator2,
2179 typename _BinaryPredicate>
2180 _GLIBCXX20_CONSTEXPR
2181 _ForwardIterator1
2182 __search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2183 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
2184 _BinaryPredicate __predicate)
2185 {
2186 // Test for empty ranges
2187 if (__first1 == __last1 || __first2 == __last2)
2188 return __first1;
2189
2190 // Test for a pattern of length 1.
2191 _ForwardIterator2 __p1(__first2);
2192 if (++__p1 == __last2)
2193 return std::__find_if(__first1, __last1,
2194 __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2));
2195
2196 // General case.
2197 _ForwardIterator1 __current = __first1;
2198
2199 for (;;)
2200 {
2201 __first1 =
2202 std::__find_if(__first1, __last1,
2203 __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2));
2204
2205 if (__first1 == __last1)
2206 return __last1;
2207
2208 _ForwardIterator2 __p = __p1;
2209 __current = __first1;
2210 if (++__current == __last1)
2211 return __last1;
2212
2213 while (__predicate(__current, __p))
2214 {
2215 if (++__p == __last2)
2216 return __first1;
2217 if (++__current == __last1)
2218 return __last1;
2219 }
2220 ++__first1;
2221 }
2222 return __first1;
2223 }
2224
2225#if __cplusplus >= 201103L
2226 template<typename _ForwardIterator1, typename _ForwardIterator2,
2227 typename _BinaryPredicate>
2228 _GLIBCXX20_CONSTEXPR
2229 bool
2230 __is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2231 _ForwardIterator2 __first2, _BinaryPredicate __pred)
2232 {
2233 // Efficiently compare identical prefixes: O(N) if sequences
2234 // have the same elements in the same order.
2235 for (; __first1 != __last1; ++__first1, (void)++__first2)
2236 if (!__pred(__first1, __first2))
2237 break;
2238
2239 if (__first1 == __last1)
2240 return true;
2241
2242 // Establish __last2 assuming equal ranges by iterating over the
2243 // rest of the list.
2244 _ForwardIterator2 __last2 = __first2;
2245 std::advance(__last2, std::distance(__first1, __last1));
2246 for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan)
2247 {
2248 if (__scan != std::__find_if(__first1, __scan,
2249 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan)))
2250 continue; // We've seen this one before.
2251
2252 auto __matches
2253 = std::__count_if(__first2, __last2,
2254 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan));
2255 if (0 == __matches ||
2256 std::__count_if(__scan, __last1,
2257 __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan))
2258 != __matches)
2259 return false;
2260 }
2261 return true;
2262 }
2263
2264 /**
2265 * @brief Checks whether a permutation of the second sequence is equal
2266 * to the first sequence.
2267 * @ingroup non_mutating_algorithms
2268 * @param __first1 Start of first range.
2269 * @param __last1 End of first range.
2270 * @param __first2 Start of second range.
2271 * @return true if there exists a permutation of the elements in the range
2272 * [__first2, __first2 + (__last1 - __first1)), beginning with
2273 * ForwardIterator2 begin, such that equal(__first1, __last1, begin)
2274 * returns true; otherwise, returns false.
2275 */
2276 template<typename _ForwardIterator1, typename _ForwardIterator2>
2277 _GLIBCXX20_CONSTEXPR
2278 inline bool
2279 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2280 _ForwardIterator2 __first2)
2281 {
2282 // concept requirements
2283 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
2284 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
2285 __glibcxx_function_requires(_EqualOpConcept<
2286 typename iterator_traits<_ForwardIterator1>::value_type,
2287 typename iterator_traits<_ForwardIterator2>::value_type>)
2288 __glibcxx_requires_valid_range(__first1, __last1);
2289
2290 return std::__is_permutation(__first1, __last1, __first2,
2291 __gnu_cxx::__ops::__iter_equal_to_iter());
2292 }
2293#endif // C++11
2294
2295_GLIBCXX_BEGIN_NAMESPACE_ALGO
2296
2297 /**
2298 * @brief Search a sequence for a matching sub-sequence using a predicate.
2299 * @ingroup non_mutating_algorithms
2300 * @param __first1 A forward iterator.
2301 * @param __last1 A forward iterator.
2302 * @param __first2 A forward iterator.
2303 * @param __last2 A forward iterator.
2304 * @param __predicate A binary predicate.
2305 * @return The first iterator @c i in the range
2306 * @p [__first1,__last1-(__last2-__first2)) such that
2307 * @p __predicate(*(i+N),*(__first2+N)) is true for each @c N in the range
2308 * @p [0,__last2-__first2), or @p __last1 if no such iterator exists.
2309 *
2310 * Searches the range @p [__first1,__last1) for a sub-sequence that
2311 * compares equal value-by-value with the sequence given by @p
2312 * [__first2,__last2), using @p __predicate to determine equality,
2313 * and returns an iterator to the first element of the
2314 * sub-sequence, or @p __last1 if no such iterator exists.
2315 *
2316 * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2)
2317 */
2318 template<typename _ForwardIterator1, typename _ForwardIterator2,
2319 typename _BinaryPredicate>
2320 _GLIBCXX20_CONSTEXPR
2321 inline _ForwardIterator1
2322 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2323 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
2324 _BinaryPredicate __predicate)
2325 {
2326 // concept requirements
2327 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
2328 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
2329 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
2330 typename iterator_traits<_ForwardIterator1>::value_type,
2331 typename iterator_traits<_ForwardIterator2>::value_type>)
2332 __glibcxx_requires_valid_range(__first1, __last1);
2333 __glibcxx_requires_valid_range(__first2, __last2);
2334
2335 return std::__search(__first1, __last1, __first2, __last2,
2336 __gnu_cxx::__ops::__iter_comp_iter(__predicate));
2337 }
2338
2339_GLIBCXX_END_NAMESPACE_ALGO
2340_GLIBCXX_END_NAMESPACE_VERSION
2341} // namespace std
2342
2343// NB: This file is included within many other C++ includes, as a way
2344// of getting the base algorithms. So, make sure that parallel bits
2345// come in too if requested.
2346#ifdef _GLIBCXX_PARALLEL
2347# include <parallel/algobase.h>
2348#endif
2349
2350#endif
2351