libstdc++
stl_algobase.h
Go to the documentation of this file.
1// Core algorithmic facilities -*- C++ -*-
2
3// Copyright (C) 2001-2025 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/cpp_type_traits.h>
61#include <ext/type_traits.h>
62#include <ext/numeric_traits.h>
63#include <bits/stl_pair.h>
64#include <bits/stl_iterator_base_types.h>
65#include <bits/stl_iterator_base_funcs.h>
66#include <bits/stl_iterator.h>
67#include <bits/concept_check.h>
68#include <debug/debug.h>
69#include <bits/move.h> // For std::swap
70#include <bits/predefined_ops.h>
71#if __cplusplus >= 201103L
72# include <type_traits>
73#endif
74#if __cplusplus >= 201402L
75# include <bit> // std::__bit_width
76#endif
77#if __cplusplus >= 202002L
78# include <compare>
79# include <bits/ptr_traits.h> // std::to_address
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_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
312
313 template<typename _Tp, typename _Ref, typename _Ptr>
314 struct _Deque_iterator;
315
316 struct _Bit_iterator;
317
318_GLIBCXX_END_NAMESPACE_CONTAINER
319
320#if _GLIBCXX_HOSTED
321 // Helpers for streambuf iterators (either istream or ostream).
322 // NB: avoid including <iosfwd>, relatively large.
323 template<typename _CharT>
324 struct char_traits;
325
326 template<typename _CharT, typename _Traits>
327 class istreambuf_iterator;
328
329 template<typename _CharT, typename _Traits>
330 class ostreambuf_iterator;
331
332 template<bool _IsMove, typename _CharT>
333 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
334 ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
335 __copy_move_a2(_CharT*, _CharT*,
336 ostreambuf_iterator<_CharT, char_traits<_CharT> >);
337
338 template<bool _IsMove, typename _CharT>
339 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
340 ostreambuf_iterator<_CharT, char_traits<_CharT> > >::__type
341 __copy_move_a2(const _CharT*, const _CharT*,
342 ostreambuf_iterator<_CharT, char_traits<_CharT> >);
343
344 template<bool _IsMove, typename _CharT>
345 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
346 _CharT*>::__type
347 __copy_move_a2(istreambuf_iterator<_CharT, char_traits<_CharT> >,
348 istreambuf_iterator<_CharT, char_traits<_CharT> >, _CharT*);
349
350 template<bool _IsMove, typename _CharT>
351 typename __gnu_cxx::__enable_if<
352 __is_char<_CharT>::__value,
353 _GLIBCXX_STD_C::_Deque_iterator<_CharT, _CharT&, _CharT*> >::__type
354 __copy_move_a2(
355 istreambuf_iterator<_CharT, char_traits<_CharT> >,
356 istreambuf_iterator<_CharT, char_traits<_CharT> >,
357 _GLIBCXX_STD_C::_Deque_iterator<_CharT, _CharT&, _CharT*>);
358#endif // HOSTED
359
360#if __cpp_lib_concepts
361 template<typename _OutIter, typename _InIter, typename _Sent = _InIter>
362 concept __memcpyable_iterators
363 = contiguous_iterator<_OutIter> && contiguous_iterator<_InIter>
364 && sized_sentinel_for<_Sent, _InIter>
365 && requires (_OutIter __o, _InIter __i) {
366 requires !!__memcpyable<decltype(std::to_address(__o)),
367 decltype(std::to_address(__i))>::__value;
368 };
369#endif
370
371#if __cplusplus < 201103L
372 // Used by __copy_move_a2, __copy_n_a and __copy_move_backward_a2 to
373 // get raw pointers so that calls to __builtin_memmove will compile,
374 // because C++98 can't use 'if constexpr' so statements that use memmove
375 // with pointer arguments need to also compile for arbitrary iterator types.
376 template<typename _Iter> __attribute__((__always_inline__))
377 inline void* __ptr_or_null(_Iter) { return 0; }
378 template<typename _Tp> __attribute__((__always_inline__))
379 inline void* __ptr_or_null(_Tp* __p) { return (void*)__p; }
380# define _GLIBCXX_TO_ADDR(P) std::__ptr_or_null(P)
381 // Used to advance output iterators (std::advance requires InputIterator).
382 template<typename _Iter> __attribute__((__always_inline__))
383 inline void __ptr_advance(_Iter&, ptrdiff_t) { }
384 template<typename _Tp> __attribute__((__always_inline__))
385 inline void __ptr_advance(_Tp*& __p, ptrdiff_t __n) { __p += __n; }
386# define _GLIBCXX_ADVANCE(P, N) std::__ptr_advance(P, N)
387#else
388 // For C++11 mode the __builtin_memmove calls are guarded by 'if constexpr'
389 // so we know the iterators used with memmove are guaranteed to be pointers.
390# define _GLIBCXX_TO_ADDR(P) P
391# define _GLIBCXX_ADVANCE(P, N) P += N
392#endif
393
394#pragma GCC diagnostic push
395#pragma GCC diagnostic ignored "-Wc++17-extensions"
396 template<bool _IsMove, typename _OutIter, typename _InIter>
397 __attribute__((__always_inline__)) _GLIBCXX20_CONSTEXPR
398 inline void
399 __assign_one(_OutIter& __out, _InIter& __in)
400 {
401#if __cplusplus >= 201103L
402 if constexpr (_IsMove)
403 *__out = std::move(*__in);
404 else
405#endif
406 *__out = *__in;
407 }
408
409 template<bool _IsMove, typename _InIter, typename _Sent, typename _OutIter>
410 _GLIBCXX20_CONSTEXPR
411 inline _OutIter
412 __copy_move_a2(_InIter __first, _Sent __last, _OutIter __result)
413 {
414 typedef __decltype(*__first) _InRef;
415 typedef __decltype(*__result) _OutRef;
416 if _GLIBCXX_CONSTEXPR (!__is_trivially_assignable(_OutRef, _InRef))
417 { } /* Skip the optimizations and use the loop at the end. */
418 else if (std::__is_constant_evaluated())
419 { } /* Skip the optimizations and use the loop at the end. */
420 else if _GLIBCXX_CONSTEXPR (__memcpyable<_OutIter, _InIter>::__value)
421 {
422 ptrdiff_t __n = std::distance(__first, __last);
423 if (__builtin_expect(__n > 1, true))
424 {
425 __builtin_memmove(_GLIBCXX_TO_ADDR(__result),
426 _GLIBCXX_TO_ADDR(__first),
427 __n * sizeof(*__first));
428 _GLIBCXX_ADVANCE(__result, __n);
429 }
430 else if (__n == 1)
431 {
432 std::__assign_one<_IsMove>(__result, __first);
433 ++__result;
434 }
435 return __result;
436 }
437#if __cpp_lib_concepts
438 else if constexpr (__memcpyable_iterators<_OutIter, _InIter, _Sent>)
439 {
440 if (auto __n = __last - __first; __n > 1) [[likely]]
441 {
442 void* __dest = std::to_address(__result);
443 const void* __src = std::to_address(__first);
444 size_t __nbytes = __n * sizeof(iter_value_t<_InIter>);
445 // Advance the iterators and convert to pointers first.
446 // This gives the iterators a chance to do bounds checking.
447 (void) std::to_address(__result += __n);
448 (void) std::to_address(__first += __n);
449 __builtin_memmove(__dest, __src, __nbytes);
450 }
451 else if (__n == 1)
452 {
453 std::__assign_one<_IsMove>(__result, __first);
454 ++__result;
455 }
456 return __result;
457 }
458#endif
459
460 for (; __first != __last; ++__result, (void)++__first)
461 std::__assign_one<_IsMove>(__result, __first);
462 return __result;
463 }
464#pragma GCC diagnostic pop
465
466 template<bool _IsMove,
467 typename _Tp, typename _Ref, typename _Ptr, typename _OI>
468 _OI
469 __copy_move_a1(_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
470 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
471 _OI);
472
473 template<bool _IsMove,
474 typename _ITp, typename _IRef, typename _IPtr, typename _OTp>
475 _GLIBCXX_STD_C::_Deque_iterator<_OTp, _OTp&, _OTp*>
476 __copy_move_a1(_GLIBCXX_STD_C::_Deque_iterator<_ITp, _IRef, _IPtr>,
477 _GLIBCXX_STD_C::_Deque_iterator<_ITp, _IRef, _IPtr>,
478 _GLIBCXX_STD_C::_Deque_iterator<_OTp, _OTp&, _OTp*>);
479
480 template<bool _IsMove, typename _II, typename _Tp>
481 typename __gnu_cxx::__enable_if<
482 __is_random_access_iter<_II>::__value,
483 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*> >::__type
484 __copy_move_a1(_II, _II, _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>);
485
486 template<bool _IsMove, typename _II, typename _OI>
487 __attribute__((__always_inline__))
488 _GLIBCXX20_CONSTEXPR
489 inline _OI
490 __copy_move_a1(_II __first, _II __last, _OI __result)
491 { return std::__copy_move_a2<_IsMove>(__first, __last, __result); }
492
493 template<bool _IsMove, typename _II, typename _OI>
494 __attribute__((__always_inline__))
495 _GLIBCXX20_CONSTEXPR
496 inline _OI
497 __copy_move_a(_II __first, _II __last, _OI __result)
498 {
499 return std::__niter_wrap(__result,
500 std::__copy_move_a1<_IsMove>(std::__niter_base(__first),
501 std::__niter_base(__last),
502 std::__niter_base(__result)));
503 }
504
505 template<bool _IsMove,
506 typename _Ite, typename _Seq, typename _Cat, typename _OI>
507 _GLIBCXX20_CONSTEXPR
508 _OI
509 __copy_move_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
510 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
511 _OI);
512
513 template<bool _IsMove,
514 typename _II, typename _Ite, typename _Seq, typename _Cat>
515 _GLIBCXX20_CONSTEXPR
516 __gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
517 __copy_move_a(_II, _II,
518 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&);
519
520 template<bool _IsMove,
521 typename _IIte, typename _ISeq, typename _ICat,
522 typename _OIte, typename _OSeq, typename _OCat>
523 _GLIBCXX20_CONSTEXPR
524 ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>
525 __copy_move_a(const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>&,
526 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>&,
527 const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>&);
528
529#pragma GCC diagnostic push
530#pragma GCC diagnostic ignored "-Wc++17-extensions" // for if-constexpr
531 template<typename _InputIterator, typename _Size, typename _OutputIterator>
532 _GLIBCXX20_CONSTEXPR
533 _OutputIterator
534 __copy_n_a(_InputIterator __first, _Size __n, _OutputIterator __result,
535 bool)
536 {
537 typedef __decltype(*__first) _InRef;
538 typedef __decltype(*__result) _OutRef;
539 if _GLIBCXX_CONSTEXPR (!__is_trivially_assignable(_OutRef, _InRef))
540 { } /* Skip the optimizations and use the loop at the end. */
541#ifdef __cpp_lib_is_constant_evaluated
542 else if (std::is_constant_evaluated())
543 { } /* Skip the optimizations and use the loop at the end. */
544#endif
545 else if _GLIBCXX_CONSTEXPR (__memcpyable<_OutputIterator,
546 _InputIterator>::__value)
547 {
548 if (__builtin_expect(__n > 1, true))
549 {
550 __builtin_memmove(_GLIBCXX_TO_ADDR(__result),
551 _GLIBCXX_TO_ADDR(__first),
552 __n * sizeof(*__first));
553 _GLIBCXX_ADVANCE(__result, __n);
554 }
555 else if (__n == 1)
556 *__result++ = *__first;
557 return __result;
558 }
559#if __cpp_lib_concepts
560 else if constexpr (__memcpyable_iterators<_OutputIterator,
561 _InputIterator>)
562 {
563 if (__n > 1) [[likely]]
564 {
565 void* __dest = std::to_address(__result);
566 const void* __src = std::to_address(__first);
567 size_t __nbytes = __n * sizeof(iter_value_t<_InputIterator>);
568 // Advance the iterators and convert to pointers first.
569 // This gives the iterators a chance to do bounds checking.
570 (void) std::to_address(__result += __n);
571 (void) std::to_address(__first += __n);
572 __builtin_memmove(__dest, __src, __nbytes);
573 }
574 else if (__n == 1)
575 *__result++ = *__first;
576 return __result;
577 }
578#endif
579
580 if (__n > 0)
581 {
582 while (true)
583 {
584 *__result = *__first;
585 ++__result;
586 if (--__n > 0)
587 ++__first;
588 else
589 break;
590 }
591 }
592 return __result;
593 }
594#pragma GCC diagnostic pop
595
596#if _GLIBCXX_HOSTED
597 template<typename _CharT, typename _Size>
598 typename __gnu_cxx::__enable_if<
599 __is_char<_CharT>::__value, _CharT*>::__type
600 __copy_n_a(istreambuf_iterator<_CharT, char_traits<_CharT> >,
601 _Size, _CharT*, bool);
602
603 template<typename _CharT, typename _Size>
604 typename __gnu_cxx::__enable_if<
605 __is_char<_CharT>::__value,
606 _GLIBCXX_STD_C::_Deque_iterator<_CharT, _CharT&, _CharT*> >::__type
607 __copy_n_a(istreambuf_iterator<_CharT, char_traits<_CharT> >, _Size,
608 _GLIBCXX_STD_C::_Deque_iterator<_CharT, _CharT&, _CharT*>,
609 bool);
610#endif
611
612 /**
613 * @brief Copies the range [first,last) into result.
614 * @ingroup mutating_algorithms
615 * @param __first An input iterator.
616 * @param __last An input iterator.
617 * @param __result An output iterator.
618 * @return result + (last - first)
619 *
620 * This inline function will boil down to a call to @c memmove whenever
621 * possible. Failing that, if random access iterators are passed, then the
622 * loop count will be known (and therefore a candidate for compiler
623 * optimizations such as unrolling). Result may not be contained within
624 * [first,last); the copy_backward function should be used instead.
625 *
626 * Note that the end of the output range is permitted to be contained
627 * within [first,last).
628 */
629 template<typename _II, typename _OI>
630 _GLIBCXX20_CONSTEXPR
631 inline _OI
632 copy(_II __first, _II __last, _OI __result)
633 {
634 // concept requirements
635 __glibcxx_function_requires(_InputIteratorConcept<_II>)
636 __glibcxx_function_requires(_OutputIteratorConcept<_OI,
637 typename iterator_traits<_II>::reference>)
638 __glibcxx_requires_can_increment_range(__first, __last, __result);
639
640 return std::__copy_move_a<__is_move_iterator<_II>::__value>
641 (std::__miter_base(__first), std::__miter_base(__last), __result);
642 }
643
644#if __cplusplus >= 201103L
645 /**
646 * @brief Moves the range [first,last) into result.
647 * @ingroup mutating_algorithms
648 * @param __first An input iterator.
649 * @param __last An input iterator.
650 * @param __result An output iterator.
651 * @return result + (last - first)
652 *
653 * This inline function will boil down to a call to @c memmove whenever
654 * possible. Failing that, if random access iterators are passed, then the
655 * loop count will be known (and therefore a candidate for compiler
656 * optimizations such as unrolling). Result may not be contained within
657 * [first,last); the move_backward function should be used instead.
658 *
659 * Note that the end of the output range is permitted to be contained
660 * within [first,last).
661 */
662 template<typename _II, typename _OI>
663 _GLIBCXX20_CONSTEXPR
664 inline _OI
665 move(_II __first, _II __last, _OI __result)
666 {
667 // concept requirements
668 __glibcxx_function_requires(_InputIteratorConcept<_II>)
669 __glibcxx_function_requires(_OutputIteratorConcept<_OI,
670 typename iterator_traits<_II>::value_type&&>)
671 __glibcxx_requires_can_increment_range(__first, __last, __result);
672
673 return std::__copy_move_a<true>(std::__miter_base(__first),
674 std::__miter_base(__last), __result);
675 }
676
677#define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::move(_Tp, _Up, _Vp)
678#else
679#define _GLIBCXX_MOVE3(_Tp, _Up, _Vp) std::copy(_Tp, _Up, _Vp)
680#endif
681
682#pragma GCC diagnostic push
683#pragma GCC diagnostic ignored "-Wc++17-extensions"
684 template<bool _IsMove, typename _BI1, typename _BI2>
685 _GLIBCXX20_CONSTEXPR
686 inline _BI2
687 __copy_move_backward_a2(_BI1 __first, _BI1 __last, _BI2 __result)
688 {
689 typedef __decltype(*__first) _InRef;
690 typedef __decltype(*__result) _OutRef;
691 if _GLIBCXX_CONSTEXPR (!__is_trivially_assignable(_OutRef, _InRef))
692 { } /* Skip the optimizations and use the loop at the end. */
693#ifdef __cpp_lib_is_constant_evaluated
694 else if (std::is_constant_evaluated())
695 { } /* Skip the optimizations and use the loop at the end. */
696#endif
697 else if _GLIBCXX_CONSTEXPR (__memcpyable<_BI2, _BI1>::__value)
698 {
699 ptrdiff_t __n = std::distance(__first, __last);
700 std::advance(__result, -__n);
701 if (__builtin_expect(__n > 1, true))
702 {
703 __builtin_memmove(_GLIBCXX_TO_ADDR(__result),
704 _GLIBCXX_TO_ADDR(__first),
705 __n * sizeof(*__first));
706 }
707 else if (__n == 1)
708 std::__assign_one<_IsMove>(__result, __first);
709 return __result;
710 }
711#if __cpp_lib_concepts
712 else if constexpr (__memcpyable_iterators<_BI2, _BI1>)
713 {
714 if (auto __n = __last - __first; __n > 1) [[likely]]
715 {
716 const void* __src = std::to_address(__first);
717 // Advance the iterators and convert to pointers first.
718 // This gives the iterators a chance to do bounds checking.
719 (void) std::to_address(__result -= __n);
720 (void) std::to_address(__first += __n);
721 void* __dest = std::to_address(__result);
722 size_t __nbytes = __n * sizeof(iter_value_t<_BI1>);
723 __builtin_memmove(__dest, __src, __nbytes);
724 }
725 else if (__n == 1)
726 {
727 --__result;
728 std::__assign_one<_IsMove>(__result, __first);
729 }
730 return __result;
731 }
732#endif
733
734 while (__first != __last)
735 {
736 --__last;
737 --__result;
738 std::__assign_one<_IsMove>(__result, __last);
739 }
740 return __result;
741 }
742#pragma GCC diagnostic pop
743
744#undef _GLIBCXX_TO_ADDR
745#undef _GLIBCXX_ADVANCE
746
747 template<bool _IsMove, typename _BI1, typename _BI2>
748 __attribute__((__always_inline__))
749 _GLIBCXX20_CONSTEXPR
750 inline _BI2
751 __copy_move_backward_a1(_BI1 __first, _BI1 __last, _BI2 __result)
752 { return std::__copy_move_backward_a2<_IsMove>(__first, __last, __result); }
753
754 template<bool _IsMove,
755 typename _Tp, typename _Ref, typename _Ptr, typename _OI>
756 _OI
757 __copy_move_backward_a1(_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
758 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
759 _OI);
760
761 template<bool _IsMove,
762 typename _ITp, typename _IRef, typename _IPtr, typename _OTp>
763 _GLIBCXX_STD_C::_Deque_iterator<_OTp, _OTp&, _OTp*>
764 __copy_move_backward_a1(
765 _GLIBCXX_STD_C::_Deque_iterator<_ITp, _IRef, _IPtr>,
766 _GLIBCXX_STD_C::_Deque_iterator<_ITp, _IRef, _IPtr>,
767 _GLIBCXX_STD_C::_Deque_iterator<_OTp, _OTp&, _OTp*>);
768
769 template<bool _IsMove, typename _II, typename _Tp>
770 typename __gnu_cxx::__enable_if<
771 __is_random_access_iter<_II>::__value,
772 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*> >::__type
773 __copy_move_backward_a1(_II, _II,
774 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>);
775
776 template<bool _IsMove, typename _II, typename _OI>
777 __attribute__((__always_inline__))
778 _GLIBCXX20_CONSTEXPR
779 inline _OI
780 __copy_move_backward_a(_II __first, _II __last, _OI __result)
781 {
782 return std::__niter_wrap(__result,
783 std::__copy_move_backward_a1<_IsMove>
784 (std::__niter_base(__first), std::__niter_base(__last),
785 std::__niter_base(__result)));
786 }
787
788 template<bool _IsMove,
789 typename _Ite, typename _Seq, typename _Cat, typename _OI>
790 _GLIBCXX20_CONSTEXPR
791 _OI
792 __copy_move_backward_a(
793 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
794 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
795 _OI);
796
797 template<bool _IsMove,
798 typename _II, typename _Ite, typename _Seq, typename _Cat>
799 _GLIBCXX20_CONSTEXPR
800 __gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
801 __copy_move_backward_a(_II, _II,
802 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&);
803
804 template<bool _IsMove,
805 typename _IIte, typename _ISeq, typename _ICat,
806 typename _OIte, typename _OSeq, typename _OCat>
807 _GLIBCXX20_CONSTEXPR
808 ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>
809 __copy_move_backward_a(
810 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>&,
811 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>&,
812 const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>&);
813
814 /**
815 * @brief Copies the range [first,last) into result.
816 * @ingroup mutating_algorithms
817 * @param __first A bidirectional iterator.
818 * @param __last A bidirectional iterator.
819 * @param __result A bidirectional iterator.
820 * @return result - (last - first)
821 *
822 * The function has the same effect as copy, but starts at the end of the
823 * range and works its way to the start, returning the start of the result.
824 * This inline function will boil down to a call to @c memmove whenever
825 * possible. Failing that, if random access iterators are passed, then the
826 * loop count will be known (and therefore a candidate for compiler
827 * optimizations such as unrolling).
828 *
829 * Result may not be in the range (first,last]. Use copy instead. Note
830 * that the start of the output range may overlap [first,last).
831 */
832 template<typename _BI1, typename _BI2>
833 __attribute__((__always_inline__))
834 _GLIBCXX20_CONSTEXPR
835 inline _BI2
836 copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
837 {
838 // concept requirements
839 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
840 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
841 __glibcxx_function_requires(_OutputIteratorConcept<_BI2,
842 typename iterator_traits<_BI1>::reference>)
843 __glibcxx_requires_can_decrement_range(__first, __last, __result);
844
845 return std::__copy_move_backward_a<__is_move_iterator<_BI1>::__value>
846 (std::__miter_base(__first), std::__miter_base(__last), __result);
847 }
848
849#if __cplusplus >= 201103L
850 /**
851 * @brief Moves the range [first,last) into result.
852 * @ingroup mutating_algorithms
853 * @param __first A bidirectional iterator.
854 * @param __last A bidirectional iterator.
855 * @param __result A bidirectional iterator.
856 * @return result - (last - first)
857 *
858 * The function has the same effect as move, but starts at the end of the
859 * range and works its way to the start, returning the start of the result.
860 * This inline function will boil down to a call to @c memmove whenever
861 * possible. Failing that, if random access iterators are passed, then the
862 * loop count will be known (and therefore a candidate for compiler
863 * optimizations such as unrolling).
864 *
865 * Result may not be in the range (first,last]. Use move instead. Note
866 * that the start of the output range may overlap [first,last).
867 */
868 template<typename _BI1, typename _BI2>
869 __attribute__((__always_inline__))
870 _GLIBCXX20_CONSTEXPR
871 inline _BI2
872 move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
873 {
874 // concept requirements
875 __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
876 __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
877 __glibcxx_function_requires(_OutputIteratorConcept<_BI2,
878 typename iterator_traits<_BI1>::value_type&&>)
879 __glibcxx_requires_can_decrement_range(__first, __last, __result);
880
881 return std::__copy_move_backward_a<true>(std::__miter_base(__first),
882 std::__miter_base(__last),
883 __result);
884 }
885
886#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::move_backward(_Tp, _Up, _Vp)
887#else
888#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::copy_backward(_Tp, _Up, _Vp)
889#endif
890
891#pragma GCC diagnostic push
892#pragma GCC diagnostic ignored "-Wc++17-extensions"
893 template<typename _ForwardIterator, typename _Tp>
894 _GLIBCXX20_CONSTEXPR
895 inline void
896 __fill_a1(_ForwardIterator __first, _ForwardIterator __last,
897 const _Tp& __value)
898 {
899#pragma GCC diagnostic push
900#pragma GCC diagnostic ignored "-Wlong-long"
901 // We can optimize this loop by moving the load from __value outside
902 // the loop, but only if we know that making that copy is trivial,
903 // and the assignment in the loop is also trivial (so that the identity
904 // of the operand doesn't matter).
905 const bool __load_outside_loop =
906#if __has_builtin(__is_trivially_constructible) \
907 && __has_builtin(__is_trivially_assignable)
908 __is_trivially_constructible(_Tp, const _Tp&)
909 && __is_trivially_assignable(__decltype(*__first), const _Tp&)
910#else
911 __is_trivially_copyable(_Tp)
912 && __is_same(_Tp, __typeof__(*__first))
913#endif
914 && sizeof(_Tp) <= sizeof(long long);
915#pragma GCC diagnostic pop
916
917 // When the condition is true, we use a copy of __value,
918 // otherwise we just use another reference.
919 typedef typename __gnu_cxx::__conditional_type<__load_outside_loop,
920 const _Tp,
921 const _Tp&>::__type _Up;
922 _Up __val(__value);
923 for (; __first != __last; ++__first)
924 *__first = __val;
925 }
926#pragma GCC diagnostic pop
927
928 // Specialization: for char types we can use memset.
929 template<typename _Up, typename _Tp>
930 _GLIBCXX20_CONSTEXPR
931 inline typename
932 __gnu_cxx::__enable_if<__is_byte<_Up>::__value
933 && (__are_same<_Up, _Tp>::__value // for std::byte
934 || __memcpyable_integer<_Tp>::__width),
935 void>::__type
936 __fill_a1(_Up* __first, _Up* __last, const _Tp& __x)
937 {
938 // This hoists the load out of the loop and also ensures that we don't
939 // use memset for cases where the assignment would be ill-formed.
940 const _Up __val = __x;
941#if __cpp_lib_is_constant_evaluated
942 if (std::is_constant_evaluated())
943 {
944 for (; __first != __last; ++__first)
945 *__first = __val;
946 return;
947 }
948#endif
949 if (const size_t __len = __last - __first)
950 __builtin_memset(__first, static_cast<unsigned char>(__val), __len);
951 }
952
953 template<typename _Ite, typename _Cont, typename _Tp>
954 __attribute__((__always_inline__))
955 _GLIBCXX20_CONSTEXPR
956 inline void
957 __fill_a1(::__gnu_cxx::__normal_iterator<_Ite, _Cont> __first,
958 ::__gnu_cxx::__normal_iterator<_Ite, _Cont> __last,
959 const _Tp& __value)
960 { std::__fill_a1(__first.base(), __last.base(), __value); }
961
962 template<typename _Tp, typename _VTp>
963 void
964 __fill_a1(const _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>&,
965 const _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>&,
966 const _VTp&);
967
968 _GLIBCXX20_CONSTEXPR
969 void
970 __fill_a1(_GLIBCXX_STD_C::_Bit_iterator, _GLIBCXX_STD_C::_Bit_iterator,
971 const bool&);
972
973 template<typename _FIte, typename _Tp>
974 __attribute__((__always_inline__))
975 _GLIBCXX20_CONSTEXPR
976 inline void
977 __fill_a(_FIte __first, _FIte __last, const _Tp& __value)
978 { std::__fill_a1(__first, __last, __value); }
979
980 template<typename _Ite, typename _Seq, typename _Cat, typename _Tp>
981 _GLIBCXX20_CONSTEXPR
982 void
983 __fill_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
984 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
985 const _Tp&);
986
987 /**
988 * @brief Fills the range [first,last) with copies of value.
989 * @ingroup mutating_algorithms
990 * @param __first A forward iterator.
991 * @param __last A forward iterator.
992 * @param __value A reference-to-const of arbitrary type.
993 * @return Nothing.
994 *
995 * This function fills a range with copies of the same value. For char
996 * types filling contiguous areas of memory, this becomes an inline call
997 * to @c memset or @c wmemset.
998 */
999 template<typename _ForwardIterator, typename _Tp>
1000 __attribute__((__always_inline__))
1001 _GLIBCXX20_CONSTEXPR
1002 inline void
1003 fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
1004 {
1005 // concept requirements
1006 __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1007 _ForwardIterator>)
1008 __glibcxx_requires_valid_range(__first, __last);
1009
1010 std::__fill_a(__first, __last, __value);
1011 }
1012
1013#pragma GCC diagnostic push
1014#pragma GCC diagnostic ignored "-Wlong-long"
1015 // Used by fill_n, generate_n, etc. to convert _Size to an integral type:
1016 inline _GLIBCXX_CONSTEXPR int
1017 __size_to_integer(int __n) { return __n; }
1018 inline _GLIBCXX_CONSTEXPR unsigned
1019 __size_to_integer(unsigned __n) { return __n; }
1020 inline _GLIBCXX_CONSTEXPR long
1021 __size_to_integer(long __n) { return __n; }
1022 inline _GLIBCXX_CONSTEXPR unsigned long
1023 __size_to_integer(unsigned long __n) { return __n; }
1024 inline _GLIBCXX_CONSTEXPR long long
1025 __size_to_integer(long long __n) { return __n; }
1026 inline _GLIBCXX_CONSTEXPR unsigned long long
1027 __size_to_integer(unsigned long long __n) { return __n; }
1028
1029#if defined(__GLIBCXX_TYPE_INT_N_0)
1030 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_0
1031 __size_to_integer(__GLIBCXX_TYPE_INT_N_0 __n) { return __n; }
1032 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_0
1033 __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_0 __n) { return __n; }
1034#endif
1035#if defined(__GLIBCXX_TYPE_INT_N_1)
1036 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_1
1037 __size_to_integer(__GLIBCXX_TYPE_INT_N_1 __n) { return __n; }
1038 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_1
1039 __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_1 __n) { return __n; }
1040#endif
1041#if defined(__GLIBCXX_TYPE_INT_N_2)
1042 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_2
1043 __size_to_integer(__GLIBCXX_TYPE_INT_N_2 __n) { return __n; }
1044 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_2
1045 __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_2 __n) { return __n; }
1046#endif
1047#if defined(__GLIBCXX_TYPE_INT_N_3)
1048 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_3
1049 __size_to_integer(__GLIBCXX_TYPE_INT_N_3 __n) { return __n; }
1050 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_3
1051 __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_3 __n) { return __n; }
1052#endif
1053
1054#if defined(__STRICT_ANSI__) && defined(__SIZEOF_INT128__)
1055 __extension__ inline _GLIBCXX_CONSTEXPR __int128
1056 __size_to_integer(__int128 __n) { return __n; }
1057 __extension__ inline _GLIBCXX_CONSTEXPR unsigned __int128
1058 __size_to_integer(unsigned __int128 __n) { return __n; }
1059#endif
1060
1061 inline _GLIBCXX_CONSTEXPR long long
1062 __size_to_integer(float __n) { return (long long)__n; }
1063 inline _GLIBCXX_CONSTEXPR long long
1064 __size_to_integer(double __n) { return (long long)__n; }
1065 inline _GLIBCXX_CONSTEXPR long long
1066 __size_to_integer(long double __n) { return (long long)__n; }
1067#ifdef _GLIBCXX_USE_FLOAT128
1068 __extension__ inline _GLIBCXX_CONSTEXPR long long
1069 __size_to_integer(__float128 __n) { return (long long)__n; }
1070#endif
1071#pragma GCC diagnostic pop
1072
1073#pragma GCC diagnostic push
1074#pragma GCC diagnostic ignored "-Wc++17-extensions"
1075#pragma GCC diagnostic ignored "-Wlong-long"
1076 template<typename _OutputIterator, typename _Size, typename _Tp>
1077 _GLIBCXX20_CONSTEXPR
1078 inline _OutputIterator
1079 __fill_n_a1(_OutputIterator __first, _Size __n, const _Tp& __value)
1080 {
1081 // See std::__fill_a1 for explanation of this condition.
1082 const bool __load_outside_loop =
1083#if __has_builtin(__is_trivially_constructible) \
1084 && __has_builtin(__is_trivially_assignable)
1085 __is_trivially_constructible(_Tp, const _Tp&)
1086 && __is_trivially_assignable(__decltype(*__first), const _Tp&)
1087#else
1088 __is_trivially_copyable(_Tp)
1089 && __is_same(_Tp, __typeof__(*__first))
1090#endif
1091 && sizeof(_Tp) <= sizeof(long long);
1092
1093 // When the condition is true, we use a copy of __value,
1094 // otherwise we just use another reference.
1095 typedef typename __gnu_cxx::__conditional_type<__load_outside_loop,
1096 const _Tp,
1097 const _Tp&>::__type _Up;
1098 _Up __val(__value);
1099 for (; __n > 0; --__n, (void) ++__first)
1100 *__first = __val;
1101 return __first;
1102 }
1103#pragma GCC diagnostic pop
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 __attribute__((__always_inline__))
1115 _GLIBCXX20_CONSTEXPR
1116 inline _OutputIterator
1117 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1118 std::output_iterator_tag)
1119 {
1120#if __cplusplus >= 201103L
1121 static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1122#endif
1123 return __fill_n_a1(__first, __n, __value);
1124 }
1125
1126 template<typename _OutputIterator, typename _Size, typename _Tp>
1127 __attribute__((__always_inline__))
1128 _GLIBCXX20_CONSTEXPR
1129 inline _OutputIterator
1130 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1131 std::input_iterator_tag)
1132 {
1133#if __cplusplus >= 201103L
1134 static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1135#endif
1136 return __fill_n_a1(__first, __n, __value);
1137 }
1138
1139 template<typename _OutputIterator, typename _Size, typename _Tp>
1140 __attribute__((__always_inline__))
1141 _GLIBCXX20_CONSTEXPR
1142 inline _OutputIterator
1143 __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1144 std::random_access_iterator_tag)
1145 {
1146#if __cplusplus >= 201103L
1147 static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1148#endif
1149 if (__n <= 0)
1150 return __first;
1151
1152 typename iterator_traits<_OutputIterator>::difference_type __d = __n;
1153 __glibcxx_requires_can_increment(__first, __d);
1154
1155 _OutputIterator __last = __first + __d;
1156 std::__fill_a(__first, __last, __value);
1157 return __last;
1158 }
1159
1160 /**
1161 * @brief Fills the range [first,first+n) with copies of value.
1162 * @ingroup mutating_algorithms
1163 * @param __first An output iterator.
1164 * @param __n The count of copies to perform.
1165 * @param __value A reference-to-const of arbitrary type.
1166 * @return The iterator at first+n.
1167 *
1168 * This function fills a range with copies of the same value. For char
1169 * types filling contiguous areas of memory, this becomes an inline call
1170 * to @c memset or @c wmemset.
1171 *
1172 * If @p __n is negative, the function does nothing.
1173 */
1174 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1175 // DR 865. More algorithms that throw away information
1176 // DR 426. search_n(), fill_n(), and generate_n() with negative n
1177 template<typename _OI, typename _Size, typename _Tp>
1178 __attribute__((__always_inline__))
1179 _GLIBCXX20_CONSTEXPR
1180 inline _OI
1181 fill_n(_OI __first, _Size __n, const _Tp& __value)
1182 {
1183 // concept requirements
1184 __glibcxx_function_requires(_OutputIteratorConcept<_OI, const _Tp&>)
1185
1186 return std::__fill_n_a(__first, std::__size_to_integer(__n), __value,
1187 std::__iterator_category(__first));
1188 }
1189
1190 template<bool _BoolType>
1191 struct __equal
1192 {
1193 template<typename _II1, typename _II2>
1194 _GLIBCXX20_CONSTEXPR
1195 static bool
1196 equal(_II1 __first1, _II1 __last1, _II2 __first2)
1197 {
1198 for (; __first1 != __last1; ++__first1, (void) ++__first2)
1199 if (!(*__first1 == *__first2))
1200 return false;
1201 return true;
1202 }
1203 };
1204
1205 template<>
1206 struct __equal<true>
1207 {
1208 template<typename _Tp>
1209 _GLIBCXX20_CONSTEXPR
1210 static bool
1211 equal(const _Tp* __first1, const _Tp* __last1, const _Tp* __first2)
1212 {
1213 if (const size_t __len = (__last1 - __first1))
1214 return !std::__memcmp(__first1, __first2, __len);
1215 return true;
1216 }
1217 };
1218
1219 template<typename _Tp, typename _Ref, typename _Ptr, typename _II>
1220 typename __gnu_cxx::__enable_if<
1221 __is_random_access_iter<_II>::__value, bool>::__type
1222 __equal_aux1(_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
1223 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
1224 _II);
1225
1226 template<typename _Tp1, typename _Ref1, typename _Ptr1,
1227 typename _Tp2, typename _Ref2, typename _Ptr2>
1228 bool
1229 __equal_aux1(_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1230 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1231 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1232
1233 template<typename _II, typename _Tp, typename _Ref, typename _Ptr>
1234 typename __gnu_cxx::__enable_if<
1235 __is_random_access_iter<_II>::__value, bool>::__type
1236 __equal_aux1(_II, _II,
1237 _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>);
1238
1239 template<typename _II1, typename _II2>
1240 _GLIBCXX20_CONSTEXPR
1241 inline bool
1242 __equal_aux1(_II1 __first1, _II1 __last1, _II2 __first2)
1243 {
1244 typedef typename iterator_traits<_II1>::value_type _ValueType1;
1245 const bool __simple = ((__is_integer<_ValueType1>::__value
1246#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer)
1247 || __is_pointer(_ValueType1)
1248#endif
1249#if __glibcxx_byte && __glibcxx_type_trait_variable_templates
1250 // bits/cpp_type_traits.h declares std::byte
1251 || is_same_v<_ValueType1, byte>
1252#endif
1253 ) && __memcmpable<_II1, _II2>::__value);
1254 return std::__equal<__simple>::equal(__first1, __last1, __first2);
1255 }
1256
1257 template<typename _II1, typename _II2>
1258 __attribute__((__always_inline__))
1259 _GLIBCXX20_CONSTEXPR
1260 inline bool
1261 __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)
1262 {
1263 return std::__equal_aux1(std::__niter_base(__first1),
1264 std::__niter_base(__last1),
1265 std::__niter_base(__first2));
1266 }
1267
1268 template<typename _II1, typename _Seq1, typename _Cat1, typename _II2>
1269 _GLIBCXX20_CONSTEXPR
1270 bool
1271 __equal_aux(const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1272 const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1273 _II2);
1274
1275 template<typename _II1, typename _II2, typename _Seq2, typename _Cat2>
1276 _GLIBCXX20_CONSTEXPR
1277 bool
1278 __equal_aux(_II1, _II1,
1279 const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>&);
1280
1281 template<typename _II1, typename _Seq1, typename _Cat1,
1282 typename _II2, typename _Seq2, typename _Cat2>
1283 _GLIBCXX20_CONSTEXPR
1284 bool
1285 __equal_aux(const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1286 const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1287 const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>&);
1288
1289 template<typename, typename>
1290 struct __lc_rai
1291 {
1292 template<typename _II1, typename _II2>
1293 _GLIBCXX20_CONSTEXPR
1294 static _II1
1295 __newlast1(_II1, _II1 __last1, _II2, _II2)
1296 { return __last1; }
1297
1298 template<typename _II>
1299 _GLIBCXX20_CONSTEXPR
1300 static bool
1301 __cnd2(_II __first, _II __last)
1302 { return __first != __last; }
1303 };
1304
1305 template<>
1306 struct __lc_rai<random_access_iterator_tag, random_access_iterator_tag>
1307 {
1308 template<typename _RAI1, typename _RAI2>
1309 _GLIBCXX20_CONSTEXPR
1310 static _RAI1
1311 __newlast1(_RAI1 __first1, _RAI1 __last1,
1312 _RAI2 __first2, _RAI2 __last2)
1313 {
1314 typedef typename iterator_traits<_RAI1>::difference_type _Diff1;
1315 typedef typename iterator_traits<_RAI2>::difference_type _Diff2;
1316 const _Diff1 __diff1 = __last1 - __first1;
1317 const _Diff2 __diff2 = __last2 - __first2;
1318 return __diff2 < __diff1 ? __first1 + _Diff1(__diff2) : __last1;
1319 }
1320
1321 template<typename _RAI>
1322 static _GLIBCXX20_CONSTEXPR bool
1323 __cnd2(_RAI, _RAI)
1324 { return true; }
1325 };
1326
1327 template<typename _II1, typename _II2, typename _Compare>
1328 _GLIBCXX20_CONSTEXPR
1329 bool
1330 __lexicographical_compare_impl(_II1 __first1, _II1 __last1,
1331 _II2 __first2, _II2 __last2,
1332 _Compare __comp)
1333 {
1334 typedef typename iterator_traits<_II1>::iterator_category _Category1;
1335 typedef typename iterator_traits<_II2>::iterator_category _Category2;
1336 typedef std::__lc_rai<_Category1, _Category2> __rai_type;
1337
1338 __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
1339 for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
1340 ++__first1, (void)++__first2)
1341 {
1342 if (__comp(*__first1, *__first2))
1343 return true;
1344 if (__comp(*__first2, *__first1))
1345 return false;
1346 }
1347 return __first1 == __last1 && __first2 != __last2;
1348 }
1349
1350 template<bool _BoolType>
1351 struct __lexicographical_compare
1352 {
1353 template<typename _II1, typename _II2>
1354 _GLIBCXX20_CONSTEXPR
1355 static bool
1356 __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1357 {
1358 using __gnu_cxx::__ops::less;
1359 return std::__lexicographical_compare_impl(__first1, __last1,
1360 __first2, __last2,
1361 less());
1362 }
1363
1364 template<typename _II1, typename _II2>
1365 _GLIBCXX20_CONSTEXPR
1366 static int
1367 __3way(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1368 {
1369 while (__first1 != __last1)
1370 {
1371 if (__first2 == __last2)
1372 return +1;
1373 if (*__first1 < *__first2)
1374 return -1;
1375 if (*__first2 < *__first1)
1376 return +1;
1377 ++__first1;
1378 ++__first2;
1379 }
1380 return int(__first2 == __last2) - 1;
1381 }
1382 };
1383
1384 template<>
1385 struct __lexicographical_compare<true>
1386 {
1387 template<typename _Tp, typename _Up>
1388 _GLIBCXX20_CONSTEXPR
1389 static bool
1390 __lc(const _Tp* __first1, const _Tp* __last1,
1391 const _Up* __first2, const _Up* __last2)
1392 { return __3way(__first1, __last1, __first2, __last2) < 0; }
1393
1394 template<typename _Tp, typename _Up>
1395 _GLIBCXX20_CONSTEXPR
1396 static ptrdiff_t
1397 __3way(const _Tp* __first1, const _Tp* __last1,
1398 const _Up* __first2, const _Up* __last2)
1399 {
1400 const size_t __len1 = __last1 - __first1;
1401 const size_t __len2 = __last2 - __first2;
1402 if (const size_t __len = std::min(__len1, __len2))
1403 if (int __result = std::__memcmp(__first1, __first2, __len))
1404 return __result;
1405 return ptrdiff_t(__len1 - __len2);
1406 }
1407 };
1408
1409 template<typename _II1, typename _II2>
1410 _GLIBCXX20_CONSTEXPR
1411 inline bool
1412 __lexicographical_compare_aux1(_II1 __first1, _II1 __last1,
1413 _II2 __first2, _II2 __last2)
1414 {
1415 typedef typename iterator_traits<_II1>::value_type _ValueType1;
1416 typedef typename iterator_traits<_II2>::value_type _ValueType2;
1417#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer)
1418 const bool __simple =
1419 (__is_memcmp_ordered_with<_ValueType1, _ValueType2>::__value
1420 && __is_pointer(_II1) && __is_pointer(_II2)
1421#if __cplusplus > 201703L && __glibcxx_concepts
1422 // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
1423 // so __is_byte<T> could be true, but we can't use memcmp with
1424 // volatile data.
1425 && !is_volatile_v<remove_reference_t<iter_reference_t<_II1>>>
1426 && !is_volatile_v<remove_reference_t<iter_reference_t<_II2>>>
1427#endif
1428 );
1429#else
1430 const bool __simple = false;
1431#endif
1432
1433 return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
1434 __first2, __last2);
1435 }
1436
1437 template<typename _Tp1, typename _Ref1, typename _Ptr1,
1438 typename _Tp2>
1439 bool
1440 __lexicographical_compare_aux1(
1441 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1442 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1443 _Tp2*, _Tp2*);
1444
1445 template<typename _Tp1,
1446 typename _Tp2, typename _Ref2, typename _Ptr2>
1447 bool
1448 __lexicographical_compare_aux1(_Tp1*, _Tp1*,
1449 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
1450 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1451
1452 template<typename _Tp1, typename _Ref1, typename _Ptr1,
1453 typename _Tp2, typename _Ref2, typename _Ptr2>
1454 bool
1455 __lexicographical_compare_aux1(
1456 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1457 _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1458 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
1459 _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1460
1461 template<typename _II1, typename _II2>
1462 _GLIBCXX20_CONSTEXPR
1463 inline bool
1464 __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
1465 _II2 __first2, _II2 __last2)
1466 {
1467 return std::__lexicographical_compare_aux1(std::__niter_base(__first1),
1468 std::__niter_base(__last1),
1469 std::__niter_base(__first2),
1470 std::__niter_base(__last2));
1471 }
1472
1473 template<typename _Iter1, typename _Seq1, typename _Cat1,
1474 typename _II2>
1475 _GLIBCXX20_CONSTEXPR
1476 bool
1477 __lexicographical_compare_aux(
1478 const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1479 const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1480 _II2, _II2);
1481
1482 template<typename _II1,
1483 typename _Iter2, typename _Seq2, typename _Cat2>
1484 _GLIBCXX20_CONSTEXPR
1485 bool
1486 __lexicographical_compare_aux(
1487 _II1, _II1,
1488 const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&,
1489 const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&);
1490
1491 template<typename _Iter1, typename _Seq1, typename _Cat1,
1492 typename _Iter2, typename _Seq2, typename _Cat2>
1493 _GLIBCXX20_CONSTEXPR
1494 bool
1495 __lexicographical_compare_aux(
1496 const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1497 const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1498 const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&,
1499 const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&);
1500
1501 template<typename _ForwardIterator, typename _Tp, typename _Compare>
1502 _GLIBCXX20_CONSTEXPR
1503 _ForwardIterator
1504 __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1505 const _Tp& __val, _Compare __comp)
1506 {
1507 typedef typename iterator_traits<_ForwardIterator>::difference_type
1508 _DistanceType;
1509
1510 _DistanceType __len = std::distance(__first, __last);
1511
1512 while (__len > 0)
1513 {
1514 _DistanceType __half = __len >> 1;
1515 _ForwardIterator __middle = __first;
1516 std::advance(__middle, __half);
1517 if (__comp(*__middle, __val))
1518 {
1519 __first = __middle;
1520 ++__first;
1521 __len = __len - __half - 1;
1522 }
1523 else
1524 __len = __half;
1525 }
1526 return __first;
1527 }
1528
1529 /**
1530 * @brief Finds the first position in which @a val could be inserted
1531 * without changing the ordering.
1532 * @param __first An iterator.
1533 * @param __last Another iterator.
1534 * @param __val The search term.
1535 * @return An iterator pointing to the first element <em>not less
1536 * than</em> @a val, or end() if every element is less than
1537 * @a val.
1538 * @ingroup binary_search_algorithms
1539 */
1540 template<typename _ForwardIterator, typename _Tp>
1541 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1542 inline _ForwardIterator
1543 lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1544 const _Tp& __val)
1545 {
1546 // concept requirements
1547 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1548 __glibcxx_function_requires(_LessThanOpConcept<
1549 typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
1550 __glibcxx_requires_partitioned_lower(__first, __last, __val);
1551
1552 return std::__lower_bound(__first, __last, __val,
1553 __gnu_cxx::__ops::less());
1554 }
1555
1556 /// This is a helper function for the sort routines and for random.tcc.
1557 // Precondition: __n > 0.
1558 template<typename _Tp>
1559 inline _GLIBCXX_CONSTEXPR _Tp
1560 __lg(_Tp __n)
1561 {
1562#if __cplusplus >= 201402L
1563 return std::__bit_width(make_unsigned_t<_Tp>(__n)) - 1;
1564#else
1565#pragma GCC diagnostic push
1566#pragma GCC diagnostic ignored "-Wlong-long"
1567 // Use +__n so it promotes to at least int.
1568 return (sizeof(+__n) * __CHAR_BIT__ - 1)
1569 - (sizeof(+__n) == sizeof(long long)
1570 ? __builtin_clzll(+__n)
1571 : (sizeof(+__n) == sizeof(long)
1572 ? __builtin_clzl(+__n)
1573 : __builtin_clz(+__n)));
1574#pragma GCC diagnostic pop
1575#endif
1576 }
1577
1578_GLIBCXX_BEGIN_NAMESPACE_ALGO
1579
1580 /**
1581 * @brief Tests a range for element-wise equality.
1582 * @ingroup non_mutating_algorithms
1583 * @param __first1 An input iterator.
1584 * @param __last1 An input iterator.
1585 * @param __first2 An input iterator.
1586 * @return A boolean true or false.
1587 *
1588 * This compares the elements of two ranges using @c == and returns true or
1589 * false depending on whether all of the corresponding elements of the
1590 * ranges are equal.
1591 */
1592 template<typename _II1, typename _II2>
1593 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1594 inline bool
1595 equal(_II1 __first1, _II1 __last1, _II2 __first2)
1596 {
1597 // concept requirements
1598 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1599 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1600 __glibcxx_function_requires(_EqualOpConcept<
1601 typename iterator_traits<_II1>::value_type,
1602 typename iterator_traits<_II2>::value_type>)
1603 __glibcxx_requires_can_increment_range(__first1, __last1, __first2);
1604
1605 return std::__equal_aux(__first1, __last1, __first2);
1606 }
1607
1608 /**
1609 * @brief Tests a range for element-wise equality.
1610 * @ingroup non_mutating_algorithms
1611 * @param __first1 An input iterator.
1612 * @param __last1 An input iterator.
1613 * @param __first2 An input iterator.
1614 * @param __binary_pred A binary predicate @link functors
1615 * functor@endlink.
1616 * @return A boolean true or false.
1617 *
1618 * This compares the elements of two ranges using the binary_pred
1619 * parameter, and returns true or
1620 * false depending on whether all of the corresponding elements of the
1621 * ranges are equal.
1622 */
1623 template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1624 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1625 inline bool
1626 equal(_IIter1 __first1, _IIter1 __last1,
1627 _IIter2 __first2, _BinaryPredicate __binary_pred)
1628 {
1629 // concept requirements
1630 __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1631 __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1632 __glibcxx_requires_valid_range(__first1, __last1);
1633
1634 for (; __first1 != __last1; ++__first1, (void)++__first2)
1635 if (!bool(__binary_pred(*__first1, *__first2)))
1636 return false;
1637 return true;
1638 }
1639
1640#if __cplusplus >= 201103L
1641#pragma GCC diagnostic push
1642#pragma GCC diagnostic ignored "-Wc++17-extensions" // if constexpr
1643
1644 // 4-iterator version of std::equal<It1, It2> for use in C++11.
1645 template<typename _II1, typename _II2>
1646 _GLIBCXX20_CONSTEXPR
1647 inline bool
1648 __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1649 {
1650 using _RATag = random_access_iterator_tag;
1651 using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1652 using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1653 using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1654 if constexpr (_RAIters::value)
1655 {
1656 if ((__last1 - __first1) != (__last2 - __first2))
1657 return false;
1658 return _GLIBCXX_STD_A::equal(__first1, __last1, __first2);
1659 }
1660 else
1661 {
1662 for (; __first1 != __last1 && __first2 != __last2;
1663 ++__first1, (void)++__first2)
1664 if (!(*__first1 == *__first2))
1665 return false;
1666 return __first1 == __last1 && __first2 == __last2;
1667 }
1668 }
1669
1670 // 4-iterator version of std::equal<It1, It2, BinaryPred> for use in C++11.
1671 template<typename _II1, typename _II2, typename _BinaryPredicate>
1672 _GLIBCXX20_CONSTEXPR
1673 inline bool
1674 __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2,
1675 _BinaryPredicate __binary_pred)
1676 {
1677 using _RATag = random_access_iterator_tag;
1678 using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1679 using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1680 using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1681 if constexpr (_RAIters::value)
1682 {
1683 if ((__last1 - __first1) != (__last2 - __first2))
1684 return false;
1685 return _GLIBCXX_STD_A::equal(__first1, __last1, __first2,
1686 __binary_pred);
1687 }
1688 else
1689 {
1690 for (; __first1 != __last1 && __first2 != __last2;
1691 ++__first1, (void)++__first2)
1692 if (!bool(__binary_pred(*__first1, *__first2)))
1693 return false;
1694 return __first1 == __last1 && __first2 == __last2;
1695 }
1696 }
1697#pragma GCC diagnostic pop
1698#endif // C++11
1699
1700#ifdef __glibcxx_robust_nonmodifying_seq_ops // C++ >= 14
1701 /**
1702 * @brief Tests a range for element-wise equality.
1703 * @ingroup non_mutating_algorithms
1704 * @param __first1 An input iterator.
1705 * @param __last1 An input iterator.
1706 * @param __first2 An input iterator.
1707 * @param __last2 An input iterator.
1708 * @return A boolean true or false.
1709 *
1710 * This compares the elements of two ranges using @c == and returns true or
1711 * false depending on whether all of the corresponding elements of the
1712 * ranges are equal.
1713 */
1714 template<typename _II1, typename _II2>
1715 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1716 inline bool
1717 equal(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1718 {
1719 // concept requirements
1720 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1721 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1722 __glibcxx_function_requires(_EqualOpConcept<
1723 typename iterator_traits<_II1>::value_type,
1724 typename iterator_traits<_II2>::value_type>)
1725 __glibcxx_requires_valid_range(__first1, __last1);
1726 __glibcxx_requires_valid_range(__first2, __last2);
1727
1728 return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2);
1729 }
1730
1731 /**
1732 * @brief Tests a range for element-wise equality.
1733 * @ingroup non_mutating_algorithms
1734 * @param __first1 An input iterator.
1735 * @param __last1 An input iterator.
1736 * @param __first2 An input iterator.
1737 * @param __last2 An input iterator.
1738 * @param __binary_pred A binary predicate @link functors
1739 * functor@endlink.
1740 * @return A boolean true or false.
1741 *
1742 * This compares the elements of two ranges using the binary_pred
1743 * parameter, and returns true or
1744 * false depending on whether all of the corresponding elements of the
1745 * ranges are equal.
1746 */
1747 template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1748 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1749 inline bool
1750 equal(_IIter1 __first1, _IIter1 __last1,
1751 _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
1752 {
1753 // concept requirements
1754 __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1755 __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1756 __glibcxx_requires_valid_range(__first1, __last1);
1757 __glibcxx_requires_valid_range(__first2, __last2);
1758
1759 return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2,
1760 __binary_pred);
1761 }
1762#endif // __glibcxx_robust_nonmodifying_seq_ops
1763
1764 /**
1765 * @brief Performs @b dictionary comparison on ranges.
1766 * @ingroup sorting_algorithms
1767 * @param __first1 An input iterator.
1768 * @param __last1 An input iterator.
1769 * @param __first2 An input iterator.
1770 * @param __last2 An input iterator.
1771 * @return A boolean true or false.
1772 *
1773 * <em>Returns true if the sequence of elements defined by the range
1774 * [first1,last1) is lexicographically less than the sequence of elements
1775 * defined by the range [first2,last2). Returns false otherwise.</em>
1776 * (Quoted from [25.3.8]/1.) If the iterators are all character pointers,
1777 * then this is an inline call to @c memcmp.
1778 */
1779 template<typename _II1, typename _II2>
1780 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1781 inline bool
1782 lexicographical_compare(_II1 __first1, _II1 __last1,
1783 _II2 __first2, _II2 __last2)
1784 {
1785#ifdef _GLIBCXX_CONCEPT_CHECKS
1786 // concept requirements
1787 typedef typename iterator_traits<_II1>::value_type _ValueType1;
1788 typedef typename iterator_traits<_II2>::value_type _ValueType2;
1789#endif
1790 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1791 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1792 __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
1793 __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
1794 __glibcxx_requires_valid_range(__first1, __last1);
1795 __glibcxx_requires_valid_range(__first2, __last2);
1796
1797 return std::__lexicographical_compare_aux(__first1, __last1,
1798 __first2, __last2);
1799 }
1800
1801 /**
1802 * @brief Performs @b dictionary comparison on ranges.
1803 * @ingroup sorting_algorithms
1804 * @param __first1 An input iterator.
1805 * @param __last1 An input iterator.
1806 * @param __first2 An input iterator.
1807 * @param __last2 An input iterator.
1808 * @param __comp A @link comparison_functors comparison functor@endlink.
1809 * @return A boolean true or false.
1810 *
1811 * The same as the four-parameter @c lexicographical_compare, but uses the
1812 * comp parameter instead of @c <.
1813 */
1814 template<typename _II1, typename _II2, typename _Compare>
1815 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1816 inline bool
1817 lexicographical_compare(_II1 __first1, _II1 __last1,
1818 _II2 __first2, _II2 __last2, _Compare __comp)
1819 {
1820 // concept requirements
1821 __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1822 __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1823 __glibcxx_requires_valid_range(__first1, __last1);
1824 __glibcxx_requires_valid_range(__first2, __last2);
1825
1826 return std::__lexicographical_compare_impl
1827 (__first1, __last1, __first2, __last2, __comp);
1828 }
1829
1830#if __cpp_lib_three_way_comparison
1831 // Both iterators refer to contiguous ranges of unsigned narrow characters,
1832 // or std::byte, or big-endian unsigned integers, suitable for comparison
1833 // using memcmp.
1834 template<typename _Iter1, typename _Iter2>
1835 concept __memcmp_ordered_with
1836 = (__is_memcmp_ordered_with<iter_value_t<_Iter1>,
1837 iter_value_t<_Iter2>>::__value)
1838 && contiguous_iterator<_Iter1> && contiguous_iterator<_Iter2>;
1839
1840 // Return a struct with two members, initialized to the smaller of x and y
1841 // (or x if they compare equal) and the result of the comparison x <=> y.
1842 template<typename _Tp>
1843 constexpr auto
1844 __min_cmp(_Tp __x, _Tp __y)
1845 {
1846 struct _Res {
1847 _Tp _M_min;
1848 decltype(__x <=> __y) _M_cmp;
1849 };
1850 auto __c = __x <=> __y;
1851 if (__c > 0)
1852 return _Res{__y, __c};
1853 return _Res{__x, __c};
1854 }
1855
1856 /**
1857 * @brief Performs dictionary comparison on ranges.
1858 * @ingroup sorting_algorithms
1859 * @param __first1 An input iterator.
1860 * @param __last1 An input iterator.
1861 * @param __first2 An input iterator.
1862 * @param __last2 An input iterator.
1863 * @param __comp A @link comparison_functors comparison functor@endlink.
1864 * @return The comparison category that `__comp(*__first1, *__first2)`
1865 * returns.
1866 */
1867 template<typename _InputIter1, typename _InputIter2, typename _Comp>
1868 [[nodiscard]] constexpr auto
1869 lexicographical_compare_three_way(_InputIter1 __first1,
1870 _InputIter1 __last1,
1871 _InputIter2 __first2,
1872 _InputIter2 __last2,
1873 _Comp __comp)
1874 -> decltype(__comp(*__first1, *__first2))
1875 {
1876 // concept requirements
1877 __glibcxx_function_requires(_InputIteratorConcept<_InputIter1>)
1878 __glibcxx_function_requires(_InputIteratorConcept<_InputIter2>)
1879 __glibcxx_requires_valid_range(__first1, __last1);
1880 __glibcxx_requires_valid_range(__first2, __last2);
1881
1882 using _Cat = decltype(__comp(*__first1, *__first2));
1883 static_assert(same_as<common_comparison_category_t<_Cat>, _Cat>);
1884
1885 if (!std::__is_constant_evaluated())
1886 if constexpr (same_as<_Comp, __detail::_Synth3way>
1887 || same_as<_Comp, compare_three_way>)
1888 if constexpr (__memcmp_ordered_with<_InputIter1, _InputIter2>)
1889 {
1890 const auto [__len, __lencmp] = _GLIBCXX_STD_A::
1891 __min_cmp(__last1 - __first1, __last2 - __first2);
1892 if (__len)
1893 {
1894 const auto __blen = __len * sizeof(*__first1);
1895 const auto __c
1896 = __builtin_memcmp(&*__first1, &*__first2, __blen) <=> 0;
1897 if (__c != 0)
1898 return __c;
1899 }
1900 return __lencmp;
1901 }
1902
1903 while (__first1 != __last1)
1904 {
1905 if (__first2 == __last2)
1906 return strong_ordering::greater;
1907 if (auto __cmp = __comp(*__first1, *__first2); __cmp != 0)
1908 return __cmp;
1909 ++__first1;
1910 ++__first2;
1911 }
1912 return (__first2 == __last2) <=> true; // See PR 94006
1913 }
1914
1915 template<typename _InputIter1, typename _InputIter2>
1916 constexpr auto
1917 lexicographical_compare_three_way(_InputIter1 __first1,
1918 _InputIter1 __last1,
1919 _InputIter2 __first2,
1920 _InputIter2 __last2)
1921 {
1922 return _GLIBCXX_STD_A::
1923 lexicographical_compare_three_way(__first1, __last1, __first2, __last2,
1924 compare_three_way{});
1925 }
1926#endif // three_way_comparison
1927
1928 template<typename _InputIterator1, typename _InputIterator2,
1929 typename _BinaryPredicate>
1930 _GLIBCXX20_CONSTEXPR
1931 pair<_InputIterator1, _InputIterator2>
1932 __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1933 _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1934 {
1935 while (__first1 != __last1 && __binary_pred(*__first1, *__first2))
1936 {
1937 ++__first1;
1938 ++__first2;
1939 }
1940 return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
1941 }
1942
1943 /**
1944 * @brief Finds the places in ranges which don't match.
1945 * @ingroup non_mutating_algorithms
1946 * @param __first1 An input iterator.
1947 * @param __last1 An input iterator.
1948 * @param __first2 An input iterator.
1949 * @return A pair of iterators pointing to the first mismatch.
1950 *
1951 * This compares the elements of two ranges using @c == and returns a pair
1952 * of iterators. The first iterator points into the first range, the
1953 * second iterator points into the second range, and the elements pointed
1954 * to by the iterators are not equal.
1955 */
1956 template<typename _InputIterator1, typename _InputIterator2>
1957 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1958 inline pair<_InputIterator1, _InputIterator2>
1959 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1960 _InputIterator2 __first2)
1961 {
1962 // concept requirements
1963 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1964 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1965 __glibcxx_function_requires(_EqualOpConcept<
1966 typename iterator_traits<_InputIterator1>::value_type,
1967 typename iterator_traits<_InputIterator2>::value_type>)
1968 __glibcxx_requires_valid_range(__first1, __last1);
1969
1970 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1971 __gnu_cxx::__ops::equal_to());
1972 }
1973
1974 /**
1975 * @brief Finds the places in ranges which don't match.
1976 * @ingroup non_mutating_algorithms
1977 * @param __first1 An input iterator.
1978 * @param __last1 An input iterator.
1979 * @param __first2 An input iterator.
1980 * @param __binary_pred A binary predicate @link functors
1981 * functor@endlink.
1982 * @return A pair of iterators pointing to the first mismatch.
1983 *
1984 * This compares the elements of two ranges using the binary_pred
1985 * parameter, and returns a pair
1986 * of iterators. The first iterator points into the first range, the
1987 * second iterator points into the second range, and the elements pointed
1988 * to by the iterators are not equal.
1989 */
1990 template<typename _InputIterator1, typename _InputIterator2,
1991 typename _BinaryPredicate>
1992 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1993 inline pair<_InputIterator1, _InputIterator2>
1994 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1995 _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1996 {
1997 // concept requirements
1998 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1999 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2000 __glibcxx_requires_valid_range(__first1, __last1);
2001
2002 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
2003 __binary_pred);
2004 }
2005
2006#if __glibcxx_robust_nonmodifying_seq_ops // C++ >= 14
2007 template<typename _InputIterator1, typename _InputIterator2,
2008 typename _BinaryPredicate>
2009 _GLIBCXX20_CONSTEXPR
2010 pair<_InputIterator1, _InputIterator2>
2011 __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2012 _InputIterator2 __first2, _InputIterator2 __last2,
2013 _BinaryPredicate __binary_pred)
2014 {
2015 while (__first1 != __last1 && __first2 != __last2
2016 && __binary_pred(*__first1, *__first2))
2017 {
2018 ++__first1;
2019 ++__first2;
2020 }
2021 return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
2022 }
2023
2024 /**
2025 * @brief Finds the places in ranges which don't match.
2026 * @ingroup non_mutating_algorithms
2027 * @param __first1 An input iterator.
2028 * @param __last1 An input iterator.
2029 * @param __first2 An input iterator.
2030 * @param __last2 An input iterator.
2031 * @return A pair of iterators pointing to the first mismatch.
2032 *
2033 * This compares the elements of two ranges using @c == and returns a pair
2034 * of iterators. The first iterator points into the first range, the
2035 * second iterator points into the second range, and the elements pointed
2036 * to by the iterators are not equal.
2037 */
2038 template<typename _InputIterator1, typename _InputIterator2>
2039 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2040 inline pair<_InputIterator1, _InputIterator2>
2041 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2042 _InputIterator2 __first2, _InputIterator2 __last2)
2043 {
2044 // concept requirements
2045 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2046 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2047 __glibcxx_function_requires(_EqualOpConcept<
2048 typename iterator_traits<_InputIterator1>::value_type,
2049 typename iterator_traits<_InputIterator2>::value_type>)
2050 __glibcxx_requires_valid_range(__first1, __last1);
2051 __glibcxx_requires_valid_range(__first2, __last2);
2052
2053 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
2054 __gnu_cxx::__ops::equal_to());
2055 }
2056
2057 /**
2058 * @brief Finds the places in ranges which don't match.
2059 * @ingroup non_mutating_algorithms
2060 * @param __first1 An input iterator.
2061 * @param __last1 An input iterator.
2062 * @param __first2 An input iterator.
2063 * @param __last2 An input iterator.
2064 * @param __binary_pred A binary predicate @link functors
2065 * functor@endlink.
2066 * @return A pair of iterators pointing to the first mismatch.
2067 *
2068 * This compares the elements of two ranges using the binary_pred
2069 * parameter, and returns a pair
2070 * of iterators. The first iterator points into the first range, the
2071 * second iterator points into the second range, and the elements pointed
2072 * to by the iterators are not equal.
2073 */
2074 template<typename _InputIterator1, typename _InputIterator2,
2075 typename _BinaryPredicate>
2076 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2077 inline pair<_InputIterator1, _InputIterator2>
2078 mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2079 _InputIterator2 __first2, _InputIterator2 __last2,
2080 _BinaryPredicate __binary_pred)
2081 {
2082 // concept requirements
2083 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2084 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2085 __glibcxx_requires_valid_range(__first1, __last1);
2086 __glibcxx_requires_valid_range(__first2, __last2);
2087
2088 return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
2089 __binary_pred);
2090 }
2091#endif // __glibcxx_robust_nonmodifying_seq_ops
2092
2093_GLIBCXX_END_NAMESPACE_ALGO
2094
2095 // Implementation of std::find_if, also used in std::remove_if and others.
2096 template<typename _Iterator, typename _Predicate>
2097 _GLIBCXX20_CONSTEXPR
2098 inline _Iterator
2099 __find_if(_Iterator __first, _Iterator __last, _Predicate __pred)
2100 {
2101#pragma GCC unroll 4
2102 while (__first != __last && !__pred(*__first))
2103 ++__first;
2104 return __first;
2105 }
2106
2107 template<typename _InputIterator, typename _Predicate>
2108 _GLIBCXX20_CONSTEXPR
2109 typename iterator_traits<_InputIterator>::difference_type
2110 __count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
2111 {
2112 typename iterator_traits<_InputIterator>::difference_type __n = 0;
2113 for (; __first != __last; ++__first)
2114 if (__pred(*__first))
2115 ++__n;
2116 return __n;
2117 }
2118
2119 template<typename _ForwardIterator, typename _Predicate>
2120 _GLIBCXX20_CONSTEXPR
2121 _ForwardIterator
2122 __remove_if(_ForwardIterator __first, _ForwardIterator __last,
2123 _Predicate __pred)
2124 {
2125 __first = std::__find_if(__first, __last, __pred);
2126 if (__first == __last)
2127 return __first;
2128 _ForwardIterator __result = __first;
2129 ++__first;
2130 for (; __first != __last; ++__first)
2131 if (!__pred(*__first))
2132 {
2133 *__result = _GLIBCXX_MOVE(*__first);
2134 ++__result;
2135 }
2136 return __result;
2137 }
2138
2139 template<typename _ForwardIterator1, typename _ForwardIterator2,
2140 typename _BinaryPredicate>
2141 _GLIBCXX20_CONSTEXPR
2142 _ForwardIterator1
2143 __search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2144 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
2145 _BinaryPredicate __predicate)
2146 {
2147 // Test for empty ranges
2148 if (__first1 == __last1 || __first2 == __last2)
2149 return __first1;
2150
2151 __decltype(*__first2) __first2_val(*__first2);
2152 __decltype(__gnu_cxx::__ops::bind2nd(__predicate, __first2_val))
2153 __match_first = __gnu_cxx::__ops::bind2nd(__predicate, __first2_val);
2154
2155 // Test for a pattern of length 1.
2156 _ForwardIterator2 __p1(__first2);
2157 if (++__p1 == __last2)
2158 return std::__find_if(__first1, __last1, __match_first);
2159
2160 // General case.
2161 _ForwardIterator1 __current = __first1;
2162
2163 for (;;)
2164 {
2165 __first1 = std::__find_if(__first1, __last1, __match_first);
2166
2167 if (__first1 == __last1)
2168 return __last1;
2169
2170 _ForwardIterator2 __p = __p1;
2171 __current = __first1;
2172 if (++__current == __last1)
2173 return __last1;
2174
2175 while (__predicate(*__current, *__p))
2176 {
2177 if (++__p == __last2)
2178 return __first1;
2179 if (++__current == __last1)
2180 return __last1;
2181 }
2182 ++__first1;
2183 }
2184 return __first1;
2185 }
2186#undef __match_first
2187
2188#if __cplusplus >= 201103L
2189 template<typename _ForwardIterator1, typename _ForwardIterator2,
2190 typename _BinaryPredicate>
2191 _GLIBCXX20_CONSTEXPR
2192 bool
2193 __is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2194 _ForwardIterator2 __first2, _BinaryPredicate __pred)
2195 {
2196 // Efficiently compare identical prefixes: O(N) if sequences
2197 // have the same elements in the same order.
2198 for (; __first1 != __last1; ++__first1, (void)++__first2)
2199 if (!__pred(*__first1, *__first2))
2200 break;
2201
2202 if (__first1 == __last1)
2203 return true;
2204
2205 // Establish __last2 assuming equal ranges by iterating over the
2206 // rest of the list.
2207 _ForwardIterator2 __last2 = __first2;
2208 std::advance(__last2, std::distance(__first1, __last1));
2209 for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan)
2210 {
2211 auto&& __scan_val = *__scan;
2212 auto __scaneq = __gnu_cxx::__ops::bind1st(__pred, __scan_val);
2213 if (__scan != std::__find_if(__first1, __scan, __scaneq))
2214 continue; // We've seen this one before.
2215
2216 auto __matches = std::__count_if(__first2, __last2, __scaneq);
2217 if (0 == __matches
2218 || std::__count_if(__scan, __last1, __scaneq) != __matches)
2219 return false;
2220 }
2221 return true;
2222 }
2223
2224 /**
2225 * @brief Checks whether a permutation of the second sequence is equal
2226 * to the first sequence.
2227 * @ingroup non_mutating_algorithms
2228 * @param __first1 Start of first range.
2229 * @param __last1 End of first range.
2230 * @param __first2 Start of second range.
2231 * @return true if there exists a permutation of the elements in the range
2232 * [__first2, __first2 + (__last1 - __first1)), beginning with
2233 * ForwardIterator2 begin, such that equal(__first1, __last1, begin)
2234 * returns true; otherwise, returns false.
2235 */
2236 template<typename _ForwardIterator1, typename _ForwardIterator2>
2237 _GLIBCXX20_CONSTEXPR
2238 inline bool
2239 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2240 _ForwardIterator2 __first2)
2241 {
2242 // concept requirements
2243 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
2244 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
2245 __glibcxx_function_requires(_EqualOpConcept<
2246 typename iterator_traits<_ForwardIterator1>::value_type,
2247 typename iterator_traits<_ForwardIterator2>::value_type>)
2248 __glibcxx_requires_valid_range(__first1, __last1);
2249
2250 return std::__is_permutation(__first1, __last1, __first2,
2251 __gnu_cxx::__ops::equal_to());
2252 }
2253#endif // C++11
2254
2255_GLIBCXX_BEGIN_NAMESPACE_ALGO
2256
2257 /**
2258 * @brief Search a sequence for a matching sub-sequence using a predicate.
2259 * @ingroup non_mutating_algorithms
2260 * @param __first1 A forward iterator.
2261 * @param __last1 A forward iterator.
2262 * @param __first2 A forward iterator.
2263 * @param __last2 A forward iterator.
2264 * @param __predicate A binary predicate.
2265 * @return The first iterator @c i in the range
2266 * @p [__first1,__last1-(__last2-__first2)) such that
2267 * @p __predicate(*(i+N),*(__first2+N)) is true for each @c N in the range
2268 * @p [0,__last2-__first2), or @p __last1 if no such iterator exists.
2269 *
2270 * Searches the range @p [__first1,__last1) for a sub-sequence that
2271 * compares equal value-by-value with the sequence given by @p
2272 * [__first2,__last2), using @p __predicate to determine equality,
2273 * and returns an iterator to the first element of the
2274 * sub-sequence, or @p __last1 if no such iterator exists.
2275 *
2276 * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2)
2277 */
2278 template<typename _ForwardIterator1, typename _ForwardIterator2,
2279 typename _BinaryPredicate>
2280 _GLIBCXX20_CONSTEXPR
2281 inline _ForwardIterator1
2282 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2283 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
2284 _BinaryPredicate __predicate)
2285 {
2286 // concept requirements
2287 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
2288 __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
2289 __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
2290 typename iterator_traits<_ForwardIterator1>::value_type,
2291 typename iterator_traits<_ForwardIterator2>::value_type>)
2292 __glibcxx_requires_valid_range(__first1, __last1);
2293 __glibcxx_requires_valid_range(__first2, __last2);
2294
2295 return std::__search(__first1, __last1, __first2, __last2, __predicate);
2296 }
2297
2298_GLIBCXX_END_NAMESPACE_ALGO
2299_GLIBCXX_END_NAMESPACE_VERSION
2300} // namespace std
2301
2302// NB: This file is included within many other C++ includes, as a way
2303// of getting the base algorithms. So, make sure that parallel bits
2304// come in too if requested.
2305#ifdef _GLIBCXX_PARALLEL
2306# include <parallel/algobase.h>
2307#endif
2308
2309#endif
algobase.h
Parallel STL function calls corresponding to the stl_algobase.h header. The functions defined here ma...
std::to_address
constexpr _Tp * to_address(_Tp *__ptr) noexcept
Obtain address referenced by a pointer to an object.
Definition ptr_traits.h:232
std::make_unsigned_t
typename make_unsigned< _Tp >::type make_unsigned_t
Alias template for make_unsigned.
Definition type_traits:2212
std::pair::pair
pair(_T1, _T2) -> pair< _T1, _T2 >
Two pairs are equal iff their members are equal.
std::move
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition move.h:138
std::move_backward
constexpr _BI2 move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
Moves the range [first,last) into result.
Definition stl_algobase.h:872
std::lexicographical_compare_three_way
constexpr auto lexicographical_compare_three_way(_InputIter1 __first1, _InputIter1 __last1, _InputIter2 __first2, _InputIter2 __last2, _Comp __comp) -> decltype(__comp(*__first1, *__first2))
Performs dictionary comparison on ranges.
Definition stl_algobase.h:1869
std::max
constexpr const _Tp & max(const _Tp &, const _Tp &)
This does what you think it does.
Definition stl_algobase.h:257
std::min
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition stl_algobase.h:233
std::__iterator_category
constexpr iterator_traits< _Iter >::iterator_category __iterator_category(const _Iter &)
Definition stl_iterator_base_types.h:241
std
ISO C++ entities toplevel namespace is std.
std::distance
constexpr iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
Definition stl_iterator_base_funcs.h:172
std::__lg
constexpr _Tp __lg(_Tp __n)
This is a helper function for the sort routines and for random.tcc.
Definition stl_algobase.h:1560
std::advance
constexpr void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
Definition stl_iterator_base_funcs.h:262
std::istreambuf_iterator
Provides input iterator semantics for streambufs.
Definition streambuf_iterator.h:59
std::is_integral
is_integral
Definition type_traits:488
std::char_traits
Basis for explicit traits specializations.
Definition char_traits.h:329
std::iterator_traits
Traits class for iterators.
Definition stl_iterator_base_types.h:180
std::pair
Struct holding two objects of arbitrary type.
Definition stl_pair.h:304
std::random_access_iterator_tag
Random-access iterators support a superset of bidirectional iterator operations.
Definition stl_iterator_base_types.h:109
std::same_as
[concept.same], concept same_as
Definition concepts:65