libstdc++
stl_algobase.h
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1 // Core algorithmic facilities -*- C++ -*-
2 
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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,
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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
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46  * in supporting documentation. Silicon Graphics makes no
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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 
82 namespace 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 #pragma GCC diagnostic push
1033 #pragma GCC diagnostic ignored "-Wlong-long"
1034  // Used by fill_n, generate_n, etc. to convert _Size to an integral type:
1035  inline _GLIBCXX_CONSTEXPR int
1036  __size_to_integer(int __n) { return __n; }
1037  inline _GLIBCXX_CONSTEXPR unsigned
1038  __size_to_integer(unsigned __n) { return __n; }
1039  inline _GLIBCXX_CONSTEXPR long
1040  __size_to_integer(long __n) { return __n; }
1041  inline _GLIBCXX_CONSTEXPR unsigned long
1042  __size_to_integer(unsigned long __n) { return __n; }
1043  inline _GLIBCXX_CONSTEXPR long long
1044  __size_to_integer(long long __n) { return __n; }
1045  inline _GLIBCXX_CONSTEXPR unsigned long long
1046  __size_to_integer(unsigned long long __n) { return __n; }
1047 
1048 #if defined(__GLIBCXX_TYPE_INT_N_0)
1049  __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_0
1050  __size_to_integer(__GLIBCXX_TYPE_INT_N_0 __n) { return __n; }
1051  __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_0
1052  __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_0 __n) { return __n; }
1053 #endif
1054 #if defined(__GLIBCXX_TYPE_INT_N_1)
1055  __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_1
1056  __size_to_integer(__GLIBCXX_TYPE_INT_N_1 __n) { return __n; }
1057  __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_1
1058  __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_1 __n) { return __n; }
1059 #endif
1060 #if defined(__GLIBCXX_TYPE_INT_N_2)
1061  __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_2
1062  __size_to_integer(__GLIBCXX_TYPE_INT_N_2 __n) { return __n; }
1063  __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_2
1064  __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_2 __n) { return __n; }
1065 #endif
1066 #if defined(__GLIBCXX_TYPE_INT_N_3)
1067  __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_3
1068  __size_to_integer(__GLIBCXX_TYPE_INT_N_3 __n) { return __n; }
1069  __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_3
1070  __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_3 __n) { return __n; }
1071 #endif
1072 
1073  inline _GLIBCXX_CONSTEXPR long long
1074  __size_to_integer(float __n) { return (long long)__n; }
1075  inline _GLIBCXX_CONSTEXPR long long
1076  __size_to_integer(double __n) { return (long long)__n; }
1077  inline _GLIBCXX_CONSTEXPR long long
1078  __size_to_integer(long double __n) { return (long long)__n; }
1079 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128) && !defined(__CUDACC__)
1080  __extension__ inline _GLIBCXX_CONSTEXPR long long
1081  __size_to_integer(__float128 __n) { return (long long)__n; }
1082 #endif
1083 #pragma GCC diagnostic pop
1084 
1085  template<typename _OutputIterator, typename _Size, typename _Tp>
1086  _GLIBCXX20_CONSTEXPR
1087  inline typename
1088  __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, _OutputIterator>::__type
1089  __fill_n_a1(_OutputIterator __first, _Size __n, const _Tp& __value)
1090  {
1091  for (; __n > 0; --__n, (void) ++__first)
1092  *__first = __value;
1093  return __first;
1094  }
1095 
1096  template<typename _OutputIterator, typename _Size, typename _Tp>
1097  _GLIBCXX20_CONSTEXPR
1098  inline typename
1099  __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, _OutputIterator>::__type
1100  __fill_n_a1(_OutputIterator __first, _Size __n, const _Tp& __value)
1101  {
1102  const _Tp __tmp = __value;
1103  for (; __n > 0; --__n, (void) ++__first)
1104  *__first = __tmp;
1105  return __first;
1106  }
1107 
1108  template<typename _Ite, typename _Seq, typename _Cat, typename _Size,
1109  typename _Tp>
1110  _GLIBCXX20_CONSTEXPR
1111  ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
1112  __fill_n_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
1113  _Size __n, const _Tp& __value,
1114  std::input_iterator_tag);
1115 
1116  template<typename _OutputIterator, typename _Size, typename _Tp>
1117  _GLIBCXX20_CONSTEXPR
1118  inline _OutputIterator
1119  __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1120  std::output_iterator_tag)
1121  {
1122 #if __cplusplus >= 201103L
1123  static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1124 #endif
1125  return __fill_n_a1(__first, __n, __value);
1126  }
1127 
1128  template<typename _OutputIterator, typename _Size, typename _Tp>
1129  _GLIBCXX20_CONSTEXPR
1130  inline _OutputIterator
1131  __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1132  std::input_iterator_tag)
1133  {
1134 #if __cplusplus >= 201103L
1135  static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1136 #endif
1137  return __fill_n_a1(__first, __n, __value);
1138  }
1139 
1140  template<typename _OutputIterator, typename _Size, typename _Tp>
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  __glibcxx_requires_can_increment(__first, __n);
1153 
1154  std::__fill_a(__first, __first + __n, __value);
1155  return __first + __n;
1156  }
1157 
1158  /**
1159  * @brief Fills the range [first,first+n) with copies of value.
1160  * @ingroup mutating_algorithms
1161  * @param __first An output iterator.
1162  * @param __n The count of copies to perform.
1163  * @param __value A reference-to-const of arbitrary type.
1164  * @return The iterator at first+n.
1165  *
1166  * This function fills a range with copies of the same value. For char
1167  * types filling contiguous areas of memory, this becomes an inline call
1168  * to @c memset or @c wmemset.
1169  *
1170  * If @p __n is negative, the function does nothing.
1171  */
1172  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1173  // DR 865. More algorithms that throw away information
1174  // DR 426. search_n(), fill_n(), and generate_n() with negative n
1175  template<typename _OI, typename _Size, typename _Tp>
1176  _GLIBCXX20_CONSTEXPR
1177  inline _OI
1178  fill_n(_OI __first, _Size __n, const _Tp& __value)
1179  {
1180  // concept requirements
1181  __glibcxx_function_requires(_OutputIteratorConcept<_OI, const _Tp&>)
1182 
1183  return std::__fill_n_a(__first, std::__size_to_integer(__n), __value,
1184  std::__iterator_category(__first));
1185  }
1186 
1187  template<bool _BoolType>
1188  struct __equal
1189  {
1190  template<typename _II1, typename _II2>
1191  _GLIBCXX20_CONSTEXPR
1192  static bool
1193  equal(_II1 __first1, _II1 __last1, _II2 __first2)
1194  {
1195  for (; __first1 != __last1; ++__first1, (void) ++__first2)
1196  if (!(*__first1 == *__first2))
1197  return false;
1198  return true;
1199  }
1200  };
1201 
1202  template<>
1203  struct __equal<true>
1204  {
1205  template<typename _Tp>
1206  _GLIBCXX20_CONSTEXPR
1207  static bool
1208  equal(const _Tp* __first1, const _Tp* __last1, const _Tp* __first2)
1209  {
1210  if (const size_t __len = (__last1 - __first1))
1211  return !std::__memcmp(__first1, __first2, __len);
1212  return true;
1213  }
1214  };
1215 
1216  template<typename _Tp, typename _Ref, typename _Ptr, typename _II>
1217  typename __gnu_cxx::__enable_if<
1218  __is_random_access_iter<_II>::__value, bool>::__type
1219  __equal_aux1(_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
1220  _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
1221  _II);
1222 
1223  template<typename _Tp1, typename _Ref1, typename _Ptr1,
1224  typename _Tp2, typename _Ref2, typename _Ptr2>
1225  bool
1226  __equal_aux1(_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1227  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1228  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1229 
1230  template<typename _II, typename _Tp, typename _Ref, typename _Ptr>
1231  typename __gnu_cxx::__enable_if<
1232  __is_random_access_iter<_II>::__value, bool>::__type
1233  __equal_aux1(_II, _II,
1234  _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>);
1235 
1236  template<typename _II1, typename _II2>
1237  _GLIBCXX20_CONSTEXPR
1238  inline bool
1239  __equal_aux1(_II1 __first1, _II1 __last1, _II2 __first2)
1240  {
1241  typedef typename iterator_traits<_II1>::value_type _ValueType1;
1242  const bool __simple = ((__is_integer<_ValueType1>::__value
1243  || __is_pointer<_ValueType1>::__value)
1244  && __memcmpable<_II1, _II2>::__value);
1245  return std::__equal<__simple>::equal(__first1, __last1, __first2);
1246  }
1247 
1248  template<typename _II1, typename _II2>
1249  _GLIBCXX20_CONSTEXPR
1250  inline bool
1251  __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)
1252  {
1253  return std::__equal_aux1(std::__niter_base(__first1),
1254  std::__niter_base(__last1),
1255  std::__niter_base(__first2));
1256  }
1257 
1258  template<typename _II1, typename _Seq1, typename _Cat1, typename _II2>
1259  _GLIBCXX20_CONSTEXPR
1260  bool
1261  __equal_aux(const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1262  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1263  _II2);
1264 
1265  template<typename _II1, typename _II2, typename _Seq2, typename _Cat2>
1266  _GLIBCXX20_CONSTEXPR
1267  bool
1268  __equal_aux(_II1, _II1,
1269  const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>&);
1270 
1271  template<typename _II1, typename _Seq1, typename _Cat1,
1272  typename _II2, typename _Seq2, typename _Cat2>
1273  _GLIBCXX20_CONSTEXPR
1274  bool
1275  __equal_aux(const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1276  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1277  const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>&);
1278 
1279  template<typename, typename>
1280  struct __lc_rai
1281  {
1282  template<typename _II1, typename _II2>
1283  _GLIBCXX20_CONSTEXPR
1284  static _II1
1285  __newlast1(_II1, _II1 __last1, _II2, _II2)
1286  { return __last1; }
1287 
1288  template<typename _II>
1289  _GLIBCXX20_CONSTEXPR
1290  static bool
1291  __cnd2(_II __first, _II __last)
1292  { return __first != __last; }
1293  };
1294 
1295  template<>
1296  struct __lc_rai<random_access_iterator_tag, random_access_iterator_tag>
1297  {
1298  template<typename _RAI1, typename _RAI2>
1299  _GLIBCXX20_CONSTEXPR
1300  static _RAI1
1301  __newlast1(_RAI1 __first1, _RAI1 __last1,
1302  _RAI2 __first2, _RAI2 __last2)
1303  {
1304  const typename iterator_traits<_RAI1>::difference_type
1305  __diff1 = __last1 - __first1;
1306  const typename iterator_traits<_RAI2>::difference_type
1307  __diff2 = __last2 - __first2;
1308  return __diff2 < __diff1 ? __first1 + __diff2 : __last1;
1309  }
1310 
1311  template<typename _RAI>
1312  static _GLIBCXX20_CONSTEXPR bool
1313  __cnd2(_RAI, _RAI)
1314  { return true; }
1315  };
1316 
1317  template<typename _II1, typename _II2, typename _Compare>
1318  _GLIBCXX20_CONSTEXPR
1319  bool
1320  __lexicographical_compare_impl(_II1 __first1, _II1 __last1,
1321  _II2 __first2, _II2 __last2,
1322  _Compare __comp)
1323  {
1324  typedef typename iterator_traits<_II1>::iterator_category _Category1;
1325  typedef typename iterator_traits<_II2>::iterator_category _Category2;
1326  typedef std::__lc_rai<_Category1, _Category2> __rai_type;
1327 
1328  __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
1329  for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
1330  ++__first1, (void)++__first2)
1331  {
1332  if (__comp(__first1, __first2))
1333  return true;
1334  if (__comp(__first2, __first1))
1335  return false;
1336  }
1337  return __first1 == __last1 && __first2 != __last2;
1338  }
1339 
1340  template<bool _BoolType>
1341  struct __lexicographical_compare
1342  {
1343  template<typename _II1, typename _II2>
1344  _GLIBCXX20_CONSTEXPR
1345  static bool
1346  __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1347  {
1348  using __gnu_cxx::__ops::__iter_less_iter;
1349  return std::__lexicographical_compare_impl(__first1, __last1,
1350  __first2, __last2,
1351  __iter_less_iter());
1352  }
1353 
1354  template<typename _II1, typename _II2>
1355  _GLIBCXX20_CONSTEXPR
1356  static int
1357  __3way(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1358  {
1359  while (__first1 != __last1)
1360  {
1361  if (__first2 == __last2)
1362  return +1;
1363  if (*__first1 < *__first2)
1364  return -1;
1365  if (*__first2 < *__first1)
1366  return +1;
1367  ++__first1;
1368  ++__first2;
1369  }
1370  return int(__first2 == __last2) - 1;
1371  }
1372  };
1373 
1374  template<>
1375  struct __lexicographical_compare<true>
1376  {
1377  template<typename _Tp, typename _Up>
1378  _GLIBCXX20_CONSTEXPR
1379  static bool
1380  __lc(const _Tp* __first1, const _Tp* __last1,
1381  const _Up* __first2, const _Up* __last2)
1382  { return __3way(__first1, __last1, __first2, __last2) < 0; }
1383 
1384  template<typename _Tp, typename _Up>
1385  _GLIBCXX20_CONSTEXPR
1386  static ptrdiff_t
1387  __3way(const _Tp* __first1, const _Tp* __last1,
1388  const _Up* __first2, const _Up* __last2)
1389  {
1390  const size_t __len1 = __last1 - __first1;
1391  const size_t __len2 = __last2 - __first2;
1392  if (const size_t __len = std::min(__len1, __len2))
1393  if (int __result = std::__memcmp(__first1, __first2, __len))
1394  return __result;
1395  return ptrdiff_t(__len1 - __len2);
1396  }
1397  };
1398 
1399  template<typename _II1, typename _II2>
1400  _GLIBCXX20_CONSTEXPR
1401  inline bool
1402  __lexicographical_compare_aux1(_II1 __first1, _II1 __last1,
1403  _II2 __first2, _II2 __last2)
1404  {
1405  typedef typename iterator_traits<_II1>::value_type _ValueType1;
1406  typedef typename iterator_traits<_II2>::value_type _ValueType2;
1407  const bool __simple =
1408  (__is_memcmp_ordered_with<_ValueType1, _ValueType2>::__value
1409  && __is_pointer<_II1>::__value
1410  && __is_pointer<_II2>::__value
1411 #if __cplusplus > 201703L && __glibcxx_concepts
1412  // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
1413  // so __is_byte<T> could be true, but we can't use memcmp with
1414  // volatile data.
1415  && !is_volatile_v<remove_reference_t<iter_reference_t<_II1>>>
1416  && !is_volatile_v<remove_reference_t<iter_reference_t<_II2>>>
1417 #endif
1418  );
1419 
1420  return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
1421  __first2, __last2);
1422  }
1423 
1424  template<typename _Tp1, typename _Ref1, typename _Ptr1,
1425  typename _Tp2>
1426  bool
1427  __lexicographical_compare_aux1(
1428  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1429  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1430  _Tp2*, _Tp2*);
1431 
1432  template<typename _Tp1,
1433  typename _Tp2, typename _Ref2, typename _Ptr2>
1434  bool
1435  __lexicographical_compare_aux1(_Tp1*, _Tp1*,
1436  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
1437  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1438 
1439  template<typename _Tp1, typename _Ref1, typename _Ptr1,
1440  typename _Tp2, typename _Ref2, typename _Ptr2>
1441  bool
1442  __lexicographical_compare_aux1(
1443  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1444  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1445  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
1446  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1447 
1448  template<typename _II1, typename _II2>
1449  _GLIBCXX20_CONSTEXPR
1450  inline bool
1451  __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
1452  _II2 __first2, _II2 __last2)
1453  {
1454  return std::__lexicographical_compare_aux1(std::__niter_base(__first1),
1455  std::__niter_base(__last1),
1456  std::__niter_base(__first2),
1457  std::__niter_base(__last2));
1458  }
1459 
1460  template<typename _Iter1, typename _Seq1, typename _Cat1,
1461  typename _II2>
1462  _GLIBCXX20_CONSTEXPR
1463  bool
1464  __lexicographical_compare_aux(
1465  const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1466  const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1467  _II2, _II2);
1468 
1469  template<typename _II1,
1470  typename _Iter2, typename _Seq2, typename _Cat2>
1471  _GLIBCXX20_CONSTEXPR
1472  bool
1473  __lexicographical_compare_aux(
1474  _II1, _II1,
1475  const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&,
1476  const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&);
1477 
1478  template<typename _Iter1, typename _Seq1, typename _Cat1,
1479  typename _Iter2, typename _Seq2, typename _Cat2>
1480  _GLIBCXX20_CONSTEXPR
1481  bool
1482  __lexicographical_compare_aux(
1483  const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1484  const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1485  const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&,
1486  const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&);
1487 
1488  template<typename _ForwardIterator, typename _Tp, typename _Compare>
1489  _GLIBCXX20_CONSTEXPR
1490  _ForwardIterator
1491  __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1492  const _Tp& __val, _Compare __comp)
1493  {
1494  typedef typename iterator_traits<_ForwardIterator>::difference_type
1495  _DistanceType;
1496 
1497  _DistanceType __len = std::distance(__first, __last);
1498 
1499  while (__len > 0)
1500  {
1501  _DistanceType __half = __len >> 1;
1502  _ForwardIterator __middle = __first;
1503  std::advance(__middle, __half);
1504  if (__comp(__middle, __val))
1505  {
1506  __first = __middle;
1507  ++__first;
1508  __len = __len - __half - 1;
1509  }
1510  else
1511  __len = __half;
1512  }
1513  return __first;
1514  }
1515 
1516  /**
1517  * @brief Finds the first position in which @a val could be inserted
1518  * without changing the ordering.
1519  * @param __first An iterator.
1520  * @param __last Another iterator.
1521  * @param __val The search term.
1522  * @return An iterator pointing to the first element <em>not less
1523  * than</em> @a val, or end() if every element is less than
1524  * @a val.
1525  * @ingroup binary_search_algorithms
1526  */
1527  template<typename _ForwardIterator, typename _Tp>
1528  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1529  inline _ForwardIterator
1530  lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1531  const _Tp& __val)
1532  {
1533  // concept requirements
1534  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1535  __glibcxx_function_requires(_LessThanOpConcept<
1536  typename iterator_traits<_ForwardIterator>::value_type, _Tp>)
1537  __glibcxx_requires_partitioned_lower(__first, __last, __val);
1538 
1539  return std::__lower_bound(__first, __last, __val,
1540  __gnu_cxx::__ops::__iter_less_val());
1541  }
1542 
1543  /// This is a helper function for the sort routines and for random.tcc.
1544  // Precondition: __n > 0.
1545  template<typename _Tp>
1546  inline _GLIBCXX_CONSTEXPR _Tp
1547  __lg(_Tp __n)
1548  {
1549 #if __cplusplus >= 201402L
1550  return std::__bit_width(make_unsigned_t<_Tp>(__n)) - 1;
1551 #else
1552 #pragma GCC diagnostic push
1553 #pragma GCC diagnostic ignored "-Wlong-long"
1554  // Use +__n so it promotes to at least int.
1555  return (sizeof(+__n) * __CHAR_BIT__ - 1)
1556  - (sizeof(+__n) == sizeof(long long)
1557  ? __builtin_clzll(+__n)
1558  : (sizeof(+__n) == sizeof(long)
1559  ? __builtin_clzl(+__n)
1560  : __builtin_clz(+__n)));
1561 #pragma GCC diagnostic pop
1562 #endif
1563  }
1564 
1565 _GLIBCXX_BEGIN_NAMESPACE_ALGO
1566 
1567  /**
1568  * @brief Tests a range for element-wise equality.
1569  * @ingroup non_mutating_algorithms
1570  * @param __first1 An input iterator.
1571  * @param __last1 An input iterator.
1572  * @param __first2 An input iterator.
1573  * @return A boolean true or false.
1574  *
1575  * This compares the elements of two ranges using @c == and returns true or
1576  * false depending on whether all of the corresponding elements of the
1577  * ranges are equal.
1578  */
1579  template<typename _II1, typename _II2>
1580  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1581  inline bool
1582  equal(_II1 __first1, _II1 __last1, _II2 __first2)
1583  {
1584  // concept requirements
1585  __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1586  __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1587  __glibcxx_function_requires(_EqualOpConcept<
1588  typename iterator_traits<_II1>::value_type,
1589  typename iterator_traits<_II2>::value_type>)
1590  __glibcxx_requires_can_increment_range(__first1, __last1, __first2);
1591 
1592  return std::__equal_aux(__first1, __last1, __first2);
1593  }
1594 
1595  /**
1596  * @brief Tests a range for element-wise equality.
1597  * @ingroup non_mutating_algorithms
1598  * @param __first1 An input iterator.
1599  * @param __last1 An input iterator.
1600  * @param __first2 An input iterator.
1601  * @param __binary_pred A binary predicate @link functors
1602  * functor@endlink.
1603  * @return A boolean true or false.
1604  *
1605  * This compares the elements of two ranges using the binary_pred
1606  * parameter, and returns true or
1607  * false depending on whether all of the corresponding elements of the
1608  * ranges are equal.
1609  */
1610  template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1611  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1612  inline bool
1613  equal(_IIter1 __first1, _IIter1 __last1,
1614  _IIter2 __first2, _BinaryPredicate __binary_pred)
1615  {
1616  // concept requirements
1617  __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1618  __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1619  __glibcxx_requires_valid_range(__first1, __last1);
1620 
1621  for (; __first1 != __last1; ++__first1, (void)++__first2)
1622  if (!bool(__binary_pred(*__first1, *__first2)))
1623  return false;
1624  return true;
1625  }
1626 
1627 #if __cplusplus >= 201103L
1628 #pragma GCC diagnostic push
1629 #pragma GCC diagnostic ignored "-Wc++17-extensions" // if constexpr
1630 
1631  // 4-iterator version of std::equal<It1, It2> for use in C++11.
1632  template<typename _II1, typename _II2>
1633  _GLIBCXX20_CONSTEXPR
1634  inline bool
1635  __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1636  {
1637  using _RATag = random_access_iterator_tag;
1638  using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1639  using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1640  using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1641  if constexpr (_RAIters::value)
1642  {
1643  if ((__last1 - __first1) != (__last2 - __first2))
1644  return false;
1645  return _GLIBCXX_STD_A::equal(__first1, __last1, __first2);
1646  }
1647  else
1648  {
1649  for (; __first1 != __last1 && __first2 != __last2;
1650  ++__first1, (void)++__first2)
1651  if (!(*__first1 == *__first2))
1652  return false;
1653  return __first1 == __last1 && __first2 == __last2;
1654  }
1655  }
1656 
1657  // 4-iterator version of std::equal<It1, It2, BinaryPred> for use in C++11.
1658  template<typename _II1, typename _II2, typename _BinaryPredicate>
1659  _GLIBCXX20_CONSTEXPR
1660  inline bool
1661  __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2,
1662  _BinaryPredicate __binary_pred)
1663  {
1664  using _RATag = random_access_iterator_tag;
1665  using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1666  using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1667  using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1668  if constexpr (_RAIters::value)
1669  {
1670  if ((__last1 - __first1) != (__last2 - __first2))
1671  return false;
1672  return _GLIBCXX_STD_A::equal(__first1, __last1, __first2,
1673  __binary_pred);
1674  }
1675  else
1676  {
1677  for (; __first1 != __last1 && __first2 != __last2;
1678  ++__first1, (void)++__first2)
1679  if (!bool(__binary_pred(*__first1, *__first2)))
1680  return false;
1681  return __first1 == __last1 && __first2 == __last2;
1682  }
1683  }
1684 #pragma GCC diagnostic pop
1685 #endif // C++11
1686 
1687 #ifdef __glibcxx_robust_nonmodifying_seq_ops // C++ >= 14
1688  /**
1689  * @brief Tests a range for element-wise equality.
1690  * @ingroup non_mutating_algorithms
1691  * @param __first1 An input iterator.
1692  * @param __last1 An input iterator.
1693  * @param __first2 An input iterator.
1694  * @param __last2 An input iterator.
1695  * @return A boolean true or false.
1696  *
1697  * This compares the elements of two ranges using @c == and returns true or
1698  * false depending on whether all of the corresponding elements of the
1699  * ranges are equal.
1700  */
1701  template<typename _II1, typename _II2>
1702  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1703  inline bool
1704  equal(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1705  {
1706  // concept requirements
1707  __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1708  __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1709  __glibcxx_function_requires(_EqualOpConcept<
1710  typename iterator_traits<_II1>::value_type,
1711  typename iterator_traits<_II2>::value_type>)
1712  __glibcxx_requires_valid_range(__first1, __last1);
1713  __glibcxx_requires_valid_range(__first2, __last2);
1714 
1715  return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2);
1716  }
1717 
1718  /**
1719  * @brief Tests a range for element-wise equality.
1720  * @ingroup non_mutating_algorithms
1721  * @param __first1 An input iterator.
1722  * @param __last1 An input iterator.
1723  * @param __first2 An input iterator.
1724  * @param __last2 An input iterator.
1725  * @param __binary_pred A binary predicate @link functors
1726  * functor@endlink.
1727  * @return A boolean true or false.
1728  *
1729  * This compares the elements of two ranges using the binary_pred
1730  * parameter, and returns true or
1731  * false depending on whether all of the corresponding elements of the
1732  * ranges are equal.
1733  */
1734  template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1735  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1736  inline bool
1737  equal(_IIter1 __first1, _IIter1 __last1,
1738  _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
1739  {
1740  // concept requirements
1741  __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1742  __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1743  __glibcxx_requires_valid_range(__first1, __last1);
1744  __glibcxx_requires_valid_range(__first2, __last2);
1745 
1746  return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2,
1747  __binary_pred);
1748  }
1749 #endif // __glibcxx_robust_nonmodifying_seq_ops
1750 
1751  /**
1752  * @brief Performs @b dictionary comparison on ranges.
1753  * @ingroup sorting_algorithms
1754  * @param __first1 An input iterator.
1755  * @param __last1 An input iterator.
1756  * @param __first2 An input iterator.
1757  * @param __last2 An input iterator.
1758  * @return A boolean true or false.
1759  *
1760  * <em>Returns true if the sequence of elements defined by the range
1761  * [first1,last1) is lexicographically less than the sequence of elements
1762  * defined by the range [first2,last2). Returns false otherwise.</em>
1763  * (Quoted from [25.3.8]/1.) If the iterators are all character pointers,
1764  * then this is an inline call to @c memcmp.
1765  */
1766  template<typename _II1, typename _II2>
1767  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1768  inline bool
1769  lexicographical_compare(_II1 __first1, _II1 __last1,
1770  _II2 __first2, _II2 __last2)
1771  {
1772 #ifdef _GLIBCXX_CONCEPT_CHECKS
1773  // concept requirements
1774  typedef typename iterator_traits<_II1>::value_type _ValueType1;
1775  typedef typename iterator_traits<_II2>::value_type _ValueType2;
1776 #endif
1777  __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1778  __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1779  __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
1780  __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
1781  __glibcxx_requires_valid_range(__first1, __last1);
1782  __glibcxx_requires_valid_range(__first2, __last2);
1783 
1784  return std::__lexicographical_compare_aux(__first1, __last1,
1785  __first2, __last2);
1786  }
1787 
1788  /**
1789  * @brief Performs @b dictionary comparison on ranges.
1790  * @ingroup sorting_algorithms
1791  * @param __first1 An input iterator.
1792  * @param __last1 An input iterator.
1793  * @param __first2 An input iterator.
1794  * @param __last2 An input iterator.
1795  * @param __comp A @link comparison_functors comparison functor@endlink.
1796  * @return A boolean true or false.
1797  *
1798  * The same as the four-parameter @c lexicographical_compare, but uses the
1799  * comp parameter instead of @c <.
1800  */
1801  template<typename _II1, typename _II2, typename _Compare>
1802  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1803  inline bool
1804  lexicographical_compare(_II1 __first1, _II1 __last1,
1805  _II2 __first2, _II2 __last2, _Compare __comp)
1806  {
1807  // concept requirements
1808  __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1809  __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1810  __glibcxx_requires_valid_range(__first1, __last1);
1811  __glibcxx_requires_valid_range(__first2, __last2);
1812 
1813  return std::__lexicographical_compare_impl
1814  (__first1, __last1, __first2, __last2,
1815  __gnu_cxx::__ops::__iter_comp_iter(__comp));
1816  }
1817 
1818 #if __cpp_lib_three_way_comparison
1819  // Both iterators refer to contiguous ranges of unsigned narrow characters,
1820  // or std::byte, or big-endian unsigned integers, suitable for comparison
1821  // using memcmp.
1822  template<typename _Iter1, typename _Iter2>
1823  concept __memcmp_ordered_with
1824  = (__is_memcmp_ordered_with<iter_value_t<_Iter1>,
1825  iter_value_t<_Iter2>>::__value)
1826  && contiguous_iterator<_Iter1> && contiguous_iterator<_Iter2>;
1827 
1828  // Return a struct with two members, initialized to the smaller of x and y
1829  // (or x if they compare equal) and the result of the comparison x <=> y.
1830  template<typename _Tp>
1831  constexpr auto
1832  __min_cmp(_Tp __x, _Tp __y)
1833  {
1834  struct _Res {
1835  _Tp _M_min;
1836  decltype(__x <=> __y) _M_cmp;
1837  };
1838  auto __c = __x <=> __y;
1839  if (__c > 0)
1840  return _Res{__y, __c};
1841  return _Res{__x, __c};
1842  }
1843 
1844  /**
1845  * @brief Performs dictionary comparison on ranges.
1846  * @ingroup sorting_algorithms
1847  * @param __first1 An input iterator.
1848  * @param __last1 An input iterator.
1849  * @param __first2 An input iterator.
1850  * @param __last2 An input iterator.
1851  * @param __comp A @link comparison_functors comparison functor@endlink.
1852  * @return The comparison category that `__comp(*__first1, *__first2)`
1853  * returns.
1854  */
1855  template<typename _InputIter1, typename _InputIter2, typename _Comp>
1856  [[nodiscard]] constexpr auto
1857  lexicographical_compare_three_way(_InputIter1 __first1,
1858  _InputIter1 __last1,
1859  _InputIter2 __first2,
1860  _InputIter2 __last2,
1861  _Comp __comp)
1862  -> decltype(__comp(*__first1, *__first2))
1863  {
1864  // concept requirements
1865  __glibcxx_function_requires(_InputIteratorConcept<_InputIter1>)
1866  __glibcxx_function_requires(_InputIteratorConcept<_InputIter2>)
1867  __glibcxx_requires_valid_range(__first1, __last1);
1868  __glibcxx_requires_valid_range(__first2, __last2);
1869 
1870  using _Cat = decltype(__comp(*__first1, *__first2));
1871  static_assert(same_as<common_comparison_category_t<_Cat>, _Cat>);
1872 
1873  if (!std::__is_constant_evaluated())
1874  if constexpr (same_as<_Comp, __detail::_Synth3way>
1875  || same_as<_Comp, compare_three_way>)
1876  if constexpr (__memcmp_ordered_with<_InputIter1, _InputIter2>)
1877  {
1878  const auto [__len, __lencmp] = _GLIBCXX_STD_A::
1879  __min_cmp(__last1 - __first1, __last2 - __first2);
1880  if (__len)
1881  {
1882  const auto __blen = __len * sizeof(*__first1);
1883  const auto __c
1884  = __builtin_memcmp(&*__first1, &*__first2, __blen) <=> 0;
1885  if (__c != 0)
1886  return __c;
1887  }
1888  return __lencmp;
1889  }
1890 
1891  while (__first1 != __last1)
1892  {
1893  if (__first2 == __last2)
1894  return strong_ordering::greater;
1895  if (auto __cmp = __comp(*__first1, *__first2); __cmp != 0)
1896  return __cmp;
1897  ++__first1;
1898  ++__first2;
1899  }
1900  return (__first2 == __last2) <=> true; // See PR 94006
1901  }
1902 
1903  template<typename _InputIter1, typename _InputIter2>
1904  constexpr auto
1905  lexicographical_compare_three_way(_InputIter1 __first1,
1906  _InputIter1 __last1,
1907  _InputIter2 __first2,
1908  _InputIter2 __last2)
1909  {
1910  return _GLIBCXX_STD_A::
1911  lexicographical_compare_three_way(__first1, __last1, __first2, __last2,
1912  compare_three_way{});
1913  }
1914 #endif // three_way_comparison
1915 
1916  template<typename _InputIterator1, typename _InputIterator2,
1917  typename _BinaryPredicate>
1918  _GLIBCXX20_CONSTEXPR
1919  pair<_InputIterator1, _InputIterator2>
1920  __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1921  _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1922  {
1923  while (__first1 != __last1 && __binary_pred(__first1, __first2))
1924  {
1925  ++__first1;
1926  ++__first2;
1927  }
1928  return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
1929  }
1930 
1931  /**
1932  * @brief Finds the places in ranges which don't match.
1933  * @ingroup non_mutating_algorithms
1934  * @param __first1 An input iterator.
1935  * @param __last1 An input iterator.
1936  * @param __first2 An input iterator.
1937  * @return A pair of iterators pointing to the first mismatch.
1938  *
1939  * This compares the elements of two ranges using @c == and returns a pair
1940  * of iterators. The first iterator points into the first range, the
1941  * second iterator points into the second range, and the elements pointed
1942  * to by the iterators are not equal.
1943  */
1944  template<typename _InputIterator1, typename _InputIterator2>
1945  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1946  inline pair<_InputIterator1, _InputIterator2>
1947  mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1948  _InputIterator2 __first2)
1949  {
1950  // concept requirements
1951  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1952  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1953  __glibcxx_function_requires(_EqualOpConcept<
1954  typename iterator_traits<_InputIterator1>::value_type,
1955  typename iterator_traits<_InputIterator2>::value_type>)
1956  __glibcxx_requires_valid_range(__first1, __last1);
1957 
1958  return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1959  __gnu_cxx::__ops::__iter_equal_to_iter());
1960  }
1961 
1962  /**
1963  * @brief Finds the places in ranges which don't match.
1964  * @ingroup non_mutating_algorithms
1965  * @param __first1 An input iterator.
1966  * @param __last1 An input iterator.
1967  * @param __first2 An input iterator.
1968  * @param __binary_pred A binary predicate @link functors
1969  * functor@endlink.
1970  * @return A pair of iterators pointing to the first mismatch.
1971  *
1972  * This compares the elements of two ranges using the binary_pred
1973  * parameter, and returns a pair
1974  * of iterators. The first iterator points into the first range, the
1975  * second iterator points into the second range, and the elements pointed
1976  * to by the iterators are not equal.
1977  */
1978  template<typename _InputIterator1, typename _InputIterator2,
1979  typename _BinaryPredicate>
1980  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1981  inline pair<_InputIterator1, _InputIterator2>
1982  mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1983  _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1984  {
1985  // concept requirements
1986  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1987  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1988  __glibcxx_requires_valid_range(__first1, __last1);
1989 
1990  return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1991  __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
1992  }
1993 
1994 #if __glibcxx_robust_nonmodifying_seq_ops // C++ >= 14
1995  template<typename _InputIterator1, typename _InputIterator2,
1996  typename _BinaryPredicate>
1997  _GLIBCXX20_CONSTEXPR
1998  pair<_InputIterator1, _InputIterator2>
1999  __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2000  _InputIterator2 __first2, _InputIterator2 __last2,
2001  _BinaryPredicate __binary_pred)
2002  {
2003  while (__first1 != __last1 && __first2 != __last2
2004  && __binary_pred(__first1, __first2))
2005  {
2006  ++__first1;
2007  ++__first2;
2008  }
2009  return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
2010  }
2011 
2012  /**
2013  * @brief Finds the places in ranges which don't match.
2014  * @ingroup non_mutating_algorithms
2015  * @param __first1 An input iterator.
2016  * @param __last1 An input iterator.
2017  * @param __first2 An input iterator.
2018  * @param __last2 An input iterator.
2019  * @return A pair of iterators pointing to the first mismatch.
2020  *
2021  * This compares the elements of two ranges using @c == and returns a pair
2022  * of iterators. The first iterator points into the first range, the
2023  * second iterator points into the second range, and the elements pointed
2024  * to by the iterators are not equal.
2025  */
2026  template<typename _InputIterator1, typename _InputIterator2>
2027  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2028  inline pair<_InputIterator1, _InputIterator2>
2029  mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2030  _InputIterator2 __first2, _InputIterator2 __last2)
2031  {
2032  // concept requirements
2033  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2034  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2035  __glibcxx_function_requires(_EqualOpConcept<
2036  typename iterator_traits<_InputIterator1>::value_type,
2037  typename iterator_traits<_InputIterator2>::value_type>)
2038  __glibcxx_requires_valid_range(__first1, __last1);
2039  __glibcxx_requires_valid_range(__first2, __last2);
2040 
2041  return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
2042  __gnu_cxx::__ops::__iter_equal_to_iter());
2043  }
2044 
2045  /**
2046  * @brief Finds the places in ranges which don't match.
2047  * @ingroup non_mutating_algorithms
2048  * @param __first1 An input iterator.
2049  * @param __last1 An input iterator.
2050  * @param __first2 An input iterator.
2051  * @param __last2 An input iterator.
2052  * @param __binary_pred A binary predicate @link functors
2053  * functor@endlink.
2054  * @return A pair of iterators pointing to the first mismatch.
2055  *
2056  * This compares the elements of two ranges using the binary_pred
2057  * parameter, and returns a pair
2058  * of iterators. The first iterator points into the first range, the
2059  * second iterator points into the second range, and the elements pointed
2060  * to by the iterators are not equal.
2061  */
2062  template<typename _InputIterator1, typename _InputIterator2,
2063  typename _BinaryPredicate>
2064  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2065  inline pair<_InputIterator1, _InputIterator2>
2066  mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2067  _InputIterator2 __first2, _InputIterator2 __last2,
2068  _BinaryPredicate __binary_pred)
2069  {
2070  // concept requirements
2071  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2072  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2073  __glibcxx_requires_valid_range(__first1, __last1);
2074  __glibcxx_requires_valid_range(__first2, __last2);
2075 
2076  return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
2077  __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
2078  }
2079 #endif
2080 
2081 _GLIBCXX_END_NAMESPACE_ALGO
2082 
2083  /// This is an overload used by find algos for the Input Iterator case.
2084  template<typename _InputIterator, typename _Predicate>
2085  _GLIBCXX20_CONSTEXPR
2086  inline _InputIterator
2087  __find_if(_InputIterator __first, _InputIterator __last,
2088  _Predicate __pred, input_iterator_tag)
2089  {
2090  while (__first != __last && !__pred(__first))
2091  ++__first;
2092  return __first;
2093  }
2094 
2095  /// This is an overload used by find algos for the RAI case.
2096  template<typename _RandomAccessIterator, typename _Predicate>
2097  _GLIBCXX20_CONSTEXPR
2098  _RandomAccessIterator
2099  __find_if(_RandomAccessIterator __first, _RandomAccessIterator __last,
2100  _Predicate __pred, random_access_iterator_tag)
2101  {
2102  typename iterator_traits<_RandomAccessIterator>::difference_type
2103  __trip_count = (__last - __first) >> 2;
2104 
2105  for (; __trip_count > 0; --__trip_count)
2106  {
2107  if (__pred(__first))
2108  return __first;
2109  ++__first;
2110 
2111  if (__pred(__first))
2112  return __first;
2113  ++__first;
2114 
2115  if (__pred(__first))
2116  return __first;
2117  ++__first;
2118 
2119  if (__pred(__first))
2120  return __first;
2121  ++__first;
2122  }
2123 
2124  switch (__last - __first)
2125  {
2126  case 3:
2127  if (__pred(__first))
2128  return __first;
2129  ++__first;
2130  // FALLTHRU
2131  case 2:
2132  if (__pred(__first))
2133  return __first;
2134  ++__first;
2135  // FALLTHRU
2136  case 1:
2137  if (__pred(__first))
2138  return __first;
2139  ++__first;
2140  // FALLTHRU
2141  case 0:
2142  default:
2143  return __last;
2144  }
2145  }
2146 
2147  template<typename _Iterator, typename _Predicate>
2148  _GLIBCXX20_CONSTEXPR
2149  inline _Iterator
2150  __find_if(_Iterator __first, _Iterator __last, _Predicate __pred)
2151  {
2152  return __find_if(__first, __last, __pred,
2153  std::__iterator_category(__first));
2154  }
2155 
2156  template<typename _InputIterator, typename _Predicate>
2157  _GLIBCXX20_CONSTEXPR
2158  typename iterator_traits<_InputIterator>::difference_type
2159  __count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
2160  {
2161  typename iterator_traits<_InputIterator>::difference_type __n = 0;
2162  for (; __first != __last; ++__first)
2163  if (__pred(__first))
2164  ++__n;
2165  return __n;
2166  }
2167 
2168  template<typename _ForwardIterator, typename _Predicate>
2169  _GLIBCXX20_CONSTEXPR
2170  _ForwardIterator
2171  __remove_if(_ForwardIterator __first, _ForwardIterator __last,
2172  _Predicate __pred)
2173  {
2174  __first = std::__find_if(__first, __last, __pred);
2175  if (__first == __last)
2176  return __first;
2177  _ForwardIterator __result = __first;
2178  ++__first;
2179  for (; __first != __last; ++__first)
2180  if (!__pred(__first))
2181  {
2182  *__result = _GLIBCXX_MOVE(*__first);
2183  ++__result;
2184  }
2185  return __result;
2186  }
2187 
2188  template<typename _ForwardIterator1, typename _ForwardIterator2,
2189  typename _BinaryPredicate>
2190  _GLIBCXX20_CONSTEXPR
2191  _ForwardIterator1
2192  __search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2193  _ForwardIterator2 __first2, _ForwardIterator2 __last2,
2194  _BinaryPredicate __predicate)
2195  {
2196  // Test for empty ranges
2197  if (__first1 == __last1 || __first2 == __last2)
2198  return __first1;
2199 
2200  // Test for a pattern of length 1.
2201  _ForwardIterator2 __p1(__first2);
2202  if (++__p1 == __last2)
2203  return std::__find_if(__first1, __last1,
2204  __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2));
2205 
2206  // General case.
2207  _ForwardIterator1 __current = __first1;
2208 
2209  for (;;)
2210  {
2211  __first1 =
2212  std::__find_if(__first1, __last1,
2213  __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2));
2214 
2215  if (__first1 == __last1)
2216  return __last1;
2217 
2218  _ForwardIterator2 __p = __p1;
2219  __current = __first1;
2220  if (++__current == __last1)
2221  return __last1;
2222 
2223  while (__predicate(__current, __p))
2224  {
2225  if (++__p == __last2)
2226  return __first1;
2227  if (++__current == __last1)
2228  return __last1;
2229  }
2230  ++__first1;
2231  }
2232  return __first1;
2233  }
2234 
2235 #if __cplusplus >= 201103L
2236  template<typename _ForwardIterator1, typename _ForwardIterator2,
2237  typename _BinaryPredicate>
2238  _GLIBCXX20_CONSTEXPR
2239  bool
2240  __is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2241  _ForwardIterator2 __first2, _BinaryPredicate __pred)
2242  {
2243  // Efficiently compare identical prefixes: O(N) if sequences
2244  // have the same elements in the same order.
2245  for (; __first1 != __last1; ++__first1, (void)++__first2)
2246  if (!__pred(__first1, __first2))
2247  break;
2248 
2249  if (__first1 == __last1)
2250  return true;
2251 
2252  // Establish __last2 assuming equal ranges by iterating over the
2253  // rest of the list.
2254  _ForwardIterator2 __last2 = __first2;
2255  std::advance(__last2, std::distance(__first1, __last1));
2256  for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan)
2257  {
2258  if (__scan != std::__find_if(__first1, __scan,
2259  __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan)))
2260  continue; // We've seen this one before.
2261 
2262  auto __matches
2263  = std::__count_if(__first2, __last2,
2264  __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan));
2265  if (0 == __matches ||
2266  std::__count_if(__scan, __last1,
2267  __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan))
2268  != __matches)
2269  return false;
2270  }
2271  return true;
2272  }
2273 
2274  /**
2275  * @brief Checks whether a permutation of the second sequence is equal
2276  * to the first sequence.
2277  * @ingroup non_mutating_algorithms
2278  * @param __first1 Start of first range.
2279  * @param __last1 End of first range.
2280  * @param __first2 Start of second range.
2281  * @return true if there exists a permutation of the elements in the range
2282  * [__first2, __first2 + (__last1 - __first1)), beginning with
2283  * ForwardIterator2 begin, such that equal(__first1, __last1, begin)
2284  * returns true; otherwise, returns false.
2285  */
2286  template<typename _ForwardIterator1, typename _ForwardIterator2>
2287  _GLIBCXX20_CONSTEXPR
2288  inline bool
2289  is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2290  _ForwardIterator2 __first2)
2291  {
2292  // concept requirements
2293  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
2294  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
2295  __glibcxx_function_requires(_EqualOpConcept<
2296  typename iterator_traits<_ForwardIterator1>::value_type,
2297  typename iterator_traits<_ForwardIterator2>::value_type>)
2298  __glibcxx_requires_valid_range(__first1, __last1);
2299 
2300  return std::__is_permutation(__first1, __last1, __first2,
2301  __gnu_cxx::__ops::__iter_equal_to_iter());
2302  }
2303 #endif // C++11
2304 
2305 _GLIBCXX_BEGIN_NAMESPACE_ALGO
2306 
2307  /**
2308  * @brief Search a sequence for a matching sub-sequence using a predicate.
2309  * @ingroup non_mutating_algorithms
2310  * @param __first1 A forward iterator.
2311  * @param __last1 A forward iterator.
2312  * @param __first2 A forward iterator.
2313  * @param __last2 A forward iterator.
2314  * @param __predicate A binary predicate.
2315  * @return The first iterator @c i in the range
2316  * @p [__first1,__last1-(__last2-__first2)) such that
2317  * @p __predicate(*(i+N),*(__first2+N)) is true for each @c N in the range
2318  * @p [0,__last2-__first2), or @p __last1 if no such iterator exists.
2319  *
2320  * Searches the range @p [__first1,__last1) for a sub-sequence that
2321  * compares equal value-by-value with the sequence given by @p
2322  * [__first2,__last2), using @p __predicate to determine equality,
2323  * and returns an iterator to the first element of the
2324  * sub-sequence, or @p __last1 if no such iterator exists.
2325  *
2326  * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2)
2327  */
2328  template<typename _ForwardIterator1, typename _ForwardIterator2,
2329  typename _BinaryPredicate>
2330  _GLIBCXX20_CONSTEXPR
2331  inline _ForwardIterator1
2332  search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2333  _ForwardIterator2 __first2, _ForwardIterator2 __last2,
2334  _BinaryPredicate __predicate)
2335  {
2336  // concept requirements
2337  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
2338  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
2339  __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
2340  typename iterator_traits<_ForwardIterator1>::value_type,
2341  typename iterator_traits<_ForwardIterator2>::value_type>)
2342  __glibcxx_requires_valid_range(__first1, __last1);
2343  __glibcxx_requires_valid_range(__first2, __last2);
2344 
2345  return std::__search(__first1, __last1, __first2, __last2,
2346  __gnu_cxx::__ops::__iter_comp_iter(__predicate));
2347  }
2348 
2349 _GLIBCXX_END_NAMESPACE_ALGO
2350 _GLIBCXX_END_NAMESPACE_VERSION
2351 } // namespace std
2352 
2353 // NB: This file is included within many other C++ includes, as a way
2354 // of getting the base algorithms. So, make sure that parallel bits
2355 // come in too if requested.
2356 #ifdef _GLIBCXX_PARALLEL
2357 # include <parallel/algobase.h>
2358 #endif
2359 
2360 #endif
stl_pair.h
std::istreambuf_iterator
Provides input iterator semantics for streambufs.
Definition: iosfwd:127
std::copy
constexpr _OI copy(_II __first, _II __last, _OI __result)
Copies the range [first,last) into result.
Definition: stl_algobase.h:642
type_traits
std::iter_swap
constexpr void iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
Swaps the contents of two iterators.
Definition: stl_algobase.h:155
std::min
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:233
std::advance
constexpr void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:220
std::__find_if
constexpr _InputIterator __find_if(_InputIterator __first, _InputIterator __last, _Predicate __pred, input_iterator_tag)
This is an overload used by find algos for the Input Iterator case.
Definition: stl_algobase.h:2087
std::_Deque_iterator
A deque::iterator.
Definition: stl_algobase.h:463
std::output_iterator_tag
Marking output iterators.
Definition: stl_iterator_base_types.h:96
__gnu_debug::_Safe_iterator
Safe iterator wrapper.
Definition: boost_concept_check.h:60
std
ISO C++ entities toplevel namespace is std.
cpp_type_traits.h
stl_iterator_base_types.h
compare
std::iterator_traits
Traits class for iterators.
Definition: cpp_type_traits.h:471
concept_check.h
std::equal
constexpr bool equal(_IIter1 __first1, _IIter1 __last1, _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
Tests a range for element-wise equality.
Definition: stl_algobase.h:1737
std::move
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:137
std::char_traits
Basis for explicit traits specializations.
Definition: char_traits.h:323
std::is_nothrow_copy_constructible
is_nothrow_copy_constructible
Definition: type_traits:1201
std::move_backward
constexpr _BI2 move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
Moves the range [first,last) into result.
Definition: stl_algobase.h:913
std::max
constexpr const _Tp & max(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:257
type_traits.h
__gnu_debug
GNU debug classes for public use.
Definition: boost_concept_check.h:57
functexcept.h
std::distance
constexpr iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:148
std::make_unsigned_t
typename make_unsigned< _Tp >::type make_unsigned_t
Alias template for make_unsigned.
Definition: type_traits:2076
move.h
debug.h
std::__lg
constexpr _Tp __lg(_Tp __n)
This is a helper function for the sort routines and for random.tcc.
Definition: stl_algobase.h:1547
std::input_iterator_tag
Marking input iterators.
Definition: stl_iterator_base_types.h:93
bit
stl_iterator.h
predefined_ops.h
std::__iterator_category
constexpr iterator_traits< _Iter >::iterator_category __iterator_category(const _Iter &)
Definition: stl_iterator_base_types.h:239
algobase.h
Parallel STL function calls corresponding to the stl_algobase.h header. The functions defined here ma...
std::ostreambuf_iterator
Provides output iterator semantics for streambufs.
Definition: iosfwd:130
stl_iterator_base_funcs.h
std::random_access_iterator_tag
Random-access iterators support a superset of bidirectional iterator operations.
Definition: stl_iterator_base_types.h:107
c++config.h
numeric_traits.h