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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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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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>
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
165  _ValueType1;
167  _ValueType2;
168 
169  __glibcxx_function_requires(_ConvertibleConcept<_ValueType1,
170  _ValueType2>)
171  __glibcxx_function_requires(_ConvertibleConcept<_ValueType2,
172  _ValueType1>)
173 
175  _ReferenceType1;
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)
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,
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,
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>
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,
484  __copy_move_a2(_CharT*, _CharT*,
486 
487  template<bool _IsMove, typename _CharT>
488  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
490  __copy_move_a2(const _CharT*, const _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(
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
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,
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,
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
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,
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,
920  __glibcxx_requires_can_decrement_range(__first, __last, __result);
921 
922  return std::__copy_move_backward_a<true>(std::__miter_base(__first),
923  std::__miter_base(__last),
924  __result);
925  }
926 
927 #define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::move_backward(_Tp, _Up, _Vp)
928 #else
929 #define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::copy_backward(_Tp, _Up, _Vp)
930 #endif
931 
932  template<typename _ForwardIterator, typename _Tp>
933  _GLIBCXX20_CONSTEXPR
934  inline typename
935  __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, void>::__type
936  __fill_a1(_ForwardIterator __first, _ForwardIterator __last,
937  const _Tp& __value)
938  {
939  for (; __first != __last; ++__first)
940  *__first = __value;
941  }
942 
943  template<typename _ForwardIterator, typename _Tp>
944  _GLIBCXX20_CONSTEXPR
945  inline typename
946  __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, void>::__type
947  __fill_a1(_ForwardIterator __first, _ForwardIterator __last,
948  const _Tp& __value)
949  {
950  const _Tp __tmp = __value;
951  for (; __first != __last; ++__first)
952  *__first = __tmp;
953  }
954 
955  // Specialization: for char types we can use memset.
956  template<typename _Tp>
957  _GLIBCXX20_CONSTEXPR
958  inline typename
959  __gnu_cxx::__enable_if<__is_byte<_Tp>::__value, void>::__type
960  __fill_a1(_Tp* __first, _Tp* __last, const _Tp& __c)
961  {
962  const _Tp __tmp = __c;
963 #if __cpp_lib_is_constant_evaluated
964  if (std::is_constant_evaluated())
965  {
966  for (; __first != __last; ++__first)
967  *__first = __tmp;
968  return;
969  }
970 #endif
971  if (const size_t __len = __last - __first)
972  __builtin_memset(__first, static_cast<unsigned char>(__tmp), __len);
973  }
974 
975  template<typename _Ite, typename _Cont, typename _Tp>
976  _GLIBCXX20_CONSTEXPR
977  inline void
978  __fill_a1(::__gnu_cxx::__normal_iterator<_Ite, _Cont> __first,
979  ::__gnu_cxx::__normal_iterator<_Ite, _Cont> __last,
980  const _Tp& __value)
981  { std::__fill_a1(__first.base(), __last.base(), __value); }
982 
983  template<typename _Tp, typename _VTp>
984  void
985  __fill_a1(const _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>&,
986  const _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>&,
987  const _VTp&);
988 
989  _GLIBCXX20_CONSTEXPR
990  void
991  __fill_a1(_GLIBCXX_STD_C::_Bit_iterator, _GLIBCXX_STD_C::_Bit_iterator,
992  const bool&);
993 
994  template<typename _FIte, typename _Tp>
995  _GLIBCXX20_CONSTEXPR
996  inline void
997  __fill_a(_FIte __first, _FIte __last, const _Tp& __value)
998  { std::__fill_a1(__first, __last, __value); }
999 
1000  template<typename _Ite, typename _Seq, typename _Cat, typename _Tp>
1001  _GLIBCXX20_CONSTEXPR
1002  void
1003  __fill_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
1004  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>&,
1005  const _Tp&);
1006 
1007  /**
1008  * @brief Fills the range [first,last) with copies of value.
1009  * @ingroup mutating_algorithms
1010  * @param __first A forward iterator.
1011  * @param __last A forward iterator.
1012  * @param __value A reference-to-const of arbitrary type.
1013  * @return Nothing.
1014  *
1015  * This function fills a range with copies of the same value. For char
1016  * types filling contiguous areas of memory, this becomes an inline call
1017  * to @c memset or @c wmemset.
1018  */
1019  template<typename _ForwardIterator, typename _Tp>
1020  _GLIBCXX20_CONSTEXPR
1021  inline void
1022  fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
1023  {
1024  // concept requirements
1025  __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
1026  _ForwardIterator>)
1027  __glibcxx_requires_valid_range(__first, __last);
1028 
1029  std::__fill_a(__first, __last, __value);
1030  }
1031 
1032  // Used by fill_n, generate_n, etc. to convert _Size to an integral type:
1033  inline _GLIBCXX_CONSTEXPR int
1034  __size_to_integer(int __n) { return __n; }
1035  inline _GLIBCXX_CONSTEXPR unsigned
1036  __size_to_integer(unsigned __n) { return __n; }
1037  inline _GLIBCXX_CONSTEXPR long
1038  __size_to_integer(long __n) { return __n; }
1039  inline _GLIBCXX_CONSTEXPR unsigned long
1040  __size_to_integer(unsigned long __n) { return __n; }
1041  inline _GLIBCXX_CONSTEXPR long long
1042  __size_to_integer(long long __n) { return __n; }
1043  inline _GLIBCXX_CONSTEXPR unsigned long long
1044  __size_to_integer(unsigned long long __n) { return __n; }
1045 
1046 #if defined(__GLIBCXX_TYPE_INT_N_0)
1047  __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_0
1048  __size_to_integer(__GLIBCXX_TYPE_INT_N_0 __n) { return __n; }
1049  __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_0
1050  __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_0 __n) { return __n; }
1051 #endif
1052 #if defined(__GLIBCXX_TYPE_INT_N_1)
1053  __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_1
1054  __size_to_integer(__GLIBCXX_TYPE_INT_N_1 __n) { return __n; }
1055  __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_1
1056  __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_1 __n) { return __n; }
1057 #endif
1058 #if defined(__GLIBCXX_TYPE_INT_N_2)
1059  __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_2
1060  __size_to_integer(__GLIBCXX_TYPE_INT_N_2 __n) { return __n; }
1061  __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_2
1062  __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_2 __n) { return __n; }
1063 #endif
1064 #if defined(__GLIBCXX_TYPE_INT_N_3)
1065  __extension__ inline _GLIBCXX_CONSTEXPR unsigned __GLIBCXX_TYPE_INT_N_3
1066  __size_to_integer(__GLIBCXX_TYPE_INT_N_3 __n) { return __n; }
1067  __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_3
1068  __size_to_integer(unsigned __GLIBCXX_TYPE_INT_N_3 __n) { return __n; }
1069 #endif
1070 
1071  inline _GLIBCXX_CONSTEXPR long long
1072  __size_to_integer(float __n) { return (long long)__n; }
1073  inline _GLIBCXX_CONSTEXPR long long
1074  __size_to_integer(double __n) { return (long long)__n; }
1075  inline _GLIBCXX_CONSTEXPR long long
1076  __size_to_integer(long double __n) { return (long long)__n; }
1077 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
1078  __extension__ inline _GLIBCXX_CONSTEXPR long long
1079  __size_to_integer(__float128 __n) { return (long long)__n; }
1080 #endif
1081 
1082  template<typename _OutputIterator, typename _Size, typename _Tp>
1083  _GLIBCXX20_CONSTEXPR
1084  inline typename
1085  __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, _OutputIterator>::__type
1086  __fill_n_a1(_OutputIterator __first, _Size __n, const _Tp& __value)
1087  {
1088  for (; __n > 0; --__n, (void) ++__first)
1089  *__first = __value;
1090  return __first;
1091  }
1092 
1093  template<typename _OutputIterator, typename _Size, typename _Tp>
1094  _GLIBCXX20_CONSTEXPR
1095  inline typename
1096  __gnu_cxx::__enable_if<__is_scalar<_Tp>::__value, _OutputIterator>::__type
1097  __fill_n_a1(_OutputIterator __first, _Size __n, const _Tp& __value)
1098  {
1099  const _Tp __tmp = __value;
1100  for (; __n > 0; --__n, (void) ++__first)
1101  *__first = __tmp;
1102  return __first;
1103  }
1104 
1105  template<typename _Ite, typename _Seq, typename _Cat, typename _Size,
1106  typename _Tp>
1107  _GLIBCXX20_CONSTEXPR
1108  ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
1109  __fill_n_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
1110  _Size __n, const _Tp& __value,
1112 
1113  template<typename _OutputIterator, typename _Size, typename _Tp>
1114  _GLIBCXX20_CONSTEXPR
1115  inline _OutputIterator
1116  __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1118  {
1119 #if __cplusplus >= 201103L
1120  static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1121 #endif
1122  return __fill_n_a1(__first, __n, __value);
1123  }
1124 
1125  template<typename _OutputIterator, typename _Size, typename _Tp>
1126  _GLIBCXX20_CONSTEXPR
1127  inline _OutputIterator
1128  __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1130  {
1131 #if __cplusplus >= 201103L
1132  static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1133 #endif
1134  return __fill_n_a1(__first, __n, __value);
1135  }
1136 
1137  template<typename _OutputIterator, typename _Size, typename _Tp>
1138  _GLIBCXX20_CONSTEXPR
1139  inline _OutputIterator
1140  __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
1142  {
1143 #if __cplusplus >= 201103L
1144  static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
1145 #endif
1146  if (__n <= 0)
1147  return __first;
1148 
1149  __glibcxx_requires_can_increment(__first, __n);
1150 
1151  std::__fill_a(__first, __first + __n, __value);
1152  return __first + __n;
1153  }
1154 
1155  /**
1156  * @brief Fills the range [first,first+n) with copies of value.
1157  * @ingroup mutating_algorithms
1158  * @param __first An output iterator.
1159  * @param __n The count of copies to perform.
1160  * @param __value A reference-to-const of arbitrary type.
1161  * @return The iterator at first+n.
1162  *
1163  * This function fills a range with copies of the same value. For char
1164  * types filling contiguous areas of memory, this becomes an inline call
1165  * to @c memset or @c wmemset.
1166  *
1167  * If @p __n is negative, the function does nothing.
1168  */
1169  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1170  // DR 865. More algorithms that throw away information
1171  // DR 426. search_n(), fill_n(), and generate_n() with negative n
1172  template<typename _OI, typename _Size, typename _Tp>
1173  _GLIBCXX20_CONSTEXPR
1174  inline _OI
1175  fill_n(_OI __first, _Size __n, const _Tp& __value)
1176  {
1177  // concept requirements
1178  __glibcxx_function_requires(_OutputIteratorConcept<_OI, const _Tp&>)
1179 
1180  return std::__fill_n_a(__first, std::__size_to_integer(__n), __value,
1181  std::__iterator_category(__first));
1182  }
1183 
1184  template<bool _BoolType>
1185  struct __equal
1186  {
1187  template<typename _II1, typename _II2>
1188  _GLIBCXX20_CONSTEXPR
1189  static bool
1190  equal(_II1 __first1, _II1 __last1, _II2 __first2)
1191  {
1192  for (; __first1 != __last1; ++__first1, (void) ++__first2)
1193  if (!(*__first1 == *__first2))
1194  return false;
1195  return true;
1196  }
1197  };
1198 
1199  template<>
1200  struct __equal<true>
1201  {
1202  template<typename _Tp>
1203  _GLIBCXX20_CONSTEXPR
1204  static bool
1205  equal(const _Tp* __first1, const _Tp* __last1, const _Tp* __first2)
1206  {
1207  if (const size_t __len = (__last1 - __first1))
1208  return !std::__memcmp(__first1, __first2, __len);
1209  return true;
1210  }
1211  };
1212 
1213  template<typename _Tp, typename _Ref, typename _Ptr, typename _II>
1214  typename __gnu_cxx::__enable_if<
1215  __is_random_access_iter<_II>::__value, bool>::__type
1216  __equal_aux1(_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
1217  _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>,
1218  _II);
1219 
1220  template<typename _Tp1, typename _Ref1, typename _Ptr1,
1221  typename _Tp2, typename _Ref2, typename _Ptr2>
1222  bool
1223  __equal_aux1(_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1224  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1225  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1226 
1227  template<typename _II, typename _Tp, typename _Ref, typename _Ptr>
1228  typename __gnu_cxx::__enable_if<
1229  __is_random_access_iter<_II>::__value, bool>::__type
1230  __equal_aux1(_II, _II,
1231  _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>);
1232 
1233  template<typename _II1, typename _II2>
1234  _GLIBCXX20_CONSTEXPR
1235  inline bool
1236  __equal_aux1(_II1 __first1, _II1 __last1, _II2 __first2)
1237  {
1238  typedef typename iterator_traits<_II1>::value_type _ValueType1;
1239  const bool __simple = ((__is_integer<_ValueType1>::__value
1240  || __is_pointer<_ValueType1>::__value)
1241  && __memcmpable<_II1, _II2>::__value);
1242  return std::__equal<__simple>::equal(__first1, __last1, __first2);
1243  }
1244 
1245  template<typename _II1, typename _II2>
1246  _GLIBCXX20_CONSTEXPR
1247  inline bool
1248  __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)
1249  {
1250  return std::__equal_aux1(std::__niter_base(__first1),
1251  std::__niter_base(__last1),
1252  std::__niter_base(__first2));
1253  }
1254 
1255  template<typename _II1, typename _Seq1, typename _Cat1, typename _II2>
1256  _GLIBCXX20_CONSTEXPR
1257  bool
1258  __equal_aux(const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1259  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1260  _II2);
1261 
1262  template<typename _II1, typename _II2, typename _Seq2, typename _Cat2>
1263  _GLIBCXX20_CONSTEXPR
1264  bool
1265  __equal_aux(_II1, _II1,
1266  const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>&);
1267 
1268  template<typename _II1, typename _Seq1, typename _Cat1,
1269  typename _II2, typename _Seq2, typename _Cat2>
1270  _GLIBCXX20_CONSTEXPR
1271  bool
1272  __equal_aux(const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1273  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>&,
1274  const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>&);
1275 
1276  template<typename, typename>
1277  struct __lc_rai
1278  {
1279  template<typename _II1, typename _II2>
1280  _GLIBCXX20_CONSTEXPR
1281  static _II1
1282  __newlast1(_II1, _II1 __last1, _II2, _II2)
1283  { return __last1; }
1284 
1285  template<typename _II>
1286  _GLIBCXX20_CONSTEXPR
1287  static bool
1288  __cnd2(_II __first, _II __last)
1289  { return __first != __last; }
1290  };
1291 
1292  template<>
1293  struct __lc_rai<random_access_iterator_tag, random_access_iterator_tag>
1294  {
1295  template<typename _RAI1, typename _RAI2>
1296  _GLIBCXX20_CONSTEXPR
1297  static _RAI1
1298  __newlast1(_RAI1 __first1, _RAI1 __last1,
1299  _RAI2 __first2, _RAI2 __last2)
1300  {
1301  const typename iterator_traits<_RAI1>::difference_type
1302  __diff1 = __last1 - __first1;
1303  const typename iterator_traits<_RAI2>::difference_type
1304  __diff2 = __last2 - __first2;
1305  return __diff2 < __diff1 ? __first1 + __diff2 : __last1;
1306  }
1307 
1308  template<typename _RAI>
1309  static _GLIBCXX20_CONSTEXPR bool
1310  __cnd2(_RAI, _RAI)
1311  { return true; }
1312  };
1313 
1314  template<typename _II1, typename _II2, typename _Compare>
1315  _GLIBCXX20_CONSTEXPR
1316  bool
1317  __lexicographical_compare_impl(_II1 __first1, _II1 __last1,
1318  _II2 __first2, _II2 __last2,
1319  _Compare __comp)
1320  {
1321  typedef typename iterator_traits<_II1>::iterator_category _Category1;
1322  typedef typename iterator_traits<_II2>::iterator_category _Category2;
1323  typedef std::__lc_rai<_Category1, _Category2> __rai_type;
1324 
1325  __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
1326  for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
1327  ++__first1, (void)++__first2)
1328  {
1329  if (__comp(__first1, __first2))
1330  return true;
1331  if (__comp(__first2, __first1))
1332  return false;
1333  }
1334  return __first1 == __last1 && __first2 != __last2;
1335  }
1336 
1337  template<bool _BoolType>
1338  struct __lexicographical_compare
1339  {
1340  template<typename _II1, typename _II2>
1341  _GLIBCXX20_CONSTEXPR
1342  static bool
1343  __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1344  {
1345  using __gnu_cxx::__ops::__iter_less_iter;
1346  return std::__lexicographical_compare_impl(__first1, __last1,
1347  __first2, __last2,
1348  __iter_less_iter());
1349  }
1350 
1351  template<typename _II1, typename _II2>
1352  _GLIBCXX20_CONSTEXPR
1353  static int
1354  __3way(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1355  {
1356  while (__first1 != __last1)
1357  {
1358  if (__first2 == __last2)
1359  return +1;
1360  if (*__first1 < *__first2)
1361  return -1;
1362  if (*__first2 < *__first1)
1363  return +1;
1364  ++__first1;
1365  ++__first2;
1366  }
1367  return int(__first2 == __last2) - 1;
1368  }
1369  };
1370 
1371  template<>
1372  struct __lexicographical_compare<true>
1373  {
1374  template<typename _Tp, typename _Up>
1375  _GLIBCXX20_CONSTEXPR
1376  static bool
1377  __lc(const _Tp* __first1, const _Tp* __last1,
1378  const _Up* __first2, const _Up* __last2)
1379  { return __3way(__first1, __last1, __first2, __last2) < 0; }
1380 
1381  template<typename _Tp, typename _Up>
1382  _GLIBCXX20_CONSTEXPR
1383  static ptrdiff_t
1384  __3way(const _Tp* __first1, const _Tp* __last1,
1385  const _Up* __first2, const _Up* __last2)
1386  {
1387  const size_t __len1 = __last1 - __first1;
1388  const size_t __len2 = __last2 - __first2;
1389  if (const size_t __len = std::min(__len1, __len2))
1390  if (int __result = std::__memcmp(__first1, __first2, __len))
1391  return __result;
1392  return ptrdiff_t(__len1 - __len2);
1393  }
1394  };
1395 
1396  template<typename _II1, typename _II2>
1397  _GLIBCXX20_CONSTEXPR
1398  inline bool
1399  __lexicographical_compare_aux1(_II1 __first1, _II1 __last1,
1400  _II2 __first2, _II2 __last2)
1401  {
1402  typedef typename iterator_traits<_II1>::value_type _ValueType1;
1403  typedef typename iterator_traits<_II2>::value_type _ValueType2;
1404  const bool __simple =
1405  (__is_memcmp_ordered_with<_ValueType1, _ValueType2>::__value
1406  && __is_pointer<_II1>::__value
1407  && __is_pointer<_II2>::__value
1408 #if __cplusplus > 201703L && __glibcxx_concepts
1409  // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
1410  // so __is_byte<T> could be true, but we can't use memcmp with
1411  // volatile data.
1412  && !is_volatile_v<remove_reference_t<iter_reference_t<_II1>>>
1413  && !is_volatile_v<remove_reference_t<iter_reference_t<_II2>>>
1414 #endif
1415  );
1416 
1417  return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
1418  __first2, __last2);
1419  }
1420 
1421  template<typename _Tp1, typename _Ref1, typename _Ptr1,
1422  typename _Tp2>
1423  bool
1424  __lexicographical_compare_aux1(
1425  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1426  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1427  _Tp2*, _Tp2*);
1428 
1429  template<typename _Tp1,
1430  typename _Tp2, typename _Ref2, typename _Ptr2>
1431  bool
1432  __lexicographical_compare_aux1(_Tp1*, _Tp1*,
1433  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
1434  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1435 
1436  template<typename _Tp1, typename _Ref1, typename _Ptr1,
1437  typename _Tp2, typename _Ref2, typename _Ptr2>
1438  bool
1439  __lexicographical_compare_aux1(
1440  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1441  _GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
1442  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
1443  _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
1444 
1445  template<typename _II1, typename _II2>
1446  _GLIBCXX20_CONSTEXPR
1447  inline bool
1448  __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
1449  _II2 __first2, _II2 __last2)
1450  {
1451  return std::__lexicographical_compare_aux1(std::__niter_base(__first1),
1452  std::__niter_base(__last1),
1453  std::__niter_base(__first2),
1454  std::__niter_base(__last2));
1455  }
1456 
1457  template<typename _Iter1, typename _Seq1, typename _Cat1,
1458  typename _II2>
1459  _GLIBCXX20_CONSTEXPR
1460  bool
1461  __lexicographical_compare_aux(
1462  const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1463  const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1464  _II2, _II2);
1465 
1466  template<typename _II1,
1467  typename _Iter2, typename _Seq2, typename _Cat2>
1468  _GLIBCXX20_CONSTEXPR
1469  bool
1470  __lexicographical_compare_aux(
1471  _II1, _II1,
1472  const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&,
1473  const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&);
1474 
1475  template<typename _Iter1, typename _Seq1, typename _Cat1,
1476  typename _Iter2, typename _Seq2, typename _Cat2>
1477  _GLIBCXX20_CONSTEXPR
1478  bool
1479  __lexicographical_compare_aux(
1480  const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1481  const ::__gnu_debug::_Safe_iterator<_Iter1, _Seq1, _Cat1>&,
1482  const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&,
1483  const ::__gnu_debug::_Safe_iterator<_Iter2, _Seq2, _Cat2>&);
1484 
1485  template<typename _ForwardIterator, typename _Tp, typename _Compare>
1486  _GLIBCXX20_CONSTEXPR
1487  _ForwardIterator
1488  __lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1489  const _Tp& __val, _Compare __comp)
1490  {
1491  typedef typename iterator_traits<_ForwardIterator>::difference_type
1492  _DistanceType;
1493 
1494  _DistanceType __len = std::distance(__first, __last);
1495 
1496  while (__len > 0)
1497  {
1498  _DistanceType __half = __len >> 1;
1499  _ForwardIterator __middle = __first;
1500  std::advance(__middle, __half);
1501  if (__comp(__middle, __val))
1502  {
1503  __first = __middle;
1504  ++__first;
1505  __len = __len - __half - 1;
1506  }
1507  else
1508  __len = __half;
1509  }
1510  return __first;
1511  }
1512 
1513  /**
1514  * @brief Finds the first position in which @a val could be inserted
1515  * without changing the ordering.
1516  * @param __first An iterator.
1517  * @param __last Another iterator.
1518  * @param __val The search term.
1519  * @return An iterator pointing to the first element <em>not less
1520  * than</em> @a val, or end() if every element is less than
1521  * @a val.
1522  * @ingroup binary_search_algorithms
1523  */
1524  template<typename _ForwardIterator, typename _Tp>
1525  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1526  inline _ForwardIterator
1527  lower_bound(_ForwardIterator __first, _ForwardIterator __last,
1528  const _Tp& __val)
1529  {
1530  // concept requirements
1531  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
1532  __glibcxx_function_requires(_LessThanOpConcept<
1534  __glibcxx_requires_partitioned_lower(__first, __last, __val);
1535 
1536  return std::__lower_bound(__first, __last, __val,
1537  __gnu_cxx::__ops::__iter_less_val());
1538  }
1539 
1540  /// This is a helper function for the sort routines and for random.tcc.
1541  // Precondition: __n > 0.
1542  template<typename _Tp>
1543  inline _GLIBCXX_CONSTEXPR _Tp
1544  __lg(_Tp __n)
1545  {
1546 #if __cplusplus >= 201402L
1547  return std::__bit_width(make_unsigned_t<_Tp>(__n)) - 1;
1548 #else
1549  // Use +__n so it promotes to at least int.
1550  return (sizeof(+__n) * __CHAR_BIT__ - 1)
1551  - (sizeof(+__n) == sizeof(long long)
1552  ? __builtin_clzll(+__n)
1553  : (sizeof(+__n) == sizeof(long)
1554  ? __builtin_clzl(+__n)
1555  : __builtin_clz(+__n)));
1556 #endif
1557  }
1558 
1559 _GLIBCXX_BEGIN_NAMESPACE_ALGO
1560 
1561  /**
1562  * @brief Tests a range for element-wise equality.
1563  * @ingroup non_mutating_algorithms
1564  * @param __first1 An input iterator.
1565  * @param __last1 An input iterator.
1566  * @param __first2 An input iterator.
1567  * @return A boolean true or false.
1568  *
1569  * This compares the elements of two ranges using @c == and returns true or
1570  * false depending on whether all of the corresponding elements of the
1571  * ranges are equal.
1572  */
1573  template<typename _II1, typename _II2>
1574  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1575  inline bool
1576  equal(_II1 __first1, _II1 __last1, _II2 __first2)
1577  {
1578  // concept requirements
1579  __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1580  __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1581  __glibcxx_function_requires(_EqualOpConcept<
1584  __glibcxx_requires_can_increment_range(__first1, __last1, __first2);
1585 
1586  return std::__equal_aux(__first1, __last1, __first2);
1587  }
1588 
1589  /**
1590  * @brief Tests a range for element-wise equality.
1591  * @ingroup non_mutating_algorithms
1592  * @param __first1 An input iterator.
1593  * @param __last1 An input iterator.
1594  * @param __first2 An input iterator.
1595  * @param __binary_pred A binary predicate @link functors
1596  * functor@endlink.
1597  * @return A boolean true or false.
1598  *
1599  * This compares the elements of two ranges using the binary_pred
1600  * parameter, and returns true or
1601  * false depending on whether all of the corresponding elements of the
1602  * ranges are equal.
1603  */
1604  template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1605  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1606  inline bool
1607  equal(_IIter1 __first1, _IIter1 __last1,
1608  _IIter2 __first2, _BinaryPredicate __binary_pred)
1609  {
1610  // concept requirements
1611  __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1612  __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1613  __glibcxx_requires_valid_range(__first1, __last1);
1614 
1615  for (; __first1 != __last1; ++__first1, (void)++__first2)
1616  if (!bool(__binary_pred(*__first1, *__first2)))
1617  return false;
1618  return true;
1619  }
1620 
1621 #if __cplusplus >= 201103L
1622  // 4-iterator version of std::equal<It1, It2> for use in C++11.
1623  template<typename _II1, typename _II2>
1624  _GLIBCXX20_CONSTEXPR
1625  inline bool
1626  __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1627  {
1628  using _RATag = random_access_iterator_tag;
1629  using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1630  using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1631  using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1632  if (_RAIters())
1633  {
1634  auto __d1 = std::distance(__first1, __last1);
1635  auto __d2 = std::distance(__first2, __last2);
1636  if (__d1 != __d2)
1637  return false;
1638  return _GLIBCXX_STD_A::equal(__first1, __last1, __first2);
1639  }
1640 
1641  for (; __first1 != __last1 && __first2 != __last2;
1642  ++__first1, (void)++__first2)
1643  if (!(*__first1 == *__first2))
1644  return false;
1645  return __first1 == __last1 && __first2 == __last2;
1646  }
1647 
1648  // 4-iterator version of std::equal<It1, It2, BinaryPred> for use in C++11.
1649  template<typename _II1, typename _II2, typename _BinaryPredicate>
1650  _GLIBCXX20_CONSTEXPR
1651  inline bool
1652  __equal4(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2,
1653  _BinaryPredicate __binary_pred)
1654  {
1655  using _RATag = random_access_iterator_tag;
1656  using _Cat1 = typename iterator_traits<_II1>::iterator_category;
1657  using _Cat2 = typename iterator_traits<_II2>::iterator_category;
1658  using _RAIters = __and_<is_same<_Cat1, _RATag>, is_same<_Cat2, _RATag>>;
1659  if (_RAIters())
1660  {
1661  auto __d1 = std::distance(__first1, __last1);
1662  auto __d2 = std::distance(__first2, __last2);
1663  if (__d1 != __d2)
1664  return false;
1665  return _GLIBCXX_STD_A::equal(__first1, __last1, __first2,
1666  __binary_pred);
1667  }
1668 
1669  for (; __first1 != __last1 && __first2 != __last2;
1670  ++__first1, (void)++__first2)
1671  if (!bool(__binary_pred(*__first1, *__first2)))
1672  return false;
1673  return __first1 == __last1 && __first2 == __last2;
1674  }
1675 #endif // C++11
1676 
1677 #ifdef __glibcxx_robust_nonmodifying_seq_ops // C++ >= 14
1678  /**
1679  * @brief Tests a range for element-wise equality.
1680  * @ingroup non_mutating_algorithms
1681  * @param __first1 An input iterator.
1682  * @param __last1 An input iterator.
1683  * @param __first2 An input iterator.
1684  * @param __last2 An input iterator.
1685  * @return A boolean true or false.
1686  *
1687  * This compares the elements of two ranges using @c == and returns true or
1688  * false depending on whether all of the corresponding elements of the
1689  * ranges are equal.
1690  */
1691  template<typename _II1, typename _II2>
1692  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1693  inline bool
1694  equal(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
1695  {
1696  // concept requirements
1697  __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1698  __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1699  __glibcxx_function_requires(_EqualOpConcept<
1702  __glibcxx_requires_valid_range(__first1, __last1);
1703  __glibcxx_requires_valid_range(__first2, __last2);
1704 
1705  return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2);
1706  }
1707 
1708  /**
1709  * @brief Tests a range for element-wise equality.
1710  * @ingroup non_mutating_algorithms
1711  * @param __first1 An input iterator.
1712  * @param __last1 An input iterator.
1713  * @param __first2 An input iterator.
1714  * @param __last2 An input iterator.
1715  * @param __binary_pred A binary predicate @link functors
1716  * functor@endlink.
1717  * @return A boolean true or false.
1718  *
1719  * This compares the elements of two ranges using the binary_pred
1720  * parameter, and returns true or
1721  * false depending on whether all of the corresponding elements of the
1722  * ranges are equal.
1723  */
1724  template<typename _IIter1, typename _IIter2, typename _BinaryPredicate>
1725  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1726  inline bool
1727  equal(_IIter1 __first1, _IIter1 __last1,
1728  _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
1729  {
1730  // concept requirements
1731  __glibcxx_function_requires(_InputIteratorConcept<_IIter1>)
1732  __glibcxx_function_requires(_InputIteratorConcept<_IIter2>)
1733  __glibcxx_requires_valid_range(__first1, __last1);
1734  __glibcxx_requires_valid_range(__first2, __last2);
1735 
1736  return _GLIBCXX_STD_A::__equal4(__first1, __last1, __first2, __last2,
1737  __binary_pred);
1738  }
1739 #endif // __glibcxx_robust_nonmodifying_seq_ops
1740 
1741  /**
1742  * @brief Performs @b dictionary comparison on ranges.
1743  * @ingroup sorting_algorithms
1744  * @param __first1 An input iterator.
1745  * @param __last1 An input iterator.
1746  * @param __first2 An input iterator.
1747  * @param __last2 An input iterator.
1748  * @return A boolean true or false.
1749  *
1750  * <em>Returns true if the sequence of elements defined by the range
1751  * [first1,last1) is lexicographically less than the sequence of elements
1752  * defined by the range [first2,last2). Returns false otherwise.</em>
1753  * (Quoted from [25.3.8]/1.) If the iterators are all character pointers,
1754  * then this is an inline call to @c memcmp.
1755  */
1756  template<typename _II1, typename _II2>
1757  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1758  inline bool
1759  lexicographical_compare(_II1 __first1, _II1 __last1,
1760  _II2 __first2, _II2 __last2)
1761  {
1762 #ifdef _GLIBCXX_CONCEPT_CHECKS
1763  // concept requirements
1764  typedef typename iterator_traits<_II1>::value_type _ValueType1;
1765  typedef typename iterator_traits<_II2>::value_type _ValueType2;
1766 #endif
1767  __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1768  __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1769  __glibcxx_function_requires(_LessThanOpConcept<_ValueType1, _ValueType2>)
1770  __glibcxx_function_requires(_LessThanOpConcept<_ValueType2, _ValueType1>)
1771  __glibcxx_requires_valid_range(__first1, __last1);
1772  __glibcxx_requires_valid_range(__first2, __last2);
1773 
1774  return std::__lexicographical_compare_aux(__first1, __last1,
1775  __first2, __last2);
1776  }
1777 
1778  /**
1779  * @brief Performs @b dictionary comparison on ranges.
1780  * @ingroup sorting_algorithms
1781  * @param __first1 An input iterator.
1782  * @param __last1 An input iterator.
1783  * @param __first2 An input iterator.
1784  * @param __last2 An input iterator.
1785  * @param __comp A @link comparison_functors comparison functor@endlink.
1786  * @return A boolean true or false.
1787  *
1788  * The same as the four-parameter @c lexicographical_compare, but uses the
1789  * comp parameter instead of @c <.
1790  */
1791  template<typename _II1, typename _II2, typename _Compare>
1792  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1793  inline bool
1794  lexicographical_compare(_II1 __first1, _II1 __last1,
1795  _II2 __first2, _II2 __last2, _Compare __comp)
1796  {
1797  // concept requirements
1798  __glibcxx_function_requires(_InputIteratorConcept<_II1>)
1799  __glibcxx_function_requires(_InputIteratorConcept<_II2>)
1800  __glibcxx_requires_valid_range(__first1, __last1);
1801  __glibcxx_requires_valid_range(__first2, __last2);
1802 
1803  return std::__lexicographical_compare_impl
1804  (__first1, __last1, __first2, __last2,
1805  __gnu_cxx::__ops::__iter_comp_iter(__comp));
1806  }
1807 
1808 #if __cpp_lib_three_way_comparison
1809  // Both iterators refer to contiguous ranges of unsigned narrow characters,
1810  // or std::byte, or big-endian unsigned integers, suitable for comparison
1811  // using memcmp.
1812  template<typename _Iter1, typename _Iter2>
1813  concept __memcmp_ordered_with
1814  = (__is_memcmp_ordered_with<iter_value_t<_Iter1>,
1815  iter_value_t<_Iter2>>::__value)
1816  && contiguous_iterator<_Iter1> && contiguous_iterator<_Iter2>;
1817 
1818  // Return a struct with two members, initialized to the smaller of x and y
1819  // (or x if they compare equal) and the result of the comparison x <=> y.
1820  template<typename _Tp>
1821  constexpr auto
1822  __min_cmp(_Tp __x, _Tp __y)
1823  {
1824  struct _Res {
1825  _Tp _M_min;
1826  decltype(__x <=> __y) _M_cmp;
1827  };
1828  auto __c = __x <=> __y;
1829  if (__c > 0)
1830  return _Res{__y, __c};
1831  return _Res{__x, __c};
1832  }
1833 
1834  /**
1835  * @brief Performs dictionary comparison on ranges.
1836  * @ingroup sorting_algorithms
1837  * @param __first1 An input iterator.
1838  * @param __last1 An input iterator.
1839  * @param __first2 An input iterator.
1840  * @param __last2 An input iterator.
1841  * @param __comp A @link comparison_functors comparison functor@endlink.
1842  * @return The comparison category that `__comp(*__first1, *__first2)`
1843  * returns.
1844  */
1845  template<typename _InputIter1, typename _InputIter2, typename _Comp>
1846  [[nodiscard]] constexpr auto
1848  _InputIter1 __last1,
1849  _InputIter2 __first2,
1850  _InputIter2 __last2,
1851  _Comp __comp)
1852  -> decltype(__comp(*__first1, *__first2))
1853  {
1854  // concept requirements
1855  __glibcxx_function_requires(_InputIteratorConcept<_InputIter1>)
1856  __glibcxx_function_requires(_InputIteratorConcept<_InputIter2>)
1857  __glibcxx_requires_valid_range(__first1, __last1);
1858  __glibcxx_requires_valid_range(__first2, __last2);
1859 
1860  using _Cat = decltype(__comp(*__first1, *__first2));
1861  static_assert(same_as<common_comparison_category_t<_Cat>, _Cat>);
1862 
1863  if (!std::__is_constant_evaluated())
1864  if constexpr (same_as<_Comp, __detail::_Synth3way>
1865  || same_as<_Comp, compare_three_way>)
1866  if constexpr (__memcmp_ordered_with<_InputIter1, _InputIter2>)
1867  {
1868  const auto [__len, __lencmp] = _GLIBCXX_STD_A::
1869  __min_cmp(__last1 - __first1, __last2 - __first2);
1870  if (__len)
1871  {
1872  const auto __blen = __len * sizeof(*__first1);
1873  const auto __c
1874  = __builtin_memcmp(&*__first1, &*__first2, __blen) <=> 0;
1875  if (__c != 0)
1876  return __c;
1877  }
1878  return __lencmp;
1879  }
1880 
1881  while (__first1 != __last1)
1882  {
1883  if (__first2 == __last2)
1884  return strong_ordering::greater;
1885  if (auto __cmp = __comp(*__first1, *__first2); __cmp != 0)
1886  return __cmp;
1887  ++__first1;
1888  ++__first2;
1889  }
1890  return (__first2 == __last2) <=> true; // See PR 94006
1891  }
1892 
1893  template<typename _InputIter1, typename _InputIter2>
1894  constexpr auto
1895  lexicographical_compare_three_way(_InputIter1 __first1,
1896  _InputIter1 __last1,
1897  _InputIter2 __first2,
1898  _InputIter2 __last2)
1899  {
1900  return _GLIBCXX_STD_A::
1901  lexicographical_compare_three_way(__first1, __last1, __first2, __last2,
1902  compare_three_way{});
1903  }
1904 #endif // three_way_comparison
1905 
1906  template<typename _InputIterator1, typename _InputIterator2,
1907  typename _BinaryPredicate>
1908  _GLIBCXX20_CONSTEXPR
1909  pair<_InputIterator1, _InputIterator2>
1910  __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1911  _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1912  {
1913  while (__first1 != __last1 && __binary_pred(__first1, __first2))
1914  {
1915  ++__first1;
1916  ++__first2;
1917  }
1918  return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
1919  }
1920 
1921  /**
1922  * @brief Finds the places in ranges which don't match.
1923  * @ingroup non_mutating_algorithms
1924  * @param __first1 An input iterator.
1925  * @param __last1 An input iterator.
1926  * @param __first2 An input iterator.
1927  * @return A pair of iterators pointing to the first mismatch.
1928  *
1929  * This compares the elements of two ranges using @c == and returns a pair
1930  * of iterators. The first iterator points into the first range, the
1931  * second iterator points into the second range, and the elements pointed
1932  * to by the iterators are not equal.
1933  */
1934  template<typename _InputIterator1, typename _InputIterator2>
1935  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1936  inline pair<_InputIterator1, _InputIterator2>
1937  mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1938  _InputIterator2 __first2)
1939  {
1940  // concept requirements
1941  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1942  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1943  __glibcxx_function_requires(_EqualOpConcept<
1946  __glibcxx_requires_valid_range(__first1, __last1);
1947 
1948  return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1949  __gnu_cxx::__ops::__iter_equal_to_iter());
1950  }
1951 
1952  /**
1953  * @brief Finds the places in ranges which don't match.
1954  * @ingroup non_mutating_algorithms
1955  * @param __first1 An input iterator.
1956  * @param __last1 An input iterator.
1957  * @param __first2 An input iterator.
1958  * @param __binary_pred A binary predicate @link functors
1959  * functor@endlink.
1960  * @return A pair of iterators pointing to the first mismatch.
1961  *
1962  * This compares the elements of two ranges using the binary_pred
1963  * parameter, and returns a pair
1964  * of iterators. The first iterator points into the first range, the
1965  * second iterator points into the second range, and the elements pointed
1966  * to by the iterators are not equal.
1967  */
1968  template<typename _InputIterator1, typename _InputIterator2,
1969  typename _BinaryPredicate>
1970  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1971  inline pair<_InputIterator1, _InputIterator2>
1972  mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1973  _InputIterator2 __first2, _BinaryPredicate __binary_pred)
1974  {
1975  // concept requirements
1976  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
1977  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
1978  __glibcxx_requires_valid_range(__first1, __last1);
1979 
1980  return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2,
1981  __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
1982  }
1983 
1984 #if __glibcxx_robust_nonmodifying_seq_ops // C++ >= 14
1985  template<typename _InputIterator1, typename _InputIterator2,
1986  typename _BinaryPredicate>
1987  _GLIBCXX20_CONSTEXPR
1988  pair<_InputIterator1, _InputIterator2>
1989  __mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
1990  _InputIterator2 __first2, _InputIterator2 __last2,
1991  _BinaryPredicate __binary_pred)
1992  {
1993  while (__first1 != __last1 && __first2 != __last2
1994  && __binary_pred(__first1, __first2))
1995  {
1996  ++__first1;
1997  ++__first2;
1998  }
1999  return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
2000  }
2001 
2002  /**
2003  * @brief Finds the places in ranges which don't match.
2004  * @ingroup non_mutating_algorithms
2005  * @param __first1 An input iterator.
2006  * @param __last1 An input iterator.
2007  * @param __first2 An input iterator.
2008  * @param __last2 An input iterator.
2009  * @return A pair of iterators pointing to the first mismatch.
2010  *
2011  * This compares the elements of two ranges using @c == and returns a pair
2012  * of iterators. The first iterator points into the first range, the
2013  * second iterator points into the second range, and the elements pointed
2014  * to by the iterators are not equal.
2015  */
2016  template<typename _InputIterator1, typename _InputIterator2>
2017  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2018  inline pair<_InputIterator1, _InputIterator2>
2019  mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2020  _InputIterator2 __first2, _InputIterator2 __last2)
2021  {
2022  // concept requirements
2023  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2024  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2025  __glibcxx_function_requires(_EqualOpConcept<
2028  __glibcxx_requires_valid_range(__first1, __last1);
2029  __glibcxx_requires_valid_range(__first2, __last2);
2030 
2031  return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
2032  __gnu_cxx::__ops::__iter_equal_to_iter());
2033  }
2034 
2035  /**
2036  * @brief Finds the places in ranges which don't match.
2037  * @ingroup non_mutating_algorithms
2038  * @param __first1 An input iterator.
2039  * @param __last1 An input iterator.
2040  * @param __first2 An input iterator.
2041  * @param __last2 An input iterator.
2042  * @param __binary_pred A binary predicate @link functors
2043  * functor@endlink.
2044  * @return A pair of iterators pointing to the first mismatch.
2045  *
2046  * This compares the elements of two ranges using the binary_pred
2047  * parameter, and returns a pair
2048  * of iterators. The first iterator points into the first range, the
2049  * second iterator points into the second range, and the elements pointed
2050  * to by the iterators are not equal.
2051  */
2052  template<typename _InputIterator1, typename _InputIterator2,
2053  typename _BinaryPredicate>
2054  _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2055  inline pair<_InputIterator1, _InputIterator2>
2056  mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
2057  _InputIterator2 __first2, _InputIterator2 __last2,
2058  _BinaryPredicate __binary_pred)
2059  {
2060  // concept requirements
2061  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
2062  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
2063  __glibcxx_requires_valid_range(__first1, __last1);
2064  __glibcxx_requires_valid_range(__first2, __last2);
2065 
2066  return _GLIBCXX_STD_A::__mismatch(__first1, __last1, __first2, __last2,
2067  __gnu_cxx::__ops::__iter_comp_iter(__binary_pred));
2068  }
2069 #endif
2070 
2071 _GLIBCXX_END_NAMESPACE_ALGO
2072 
2073  /// This is an overload used by find algos for the Input Iterator case.
2074  template<typename _InputIterator, typename _Predicate>
2075  _GLIBCXX20_CONSTEXPR
2076  inline _InputIterator
2077  __find_if(_InputIterator __first, _InputIterator __last,
2078  _Predicate __pred, input_iterator_tag)
2079  {
2080  while (__first != __last && !__pred(__first))
2081  ++__first;
2082  return __first;
2083  }
2084 
2085  /// This is an overload used by find algos for the RAI case.
2086  template<typename _RandomAccessIterator, typename _Predicate>
2087  _GLIBCXX20_CONSTEXPR
2088  _RandomAccessIterator
2089  __find_if(_RandomAccessIterator __first, _RandomAccessIterator __last,
2090  _Predicate __pred, random_access_iterator_tag)
2091  {
2093  __trip_count = (__last - __first) >> 2;
2094 
2095  for (; __trip_count > 0; --__trip_count)
2096  {
2097  if (__pred(__first))
2098  return __first;
2099  ++__first;
2100 
2101  if (__pred(__first))
2102  return __first;
2103  ++__first;
2104 
2105  if (__pred(__first))
2106  return __first;
2107  ++__first;
2108 
2109  if (__pred(__first))
2110  return __first;
2111  ++__first;
2112  }
2113 
2114  switch (__last - __first)
2115  {
2116  case 3:
2117  if (__pred(__first))
2118  return __first;
2119  ++__first;
2120  // FALLTHRU
2121  case 2:
2122  if (__pred(__first))
2123  return __first;
2124  ++__first;
2125  // FALLTHRU
2126  case 1:
2127  if (__pred(__first))
2128  return __first;
2129  ++__first;
2130  // FALLTHRU
2131  case 0:
2132  default:
2133  return __last;
2134  }
2135  }
2136 
2137  template<typename _Iterator, typename _Predicate>
2138  _GLIBCXX20_CONSTEXPR
2139  inline _Iterator
2140  __find_if(_Iterator __first, _Iterator __last, _Predicate __pred)
2141  {
2142  return __find_if(__first, __last, __pred,
2143  std::__iterator_category(__first));
2144  }
2145 
2146  template<typename _InputIterator, typename _Predicate>
2147  _GLIBCXX20_CONSTEXPR
2148  typename iterator_traits<_InputIterator>::difference_type
2149  __count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
2150  {
2151  typename iterator_traits<_InputIterator>::difference_type __n = 0;
2152  for (; __first != __last; ++__first)
2153  if (__pred(__first))
2154  ++__n;
2155  return __n;
2156  }
2157 
2158  template<typename _ForwardIterator, typename _Predicate>
2159  _GLIBCXX20_CONSTEXPR
2160  _ForwardIterator
2161  __remove_if(_ForwardIterator __first, _ForwardIterator __last,
2162  _Predicate __pred)
2163  {
2164  __first = std::__find_if(__first, __last, __pred);
2165  if (__first == __last)
2166  return __first;
2167  _ForwardIterator __result = __first;
2168  ++__first;
2169  for (; __first != __last; ++__first)
2170  if (!__pred(__first))
2171  {
2172  *__result = _GLIBCXX_MOVE(*__first);
2173  ++__result;
2174  }
2175  return __result;
2176  }
2177 
2178  template<typename _ForwardIterator1, typename _ForwardIterator2,
2179  typename _BinaryPredicate>
2180  _GLIBCXX20_CONSTEXPR
2181  _ForwardIterator1
2182  __search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2183  _ForwardIterator2 __first2, _ForwardIterator2 __last2,
2184  _BinaryPredicate __predicate)
2185  {
2186  // Test for empty ranges
2187  if (__first1 == __last1 || __first2 == __last2)
2188  return __first1;
2189 
2190  // Test for a pattern of length 1.
2191  _ForwardIterator2 __p1(__first2);
2192  if (++__p1 == __last2)
2193  return std::__find_if(__first1, __last1,
2194  __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2));
2195 
2196  // General case.
2197  _ForwardIterator1 __current = __first1;
2198 
2199  for (;;)
2200  {
2201  __first1 =
2202  std::__find_if(__first1, __last1,
2203  __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2));
2204 
2205  if (__first1 == __last1)
2206  return __last1;
2207 
2208  _ForwardIterator2 __p = __p1;
2209  __current = __first1;
2210  if (++__current == __last1)
2211  return __last1;
2212 
2213  while (__predicate(__current, __p))
2214  {
2215  if (++__p == __last2)
2216  return __first1;
2217  if (++__current == __last1)
2218  return __last1;
2219  }
2220  ++__first1;
2221  }
2222  return __first1;
2223  }
2224 
2225 #if __cplusplus >= 201103L
2226  template<typename _ForwardIterator1, typename _ForwardIterator2,
2227  typename _BinaryPredicate>
2228  _GLIBCXX20_CONSTEXPR
2229  bool
2230  __is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2231  _ForwardIterator2 __first2, _BinaryPredicate __pred)
2232  {
2233  // Efficiently compare identical prefixes: O(N) if sequences
2234  // have the same elements in the same order.
2235  for (; __first1 != __last1; ++__first1, (void)++__first2)
2236  if (!__pred(__first1, __first2))
2237  break;
2238 
2239  if (__first1 == __last1)
2240  return true;
2241 
2242  // Establish __last2 assuming equal ranges by iterating over the
2243  // rest of the list.
2244  _ForwardIterator2 __last2 = __first2;
2245  std::advance(__last2, std::distance(__first1, __last1));
2246  for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan)
2247  {
2248  if (__scan != std::__find_if(__first1, __scan,
2249  __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan)))
2250  continue; // We've seen this one before.
2251 
2252  auto __matches
2253  = std::__count_if(__first2, __last2,
2254  __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan));
2255  if (0 == __matches ||
2256  std::__count_if(__scan, __last1,
2257  __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan))
2258  != __matches)
2259  return false;
2260  }
2261  return true;
2262  }
2263 
2264  /**
2265  * @brief Checks whether a permutation of the second sequence is equal
2266  * to the first sequence.
2267  * @ingroup non_mutating_algorithms
2268  * @param __first1 Start of first range.
2269  * @param __last1 End of first range.
2270  * @param __first2 Start of second range.
2271  * @return true if there exists a permutation of the elements in the range
2272  * [__first2, __first2 + (__last1 - __first1)), beginning with
2273  * ForwardIterator2 begin, such that equal(__first1, __last1, begin)
2274  * returns true; otherwise, returns false.
2275  */
2276  template<typename _ForwardIterator1, typename _ForwardIterator2>
2277  _GLIBCXX20_CONSTEXPR
2278  inline bool
2279  is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2280  _ForwardIterator2 __first2)
2281  {
2282  // concept requirements
2283  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
2284  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
2285  __glibcxx_function_requires(_EqualOpConcept<
2288  __glibcxx_requires_valid_range(__first1, __last1);
2289 
2290  return std::__is_permutation(__first1, __last1, __first2,
2291  __gnu_cxx::__ops::__iter_equal_to_iter());
2292  }
2293 #endif // C++11
2294 
2295 _GLIBCXX_BEGIN_NAMESPACE_ALGO
2296 
2297  /**
2298  * @brief Search a sequence for a matching sub-sequence using a predicate.
2299  * @ingroup non_mutating_algorithms
2300  * @param __first1 A forward iterator.
2301  * @param __last1 A forward iterator.
2302  * @param __first2 A forward iterator.
2303  * @param __last2 A forward iterator.
2304  * @param __predicate A binary predicate.
2305  * @return The first iterator @c i in the range
2306  * @p [__first1,__last1-(__last2-__first2)) such that
2307  * @p __predicate(*(i+N),*(__first2+N)) is true for each @c N in the range
2308  * @p [0,__last2-__first2), or @p __last1 if no such iterator exists.
2309  *
2310  * Searches the range @p [__first1,__last1) for a sub-sequence that
2311  * compares equal value-by-value with the sequence given by @p
2312  * [__first2,__last2), using @p __predicate to determine equality,
2313  * and returns an iterator to the first element of the
2314  * sub-sequence, or @p __last1 if no such iterator exists.
2315  *
2316  * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2)
2317  */
2318  template<typename _ForwardIterator1, typename _ForwardIterator2,
2319  typename _BinaryPredicate>
2320  _GLIBCXX20_CONSTEXPR
2321  inline _ForwardIterator1
2322  search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
2323  _ForwardIterator2 __first2, _ForwardIterator2 __last2,
2324  _BinaryPredicate __predicate)
2325  {
2326  // concept requirements
2327  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>)
2328  __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>)
2329  __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate,
2332  __glibcxx_requires_valid_range(__first1, __last1);
2333  __glibcxx_requires_valid_range(__first2, __last2);
2334 
2335  return std::__search(__first1, __last1, __first2, __last2,
2336  __gnu_cxx::__ops::__iter_comp_iter(__predicate));
2337  }
2338 
2339 _GLIBCXX_END_NAMESPACE_ALGO
2340 _GLIBCXX_END_NAMESPACE_VERSION
2341 } // namespace std
2342 
2343 // NB: This file is included within many other C++ includes, as a way
2344 // of getting the base algorithms. So, make sure that parallel bits
2345 // come in too if requested.
2346 #ifdef _GLIBCXX_PARALLEL
2347 # include <parallel/algobase.h>
2348 #endif
2349 
2350 #endif
ISO C++ entities toplevel namespace is std.
constexpr const _Tp & max(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:257
Random-access iterators support a superset of bidirectional iterator operations.
Marking output iterators.
constexpr void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
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.
Safe iterator wrapper.
constexpr _Tp __lg(_Tp __n)
This is a helper function for the sort routines and for random.tcc.
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.
constexpr iterator_traits< _Iter >::iterator_category __iterator_category(const _Iter &)
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:233
constexpr bool equal(_IIter1 __first1, _IIter1 __last1, _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
Tests a range for element-wise equality.
Provides input iterator semantics for streambufs.
Definition: iosfwd:127
constexpr _OI copy(_II __first, _II __last, _OI __result)
Copies the range [first,last) into result.
Definition: stl_algobase.h:642
constexpr _BI2 move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
Moves the range [first,last) into result.
Definition: stl_algobase.h:913
A deque::iterator.
Definition: stl_algobase.h:463
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:126
GNU debug classes for public use.
Basis for explicit traits specializations.
Definition: char_traits.h:323
constexpr iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
Traits class for iterators.
Marking input iterators.
Parallel STL function calls corresponding to the stl_algobase.h header. The functions defined here ma...
Provides output iterator semantics for streambufs.
Definition: iosfwd:130
typename make_unsigned< _Tp >::type make_unsigned_t
Alias template for make_unsigned.
Definition: type_traits:2061
is_nothrow_copy_constructible
Definition: type_traits:1201
constexpr void iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
Swaps the contents of two iterators.
Definition: stl_algobase.h:155