libstdc++
debug/forward_list
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1 // <forward_list> -*- C++ -*-
2 
3 // Copyright (C) 2010-2019 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file debug/forward_list
26  * This file is a GNU debug extension to the Standard C++ Library.
27  */
28 
29 #ifndef _GLIBCXX_DEBUG_FORWARD_LIST
30 #define _GLIBCXX_DEBUG_FORWARD_LIST 1
31 
32 #pragma GCC system_header
33 
34 #include <bits/c++config.h>
35 namespace std _GLIBCXX_VISIBILITY(default) { namespace __debug {
36  template<typename _Tp, typename _Allocator> class forward_list;
37 } } // namespace std::__debug
38 
39 #include <forward_list>
40 #include <debug/safe_sequence.h>
41 #include <debug/safe_container.h>
42 #include <debug/safe_iterator.h>
43 
44 // Special validity check for forward_list ranges.
45 #define __glibcxx_check_valid_fl_range(_First,_Last,_Dist) \
46 _GLIBCXX_DEBUG_VERIFY(_First._M_valid_range(_Last, _Dist, false), \
47  _M_message(__gnu_debug::__msg_valid_range) \
48  ._M_iterator(_First, #_First) \
49  ._M_iterator(_Last, #_Last))
50 
51 namespace __gnu_debug
52 {
53  /// Special iterators swap and invalidation for forward_list because of the
54  /// before_begin iterator.
55  template<typename _SafeSequence>
56  class _Safe_forward_list
57  : public _Safe_sequence<_SafeSequence>
58  {
59  _SafeSequence&
60  _M_this() noexcept
61  { return *static_cast<_SafeSequence*>(this); }
62 
63  static void
64  _M_swap_aux(_Safe_sequence_base& __lhs,
65  _Safe_iterator_base*& __lhs_iterators,
66  _Safe_sequence_base& __rhs,
67  _Safe_iterator_base*& __rhs_iterators);
68 
69  void _M_swap_single(_Safe_sequence_base&) noexcept;
70 
71  protected:
72  void
73  _M_invalidate_all()
74  {
75  using _Base_const_iterator = __decltype(_M_this()._M_base().cend());
76  this->_M_invalidate_if([this](_Base_const_iterator __it)
77  {
78  return __it != _M_this()._M_base().cbefore_begin()
79  && __it != _M_this()._M_base().cend(); });
80  }
81 
82  void _M_swap(_Safe_sequence_base&) noexcept;
83  };
84 
85  template<typename _SafeSequence>
86  void
87  _Safe_forward_list<_SafeSequence>::
88  _M_swap_aux(_Safe_sequence_base& __lhs,
89  _Safe_iterator_base*& __lhs_iterators,
90  _Safe_sequence_base& __rhs,
91  _Safe_iterator_base*& __rhs_iterators)
92  {
93  using const_iterator = typename _SafeSequence::const_iterator;
94  _Safe_iterator_base* __bbegin_its = 0;
95  _Safe_iterator_base* __last_bbegin = 0;
96  _SafeSequence& __rseq = static_cast<_SafeSequence&>(__rhs);
97 
98  for (_Safe_iterator_base* __iter = __lhs_iterators; __iter;)
99  {
100  // Even iterator is cast to const_iterator, not a problem.
101  _Safe_iterator_base* __victim_base = __iter;
102  const_iterator* __victim =
103  static_cast<const_iterator*>(__victim_base);
104  __iter = __iter->_M_next;
105  if (__victim->base() == __rseq._M_base().cbefore_begin())
106  {
107  __victim->_M_unlink();
108  if (__lhs_iterators == __victim_base)
109  __lhs_iterators = __victim_base->_M_next;
110  if (__bbegin_its)
111  {
112  __victim_base->_M_next = __bbegin_its;
113  __bbegin_its->_M_prior = __victim_base;
114  }
115  else
116  __last_bbegin = __victim_base;
117  __bbegin_its = __victim_base;
118  }
119  else
120  __victim_base->_M_sequence = std::__addressof(__lhs);
121  }
122 
123  if (__bbegin_its)
124  {
125  if (__rhs_iterators)
126  {
127  __rhs_iterators->_M_prior = __last_bbegin;
128  __last_bbegin->_M_next = __rhs_iterators;
129  }
130  __rhs_iterators = __bbegin_its;
131  }
132  }
133 
134  template<typename _SafeSequence>
135  void
136  _Safe_forward_list<_SafeSequence>::
137  _M_swap_single(_Safe_sequence_base& __other) noexcept
138  {
139  std::swap(_M_this()._M_iterators, __other._M_iterators);
140  std::swap(_M_this()._M_const_iterators, __other._M_const_iterators);
141  // Useless, always 1 on forward_list
142  //std::swap(_M_this()_M_version, __other._M_version);
143  _Safe_iterator_base* __this_its = _M_this()._M_iterators;
144  _M_swap_aux(__other, __other._M_iterators,
145  _M_this(), _M_this()._M_iterators);
146  _Safe_iterator_base* __this_const_its = _M_this()._M_const_iterators;
147  _M_swap_aux(__other, __other._M_const_iterators,
148  _M_this(), _M_this()._M_const_iterators);
149  _M_swap_aux(_M_this(), __this_its,
150  __other, __other._M_iterators);
151  _M_swap_aux(_M_this(), __this_const_its,
152  __other, __other._M_const_iterators);
153  }
154 
155  /* Special forward_list _M_swap version that does not swap the
156  * before-begin ownership.*/
157  template<typename _SafeSequence>
158  void
159  _Safe_forward_list<_SafeSequence>::
160  _M_swap(_Safe_sequence_base& __other) noexcept
161  {
162  // We need to lock both sequences to swap
163  using namespace __gnu_cxx;
164  __mutex *__this_mutex = &_M_this()._M_get_mutex();
165  __mutex *__other_mutex =
166  &static_cast<_SafeSequence&>(__other)._M_get_mutex();
167  if (__this_mutex == __other_mutex)
168  {
169  __scoped_lock __lock(*__this_mutex);
170  _M_swap_single(__other);
171  }
172  else
173  {
174  __scoped_lock __l1(__this_mutex < __other_mutex
175  ? *__this_mutex : *__other_mutex);
176  __scoped_lock __l2(__this_mutex < __other_mutex
177  ? *__other_mutex : *__this_mutex);
178  _M_swap_single(__other);
179  }
180  }
181 }
182 
183 namespace std _GLIBCXX_VISIBILITY(default)
184 {
185 namespace __debug
186 {
187  /// Class std::forward_list with safety/checking/debug instrumentation.
188  template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
189  class forward_list
190  : public __gnu_debug::_Safe_container<
191  forward_list<_Tp, _Alloc>, _Alloc, __gnu_debug::_Safe_forward_list>,
192  public _GLIBCXX_STD_C::forward_list<_Tp, _Alloc>
193  {
194  typedef _GLIBCXX_STD_C::forward_list<_Tp, _Alloc> _Base;
195  typedef __gnu_debug::_Safe_container<
196  forward_list, _Alloc, __gnu_debug::_Safe_forward_list> _Safe;
197 
198  typedef typename _Base::iterator _Base_iterator;
199  typedef typename _Base::const_iterator _Base_const_iterator;
200 
201  template<typename _ItT, typename _SeqT, typename _CatT>
202  friend class ::__gnu_debug::_Safe_iterator;
203 
204  public:
205  typedef typename _Base::reference reference;
206  typedef typename _Base::const_reference const_reference;
207 
208  typedef __gnu_debug::_Safe_iterator<
209  _Base_iterator, forward_list> iterator;
210  typedef __gnu_debug::_Safe_iterator<
211  _Base_const_iterator, forward_list> const_iterator;
212 
213  typedef typename _Base::size_type size_type;
214  typedef typename _Base::difference_type difference_type;
215 
216  typedef _Tp value_type;
217  typedef typename _Base::allocator_type allocator_type;
218  typedef typename _Base::pointer pointer;
219  typedef typename _Base::const_pointer const_pointer;
220 
221  // 23.2.3.1 construct/copy/destroy:
222 
223  forward_list() = default;
224 
225  explicit
226  forward_list(const allocator_type& __al) noexcept
227  : _Base(__al) { }
228 
229  forward_list(const forward_list& __list, const allocator_type& __al)
230  : _Base(__list, __al)
231  { }
232 
233  forward_list(forward_list&& __list, const allocator_type& __al)
234  : _Safe(std::move(__list._M_safe()), __al),
235  _Base(std::move(__list._M_base()), __al)
236  { }
237 
238  explicit
239  forward_list(size_type __n, const allocator_type& __al = allocator_type())
240  : _Base(__n, __al)
241  { }
242 
243  forward_list(size_type __n, const _Tp& __value,
244  const allocator_type& __al = allocator_type())
245  : _Base(__n, __value, __al)
246  { }
247 
248  template<typename _InputIterator,
249  typename = std::_RequireInputIter<_InputIterator>>
250  forward_list(_InputIterator __first, _InputIterator __last,
251  const allocator_type& __al = allocator_type())
252  : _Base(__gnu_debug::__base(
253  __glibcxx_check_valid_constructor_range(__first, __last)),
254  __gnu_debug::__base(__last), __al)
255  { }
256 
257  forward_list(const forward_list&) = default;
258 
259  forward_list(forward_list&&) = default;
260 
261  forward_list(std::initializer_list<_Tp> __il,
262  const allocator_type& __al = allocator_type())
263  : _Base(__il, __al)
264  { }
265 
266  ~forward_list() = default;
267 
268  forward_list&
269  operator=(const forward_list&) = default;
270 
271  forward_list&
272  operator=(forward_list&&) = default;
273 
274  forward_list&
275  operator=(std::initializer_list<_Tp> __il)
276  {
277  _M_base() = __il;
278  this->_M_invalidate_all();
279  return *this;
280  }
281 
282  template<typename _InputIterator,
283  typename = std::_RequireInputIter<_InputIterator>>
284  void
285  assign(_InputIterator __first, _InputIterator __last)
286  {
287  typename __gnu_debug::_Distance_traits<_InputIterator>::__type __dist;
288  __glibcxx_check_valid_range2(__first, __last, __dist);
289 
290  if (__dist.second >= __gnu_debug::__dp_sign)
291  _Base::assign(__gnu_debug::__unsafe(__first),
292  __gnu_debug::__unsafe(__last));
293  else
294  _Base::assign(__first, __last);
295 
296  this->_M_invalidate_all();
297  }
298 
299  void
300  assign(size_type __n, const _Tp& __val)
301  {
302  _Base::assign(__n, __val);
303  this->_M_invalidate_all();
304  }
305 
306  void
307  assign(std::initializer_list<_Tp> __il)
308  {
309  _Base::assign(__il);
310  this->_M_invalidate_all();
311  }
312 
313  using _Base::get_allocator;
314 
315  // iterators:
316 
317  iterator
318  before_begin() noexcept
319  { return { _Base::before_begin(), this }; }
320 
321  const_iterator
322  before_begin() const noexcept
323  { return { _Base::before_begin(), this }; }
324 
325  iterator
326  begin() noexcept
327  { return { _Base::begin(), this }; }
328 
329  const_iterator
330  begin() const noexcept
331  { return { _Base::begin(), this }; }
332 
333  iterator
334  end() noexcept
335  { return { _Base::end(), this }; }
336 
337  const_iterator
338  end() const noexcept
339  { return { _Base::end(), this }; }
340 
341  const_iterator
342  cbegin() const noexcept
343  { return { _Base::cbegin(), this }; }
344 
345  const_iterator
346  cbefore_begin() const noexcept
347  { return { _Base::cbefore_begin(), this }; }
348 
349  const_iterator
350  cend() const noexcept
351  { return { _Base::cend(), this }; }
352 
353  using _Base::empty;
354  using _Base::max_size;
355 
356  // element access:
357 
358  reference
359  front()
360  {
361  __glibcxx_check_nonempty();
362  return _Base::front();
363  }
364 
365  const_reference
366  front() const
367  {
368  __glibcxx_check_nonempty();
369  return _Base::front();
370  }
371 
372  // modifiers:
373 
374  using _Base::emplace_front;
375  using _Base::push_front;
376 
377  void
378  pop_front()
379  {
380  __glibcxx_check_nonempty();
381  this->_M_invalidate_if([this](_Base_const_iterator __it)
382  { return __it == this->_M_base().cbegin(); });
383  _Base::pop_front();
384  }
385 
386  template<typename... _Args>
387  iterator
388  emplace_after(const_iterator __pos, _Args&&... __args)
389  {
390  __glibcxx_check_insert_after(__pos);
391  return { _Base::emplace_after(__pos.base(),
392  std::forward<_Args>(__args)...),
393  this };
394  }
395 
396  iterator
397  insert_after(const_iterator __pos, const _Tp& __val)
398  {
399  __glibcxx_check_insert_after(__pos);
400  return { _Base::insert_after(__pos.base(), __val), this };
401  }
402 
403  iterator
404  insert_after(const_iterator __pos, _Tp&& __val)
405  {
406  __glibcxx_check_insert_after(__pos);
407  return { _Base::insert_after(__pos.base(), std::move(__val)), this };
408  }
409 
410  iterator
411  insert_after(const_iterator __pos, size_type __n, const _Tp& __val)
412  {
413  __glibcxx_check_insert_after(__pos);
414  return { _Base::insert_after(__pos.base(), __n, __val), this };
415  }
416 
417  template<typename _InputIterator,
418  typename = std::_RequireInputIter<_InputIterator>>
419  iterator
420  insert_after(const_iterator __pos,
421  _InputIterator __first, _InputIterator __last)
422  {
423  typename __gnu_debug::_Distance_traits<_InputIterator>::__type __dist;
424  __glibcxx_check_insert_range_after(__pos, __first, __last, __dist);
425 
426  if (__dist.second >= __gnu_debug::__dp_sign)
427  return
428  {
429  _Base::insert_after(__pos.base(),
430  __gnu_debug::__unsafe(__first),
431  __gnu_debug::__unsafe(__last)),
432  this
433  };
434  else
435  return { _Base::insert_after(__pos.base(), __first, __last), this };
436  }
437 
438  iterator
439  insert_after(const_iterator __pos, std::initializer_list<_Tp> __il)
440  {
441  __glibcxx_check_insert_after(__pos);
442  return { _Base::insert_after(__pos.base(), __il), this };
443  }
444 
445  private:
446  _Base_iterator
447  _M_erase_after(_Base_const_iterator __pos)
448  {
449  _Base_const_iterator __next = std::next(__pos);
450  this->_M_invalidate_if([__next](_Base_const_iterator __it)
451  { return __it == __next; });
452  return _Base::erase_after(__pos);
453  }
454  public:
455  iterator
456  erase_after(const_iterator __pos)
457  {
458  __glibcxx_check_erase_after(__pos);
459  return { _M_erase_after(__pos.base()), this };
460  }
461 
462  iterator
463  erase_after(const_iterator __pos, const_iterator __last)
464  {
465  __glibcxx_check_erase_range_after(__pos, __last);
466  for (_Base_const_iterator __victim = std::next(__pos.base());
467  __victim != __last.base(); ++__victim)
468  {
469  _GLIBCXX_DEBUG_VERIFY(__victim != _Base::cend(),
470  _M_message(__gnu_debug::__msg_valid_range2)
471  ._M_sequence(*this, "this")
472  ._M_iterator(__pos, "pos")
473  ._M_iterator(__last, "last"));
474  this->_M_invalidate_if([__victim](_Base_const_iterator __it)
475  { return __it == __victim; });
476  }
477 
478  return { _Base::erase_after(__pos.base(), __last.base()), this };
479  }
480 
481  void
482  swap(forward_list& __list)
483  noexcept( noexcept(declval<_Base&>().swap(__list)) )
484  {
485  _Safe::_M_swap(__list);
486  _Base::swap(__list);
487  }
488 
489  void
490  resize(size_type __sz)
491  {
492  this->_M_detach_singular();
493 
494  // if __sz < size(), invalidate all iterators in [begin+__sz, end()
495  _Base_iterator __victim = _Base::begin();
496  _Base_iterator __end = _Base::end();
497  for (size_type __i = __sz; __victim != __end && __i > 0; --__i)
498  ++__victim;
499 
500  for (; __victim != __end; ++__victim)
501  {
502  this->_M_invalidate_if([__victim](_Base_const_iterator __it)
503  { return __it == __victim; });
504  }
505 
506  __try
507  {
508  _Base::resize(__sz);
509  }
510  __catch(...)
511  {
512  this->_M_revalidate_singular();
513  __throw_exception_again;
514  }
515  }
516 
517  void
518  resize(size_type __sz, const value_type& __val)
519  {
520  this->_M_detach_singular();
521 
522  // if __sz < size(), invalidate all iterators in [begin+__sz, end())
523  _Base_iterator __victim = _Base::begin();
524  _Base_iterator __end = _Base::end();
525  for (size_type __i = __sz; __victim != __end && __i > 0; --__i)
526  ++__victim;
527 
528  for (; __victim != __end; ++__victim)
529  {
530  this->_M_invalidate_if([__victim](_Base_const_iterator __it)
531  { return __it == __victim; });
532  }
533 
534  __try
535  {
536  _Base::resize(__sz, __val);
537  }
538  __catch(...)
539  {
540  this->_M_revalidate_singular();
541  __throw_exception_again;
542  }
543  }
544 
545  void
546  clear() noexcept
547  {
548  _Base::clear();
549  this->_M_invalidate_all();
550  }
551 
552  // 23.2.3.5 forward_list operations:
553  void
554  splice_after(const_iterator __pos, forward_list&& __list)
555  {
556  __glibcxx_check_insert_after(__pos);
557  _GLIBCXX_DEBUG_VERIFY(std::__addressof(__list) != this,
558  _M_message(__gnu_debug::__msg_self_splice)
559  ._M_sequence(*this, "this"));
560  _GLIBCXX_DEBUG_VERIFY(__list.get_allocator() == this->get_allocator(),
561  _M_message(__gnu_debug::__msg_splice_alloc)
562  ._M_sequence(*this)
563  ._M_sequence(__list, "__list"));
564  this->_M_transfer_from_if(__list, [&__list](_Base_const_iterator __it)
565  {
566  return __it != __list._M_base().cbefore_begin()
567  && __it != __list._M_base().end();
568  });
569  _Base::splice_after(__pos.base(), std::move(__list._M_base()));
570  }
571 
572  void
573  splice_after(const_iterator __pos, forward_list& __list)
574  { splice_after(__pos, std::move(__list)); }
575 
576  void
577  splice_after(const_iterator __pos, forward_list&& __list,
578  const_iterator __i)
579  {
580  __glibcxx_check_insert_after(__pos);
581  _GLIBCXX_DEBUG_VERIFY(__i._M_before_dereferenceable(),
582  _M_message(__gnu_debug::__msg_splice_bad)
583  ._M_iterator(__i, "__i"));
584  _GLIBCXX_DEBUG_VERIFY(__i._M_attached_to(std::__addressof(__list)),
585  _M_message(__gnu_debug::__msg_splice_other)
586  ._M_iterator(__i, "__i")
587  ._M_sequence(__list, "__list"));
588  _GLIBCXX_DEBUG_VERIFY(__list.get_allocator() == this->get_allocator(),
589  _M_message(__gnu_debug::__msg_splice_alloc)
590  ._M_sequence(*this)
591  ._M_sequence(__list, "__list"));
592 
593  // _GLIBCXX_RESOLVE_LIB_DEFECTS
594  // 250. splicing invalidates iterators
595  _Base_const_iterator __next = std::next(__i.base());
596  this->_M_transfer_from_if(__list, [__next](_Base_const_iterator __it)
597  { return __it == __next; });
598  _Base::splice_after(__pos.base(), std::move(__list._M_base()),
599  __i.base());
600  }
601 
602  void
603  splice_after(const_iterator __pos, forward_list& __list,
604  const_iterator __i)
605  { splice_after(__pos, std::move(__list), __i); }
606 
607  void
608  splice_after(const_iterator __pos, forward_list&& __list,
609  const_iterator __before, const_iterator __last)
610  {
611  typename __gnu_debug::_Distance_traits<const_iterator>::__type __dist;
612  auto __listptr = std::__addressof(__list);
613  __glibcxx_check_insert_after(__pos);
614  __glibcxx_check_valid_fl_range(__before, __last, __dist);
615  _GLIBCXX_DEBUG_VERIFY(__before._M_attached_to(__listptr),
616  _M_message(__gnu_debug::__msg_splice_other)
617  ._M_sequence(__list, "list")
618  ._M_iterator(__before, "before"));
619  _GLIBCXX_DEBUG_VERIFY(__before._M_dereferenceable()
620  || __before._M_is_before_begin(),
621  _M_message(__gnu_debug::__msg_valid_range2)
622  ._M_sequence(__list, "list")
623  ._M_iterator(__before, "before")
624  ._M_iterator(__last, "last"));
625  _GLIBCXX_DEBUG_VERIFY(__before != __last,
626  _M_message(__gnu_debug::__msg_valid_range2)
627  ._M_sequence(__list, "list")
628  ._M_iterator(__before, "before")
629  ._M_iterator(__last, "last"));
630  _GLIBCXX_DEBUG_VERIFY(__list.get_allocator() == this->get_allocator(),
631  _M_message(__gnu_debug::__msg_splice_alloc)
632  ._M_sequence(*this)
633  ._M_sequence(__list, "__list"));
634 
635  for (_Base_const_iterator __tmp = std::next(__before.base());
636  __tmp != __last.base(); ++__tmp)
637  {
638  _GLIBCXX_DEBUG_VERIFY(__tmp != __list._M_base().end(),
639  _M_message(__gnu_debug::__msg_valid_range2)
640  ._M_sequence(__list, "list")
641  ._M_iterator(__before, "before")
642  ._M_iterator(__last, "last"));
643  _GLIBCXX_DEBUG_VERIFY(__listptr != this || __tmp != __pos.base(),
644  _M_message(__gnu_debug::__msg_splice_overlap)
645  ._M_iterator(__tmp, "position")
646  ._M_iterator(__before, "before")
647  ._M_iterator(__last, "last"));
648  // _GLIBCXX_RESOLVE_LIB_DEFECTS
649  // 250. splicing invalidates iterators
650  this->_M_transfer_from_if(__list, [__tmp](_Base_const_iterator __it)
651  { return __it == __tmp; });
652  }
653 
654  _Base::splice_after(__pos.base(), std::move(__list._M_base()),
655  __before.base(), __last.base());
656  }
657 
658  void
659  splice_after(const_iterator __pos, forward_list& __list,
660  const_iterator __before, const_iterator __last)
661  { splice_after(__pos, std::move(__list), __before, __last); }
662 
663  private:
664 #if __cplusplus > 201703L
665  using __remove_return_type = size_type;
666 # define _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG \
667  __attribute__((__abi_tag__("__cxx20")))
668 # define _GLIBCXX20_ONLY(__expr) __expr
669 #else
670  using __remove_return_type = void;
671 # define _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
672 # define _GLIBCXX20_ONLY(__expr)
673 #endif
674 
675  public:
676  _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
677  __remove_return_type
678  remove(const _Tp& __val)
679  {
680  if (!this->_M_iterators && !this->_M_const_iterators)
681  return _Base::remove(__val);
682 
683  size_type __removed __attribute__((__unused__)) = 0;
684  _Base_iterator __x = _Base::before_begin();
685  _Base_iterator __old = __x++;
686  _Base_iterator __extra = _Base::end();
687  while (__x != _Base::end())
688  {
689  if (*__x == __val)
690  {
691  if (std::__addressof(*__x) != std::__addressof(__val))
692  {
693  __x = _M_erase_after(__old);
694  _GLIBCXX20_ONLY( __removed++ );
695  continue;
696  }
697  else
698  __extra = __old;
699  }
700  __old = __x++;
701  }
702 
703  if (__extra != _Base::end())
704  {
705  this->_M_erase_after(__extra);
706  _GLIBCXX20_ONLY( __removed++ );
707  }
708 
709  return _GLIBCXX20_ONLY( __removed );
710  }
711 
712  template<typename _Pred>
713  __remove_return_type
714  remove_if(_Pred __pred)
715  {
716  if (!this->_M_iterators && !this->_M_const_iterators)
717  return _Base::remove_if(__pred);
718 
719  size_type __removed __attribute__((__unused__)) = 0;
720  _Base_iterator __x = _Base::before_begin();
721  _Base_iterator __old = __x++;
722  while (__x != _Base::end())
723  if (__pred(*__x))
724  {
725  __x = _M_erase_after(__old);
726  _GLIBCXX20_ONLY( __removed++ );
727  }
728  else
729  __old = __x++;
730 
731  return _GLIBCXX20_ONLY( __removed );
732  }
733 
734  _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
735  __remove_return_type
736  unique()
737  { return unique(std::equal_to<_Tp>()); }
738 
739  template<typename _BinPred>
740  __remove_return_type
741  unique(_BinPred __binary_pred)
742  {
743  if (!this->_M_iterators && !this->_M_const_iterators)
744  return _Base::unique(__binary_pred);
745 
746  _Base_iterator __first = _Base::begin();
747  _Base_iterator __last = _Base::end();
748  if (__first == __last)
749  return _GLIBCXX20_ONLY(0);
750 
751  size_type __removed __attribute__((__unused__)) = 0;
752  _Base_iterator __next = std::next(__first);
753  while (__next != __last)
754  {
755  if (__binary_pred(*__first, *__next))
756  {
757  __next = _M_erase_after(__first);
758  _GLIBCXX20_ONLY( __removed++ );
759  }
760  else
761  __first = __next++;
762  }
763 
764  return _GLIBCXX20_ONLY( __removed );
765  }
766 
767 #undef _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
768 #undef _GLIBCXX20_ONLY
769 
770  void
771  merge(forward_list&& __list)
772  {
773  if (this != std::__addressof(__list))
774  {
775  __glibcxx_check_sorted(_Base::begin(), _Base::end());
776  __glibcxx_check_sorted(__list._M_base().begin(),
777  __list._M_base().end());
778  this->_M_transfer_from_if(__list, [&__list](_Base_const_iterator __it)
779  {
780  return __it != __list._M_base().cbefore_begin()
781  && __it != __list._M_base().cend();
782  });
783  _Base::merge(std::move(__list._M_base()));
784  }
785  }
786 
787  void
788  merge(forward_list& __list)
789  { merge(std::move(__list)); }
790 
791  template<typename _Comp>
792  void
793  merge(forward_list&& __list, _Comp __comp)
794  {
795  if (this != std::__addressof(__list))
796  {
797  __glibcxx_check_sorted_pred(_Base::begin(), _Base::end(), __comp);
798  __glibcxx_check_sorted_pred(__list._M_base().begin(),
799  __list._M_base().end(), __comp);
800  this->_M_transfer_from_if(__list,
801  [&__list](_Base_const_iterator __it)
802  {
803  return __it != __list._M_base().cbefore_begin()
804  && __it != __list._M_base().cend();
805  });
806  _Base::merge(std::move(__list._M_base()), __comp);
807  }
808  }
809 
810  template<typename _Comp>
811  void
812  merge(forward_list& __list, _Comp __comp)
813  { merge(std::move(__list), __comp); }
814 
815  using _Base::sort;
816  using _Base::reverse;
817 
818  _Base&
819  _M_base() noexcept { return *this; }
820 
821  const _Base&
822  _M_base() const noexcept { return *this; }
823  };
824 
825 #if __cpp_deduction_guides >= 201606
826  template<typename _InputIterator, typename _ValT
827  = typename iterator_traits<_InputIterator>::value_type,
828  typename _Allocator = allocator<_ValT>,
829  typename = _RequireInputIter<_InputIterator>,
830  typename = _RequireAllocator<_Allocator>>
831  forward_list(_InputIterator, _InputIterator, _Allocator = _Allocator())
832  -> forward_list<_ValT, _Allocator>;
833 #endif
834 
835  template<typename _Tp, typename _Alloc>
836  bool
837  operator==(const forward_list<_Tp, _Alloc>& __lx,
838  const forward_list<_Tp, _Alloc>& __ly)
839  { return __lx._M_base() == __ly._M_base(); }
840 
841  template<typename _Tp, typename _Alloc>
842  inline bool
843  operator<(const forward_list<_Tp, _Alloc>& __lx,
844  const forward_list<_Tp, _Alloc>& __ly)
845  { return __lx._M_base() < __ly._M_base(); }
846 
847  template<typename _Tp, typename _Alloc>
848  inline bool
849  operator!=(const forward_list<_Tp, _Alloc>& __lx,
850  const forward_list<_Tp, _Alloc>& __ly)
851  { return !(__lx == __ly); }
852 
853  /// Based on operator<
854  template<typename _Tp, typename _Alloc>
855  inline bool
856  operator>(const forward_list<_Tp, _Alloc>& __lx,
857  const forward_list<_Tp, _Alloc>& __ly)
858  { return (__ly < __lx); }
859 
860  /// Based on operator<
861  template<typename _Tp, typename _Alloc>
862  inline bool
863  operator>=(const forward_list<_Tp, _Alloc>& __lx,
864  const forward_list<_Tp, _Alloc>& __ly)
865  { return !(__lx < __ly); }
866 
867  /// Based on operator<
868  template<typename _Tp, typename _Alloc>
869  inline bool
870  operator<=(const forward_list<_Tp, _Alloc>& __lx,
871  const forward_list<_Tp, _Alloc>& __ly)
872  { return !(__ly < __lx); }
873 
874  /// See std::forward_list::swap().
875  template<typename _Tp, typename _Alloc>
876  inline void
877  swap(forward_list<_Tp, _Alloc>& __lx, forward_list<_Tp, _Alloc>& __ly)
878  noexcept(noexcept(__lx.swap(__ly)))
879  { __lx.swap(__ly); }
880 
881 } // namespace __debug
882 } // namespace std
883 
884 namespace __gnu_debug
885 {
886  template<typename _Tp, typename _Alloc>
887  struct _BeforeBeginHelper<std::__debug::forward_list<_Tp, _Alloc> >
888  {
889  typedef std::__debug::forward_list<_Tp, _Alloc> _Sequence;
890 
891  template<typename _Iterator>
892  static bool
893  _S_Is(const _Safe_iterator<_Iterator, _Sequence>& __it)
894  {
895  return
896  __it.base() == __it._M_get_sequence()->_M_base().before_begin();
897  }
898 
899  template<typename _Iterator>
900  static bool
901  _S_Is_Beginnest(const _Safe_iterator<_Iterator, _Sequence>& __it)
902  { return _S_Is(__it); }
903  };
904 
905  template<typename _Tp, typename _Alloc>
906  struct _Sequence_traits<std::__debug::forward_list<_Tp, _Alloc> >
907  {
908  typedef typename std::__debug::forward_list<_Tp, _Alloc>::iterator _It;
909 
910  static typename _Distance_traits<_It>::__type
911  _S_size(const std::__debug::forward_list<_Tp, _Alloc>& __seq)
912  {
913  return __seq.empty()
914  ? std::make_pair(0, __dp_exact) : std::make_pair(1, __dp_equality);
915  }
916  };
917 
918 #ifndef _GLIBCXX_DEBUG_PEDANTIC
919  template<class _Tp, class _Alloc>
920  struct _Insert_range_from_self_is_safe<
921  std::__debug::forward_list<_Tp, _Alloc> >
922  { enum { __value = 1 }; };
923 #endif
924 }
925 
926 #endif