libstdc++
debug/forward_list
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1 // <forward_list> -*- C++ -*-
2 
3 // Copyright (C) 2010-2022 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  // Reference wrapper for base class. See PR libstdc++/90102.
205  struct _Base_ref
206  {
207  _Base_ref(const _Base& __r) : _M_ref(__r) { }
208 
209  const _Base& _M_ref;
210  };
211 
212  public:
213  typedef typename _Base::reference reference;
214  typedef typename _Base::const_reference const_reference;
215 
216  typedef __gnu_debug::_Safe_iterator<
217  _Base_iterator, forward_list> iterator;
218  typedef __gnu_debug::_Safe_iterator<
219  _Base_const_iterator, forward_list> const_iterator;
220 
221  typedef typename _Base::size_type size_type;
222  typedef typename _Base::difference_type difference_type;
223 
224  typedef _Tp value_type;
225  typedef typename _Base::allocator_type allocator_type;
226  typedef typename _Base::pointer pointer;
227  typedef typename _Base::const_pointer const_pointer;
228 
229  // 23.2.3.1 construct/copy/destroy:
230 
231  forward_list() = default;
232 
233  explicit
234  forward_list(const allocator_type& __al) noexcept
235  : _Base(__al) { }
236 
237  forward_list(const forward_list& __list, const allocator_type& __al)
238  : _Base(__list, __al)
239  { }
240 
241  forward_list(forward_list&& __list, const allocator_type& __al)
242  noexcept(
243  std::is_nothrow_constructible<_Base,
244  _Base, const allocator_type&>::value )
245  : _Safe(std::move(__list), __al),
246  _Base(std::move(__list), __al)
247  { }
248 
249  explicit
250  forward_list(size_type __n, const allocator_type& __al = allocator_type())
251  : _Base(__n, __al)
252  { }
253 
254  forward_list(size_type __n, const __type_identity_t<_Tp>& __value,
255  const allocator_type& __al = allocator_type())
256  : _Base(__n, __value, __al)
257  { }
258 
259  template<typename _InputIterator,
260  typename = std::_RequireInputIter<_InputIterator>>
261  forward_list(_InputIterator __first, _InputIterator __last,
262  const allocator_type& __al = allocator_type())
263  : _Base(__gnu_debug::__base(
264  __glibcxx_check_valid_constructor_range(__first, __last)),
265  __gnu_debug::__base(__last), __al)
266  { }
267 
268  forward_list(const forward_list&) = default;
269 
270  forward_list(forward_list&&) = default;
271 
272  forward_list(std::initializer_list<_Tp> __il,
273  const allocator_type& __al = allocator_type())
274  : _Base(__il, __al)
275  { }
276 
277  ~forward_list() = default;
278 
279  forward_list(_Base_ref __x) : _Base(__x._M_ref) { }
280 
281  forward_list&
282  operator=(const forward_list&) = default;
283 
284  forward_list&
285  operator=(forward_list&&) = default;
286 
287  forward_list&
288  operator=(std::initializer_list<_Tp> __il)
289  {
290  _Base::operator=(__il);
291  this->_M_invalidate_all();
292  return *this;
293  }
294 
295  template<typename _InputIterator,
296  typename = std::_RequireInputIter<_InputIterator>>
297  void
298  assign(_InputIterator __first, _InputIterator __last)
299  {
300  typename __gnu_debug::_Distance_traits<_InputIterator>::__type __dist;
301  __glibcxx_check_valid_range2(__first, __last, __dist);
302 
303  if (__dist.second >= __gnu_debug::__dp_sign)
304  _Base::assign(__gnu_debug::__unsafe(__first),
305  __gnu_debug::__unsafe(__last));
306  else
307  _Base::assign(__first, __last);
308 
309  this->_M_invalidate_all();
310  }
311 
312  void
313  assign(size_type __n, const _Tp& __val)
314  {
315  _Base::assign(__n, __val);
316  this->_M_invalidate_all();
317  }
318 
319  void
320  assign(std::initializer_list<_Tp> __il)
321  {
322  _Base::assign(__il);
323  this->_M_invalidate_all();
324  }
325 
326  using _Base::get_allocator;
327 
328  // iterators:
329 
330  [[__nodiscard__]]
331  iterator
332  before_begin() noexcept
333  { return { _Base::before_begin(), this }; }
334 
335  [[__nodiscard__]]
336  const_iterator
337  before_begin() const noexcept
338  { return { _Base::before_begin(), this }; }
339 
340  [[__nodiscard__]]
341  iterator
342  begin() noexcept
343  { return { _Base::begin(), this }; }
344 
345  [[__nodiscard__]]
346  const_iterator
347  begin() const noexcept
348  { return { _Base::begin(), this }; }
349 
350  [[__nodiscard__]]
351  iterator
352  end() noexcept
353  { return { _Base::end(), this }; }
354 
355  [[__nodiscard__]]
356  const_iterator
357  end() const noexcept
358  { return { _Base::end(), this }; }
359 
360  [[__nodiscard__]]
361  const_iterator
362  cbegin() const noexcept
363  { return { _Base::cbegin(), this }; }
364 
365  [[__nodiscard__]]
366  const_iterator
367  cbefore_begin() const noexcept
368  { return { _Base::cbefore_begin(), this }; }
369 
370  [[__nodiscard__]]
371  const_iterator
372  cend() const noexcept
373  { return { _Base::cend(), this }; }
374 
375  using _Base::empty;
376  using _Base::max_size;
377 
378  // element access:
379 
380  [[__nodiscard__]]
381  reference
382  front()
383  {
384  __glibcxx_check_nonempty();
385  return _Base::front();
386  }
387 
388  [[__nodiscard__]]
389  const_reference
390  front() const
391  {
392  __glibcxx_check_nonempty();
393  return _Base::front();
394  }
395 
396  // modifiers:
397 
398  using _Base::emplace_front;
399  using _Base::push_front;
400 
401  void
402  pop_front()
403  {
404  __glibcxx_check_nonempty();
405  this->_M_invalidate_if([this](_Base_const_iterator __it)
406  { return __it == this->_M_base().cbegin(); });
407  _Base::pop_front();
408  }
409 
410  template<typename... _Args>
411  iterator
412  emplace_after(const_iterator __pos, _Args&&... __args)
413  {
414  __glibcxx_check_insert_after(__pos);
415  return { _Base::emplace_after(__pos.base(),
416  std::forward<_Args>(__args)...),
417  this };
418  }
419 
420  iterator
421  insert_after(const_iterator __pos, const _Tp& __val)
422  {
423  __glibcxx_check_insert_after(__pos);
424  return { _Base::insert_after(__pos.base(), __val), this };
425  }
426 
427  iterator
428  insert_after(const_iterator __pos, _Tp&& __val)
429  {
430  __glibcxx_check_insert_after(__pos);
431  return { _Base::insert_after(__pos.base(), std::move(__val)), this };
432  }
433 
434  iterator
435  insert_after(const_iterator __pos, size_type __n, const _Tp& __val)
436  {
437  __glibcxx_check_insert_after(__pos);
438  return { _Base::insert_after(__pos.base(), __n, __val), this };
439  }
440 
441  template<typename _InputIterator,
442  typename = std::_RequireInputIter<_InputIterator>>
443  iterator
444  insert_after(const_iterator __pos,
445  _InputIterator __first, _InputIterator __last)
446  {
447  typename __gnu_debug::_Distance_traits<_InputIterator>::__type __dist;
448  __glibcxx_check_insert_range_after(__pos, __first, __last, __dist);
449 
450  if (__dist.second >= __gnu_debug::__dp_sign)
451  return
452  {
453  _Base::insert_after(__pos.base(),
454  __gnu_debug::__unsafe(__first),
455  __gnu_debug::__unsafe(__last)),
456  this
457  };
458  else
459  return { _Base::insert_after(__pos.base(), __first, __last), this };
460  }
461 
462  iterator
463  insert_after(const_iterator __pos, std::initializer_list<_Tp> __il)
464  {
465  __glibcxx_check_insert_after(__pos);
466  return { _Base::insert_after(__pos.base(), __il), this };
467  }
468 
469  iterator
470  erase_after(const_iterator __pos)
471  {
472  __glibcxx_check_erase_after(__pos);
473 
474  _Base_const_iterator __next = std::next(__pos.base());
475  this->_M_invalidate_if([__next](_Base_const_iterator __it)
476  { return __it == __next; });
477  return { _Base::erase_after(__pos.base()), this };
478  }
479 
480  iterator
481  erase_after(const_iterator __pos, const_iterator __last)
482  {
483  __glibcxx_check_erase_range_after(__pos, __last);
484  for (_Base_const_iterator __victim = std::next(__pos.base());
485  __victim != __last.base(); ++__victim)
486  {
487  _GLIBCXX_DEBUG_VERIFY(__victim != _Base::cend(),
488  _M_message(__gnu_debug::__msg_valid_range2)
489  ._M_sequence(*this, "this")
490  ._M_iterator(__pos, "pos")
491  ._M_iterator(__last, "last"));
492  this->_M_invalidate_if([__victim](_Base_const_iterator __it)
493  { return __it == __victim; });
494  }
495 
496  return { _Base::erase_after(__pos.base(), __last.base()), this };
497  }
498 
499  void
500  swap(forward_list& __list)
501  noexcept( noexcept(declval<_Base&>().swap(__list)) )
502  {
503  _Safe::_M_swap(__list);
504  _Base::swap(__list);
505  }
506 
507  void
508  resize(size_type __sz)
509  {
510  this->_M_detach_singular();
511 
512  // if __sz < size(), invalidate all iterators in [begin+__sz, end()
513  _Base_iterator __victim = _Base::begin();
514  _Base_iterator __end = _Base::end();
515  for (size_type __i = __sz; __victim != __end && __i > 0; --__i)
516  ++__victim;
517 
518  for (; __victim != __end; ++__victim)
519  {
520  this->_M_invalidate_if([__victim](_Base_const_iterator __it)
521  { return __it == __victim; });
522  }
523 
524  __try
525  {
526  _Base::resize(__sz);
527  }
528  __catch(...)
529  {
530  this->_M_revalidate_singular();
531  __throw_exception_again;
532  }
533  }
534 
535  void
536  resize(size_type __sz, const value_type& __val)
537  {
538  this->_M_detach_singular();
539 
540  // if __sz < size(), invalidate all iterators in [begin+__sz, end())
541  _Base_iterator __victim = _Base::begin();
542  _Base_iterator __end = _Base::end();
543  for (size_type __i = __sz; __victim != __end && __i > 0; --__i)
544  ++__victim;
545 
546  for (; __victim != __end; ++__victim)
547  {
548  this->_M_invalidate_if([__victim](_Base_const_iterator __it)
549  { return __it == __victim; });
550  }
551 
552  __try
553  {
554  _Base::resize(__sz, __val);
555  }
556  __catch(...)
557  {
558  this->_M_revalidate_singular();
559  __throw_exception_again;
560  }
561  }
562 
563  void
564  clear() noexcept
565  {
566  _Base::clear();
567  this->_M_invalidate_all();
568  }
569 
570  // 23.2.3.5 forward_list operations:
571  void
572  splice_after(const_iterator __pos, forward_list&& __list)
573  {
574  __glibcxx_check_insert_after(__pos);
575  _GLIBCXX_DEBUG_VERIFY(std::__addressof(__list) != this,
576  _M_message(__gnu_debug::__msg_self_splice)
577  ._M_sequence(*this, "this"));
578  _GLIBCXX_DEBUG_VERIFY(__list.get_allocator() == this->get_allocator(),
579  _M_message(__gnu_debug::__msg_splice_alloc)
580  ._M_sequence(*this)
581  ._M_sequence(__list, "__list"));
582  this->_M_transfer_from_if(__list, [&__list](_Base_const_iterator __it)
583  {
584  return __it != __list._M_base().cbefore_begin()
585  && __it != __list._M_base().end();
586  });
587  _Base::splice_after(__pos.base(), std::move(__list));
588  }
589 
590  void
591  splice_after(const_iterator __pos, forward_list& __list)
592  { splice_after(__pos, std::move(__list)); }
593 
594  void
595  splice_after(const_iterator __pos, forward_list&& __list,
596  const_iterator __i)
597  {
598  __glibcxx_check_insert_after(__pos);
599  _GLIBCXX_DEBUG_VERIFY(__i._M_before_dereferenceable(),
600  _M_message(__gnu_debug::__msg_splice_bad)
601  ._M_iterator(__i, "__i"));
602  _GLIBCXX_DEBUG_VERIFY(__i._M_attached_to(std::__addressof(__list)),
603  _M_message(__gnu_debug::__msg_splice_other)
604  ._M_iterator(__i, "__i")
605  ._M_sequence(__list, "__list"));
606  _GLIBCXX_DEBUG_VERIFY(__list.get_allocator() == this->get_allocator(),
607  _M_message(__gnu_debug::__msg_splice_alloc)
608  ._M_sequence(*this)
609  ._M_sequence(__list, "__list"));
610 
611  // _GLIBCXX_RESOLVE_LIB_DEFECTS
612  // 250. splicing invalidates iterators
613  _Base_const_iterator __next = std::next(__i.base());
614  this->_M_transfer_from_if(__list, [__next](_Base_const_iterator __it)
615  { return __it == __next; });
616  _Base::splice_after(__pos.base(), std::move(__list), __i.base());
617  }
618 
619  void
620  splice_after(const_iterator __pos, forward_list& __list,
621  const_iterator __i)
622  { splice_after(__pos, std::move(__list), __i); }
623 
624  void
625  splice_after(const_iterator __pos, forward_list&& __list,
626  const_iterator __before, const_iterator __last)
627  {
628  typename __gnu_debug::_Distance_traits<const_iterator>::__type __dist;
629  auto __listptr = std::__addressof(__list);
630  __glibcxx_check_insert_after(__pos);
631  __glibcxx_check_valid_fl_range(__before, __last, __dist);
632  _GLIBCXX_DEBUG_VERIFY(__before._M_attached_to(__listptr),
633  _M_message(__gnu_debug::__msg_splice_other)
634  ._M_sequence(__list, "list")
635  ._M_iterator(__before, "before"));
636  _GLIBCXX_DEBUG_VERIFY(__before._M_dereferenceable()
637  || __before._M_is_before_begin(),
638  _M_message(__gnu_debug::__msg_valid_range2)
639  ._M_sequence(__list, "list")
640  ._M_iterator(__before, "before")
641  ._M_iterator(__last, "last"));
642  _GLIBCXX_DEBUG_VERIFY(__before != __last,
643  _M_message(__gnu_debug::__msg_valid_range2)
644  ._M_sequence(__list, "list")
645  ._M_iterator(__before, "before")
646  ._M_iterator(__last, "last"));
647  _GLIBCXX_DEBUG_VERIFY(__list.get_allocator() == this->get_allocator(),
648  _M_message(__gnu_debug::__msg_splice_alloc)
649  ._M_sequence(*this)
650  ._M_sequence(__list, "__list"));
651 
652  for (_Base_const_iterator __tmp = std::next(__before.base());
653  __tmp != __last.base(); ++__tmp)
654  {
655  _GLIBCXX_DEBUG_VERIFY(__tmp != __list._M_base().end(),
656  _M_message(__gnu_debug::__msg_valid_range2)
657  ._M_sequence(__list, "list")
658  ._M_iterator(__before, "before")
659  ._M_iterator(__last, "last"));
660  _GLIBCXX_DEBUG_VERIFY(__listptr != this || __tmp != __pos.base(),
661  _M_message(__gnu_debug::__msg_splice_overlap)
662  ._M_iterator(__tmp, "position")
663  ._M_iterator(__before, "before")
664  ._M_iterator(__last, "last"));
665  // _GLIBCXX_RESOLVE_LIB_DEFECTS
666  // 250. splicing invalidates iterators
667  this->_M_transfer_from_if(__list, [__tmp](_Base_const_iterator __it)
668  { return __it == __tmp; });
669  }
670 
671  _Base::splice_after(__pos.base(), std::move(__list),
672  __before.base(), __last.base());
673  }
674 
675  void
676  splice_after(const_iterator __pos, forward_list& __list,
677  const_iterator __before, const_iterator __last)
678  { splice_after(__pos, std::move(__list), __before, __last); }
679 
680  private:
681 #if __cplusplus > 201703L
682  using __remove_return_type = size_type;
683 # define _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG \
684  __attribute__((__abi_tag__("__cxx20")))
685 # define _GLIBCXX20_ONLY(__expr) __expr
686 #else
687  using __remove_return_type = void;
688 # define _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
689 # define _GLIBCXX20_ONLY(__expr)
690 #endif
691 
692  public:
693  _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
694  __remove_return_type
695  remove(const _Tp& __val)
696  {
697  if (!this->_M_iterators && !this->_M_const_iterators)
698  return _Base::remove(__val);
699 
700  size_type __removed __attribute__((__unused__)) = 0;
701  _Base __to_destroy(get_allocator());
702  _Base_const_iterator __x = _Base::cbefore_begin();
703  _Base_const_iterator __old = __x++;
704  while (__x != _Base::cend())
705  {
706  if (*__x == __val)
707  {
708  _Base_const_iterator __next = std::next(__old);
709  this->_M_invalidate_if([__next](_Base_const_iterator __it)
710  { return __it == __next; });
711  __to_destroy.splice_after(__to_destroy.cbefore_begin(),
712  *this, __old);
713  __x = __old;
714  _GLIBCXX20_ONLY( __removed++ );
715  }
716 
717  __old = __x++;
718  }
719 
720  return _GLIBCXX20_ONLY( __removed );
721  }
722 
723  template<typename _Pred>
724  __remove_return_type
725  remove_if(_Pred __pred)
726  {
727  if (!this->_M_iterators && !this->_M_const_iterators)
728  return _Base::remove_if(__pred);
729 
730  size_type __removed __attribute__((__unused__)) = 0;
731  _Base __to_destroy(get_allocator());
732  _Base_iterator __x = _Base::before_begin();
733  _Base_iterator __old = __x++;
734  while (__x != _Base::end())
735  {
736  if (__pred(*__x))
737  {
738  this->_M_invalidate_if([__x](_Base_const_iterator __it)
739  { return __it == __x; });
740  __to_destroy.splice_after(__to_destroy.cbefore_begin(),
741  *this, __old);
742  __x = __old;
743  _GLIBCXX20_ONLY( __removed++ );
744  }
745 
746  __old = __x++;
747  }
748 
749  return _GLIBCXX20_ONLY( __removed );
750  }
751 
752  _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
753  __remove_return_type
754  unique()
755  { return unique(std::equal_to<_Tp>()); }
756 
757  template<typename _BinPred>
758  __remove_return_type
759  unique(_BinPred __binary_pred)
760  {
761  if (!this->_M_iterators && !this->_M_const_iterators)
762  return _Base::unique(__binary_pred);
763 
764  _Base_const_iterator __first = _Base::cbegin();
765  _Base_const_iterator __last = _Base::cend();
766  if (__first == __last)
767  return _GLIBCXX20_ONLY(0);
768 
769  size_type __removed __attribute__((__unused__)) = 0;
770  _Base __to_destroy(get_allocator());
771  _Base_const_iterator __next = std::next(__first);
772  while (__next != __last)
773  {
774  if (__binary_pred(*__first, *__next))
775  {
776  this->_M_invalidate_if([__next](_Base_const_iterator __it)
777  { return __it == __next; });
778  __to_destroy.splice_after(__to_destroy.cbefore_begin(),
779  *this, __first);
780  __next = __first;
781  _GLIBCXX20_ONLY( __removed++ );
782  }
783 
784  __first = __next++;
785  }
786 
787  return _GLIBCXX20_ONLY( __removed );
788  }
789 
790 #undef _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
791 #undef _GLIBCXX20_ONLY
792 
793  void
794  merge(forward_list&& __list)
795  {
796  if (this != std::__addressof(__list))
797  {
798  __glibcxx_check_sorted(_Base::begin(), _Base::end());
799  __glibcxx_check_sorted(__list._M_base().begin(),
800  __list._M_base().end());
801  this->_M_transfer_from_if(__list, [&__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));
807  }
808  }
809 
810  void
811  merge(forward_list& __list)
812  { merge(std::move(__list)); }
813 
814  template<typename _Comp>
815  void
816  merge(forward_list&& __list, _Comp __comp)
817  {
818  if (this != std::__addressof(__list))
819  {
820  __glibcxx_check_sorted_pred(_Base::begin(), _Base::end(), __comp);
821  __glibcxx_check_sorted_pred(__list._M_base().begin(),
822  __list._M_base().end(), __comp);
823  this->_M_transfer_from_if(__list,
824  [&__list](_Base_const_iterator __it)
825  {
826  return __it != __list._M_base().cbefore_begin()
827  && __it != __list._M_base().cend();
828  });
829  _Base::merge(std::move(__list), __comp);
830  }
831  }
832 
833  template<typename _Comp>
834  void
835  merge(forward_list& __list, _Comp __comp)
836  { merge(std::move(__list), __comp); }
837 
838  using _Base::sort;
839  using _Base::reverse;
840 
841  _Base&
842  _M_base() noexcept { return *this; }
843 
844  const _Base&
845  _M_base() const noexcept { return *this; }
846  };
847 
848 #if __cpp_deduction_guides >= 201606
849  template<typename _InputIterator, typename _ValT
850  = typename iterator_traits<_InputIterator>::value_type,
851  typename _Allocator = allocator<_ValT>,
852  typename = _RequireInputIter<_InputIterator>,
853  typename = _RequireAllocator<_Allocator>>
854  forward_list(_InputIterator, _InputIterator, _Allocator = _Allocator())
855  -> forward_list<_ValT, _Allocator>;
856 
857  template<typename _Tp, typename _Allocator = allocator<_Tp>,
858  typename = _RequireAllocator<_Allocator>>
859  forward_list(size_t, _Tp, _Allocator = _Allocator())
860  -> forward_list<_Tp, _Allocator>;
861 #endif
862 
863  template<typename _Tp, typename _Alloc>
864  bool
865  operator==(const forward_list<_Tp, _Alloc>& __lx,
866  const forward_list<_Tp, _Alloc>& __ly)
867  { return __lx._M_base() == __ly._M_base(); }
868 
869 #if __cpp_lib_three_way_comparison
870  template<typename _Tp, typename _Alloc>
871  constexpr __detail::__synth3way_t<_Tp>
872  operator<=>(const forward_list<_Tp, _Alloc>& __x,
873  const forward_list<_Tp, _Alloc>& __y)
874  { return __x._M_base() <=> __y._M_base(); }
875 #else
876  template<typename _Tp, typename _Alloc>
877  inline bool
878  operator<(const forward_list<_Tp, _Alloc>& __lx,
879  const forward_list<_Tp, _Alloc>& __ly)
880  { return __lx._M_base() < __ly._M_base(); }
881 
882  template<typename _Tp, typename _Alloc>
883  inline bool
884  operator!=(const forward_list<_Tp, _Alloc>& __lx,
885  const forward_list<_Tp, _Alloc>& __ly)
886  { return !(__lx == __ly); }
887 
888  /// Based on operator<
889  template<typename _Tp, typename _Alloc>
890  inline bool
891  operator>(const forward_list<_Tp, _Alloc>& __lx,
892  const forward_list<_Tp, _Alloc>& __ly)
893  { return (__ly < __lx); }
894 
895  /// Based on operator<
896  template<typename _Tp, typename _Alloc>
897  inline bool
898  operator>=(const forward_list<_Tp, _Alloc>& __lx,
899  const forward_list<_Tp, _Alloc>& __ly)
900  { return !(__lx < __ly); }
901 
902  /// Based on operator<
903  template<typename _Tp, typename _Alloc>
904  inline bool
905  operator<=(const forward_list<_Tp, _Alloc>& __lx,
906  const forward_list<_Tp, _Alloc>& __ly)
907  { return !(__ly < __lx); }
908 #endif // three-way comparison
909 
910  /// See std::forward_list::swap().
911  template<typename _Tp, typename _Alloc>
912  inline void
913  swap(forward_list<_Tp, _Alloc>& __lx, forward_list<_Tp, _Alloc>& __ly)
914  noexcept(noexcept(__lx.swap(__ly)))
915  { __lx.swap(__ly); }
916 
917 } // namespace __debug
918 } // namespace std
919 
920 namespace __gnu_debug
921 {
922  template<typename _Tp, typename _Alloc>
923  struct _BeforeBeginHelper<std::__debug::forward_list<_Tp, _Alloc> >
924  {
925  typedef std::__debug::forward_list<_Tp, _Alloc> _Sequence;
926 
927  template<typename _Iterator>
928  static bool
929  _S_Is(const _Safe_iterator<_Iterator, _Sequence>& __it)
930  {
931  return
932  __it.base() == __it._M_get_sequence()->_M_base().before_begin();
933  }
934 
935  template<typename _Iterator>
936  static bool
937  _S_Is_Beginnest(const _Safe_iterator<_Iterator, _Sequence>& __it)
938  { return _S_Is(__it); }
939  };
940 
941  template<typename _Tp, typename _Alloc>
942  struct _Sequence_traits<std::__debug::forward_list<_Tp, _Alloc> >
943  {
944  typedef typename std::__debug::forward_list<_Tp, _Alloc>::iterator _It;
945 
946  static typename _Distance_traits<_It>::__type
947  _S_size(const std::__debug::forward_list<_Tp, _Alloc>& __seq)
948  {
949  return __seq.empty()
950  ? std::make_pair(0, __dp_exact) : std::make_pair(1, __dp_sign);
951  }
952  };
953 
954 #ifndef _GLIBCXX_DEBUG_PEDANTIC
955  template<class _Tp, class _Alloc>
956  struct _Insert_range_from_self_is_safe<
957  std::__debug::forward_list<_Tp, _Alloc> >
958  { enum { __value = 1 }; };
959 #endif
960 }
961 
962 #endif