libstdc++
safe_iterator.tcc
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1 // Debugging iterator implementation (out of line) -*- C++ -*-
2 
3 // Copyright (C) 2003-2021 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/safe_iterator.tcc
26  * This file is a GNU debug extension to the Standard C++ Library.
27  */
28 
29 #ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC
30 #define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1
31 
32 #include <bits/stl_algobase.h>
33 
34 namespace __gnu_debug
35 {
36  template<typename _Iterator, typename _Sequence, typename _Category>
37  typename _Distance_traits<_Iterator>::__type
38  _Safe_iterator<_Iterator, _Sequence, _Category>::
39  _M_get_distance_from_begin() const
40  {
41  typedef _Sequence_traits<_Sequence> _SeqTraits;
42 
43  // No need to consider before_begin as this function is only used in
44  // _M_can_advance which won't be used for forward_list iterators.
45  if (_M_is_begin())
46  return std::make_pair(0, __dp_exact);
47 
48  if (_M_is_end())
49  return _SeqTraits::_S_size(*_M_get_sequence());
50 
51  typename _Distance_traits<_Iterator>::__type __res
52  = __get_distance(_M_get_sequence()->_M_base().begin(), base());
53 
54  if (__res.second == __dp_equality)
55  return std::make_pair(1, __dp_sign);
56 
57  return __res;
58  }
59 
60  template<typename _Iterator, typename _Sequence, typename _Category>
61  typename _Distance_traits<_Iterator>::__type
62  _Safe_iterator<_Iterator, _Sequence, _Category>::
63  _M_get_distance_to_end() const
64  {
65  typedef _Sequence_traits<_Sequence> _SeqTraits;
66 
67  // No need to consider before_begin as this function is only used in
68  // _M_can_advance which won't be used for forward_list iterators.
69  if (_M_is_begin())
70  return _SeqTraits::_S_size(*_M_get_sequence());
71 
72  if (_M_is_end())
73  return std::make_pair(0, __dp_exact);
74 
75  typename _Distance_traits<_Iterator>::__type __res
76  = __get_distance(base(), _M_get_sequence()->_M_base().end());
77 
78  if (__res.second == __dp_equality)
79  return std::make_pair(1, __dp_sign);
80 
81  return __res;
82  }
83 
84  template<typename _Iterator, typename _Sequence, typename _Category>
85  bool
86  _Safe_iterator<_Iterator, _Sequence, _Category>::
87  _M_can_advance(difference_type __n, bool __strict) const
88  {
89  if (this->_M_singular())
90  return false;
91 
92  if (__n == 0)
93  return true;
94 
95  if (__n < 0)
96  {
98  _M_get_distance_from_begin();
99  return __dist.second == __dp_exact
100  ? __dist.first >= -__n
101  : !__strict && __dist.first > 0;
102  }
103  else
104  {
106  _M_get_distance_to_end();
107  return __dist.second == __dp_exact
108  ? __dist.first >= __n
109  : !__strict && __dist.first > 0;
110  }
111  }
112 
113  template<typename _Iterator, typename _Sequence, typename _Category>
114  typename _Distance_traits<_Iterator>::__type
115  _Safe_iterator<_Iterator, _Sequence, _Category>::
116  _M_get_distance_to(const _Safe_iterator& __rhs) const
117  {
118  typedef typename _Distance_traits<_Iterator>::__type _Dist;
119  typedef _Sequence_traits<_Sequence> _SeqTraits;
120 
121  _Dist __base_dist = __get_distance(this->base(), __rhs.base());
122  if (__base_dist.second == __dp_exact)
123  return __base_dist;
124 
125  _Dist __seq_dist = _SeqTraits::_S_size(*this->_M_get_sequence());
126  if (this->_M_is_before_begin())
127  {
128  if (__rhs._M_is_begin())
129  return std::make_pair(1, __dp_exact);
130 
131  return __seq_dist.second == __dp_exact
132  ? std::make_pair(__seq_dist.first + 1, __dp_exact)
133  : __seq_dist;
134  }
135 
136  if (this->_M_is_begin())
137  {
138  if (__rhs._M_is_before_begin())
139  return std::make_pair(-1, __dp_exact);
140 
141  if (__rhs._M_is_end())
142  return __seq_dist;
143 
144  return std::make_pair(__seq_dist.first,
145  __seq_dist.second == __dp_exact
146  ? __dp_sign_max_size : __seq_dist.second);
147  }
148 
149  if (this->_M_is_end())
150  {
151  if (__rhs._M_is_before_begin())
152  return __seq_dist.second == __dp_exact
153  ? std::make_pair(-__seq_dist.first - 1, __dp_exact)
154  : std::make_pair(-__seq_dist.first, __dp_sign);
155 
156  if (__rhs._M_is_begin())
157  return std::make_pair(-__seq_dist.first, __seq_dist.second);
158 
159  return std::make_pair(-__seq_dist.first,
160  __seq_dist.second == __dp_exact
161  ? __dp_sign_max_size : __seq_dist.second);
162  }
163 
164  if (__rhs._M_is_before_begin())
165  return __seq_dist.second == __dp_exact
166  ? std::make_pair(__seq_dist.first - 1, __dp_exact)
167  : std::make_pair(-__seq_dist.first, __dp_sign);
168 
169  if (__rhs._M_is_begin())
170  return std::make_pair(-__seq_dist.first,
171  __seq_dist.second == __dp_exact
172  ? __dp_sign_max_size : __seq_dist.second);
173 
174  if (__rhs._M_is_end())
175  return std::make_pair(__seq_dist.first,
176  __seq_dist.second == __dp_exact
177  ? __dp_sign_max_size : __seq_dist.second);
178 
179  return std::make_pair(1, __dp_equality);
180  }
181 
182  template<typename _Iterator, typename _Sequence, typename _Category>
183  bool
184  _Safe_iterator<_Iterator, _Sequence, _Category>::
185  _M_valid_range(const _Safe_iterator& __rhs,
187  bool __check_dereferenceable) const
188  {
189  if (_M_singular() || __rhs._M_singular() || !_M_can_compare(__rhs))
190  return false;
191 
192  /* Determine iterators order */
193  __dist = _M_get_distance_to(__rhs);
194  switch (__dist.second)
195  {
196  case __dp_equality:
197  if (__dist.first == 0)
198  return true;
199  break;
200 
201  case __dp_sign:
202  case __dp_exact:
203  // If range is not empty first iterator must be dereferenceable.
204  if (__dist.first > 0)
205  return !__check_dereferenceable || _M_dereferenceable();
206  return __dist.first == 0;
207  }
208 
209  // Assume that this is a valid range; we can't check anything else.
210  return true;
211  }
212 
213  template<typename _Iterator, typename _Sequence>
214  bool
215  _Safe_iterator<_Iterator, _Sequence, std::random_access_iterator_tag>::
216  _M_valid_range(const _Safe_iterator& __rhs,
217  std::pair<difference_type,
218  _Distance_precision>& __dist) const
219  {
220  if (this->_M_singular() || __rhs._M_singular()
221  || !this->_M_can_compare(__rhs))
222  return false;
223 
224  /* Determine iterators order */
225  __dist = std::make_pair(__rhs.base() - this->base(), __dp_exact);
226 
227  // If range is not empty first iterator must be dereferenceable.
228  if (__dist.first > 0)
229  return this->_M_dereferenceable();
230  return __dist.first == 0;
231  }
232 } // namespace __gnu_debug
233 
234 namespace std _GLIBCXX_VISIBILITY(default)
235 {
236 _GLIBCXX_BEGIN_NAMESPACE_VERSION
237 
238  template<typename _Ite, typename _Seq>
239  _Ite
240  __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
242  { return __it.base(); }
243 
244  template<bool _IsMove,
245  typename _Ite, typename _Seq, typename _Cat, typename _OI>
246  _OI
247  __copy_move_a(
248  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
249  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
250  _OI __result)
251  {
252  typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
253  __glibcxx_check_valid_range2(__first, __last, __dist);
254  __glibcxx_check_can_increment(__result, __dist.first);
255 
256  if (__dist.second > ::__gnu_debug::__dp_equality)
257  return std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
258  __result);
259 
260  return std::__copy_move_a1<_IsMove>(__first, __last, __result);
261  }
262 
263  template<bool _IsMove,
264  typename _II, typename _Ite, typename _Seq, typename _Cat>
266  __copy_move_a(_II __first, _II __last,
267  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __result)
268  {
269  typename ::__gnu_debug::_Distance_traits<_II>::__type __dist;
270  __glibcxx_check_valid_range2(__first, __last, __dist);
271  __glibcxx_check_can_increment(__result, __dist.first);
272 
273  if (__dist.second > ::__gnu_debug::__dp_sign
274  && __result._M_can_advance(__dist.first, true))
275  return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
276  std::__copy_move_a<_IsMove>(__first, __last, __result.base()),
277  __result._M_sequence);
278 
279  return std::__copy_move_a1<_IsMove>(__first, __last, __result);
280  }
281 
282  template<bool _IsMove,
283  typename _IIte, typename _ISeq, typename _ICat,
284  typename _OIte, typename _OSeq, typename _OCat>
286  __copy_move_a(
287  const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __first,
288  const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __last,
289  const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>& __result)
290  {
291  typename ::__gnu_debug::_Distance_traits<_IIte>::__type __dist;
292  __glibcxx_check_valid_range2(__first, __last, __dist);
293  __glibcxx_check_can_increment(__result, __dist.first);
294 
295  if (__dist.second > ::__gnu_debug::__dp_equality)
296  {
297  if (__dist.second > ::__gnu_debug::__dp_sign
298  && __result._M_can_advance(__dist.first, true))
299  return ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>(
300  std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
301  __result.base()),
302  __result._M_sequence);
303 
304  return std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
305  __result);
306  }
307 
308  return std::__copy_move_a1<_IsMove>(__first, __last, __result);
309  }
310 
311  template<bool _IsMove,
312  typename _Ite, typename _Seq, typename _Cat, typename _OI>
313  _OI
314  __copy_move_backward_a(
315  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
316  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
317  _OI __result)
318  {
319  typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
320  __glibcxx_check_valid_range2(__first, __last, __dist);
321  __glibcxx_check_can_increment(__result, -__dist.first);
322 
323  if (__dist.second > ::__gnu_debug::__dp_equality)
324  return std::__copy_move_backward_a<_IsMove>(
325  __first.base(), __last.base(), __result);
326 
327  return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
328  }
329 
330  template<bool _IsMove,
331  typename _II, typename _Ite, typename _Seq, typename _Cat>
333  __copy_move_backward_a(_II __first, _II __last,
334  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __result)
335  {
336  typename ::__gnu_debug::_Distance_traits<_II>::__type __dist;
337  __glibcxx_check_valid_range2(__first, __last, __dist);
338  __glibcxx_check_can_increment(__result, -__dist.first);
339 
340  if (__dist.second > ::__gnu_debug::__dp_sign
341  && __result._M_can_advance(-__dist.first, true))
342  return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
343  std::__copy_move_backward_a<_IsMove>(__first, __last,
344  __result.base()),
345  __result._M_sequence);
346 
347  return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
348  }
349 
350  template<bool _IsMove,
351  typename _IIte, typename _ISeq, typename _ICat,
352  typename _OIte, typename _OSeq, typename _OCat>
354  __copy_move_backward_a(
355  const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __first,
356  const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __last,
357  const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>& __result)
358  {
359  typename ::__gnu_debug::_Distance_traits<_IIte>::__type __dist;
360  __glibcxx_check_valid_range2(__first, __last, __dist);
361  __glibcxx_check_can_increment(__result, -__dist.first);
362 
363  if (__dist.second > ::__gnu_debug::__dp_equality)
364  {
365  if (__dist.second > ::__gnu_debug::__dp_sign
366  && __result._M_can_advance(-__dist.first, true))
367  return ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>(
368  std::__copy_move_backward_a<_IsMove>(__first.base(), __last.base(),
369  __result.base()),
370  __result._M_sequence);
371 
372  return std::__copy_move_backward_a<_IsMove>(
373  __first.base(), __last.base(), __result);
374  }
375 
376  return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
377  }
378 
379  template<typename _Ite, typename _Seq, typename _Cat, typename _Tp>
380  void
381  __fill_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
382  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
383  const _Tp& __value)
384  {
385  typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
386  __glibcxx_check_valid_range2(__first, __last, __dist);
387 
388  if (__dist.second > ::__gnu_debug::__dp_equality)
389  std::__fill_a(__first.base(), __last.base(), __value);
390 
391  std::__fill_a1(__first, __last, __value);
392  }
393 
394  template<typename _Ite, typename _Seq, typename _Cat, typename _Size,
395  typename _Tp>
397  __fill_n_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
398  _Size __n, const _Tp& __value,
400  {
401 #if __cplusplus >= 201103L
402  static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
403 #endif
404 
405  if (__n <= 0)
406  return __first;
407 
408  __glibcxx_check_can_increment(__first, __n);
409  if (__first._M_can_advance(__n, true))
410  return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
411  std::__fill_n_a(__first.base(), __n, __value, _Cat()),
412  __first._M_sequence);
413 
414  return std::__fill_n_a1(__first, __n, __value);
415  }
416 
417  template<typename _II1, typename _Seq1, typename _Cat1, typename _II2>
418  bool
419  __equal_aux(
420  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __first1,
421  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __last1,
422  _II2 __first2)
423  {
424  typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
425  __glibcxx_check_valid_range2(__first1, __last1, __dist);
426  __glibcxx_check_can_increment(__first2, __dist.first);
427 
428  if (__dist.second > ::__gnu_debug::__dp_equality)
429  return std::__equal_aux(__first1.base(), __last1.base(), __first2);
430 
431  return std::__equal_aux1(__first1, __last1, __first2);
432  }
433 
434  template<typename _II1, typename _II2, typename _Seq2, typename _Cat2>
435  bool
436  __equal_aux(_II1 __first1, _II1 __last1,
437  const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>& __first2)
438  {
439  typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
440  __glibcxx_check_valid_range2(__first1, __last1, __dist);
441  __glibcxx_check_can_increment(__first2, __dist.first);
442 
443  if (__dist.second > ::__gnu_debug::__dp_sign
444  && __first2._M_can_advance(__dist.first, true))
445  return std::__equal_aux(__first1, __last1, __first2.base());
446 
447  return std::__equal_aux1(__first1, __last1, __first2);
448  }
449 
450  template<typename _II1, typename _Seq1, typename _Cat1,
451  typename _II2, typename _Seq2, typename _Cat2>
452  bool
453  __equal_aux(
454  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __first1,
455  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __last1,
456  const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>& __first2)
457  {
458  typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
459  __glibcxx_check_valid_range2(__first1, __last1, __dist);
460  __glibcxx_check_can_increment(__first2, __dist.first);
461 
462  if (__dist.second > ::__gnu_debug::__dp_equality)
463  {
464  if (__dist.second > ::__gnu_debug::__dp_sign &&
465  __first2._M_can_advance(__dist.first, true))
466  return std::__equal_aux(__first1.base(), __last1.base(),
467  __first2.base());
468  return std::__equal_aux(__first1.base(), __last1.base(), __first2);
469  }
470 
471  return __equal_aux1(__first1, __last1, __first2);
472  }
473 
474  template<typename _Ite1, typename _Seq1, typename _Cat1,
475  typename _II2>
476  bool
477  __lexicographical_compare_aux(
478  const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __first1,
479  const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __last1,
480  _II2 __first2, _II2 __last2)
481  {
482  typename ::__gnu_debug::_Distance_traits<_Ite1>::__type __dist1;
483  __glibcxx_check_valid_range2(__first1, __last1, __dist1);
484  __glibcxx_check_valid_range(__first2, __last2);
485 
486  if (__dist1.second > ::__gnu_debug::__dp_equality)
487  return std::__lexicographical_compare_aux(__first1.base(),
488  __last1.base(),
489  __first2, __last2);
490  return std::__lexicographical_compare_aux1(__first1, __last1,
491  __first2, __last2);
492  }
493 
494  template<typename _II1,
495  typename _Ite2, typename _Seq2, typename _Cat2>
496  bool
497  __lexicographical_compare_aux(
498  _II1 __first1, _II1 __last1,
499  const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __first2,
500  const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __last2)
501  {
502  __glibcxx_check_valid_range(__first1, __last1);
503  typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist2;
504  __glibcxx_check_valid_range2(__first2, __last2, __dist2);
505 
506  if (__dist2.second > ::__gnu_debug::__dp_equality)
507  return std::__lexicographical_compare_aux(__first1, __last1,
508  __first2.base(),
509  __last2.base());
510  return std::__lexicographical_compare_aux1(__first1, __last1,
511  __first2, __last2);
512  }
513 
514  template<typename _Ite1, typename _Seq1, typename _Cat1,
515  typename _Ite2, typename _Seq2, typename _Cat2>
516  bool
517  __lexicographical_compare_aux(
518  const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __first1,
519  const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __last1,
520  const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __first2,
521  const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __last2)
522  {
523  typename ::__gnu_debug::_Distance_traits<_Ite1>::__type __dist1;
524  __glibcxx_check_valid_range2(__first1, __last1, __dist1);
525  typename ::__gnu_debug::_Distance_traits<_Ite2>::__type __dist2;
526  __glibcxx_check_valid_range2(__first2, __last2, __dist2);
527 
528  if (__dist1.second > ::__gnu_debug::__dp_equality)
529  {
530  if (__dist2.second > ::__gnu_debug::__dp_equality)
531  return std::__lexicographical_compare_aux(__first1.base(),
532  __last1.base(),
533  __first2.base(),
534  __last2.base());
535  return std::__lexicographical_compare_aux(__first1.base(),
536  __last1.base(),
537  __first2, __last2);
538  }
539 
540  if (__dist2.second > ::__gnu_debug::__dp_equality)
541  return std::__lexicographical_compare_aux(__first1, __last1,
542  __first2.base(),
543  __last2.base());
544  return std::__lexicographical_compare_aux1(__first1, __last1,
545  __first2, __last2);
546  }
547 
548 _GLIBCXX_END_NAMESPACE_VERSION
549 } // namespace std
550 
551 #endif
_T1 first
The first member.
Definition: stl_pair.h:217
_T2 second
The second member.
Definition: stl_pair.h:218
_Tp * begin(valarray< _Tp > &__va)
Return an iterator pointing to the first element of the valarray.
Definition: valarray:1214
_Tp * end(valarray< _Tp > &__va)
Return an iterator pointing to one past the last element of the valarray.
Definition: valarray:1234
ISO C++ entities toplevel namespace is std.
GNU debug classes for public use.
constexpr _Distance_traits< _Iterator >::__type __get_distance(_Iterator __lhs, _Iterator __rhs, std::random_access_iterator_tag)
Marking input iterators.
Random-access iterators support a superset of bidirectional iterator operations.
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:213
Safe iterator wrapper.