libstdc++
safe_iterator.tcc
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1 // Debugging iterator implementation (out of line) -*- C++ -*-
2 
3 // Copyright (C) 2003-2018 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 namespace __gnu_debug
33 {
34  template<typename _Iterator, typename _Sequence>
35  bool
36  _Safe_iterator<_Iterator, _Sequence>::
37  _M_can_advance(const difference_type& __n) const
38  {
39  if (this->_M_singular())
40  return false;
41 
42  if (__n == 0)
43  return true;
44 
45  if (__n < 0)
46  {
48  __get_distance_from_begin(*this);
49  bool __ok = ((__dist.second == __dp_exact && __dist.first >= -__n)
50  || (__dist.second != __dp_exact && __dist.first > 0));
51  return __ok;
52  }
53  else
54  {
56  __get_distance_to_end(*this);
57  bool __ok = ((__dist.second == __dp_exact && __dist.first >= __n)
58  || (__dist.second != __dp_exact && __dist.first > 0));
59  return __ok;
60  }
61  }
62 
63  template<typename _Iterator, typename _Sequence>
64  bool
65  _Safe_iterator<_Iterator, _Sequence>::
66  _M_valid_range(const _Safe_iterator& __rhs,
68  bool __check_dereferenceable) const
69  {
70  if (!_M_can_compare(__rhs))
71  return false;
72 
73  /* Determine iterators order */
74  __dist = __get_distance(*this, __rhs);
75  switch (__dist.second)
76  {
77  case __dp_equality:
78  if (__dist.first == 0)
79  return true;
80  break;
81 
82  case __dp_sign:
83  case __dp_exact:
84  // If range is not empty first iterator must be dereferenceable.
85  if (__dist.first > 0)
86  return !__check_dereferenceable || _M_dereferenceable();
87  return __dist.first == 0;
88  }
89 
90  // Assume that this is a valid range; we can't check anything else.
91  return true;
92  }
93 } // namespace __gnu_debug
94 
95 #endif
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:208
GNU debug classes for public use.
_Distance_traits< _Iterator >::__type __get_distance(const _Iterator &__lhs, const _Iterator &__rhs, std::random_access_iterator_tag)
bool __check_dereferenceable(const _Iterator &)
Definition: functions.h:74
_T1 first
second_type is the second bound type
Definition: stl_pair.h:214
_T2 second
first is a copy of the first object
Definition: stl_pair.h:215