libstdc++
safe_iterator.tcc
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1 // Debugging iterator implementation (out of line) -*- C++ -*-
2 
3 // Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2011, 2012
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 3, or (at your option)
10 // any later version.
11 
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
16 
17 // Under Section 7 of GPL version 3, you are granted additional
18 // permissions described in the GCC Runtime Library Exception, version
19 // 3.1, as published by the Free Software Foundation.
20 
21 // You should have received a copy of the GNU General Public License and
22 // a copy of the GCC Runtime Library Exception along with this program;
23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 // <http://www.gnu.org/licenses/>.
25 
26 /** @file debug/safe_iterator.tcc
27  * This file is a GNU debug extension to the Standard C++ Library.
28  */
29 
30 #ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC
31 #define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1
32 
33 namespace __gnu_debug
34 {
35  template<typename _Iterator, typename _Sequence>
36  bool
37  _Safe_iterator<_Iterator, _Sequence>::
38  _M_can_advance(const difference_type& __n) const
39  {
40  typedef typename _Sequence::const_iterator const_debug_iterator;
41  typedef typename const_debug_iterator::iterator_type const_iterator;
42 
43  if (this->_M_singular())
44  return false;
45  if (__n == 0)
46  return true;
47  if (__n < 0)
48  {
49  const_iterator __begin = _M_get_sequence()->_M_base().begin();
51  __get_distance(__begin, base());
52  bool __ok = ((__dist.second == __dp_exact && __dist.first >= -__n)
53  || (__dist.second != __dp_exact && __dist.first > 0));
54  return __ok;
55  }
56  else
57  {
58  const_iterator __end = _M_get_sequence()->_M_base().end();
60  __get_distance(base(), __end);
61  bool __ok = ((__dist.second == __dp_exact && __dist.first >= __n)
62  || (__dist.second != __dp_exact && __dist.first > 0));
63  return __ok;
64  }
65  }
66 
67  template<typename _Iterator, typename _Sequence>
68  template<typename _Other>
69  bool
70  _Safe_iterator<_Iterator, _Sequence>::
71  _M_valid_range(const _Safe_iterator<_Other, _Sequence>& __rhs) const
72  {
73  if (!_M_can_compare(__rhs))
74  return false;
75 
76  /* Determine if we can order the iterators without the help of
77  the container */
79  __get_distance(base(), __rhs.base());
80  switch (__dist.second) {
81  case __dp_equality:
82  if (__dist.first == 0)
83  return true;
84  break;
85 
86  case __dp_sign:
87  case __dp_exact:
88  return __dist.first >= 0;
89  }
90 
91  /* We can only test for equality, but check if one of the
92  iterators is at an extreme. */
93  /* Optim for classic [begin, it) or [it, end) ranges, limit checks
94  * when code is valid. Note, for the special case of forward_list,
95  * before_begin replaces the role of begin. */
96  if (_M_is_beginnest() || __rhs._M_is_end())
97  return true;
98  if (_M_is_end() || __rhs._M_is_beginnest())
99  return false;
100 
101  // Assume that this is a valid range; we can't check anything else
102  return true;
103  }
104 } // namespace __gnu_debug
105 
106 #endif
107