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1 // Debugging iterator implementation (out of line) -*- C++ -*-
2
3 // Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2011
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();
50 std::pair<difference_type, _Distance_precision> __dist =
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();
59 std::pair<difference_type, _Distance_precision> __dist =
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 */
78 std::pair<difference_type, _Distance_precision> __dist =
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. */
95 if (_M_is_begin() || __rhs._M_is_end())
96 return true;
97 if (_M_is_end() || __rhs._M_is_begin())
98 return false;
99
100 // Assume that this is a valid range; we can't check anything else
101 return true;
102 }
103 } // namespace __gnu_debug
104
105 #endif
106