1// Debugging iterator implementation (out of line) -*- C++ -*-
2
3// Copyright (C) 2003-2013 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
32namespace __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      typedef typename _Sequence::const_iterator const_debug_iterator;
40      typedef typename const_debug_iterator::iterator_type const_iterator;
41
42      if (this->_M_singular())
43	return false;
44      if (__n == 0)
45	return true;
46      if (__n < 0)
47	{
48	  const_iterator __begin = _M_get_sequence()->_M_base().begin();
49	  std::pair<difference_type, _Distance_precision> __dist =
50	    __get_distance(__begin, base());
51	  bool __ok =  ((__dist.second == __dp_exact && __dist.first >= -__n)
52			|| (__dist.second != __dp_exact && __dist.first > 0));
53	  return __ok;
54	}
55      else
56	{
57	  const_iterator __end = _M_get_sequence()->_M_base().end();
58	  std::pair<difference_type, _Distance_precision> __dist =
59	    __get_distance(base(), __end);
60	  bool __ok = ((__dist.second == __dp_exact && __dist.first >= __n)
61		       || (__dist.second != __dp_exact && __dist.first > 0));
62	  return __ok;
63	}
64    }
65
66  template<typename _Iterator, typename _Sequence>
67    template<typename _Other>
68      bool
69      _Safe_iterator<_Iterator, _Sequence>::
70      _M_valid_range(const _Safe_iterator<_Other, _Sequence>& __rhs) const
71      {
72	if (!_M_can_compare(__rhs))
73	  return false;
74
75	/* Determine if we can order the iterators without the help of
76	   the container */
77	std::pair<difference_type, _Distance_precision> __dist =
78	  __get_distance(base(), __rhs.base());
79	switch (__dist.second) {
80	case __dp_equality:
81	  if (__dist.first == 0)
82	    return true;
83	  break;
84
85	case __dp_sign:
86	case __dp_exact:
87	  return __dist.first >= 0;
88	}
89
90	/* We can only test for equality, but check if one of the
91	   iterators is at an extreme. */
92	/* Optim for classic [begin, it) or [it, end) ranges, limit checks
93	 * when code is valid.  Note, for the special case of forward_list,
94	 * before_begin replaces the role of begin.  */ 
95	if (_M_is_beginnest() || __rhs._M_is_end())
96	  return true;
97	if (_M_is_end() || __rhs._M_is_beginnest())
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
107