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
33namespace __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.  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
108