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>::
_M_can_advance(const difference_type & __n) const37     _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 	{
47 	  std::pair<difference_type, _Distance_precision> __dist =
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 	{
55 	  std::pair<difference_type, _Distance_precision> __dist =
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>::
_M_valid_range(const _Safe_iterator & __rhs,std::pair<difference_type,_Distance_precision> & __dist,bool __check_dereferenceable) const66     _M_valid_range(const _Safe_iterator& __rhs,
67 		   std::pair<difference_type, _Distance_precision>& __dist,
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
96