libstdc++-v3/include/debug/safe_iterator.tcc

   1 // Debugging iterator implementation (out of line) -*- C++ -*-
   2
   3 // Copyright (C) 2003, 2004
   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 2, 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 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /** @file safe_iterator.tcc
  32  *  This is an internal header file, included by other library headers.
  33  *  You should not attempt to use it directly.
  34  */
  35
  36 #ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC
  37 #define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1
  38
  39 namespace __gnu_debug
  40 {
  41   template<typename _Iterator, typename _Sequence>
  42     bool
  43     _Safe_iterator<_Iterator, _Sequence>::
  44     _M_can_advance(const difference_type& __n) const
  45     {
  46       typedef typename _Sequence::const_iterator const_iterator;
  47
  48       if (this->_M_singular())
  49         return false;
  50       if (__n == 0)
  51         return true;
  52       if (__n < 0)
  53         {
  54           const_iterator __begin =
  55             static_cast<const _Sequence*>(_M_sequence)->begin();
  56           pair<difference_type, _Distance_precision> __dist =
  57             this->_M_get_distance(__begin, *this);
  58           bool __ok =  (__dist.second == __dp_exact && __dist.first >= -__n
  59                         || __dist.second != __dp_exact && __dist.first > 0);
  60           return __ok;
  61         }
  62       else
  63         {
  64           const_iterator __end =
  65             static_cast<const _Sequence*>(_M_sequence)->end();
  66           pair<difference_type, _Distance_precision> __dist =
  67             this->_M_get_distance(*this, __end);
  68           bool __ok = (__dist.second == __dp_exact && __dist.first >= __n
  69                        || __dist.second != __dp_exact && __dist.first > 0);
  70           return __ok;
  71         }
  72     }
  73
  74   template<typename _Iterator, typename _Sequence>
  75     template<typename _Other>
  76       bool
  77       _Safe_iterator<_Iterator, _Sequence>::
  78       _M_valid_range(const _Safe_iterator<_Other, _Sequence>& __rhs) const
  79       {
  80         if (!_M_can_compare(__rhs))
  81           return false;
  82
  83         /* Determine if we can order the iterators without the help of
  84            the container */
  85         pair<difference_type, _Distance_precision> __dist =
  86           this->_M_get_distance(*this, __rhs);
  87         switch (__dist.second) {
  88         case __dp_equality:
  89           if (__dist.first == 0)
  90             return true;
  91           break;
  92
  93         case __dp_sign:
  94         case __dp_exact:
  95           return __dist.first >= 0;
  96         }
  97
  98         /* We can only test for equality, but check if one of the
  99            iterators is at an extreme. */
 100         if (_M_is_begin() || __rhs._M_is_end())
 101           return true;
 102         else if (_M_is_end() || __rhs._M_is_begin())
 103           return false;
 104
 105         // Assume that this is a valid range; we can't check anything else
 106         return true;
 107       }
 108
 109   template<typename _Iterator, typename _Sequence>
 110     void
 111     _Safe_iterator<_Iterator, _Sequence>::
 112     _M_invalidate()
 113     {
 114       typedef typename _Sequence::iterator iterator;
 115       typedef typename _Sequence::const_iterator const_iterator;
 116
 117       if (!this->_M_singular())
 118         {
 119           for (_Safe_iterator_base* iter = _M_sequence->_M_iterators; iter; )
 120             {
 121               iterator* __victim = static_cast<iterator*>(iter);
 122               iter = iter->_M_next;
 123               if (this->base() == __victim->base())
 124                 __victim->_M_version = 0;
 125             }
 126           for (_Safe_iterator_base* iter2 = _M_sequence->_M_const_iterators;
 127                iter2; /* increment in loop */)
 128             {
 129               const_iterator* __victim = static_cast<const_iterator*>(iter2);
 130               iter2 = iter2->_M_next;
 131               if (this->base() == __victim->base())
 132                 __victim->_M_version = 0;
 133             }
 134           _M_version = 0;
 135         }
 136     }
 137 } // namespace __gnu_debug
 138
 139 #endif
 140