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

   1 // Debugging iterator implementation (out of line) -*- C++ -*-
   2
   3 // Copyright (C) 2011-2021 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_local_iterator.tcc
  26  *  This file is a GNU debug extension to the Standard C++ Library.
  27  */
  28
  29 #ifndef _GLIBCXX_DEBUG_SAFE_LOCAL_ITERATOR_TCC
  30 #define _GLIBCXX_DEBUG_SAFE_LOCAL_ITERATOR_TCC 1
  31
  32 namespace __gnu_debug
  33 {
  34   template<typename _Iterator, typename _Sequence>
  35     typename _Distance_traits<_Iterator>::__type
  36     _Safe_local_iterator<_Iterator, _Sequence>::
  37     _M_get_distance_to(const _Safe_local_iterator& __rhs) const
  38     {
  39       if (base() == __rhs.base())
  40         return { 0, __dp_exact };
  41
  42       if (_M_is_begin())
  43         {
  44           if (__rhs._M_is_end())
  45             return
  46               {
  47                 _M_get_sequence()->bucket_size(bucket()),
  48                 __dp_exact
  49               };
  50
  51           return { 1, __dp_sign };
  52         }
  53
  54       if (_M_is_end())
  55         {
  56           if (__rhs._M_is_begin())
  57             return
  58               {
  59                 -_M_get_sequence()->bucket_size(bucket()),
  60                 __dp_exact
  61               };
  62
  63           return { -1, __dp_sign };
  64         }
  65
  66       if (__rhs._M_is_begin())
  67         return { -1, __dp_sign };
  68
  69       if (__rhs._M_is_end())
  70         return { 1, __dp_sign };
  71
  72       return { 1, __dp_equality };
  73     }
  74
  75   template<typename _Iterator, typename _Sequence>
  76     bool
  77     _Safe_local_iterator<_Iterator, _Sequence>::
  78     _M_valid_range(const _Safe_local_iterator& __rhs,
  79                 std::pair<difference_type, _Distance_precision>& __dist) const
  80     {
  81       if (!_M_can_compare(__rhs))
  82         return false;
  83
  84       if (bucket() != __rhs.bucket())
  85         return false;
  86
  87       /* Determine if we can order the iterators without the help of
  88          the container */
  89       __dist = _M_get_distance_to(__rhs);
  90       switch (__dist.second)
  91         {
  92         case __dp_equality:
  93           if (__dist.first == 0)
  94             return true;
  95           break;
  96
  97         case __dp_sign:
  98         case __dp_exact:
  99           return __dist.first >= 0;
 100         }
 101
 102       // Assume that this is a valid range; we can't check anything else
 103       return true;
 104     }
 105 } // namespace __gnu_debug
 106
 107 #endif