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

   1 // Debugging iterator implementation (out of line) -*- C++ -*-
   2
   3 // Copyright (C) 2011-2013 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_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     bool
  36     _Safe_local_iterator<_Iterator, _Sequence>::
  37     _M_valid_range(const _Safe_local_iterator& __rhs) const
  38     {
  39       if (!_M_can_compare(__rhs))
  40         return false;
  41       if (bucket() != __rhs.bucket())
  42         return false;
  43
  44       /* Determine if we can order the iterators without the help of
  45          the container */
  46       std::pair<difference_type, _Distance_precision> __dist =
  47         __get_distance(base(), __rhs.base());
  48       switch (__dist.second)
  49         {
  50         case __dp_equality:
  51           if (__dist.first == 0)
  52             return true;
  53           break;
  54
  55         case __dp_sign:
  56         case __dp_exact:
  57           return __dist.first >= 0;
  58         }
  59
  60       /* We can only test for equality, but check if one of the
  61          iterators is at an extreme. */
  62       /* Optim for classic [begin, it) or [it, end) ranges, limit checks
  63        * when code is valid. */
  64       if (_M_is_begin() || __rhs._M_is_end())
  65         return true;
  66       if (_M_is_end() || __rhs._M_is_begin())
  67         return false;
  68
  69       // Assume that this is a valid range; we can't check anything else
  70       return true;
  71     }
  72 } // namespace __gnu_debug
  73
  74 #endif