libstdc++
safe_local_iterator.tcc
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00001 // Debugging iterator implementation (out of line) -*- C++ -*-
00002 
00003 // Copyright (C) 2011-2015 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /** @file debug/safe_local_iterator.tcc
00026  *  This file is a GNU debug extension to the Standard C++ Library.
00027  */
00028 
00029 #ifndef _GLIBCXX_DEBUG_SAFE_LOCAL_ITERATOR_TCC
00030 #define _GLIBCXX_DEBUG_SAFE_LOCAL_ITERATOR_TCC 1
00031 
00032 namespace __gnu_debug
00033 {
00034   template<typename _Iterator, typename _Sequence>
00035     bool
00036     _Safe_local_iterator<_Iterator, _Sequence>::
00037     _M_valid_range(const _Safe_local_iterator& __rhs) const
00038     {
00039       if (!_M_can_compare(__rhs))
00040         return false;
00041       if (bucket() != __rhs.bucket())
00042         return false;
00043 
00044       /* Determine if we can order the iterators without the help of
00045          the container */
00046       std::pair<difference_type, _Distance_precision> __dist =
00047         __get_distance(base(), __rhs.base());
00048       switch (__dist.second)
00049         {
00050         case __dp_equality:
00051           if (__dist.first == 0)
00052             return true;
00053           break;
00054 
00055         case __dp_sign:
00056         case __dp_exact:
00057           return __dist.first >= 0;
00058         }
00059 
00060       /* We can only test for equality, but check if one of the
00061          iterators is at an extreme. */
00062       /* Optim for classic [begin, it) or [it, end) ranges, limit checks
00063        * when code is valid. */
00064       if (_M_is_begin() || __rhs._M_is_end())
00065         return true;
00066       if (_M_is_end() || __rhs._M_is_begin())
00067         return false;
00068 
00069       // Assume that this is a valid range; we can't check anything else
00070       return true;
00071     }
00072 } // namespace __gnu_debug
00073 
00074 #endif