safe_iterator.tcc

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// Debugging iterator implementation (out of line) -*- C++ -*-

// Copyright (C) 2003, 2004
// Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/** @file safe_iterator.tcc
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

#ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC
#define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1

namespace __gnu_debug
{
  template<typename _Iterator, typename _Sequence>
    bool
    _Safe_iterator<_Iterator, _Sequence>::
    _M_can_advance(const difference_type& __n) const
    {
      typedef typename _Sequence::const_iterator const_iterator;

      if (this->_M_singular())
    return false;
      if (__n == 0)
    return true;
      if (__n < 0)
    {
      const_iterator __begin =
        static_cast<const _Sequence*>(_M_sequence)->begin();
      pair<difference_type, _Distance_precision> __dist =
        this->_M_get_distance(__begin, *this);
      bool __ok =  (__dist.second == __dp_exact && __dist.first >= -__n
            || __dist.second != __dp_exact && __dist.first > 0);
      return __ok;
    }
      else
    {
      const_iterator __end =
        static_cast<const _Sequence*>(_M_sequence)->end();
      pair<difference_type, _Distance_precision> __dist =
        this->_M_get_distance(*this, __end);
      bool __ok = (__dist.second == __dp_exact && __dist.first >= __n
               || __dist.second != __dp_exact && __dist.first > 0);
      return __ok;
    }
    }

  template<typename _Iterator, typename _Sequence>
    template<typename _Other>
      bool
      _Safe_iterator<_Iterator, _Sequence>::
      _M_valid_range(const _Safe_iterator<_Other, _Sequence>& __rhs) const
      {
    if (!_M_can_compare(__rhs))
      return false;

    /* Determine if we can order the iterators without the help of
       the container */
    pair<difference_type, _Distance_precision> __dist =
      this->_M_get_distance(*this, __rhs);
    switch (__dist.second) {
    case __dp_equality:
      if (__dist.first == 0)
        return true;
      break;

    case __dp_sign:
    case __dp_exact:
      return __dist.first >= 0;
    }

    /* We can only test for equality, but check if one of the
       iterators is at an extreme. */
    if (_M_is_begin() || __rhs._M_is_end())
      return true;
    else if (_M_is_end() || __rhs._M_is_begin())
      return false;

    // Assume that this is a valid range; we can't check anything else
    return true;
      }

  template<typename _Iterator, typename _Sequence>
    void
    _Safe_iterator<_Iterator, _Sequence>::
    _M_invalidate()
    {
      typedef typename _Sequence::iterator iterator;
      typedef typename _Sequence::const_iterator const_iterator;

      if (!this->_M_singular())
    {
      for (_Safe_iterator_base* iter = _M_sequence->_M_iterators; iter; )
        {
          iterator* __victim = static_cast<iterator*>(iter);
          iter = iter->_M_next;
          if (this->base() == __victim->base())
        __victim->_M_version = 0;
        }
      for (_Safe_iterator_base* iter2 = _M_sequence->_M_const_iterators;
           iter2; /* increment in loop */)
        {
          const_iterator* __victim = static_cast<const_iterator*>(iter2);
          iter2 = iter2->_M_next;
          if (this->base() == __victim->base())
        __victim->_M_version = 0;
        }
      _M_version = 0;
    }
    }
} // namespace __gnu_debug

#endif

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