safe_iterator.tcc
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// Debugging iterator implementation (out of line) -*- C++ -*-
// Copyright (C) 2003-2019 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 3, 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.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file debug/safe_iterator.tcc
* This file is a GNU debug extension to the Standard C++ Library.
*/
#ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC
#define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1
namespace __gnu_debug
{
template<typename _Iterator, typename _Sequence, typename _Category>
typename _Distance_traits<_Iterator>::__type
_Safe_iterator<_Iterator, _Sequence, _Category>::
_M_get_distance_from_begin() const
{
typedef _Sequence_traits<_Sequence> _SeqTraits;
// No need to consider before_begin as this function is only used in
// _M_can_advance which won't be used for forward_list iterators.
if (_M_is_begin())
return std::make_pair(0, __dp_exact);
if (_M_is_end())
return _SeqTraits::_S_size(*_M_get_sequence());
typename _Distance_traits<_Iterator>::__type __res
= __get_distance(_M_get_sequence()->_M_base().begin(), base());
if (__res.second == __dp_equality)
return std::make_pair(1, __dp_sign);
return __res;
}
template<typename _Iterator, typename _Sequence, typename _Category>
typename _Distance_traits<_Iterator>::__type
_Safe_iterator<_Iterator, _Sequence, _Category>::
_M_get_distance_to_end() const
{
typedef _Sequence_traits<_Sequence> _SeqTraits;
// No need to consider before_begin as this function is only used in
// _M_can_advance which won't be used for forward_list iterators.
if (_M_is_begin())
return _SeqTraits::_S_size(*_M_get_sequence());
if (_M_is_end())
return std::make_pair(0, __dp_exact);
typename _Distance_traits<_Iterator>::__type __res
= __get_distance(base(), _M_get_sequence()->_M_base().end());
if (__res.second == __dp_equality)
return std::make_pair(1, __dp_sign);
return __res;
}
template<typename _Iterator, typename _Sequence, typename _Category>
bool
_Safe_iterator<_Iterator, _Sequence, _Category>::
_M_can_advance(difference_type __n) const
{
if (this->_M_singular())
return false;
if (__n == 0)
return true;
if (__n < 0)
{
std::pair<difference_type, _Distance_precision> __dist =
_M_get_distance_from_begin();
bool __ok = ((__dist.second == __dp_exact && __dist.first >= -__n)
|| (__dist.second != __dp_exact && __dist.first > 0));
return __ok;
}
else
{
std::pair<difference_type, _Distance_precision> __dist =
_M_get_distance_to_end();
bool __ok = ((__dist.second == __dp_exact && __dist.first >= __n)
|| (__dist.second != __dp_exact && __dist.first > 0));
return __ok;
}
}
template<typename _Iterator, typename _Sequence, typename _Category>
typename _Distance_traits<_Iterator>::__type
_Safe_iterator<_Iterator, _Sequence, _Category>::
_M_get_distance_to(const _Safe_iterator& __rhs) const
{
typedef typename _Distance_traits<_Iterator>::__type _Diff;
typedef _Sequence_traits<_Sequence> _SeqTraits;
if (this->base() == __rhs.base())
return std::make_pair(0, __dp_exact);
if (this->_M_is_before_begin())
{
if (__rhs._M_is_begin())
return std::make_pair(1, __dp_exact);
return std::make_pair(1, __dp_sign);
}
if (this->_M_is_begin())
{
if (__rhs._M_is_before_begin())
return std::make_pair(-1, __dp_exact);
if (__rhs._M_is_end())
return _SeqTraits::_S_size(*this->_M_get_sequence());
return std::make_pair(1, __dp_sign);
}
if (this->_M_is_end())
{
if (__rhs._M_is_before_begin())
return std::make_pair(-1, __dp_exact);
if (__rhs._M_is_begin())
{
_Diff __diff = _SeqTraits::_S_size(*this->_M_get_sequence());
return std::make_pair(-__diff.first, __diff.second);
}
return std::make_pair(-1, __dp_sign);
}
if (__rhs._M_is_before_begin() || __rhs._M_is_begin())
return std::make_pair(-1, __dp_sign);
if (__rhs._M_is_end())
return std::make_pair(1, __dp_sign);
return std::make_pair(1, __dp_equality);
}
template<typename _Iterator, typename _Sequence, typename _Category>
bool
_Safe_iterator<_Iterator, _Sequence, _Category>::
_M_valid_range(const _Safe_iterator& __rhs,
std::pair<difference_type, _Distance_precision>& __dist,
bool __check_dereferenceable) const
{
if (!_M_can_compare(__rhs))
return false;
/* Determine iterators order */
__dist = _M_get_distance_to(__rhs);
switch (__dist.second)
{
case __dp_equality:
if (__dist.first == 0)
return true;
break;
case __dp_sign:
case __dp_exact:
// If range is not empty first iterator must be dereferenceable.
if (__dist.first > 0)
return !__check_dereferenceable || _M_dereferenceable();
return __dist.first == 0;
}
// Assume that this is a valid range; we can't check anything else.
return true;
}
template<typename _Iterator, typename _Sequence>
bool
_Safe_iterator<_Iterator, _Sequence, std::random_access_iterator_tag>::
_M_valid_range(const _Safe_iterator& __rhs,
std::pair<difference_type,
_Distance_precision>& __dist) const
{
if (!this->_M_can_compare(__rhs))
return false;
/* Determine iterators order */
__dist = std::make_pair(__rhs.base() - this->base(), __dp_exact);
// If range is not empty first iterator must be dereferenceable.
if (__dist.first > 0)
return this->_M_dereferenceable();
return __dist.first == 0;
}
} // namespace __gnu_debug
#endif
std::make_pair
constexpr pair< typename __decay_and_strip< _T1 >::__type, typename __decay_and_strip< _T2 >::__type > make_pair(_T1 &&__x, _T2 &&__y)
A convenience wrapper for creating a pair from two objects.
Definition stl_pair.h:524
std::begin
constexpr const _Tp * begin(initializer_list< _Tp > __ils) noexcept
Return an iterator pointing to the first element of the initializer_list.
Definition initializer_list:89
std::end
constexpr const _Tp * end(initializer_list< _Tp > __ils) noexcept
Return an iterator pointing to one past the last element of the initializer_list.
Definition initializer_list:99
__gnu_debug
GNU debug classes for public use.
__gnu_debug::__get_distance
_Distance_traits< _Iterator >::__type __get_distance(_Iterator __lhs, _Iterator __rhs, std::random_access_iterator_tag)
Definition helper_functions.h:91
__gnu_debug::_Distance_precision
_Distance_precision
Definition helper_functions.h:52
std::pair
Struct holding two objects of arbitrary type.
Definition stl_pair.h:210
std::auto_ptr_ref
Definition auto_ptr.h:49