safe_iterator.tcc
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// Debugging iterator implementation (out of line) -*- C++ -*-
// Copyright (C) 2003-2015 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>
bool
_Safe_iterator<_Iterator, _Sequence>::
_M_can_advance(const 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 =
__get_distance(_M_get_sequence()->_M_base().begin(), base());
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 =
__get_distance(base(), _M_get_sequence()->_M_base().end());
bool __ok = ((__dist.second == __dp_exact && __dist.first >= __n)
|| (__dist.second != __dp_exact && __dist.first > 0));
return __ok;
}
}
template<typename _Iterator, typename _Sequence>
bool
_Safe_iterator<_Iterator, _Sequence>::
_M_valid_range(const _Safe_iterator& __rhs) const
{
if (!_M_can_compare(__rhs))
return false;
/* Determine if we can order the iterators without the help of
the container */
std::pair<difference_type, _Distance_precision> __dist =
__get_distance(base(), __rhs.base());
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. */
/* Optim for classic [begin, it) or [it, end) ranges, limit checks
* when code is valid. Note, for the special case of forward_list,
* before_begin replaces the role of begin. */
if (_M_is_beginnest() || __rhs._M_is_end())
return true;
if (_M_is_end() || __rhs._M_is_beginnest())
return false;
// Assume that this is a valid range; we can't check anything else
return true;
}
} // namespace __gnu_debug
#endif
__gnu_debug::__get_distance
std::pair< typename std::iterator_traits< _Iterator >::difference_type, _Distance_precision > __get_distance(const _Iterator &__lhs, const _Iterator &__rhs, std::random_access_iterator_tag)
Definition: safe_iterator.h:81
__gnu_debug
GNU debug classes for public use.
std::pair::second
_T2 second
first is a copy of the first object
Definition: stl_pair.h:102
std::pair
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:96
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
std::pair::first
_T1 first
second_type is the second bound type
Definition: stl_pair.h:101