safe_iterator.h
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// Safe iterator implementation -*- C++ -*-
// Copyright (C) 2003-2013 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.h
* This file is a GNU debug extension to the Standard C++ Library.
*/
#ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_H
#define _GLIBCXX_DEBUG_SAFE_ITERATOR_H 1
#include <debug/debug.h>
#include <debug/macros.h>
#include <debug/functions.h>
#include <debug/safe_base.h>
#include <bits/stl_pair.h>
#include <ext/type_traits.h>
namespace __gnu_debug
{
/** Helper struct to deal with sequence offering a before_begin
* iterator.
**/
template <typename _Sequence>
struct _BeforeBeginHelper
{
typedef typename _Sequence::const_iterator _It;
typedef typename _It::iterator_type _BaseIt;
static bool
_S_Is(_BaseIt, const _Sequence*)
{ return false; }
static bool
_S_Is_Beginnest(_BaseIt __it, const _Sequence* __seq)
{ return __it == __seq->_M_base().begin(); }
};
/** Iterators that derive from _Safe_iterator_base but that aren't
* _Safe_iterators can be determined singular or non-singular via
* _Safe_iterator_base.
*/
inline bool
__check_singular_aux(const _Safe_iterator_base* __x)
{ return __x->_M_singular(); }
/** The precision to which we can calculate the distance between
* two iterators.
*/
enum _Distance_precision
{
__dp_equality, //< Can compare iterator equality, only
__dp_sign, //< Can determine equality and ordering
__dp_exact //< Can determine distance precisely
};
/** Determine the distance between two iterators with some known
* precision.
*/
template<typename _Iterator1, typename _Iterator2>
inline std::pair<typename std::iterator_traits<_Iterator1>::difference_type,
_Distance_precision>
__get_distance(const _Iterator1& __lhs, const _Iterator2& __rhs,
std::random_access_iterator_tag)
{ return std::make_pair(__rhs - __lhs, __dp_exact); }
template<typename _Iterator1, typename _Iterator2>
inline std::pair<typename std::iterator_traits<_Iterator1>::difference_type,
_Distance_precision>
__get_distance(const _Iterator1& __lhs, const _Iterator2& __rhs,
std::forward_iterator_tag)
{ return std::make_pair(__lhs == __rhs? 0 : 1, __dp_equality); }
template<typename _Iterator1, typename _Iterator2>
inline std::pair<typename std::iterator_traits<_Iterator1>::difference_type,
_Distance_precision>
__get_distance(const _Iterator1& __lhs, const _Iterator2& __rhs)
{
typedef typename std::iterator_traits<_Iterator1>::iterator_category
_Category;
return __get_distance(__lhs, __rhs, _Category());
}
/** \brief Safe iterator wrapper.
*
* The class template %_Safe_iterator is a wrapper around an
* iterator that tracks the iterator's movement among sequences and
* checks that operations performed on the "safe" iterator are
* legal. In additional to the basic iterator operations (which are
* validated, and then passed to the underlying iterator),
* %_Safe_iterator has member functions for iterator invalidation,
* attaching/detaching the iterator from sequences, and querying
* the iterator's state.
*/
template<typename _Iterator, typename _Sequence>
class _Safe_iterator : public _Safe_iterator_base
{
typedef _Safe_iterator _Self;
/// The underlying iterator
_Iterator _M_current;
/// Determine if this is a constant iterator.
bool
_M_constant() const
{
typedef typename _Sequence::const_iterator const_iterator;
return std::__are_same<const_iterator, _Safe_iterator>::__value;
}
typedef std::iterator_traits<_Iterator> _Traits;
public:
typedef _Iterator iterator_type;
typedef typename _Traits::iterator_category iterator_category;
typedef typename _Traits::value_type value_type;
typedef typename _Traits::difference_type difference_type;
typedef typename _Traits::reference reference;
typedef typename _Traits::pointer pointer;
/// @post the iterator is singular and unattached
_Safe_iterator() : _M_current() { }
/**
* @brief Safe iterator construction from an unsafe iterator and
* its sequence.
*
* @pre @p seq is not NULL
* @post this is not singular
*/
_Safe_iterator(const _Iterator& __i, const _Sequence* __seq)
: _Safe_iterator_base(__seq, _M_constant()), _M_current(__i)
{
_GLIBCXX_DEBUG_VERIFY(! this->_M_singular(),
_M_message(__msg_init_singular)
._M_iterator(*this, "this"));
}
/**
* @brief Copy construction.
*/
_Safe_iterator(const _Safe_iterator& __x)
: _Safe_iterator_base(__x, _M_constant()), _M_current(__x._M_current)
{
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 408. Is vector<reverse_iterator<char*> > forbidden?
_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
|| __x._M_current == _Iterator(),
_M_message(__msg_init_copy_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
}
#if __cplusplus >= 201103L
/**
* @brief Move construction.
* @post __x is singular and unattached
*/
_Safe_iterator(_Safe_iterator&& __x) : _M_current()
{
_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
|| __x._M_current == _Iterator(),
_M_message(__msg_init_copy_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
std::swap(_M_current, __x._M_current);
this->_M_attach(__x._M_sequence);
__x._M_detach();
}
#endif
/**
* @brief Converting constructor from a mutable iterator to a
* constant iterator.
*/
template<typename _MutableIterator>
_Safe_iterator(
const _Safe_iterator<_MutableIterator,
typename __gnu_cxx::__enable_if<(std::__are_same<_MutableIterator,
typename _Sequence::iterator::iterator_type>::__value),
_Sequence>::__type>& __x)
: _Safe_iterator_base(__x, _M_constant()), _M_current(__x.base())
{
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 408. Is vector<reverse_iterator<char*> > forbidden?
_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
|| __x.base() == _Iterator(),
_M_message(__msg_init_const_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
}
/**
* @brief Copy assignment.
*/
_Safe_iterator&
operator=(const _Safe_iterator& __x)
{
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 408. Is vector<reverse_iterator<char*> > forbidden?
_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
|| __x._M_current == _Iterator(),
_M_message(__msg_copy_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
_M_current = __x._M_current;
this->_M_attach(__x._M_sequence);
return *this;
}
#if __cplusplus >= 201103L
/**
* @brief Move assignment.
* @post __x is singular and unattached
*/
_Safe_iterator&
operator=(_Safe_iterator&& __x)
{
_GLIBCXX_DEBUG_VERIFY(this != &__x,
_M_message(__msg_self_move_assign)
._M_iterator(*this, "this"));
_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
|| __x._M_current == _Iterator(),
_M_message(__msg_copy_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
_M_current = __x._M_current;
_M_attach(__x._M_sequence);
__x._M_detach();
__x._M_current = _Iterator();
return *this;
}
#endif
/**
* @brief Iterator dereference.
* @pre iterator is dereferenceable
*/
reference
operator*() const
{
_GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(),
_M_message(__msg_bad_deref)
._M_iterator(*this, "this"));
return *_M_current;
}
/**
* @brief Iterator dereference.
* @pre iterator is dereferenceable
* @todo Make this correct w.r.t. iterators that return proxies
* @todo Use addressof() instead of & operator
*/
pointer
operator->() const
{
_GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(),
_M_message(__msg_bad_deref)
._M_iterator(*this, "this"));
return &*_M_current;
}
// ------ Input iterator requirements ------
/**
* @brief Iterator preincrement
* @pre iterator is incrementable
*/
_Safe_iterator&
operator++()
{
_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
_M_message(__msg_bad_inc)
._M_iterator(*this, "this"));
++_M_current;
return *this;
}
/**
* @brief Iterator postincrement
* @pre iterator is incrementable
*/
_Safe_iterator
operator++(int)
{
_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
_M_message(__msg_bad_inc)
._M_iterator(*this, "this"));
_Safe_iterator __tmp(*this);
++_M_current;
return __tmp;
}
// ------ Bidirectional iterator requirements ------
/**
* @brief Iterator predecrement
* @pre iterator is decrementable
*/
_Safe_iterator&
operator--()
{
_GLIBCXX_DEBUG_VERIFY(this->_M_decrementable(),
_M_message(__msg_bad_dec)
._M_iterator(*this, "this"));
--_M_current;
return *this;
}
/**
* @brief Iterator postdecrement
* @pre iterator is decrementable
*/
_Safe_iterator
operator--(int)
{
_GLIBCXX_DEBUG_VERIFY(this->_M_decrementable(),
_M_message(__msg_bad_dec)
._M_iterator(*this, "this"));
_Safe_iterator __tmp(*this);
--_M_current;
return __tmp;
}
// ------ Random access iterator requirements ------
reference
operator[](const difference_type& __n) const
{
_GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(__n)
&& this->_M_can_advance(__n+1),
_M_message(__msg_iter_subscript_oob)
._M_iterator(*this)._M_integer(__n));
return _M_current[__n];
}
_Safe_iterator&
operator+=(const difference_type& __n)
{
_GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(__n),
_M_message(__msg_advance_oob)
._M_iterator(*this)._M_integer(__n));
_M_current += __n;
return *this;
}
_Safe_iterator
operator+(const difference_type& __n) const
{
_Safe_iterator __tmp(*this);
__tmp += __n;
return __tmp;
}
_Safe_iterator&
operator-=(const difference_type& __n)
{
_GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(-__n),
_M_message(__msg_retreat_oob)
._M_iterator(*this)._M_integer(__n));
_M_current += -__n;
return *this;
}
_Safe_iterator
operator-(const difference_type& __n) const
{
_Safe_iterator __tmp(*this);
__tmp -= __n;
return __tmp;
}
// ------ Utilities ------
/**
* @brief Return the underlying iterator
*/
_Iterator
base() const { return _M_current; }
/**
* @brief Conversion to underlying non-debug iterator to allow
* better interaction with non-debug containers.
*/
operator _Iterator() const { return _M_current; }
/** Attach iterator to the given sequence. */
void
_M_attach(_Safe_sequence_base* __seq)
{
_Safe_iterator_base::_M_attach(__seq, _M_constant());
}
/** Likewise, but not thread-safe. */
void
_M_attach_single(_Safe_sequence_base* __seq)
{
_Safe_iterator_base::_M_attach_single(__seq, _M_constant());
}
/// Is the iterator dereferenceable?
bool
_M_dereferenceable() const
{ return !this->_M_singular() && !_M_is_end() && !_M_is_before_begin(); }
/// Is the iterator before a dereferenceable one?
bool
_M_before_dereferenceable() const
{
if (this->_M_incrementable())
{
_Iterator __base = base();
return ++__base != _M_get_sequence()->_M_base().end();
}
return false;
}
/// Is the iterator incrementable?
bool
_M_incrementable() const
{ return !this->_M_singular() && !_M_is_end(); }
// Is the iterator decrementable?
bool
_M_decrementable() const { return !_M_singular() && !_M_is_begin(); }
// Can we advance the iterator @p __n steps (@p __n may be negative)
bool
_M_can_advance(const difference_type& __n) const;
// Is the iterator range [*this, __rhs) valid?
template<typename _Other>
bool
_M_valid_range(const _Safe_iterator<_Other, _Sequence>& __rhs) const;
// The sequence this iterator references.
const _Sequence*
_M_get_sequence() const
{ return static_cast<const _Sequence*>(_M_sequence); }
/// Is this iterator equal to the sequence's begin() iterator?
bool _M_is_begin() const
{ return base() == _M_get_sequence()->_M_base().begin(); }
/// Is this iterator equal to the sequence's end() iterator?
bool _M_is_end() const
{ return base() == _M_get_sequence()->_M_base().end(); }
/// Is this iterator equal to the sequence's before_begin() iterator if
/// any?
bool _M_is_before_begin() const
{
return _BeforeBeginHelper<_Sequence>::_S_Is(base(), _M_get_sequence());
}
/// Is this iterator equal to the sequence's before_begin() iterator if
/// any or begin() otherwise?
bool _M_is_beginnest() const
{
return _BeforeBeginHelper<_Sequence>::_S_Is_Beginnest(base(),
_M_get_sequence());
}
};
template<typename _IteratorL, typename _IteratorR, typename _Sequence>
inline bool
operator==(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_compare_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_compare_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() == __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline bool
operator==(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_iterator<_Iterator, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_compare_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_compare_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() == __rhs.base();
}
template<typename _IteratorL, typename _IteratorR, typename _Sequence>
inline bool
operator!=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_compare_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_compare_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() != __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline bool
operator!=(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_iterator<_Iterator, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_compare_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_compare_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() != __rhs.base();
}
template<typename _IteratorL, typename _IteratorR, typename _Sequence>
inline bool
operator<(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_order_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_order_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() < __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline bool
operator<(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_iterator<_Iterator, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_order_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_order_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() < __rhs.base();
}
template<typename _IteratorL, typename _IteratorR, typename _Sequence>
inline bool
operator<=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_order_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_order_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() <= __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline bool
operator<=(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_iterator<_Iterator, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_order_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_order_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() <= __rhs.base();
}
template<typename _IteratorL, typename _IteratorR, typename _Sequence>
inline bool
operator>(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_order_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_order_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() > __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline bool
operator>(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_iterator<_Iterator, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_order_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_order_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() > __rhs.base();
}
template<typename _IteratorL, typename _IteratorR, typename _Sequence>
inline bool
operator>=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_order_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_order_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() >= __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline bool
operator>=(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_iterator<_Iterator, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_iter_order_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_order_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() >= __rhs.base();
}
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// According to the resolution of DR179 not only the various comparison
// operators but also operator- must accept mixed iterator/const_iterator
// parameters.
template<typename _IteratorL, typename _IteratorR, typename _Sequence>
inline typename _Safe_iterator<_IteratorL, _Sequence>::difference_type
operator-(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_distance_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_distance_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() - __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline typename _Safe_iterator<_Iterator, _Sequence>::difference_type
operator-(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_iterator<_Iterator, _Sequence>& __rhs)
{
_GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
_M_message(__msg_distance_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_distance_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() - __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline _Safe_iterator<_Iterator, _Sequence>
operator+(typename _Safe_iterator<_Iterator,_Sequence>::difference_type __n,
const _Safe_iterator<_Iterator, _Sequence>& __i)
{ return __i + __n; }
} // namespace __gnu_debug
#include <debug/safe_iterator.tcc>
#endif