safe_local_iterator.h
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// Safe iterator implementation -*- C++ -*-
// Copyright (C) 2011-2013 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_local_iterator.h
* This file is a GNU debug extension to the Standard C++ Library.
*/
#ifndef _GLIBCXX_DEBUG_SAFE_LOCAL_ITERATOR_H
#define _GLIBCXX_DEBUG_SAFE_LOCAL_ITERATOR_H 1
#include <debug/debug.h>
#include <debug/macros.h>
#include <debug/functions.h>
#include <debug/safe_unordered_base.h>
#include <ext/type_traits.h>
namespace __gnu_debug
{
/** \brief Safe iterator wrapper.
*
* The class template %_Safe_local_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_local_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_local_iterator : public _Safe_local_iterator_base
{
typedef _Safe_local_iterator _Self;
typedef typename _Sequence::size_type size_type;
/// The underlying iterator
_Iterator _M_current;
/// The bucket this local iterator belongs to
size_type _M_bucket;
/// Determine if this is a constant iterator.
bool
_M_constant() const
{
typedef typename _Sequence::const_local_iterator const_iterator;
return std::__are_same<const_iterator, _Safe_local_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_local_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_local_iterator(const _Iterator& __i, size_type __bucket,
const _Sequence* __seq)
: _Safe_local_iterator_base(__seq, _M_constant()), _M_current(__i),
_M_bucket(__bucket)
{
_GLIBCXX_DEBUG_VERIFY(!this->_M_singular(),
_M_message(__msg_init_singular)
._M_iterator(*this, "this"));
}
/**
* @brief Copy construction.
*/
_Safe_local_iterator(const _Safe_local_iterator& __x)
: _Safe_local_iterator_base(__x, _M_constant()),
_M_current(__x._M_current), _M_bucket(__x._M_bucket)
{
// _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"));
}
/**
* @brief Converting constructor from a mutable iterator to a
* constant iterator.
*/
template<typename _MutableIterator>
_Safe_local_iterator(
const _Safe_local_iterator<_MutableIterator,
typename __gnu_cxx::__enable_if<std::__are_same<
_MutableIterator,
typename _Sequence::local_iterator::iterator_type>::__value,
_Sequence>::__type>& __x)
: _Safe_local_iterator_base(__x, _M_constant()),
_M_current(__x.base()), _M_bucket(__x._M_bucket)
{
// _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_local_iterator&
operator=(const _Safe_local_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;
_M_bucket = __x._M_bucket;
this->_M_attach(__x._M_sequence);
return *this;
}
/**
* @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_local_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_local_iterator
operator++(int)
{
_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
_M_message(__msg_bad_inc)
._M_iterator(*this, "this"));
_Safe_local_iterator __tmp(*this);
++_M_current;
return __tmp;
}
// ------ Utilities ------
/**
* @brief Return the underlying iterator
*/
_Iterator
base() const { return _M_current; }
/**
* @brief Return the bucket
*/
size_type
bucket() const { return _M_bucket; }
/**
* @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(); }
/// Is the iterator incrementable?
bool
_M_incrementable() const
{ return !this->_M_singular() && !_M_is_end(); }
// Is the iterator range [*this, __rhs) valid?
template<typename _Other>
bool
_M_valid_range(const _Safe_local_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(_M_bucket); }
/// Is this iterator equal to the sequence's end() iterator?
bool _M_is_end() const
{ return base() == _M_get_sequence()->_M_base().end(_M_bucket); }
/// Is this iterator part of the same bucket as the other one?
template <typename _Other>
bool _M_in_same_bucket(const _Safe_local_iterator<_Other,
_Sequence>& __other) const
{ return _M_bucket == __other.bucket(); }
};
template<typename _IteratorL, typename _IteratorR, typename _Sequence>
inline bool
operator==(const _Safe_local_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_local_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"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
_M_message(__msg_compare_different)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_in_same_bucket(__rhs),
_M_message(__msg_local_iter_compare_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() == __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline bool
operator==(const _Safe_local_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_local_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"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_in_same_bucket(__rhs),
_M_message(__msg_local_iter_compare_bad)
._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_local_iterator<_IteratorL, _Sequence>& __lhs,
const _Safe_local_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"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_in_same_bucket(__rhs),
_M_message(__msg_local_iter_compare_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() != __rhs.base();
}
template<typename _Iterator, typename _Sequence>
inline bool
operator!=(const _Safe_local_iterator<_Iterator, _Sequence>& __lhs,
const _Safe_local_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"));
_GLIBCXX_DEBUG_VERIFY(__lhs._M_in_same_bucket(__rhs),
_M_message(__msg_local_iter_compare_bad)
._M_iterator(__lhs, "lhs")
._M_iterator(__rhs, "rhs"));
return __lhs.base() != __rhs.base();
}
} // namespace __gnu_debug
#include <debug/safe_local_iterator.tcc>
#endif