iterator.h
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// -*- C++ -*-
// Copyright (C) 2007-2026 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 parallel/iterator.h
* @brief Helper iterator classes for the std::transform() functions.
* This file is a GNU parallel extension to the Standard C++ Library.
*/
// Written by Johannes Singler.
#ifndef _GLIBCXX_PARALLEL_ITERATOR_H
#define _GLIBCXX_PARALLEL_ITERATOR_H 1
#include <parallel/basic_iterator.h>
#include <bits/stl_pair.h>
namespace __gnu_parallel
{
/** @brief A pair of iterators. The usual iterator operations are
* applied to both child iterators.
*/
template<typename _Iterator1, typename _Iterator2,
typename _IteratorCategory>
class _IteratorPair : public std::pair<_Iterator1, _Iterator2>
{
private:
typedef std::pair<_Iterator1, _Iterator2> _Base;
public:
typedef _IteratorCategory iterator_category;
typedef void value_type;
typedef std::iterator_traits<_Iterator1> _TraitsType;
typedef typename _TraitsType::difference_type difference_type;
typedef _IteratorPair* pointer;
typedef _IteratorPair& reference;
_IteratorPair() { }
_IteratorPair(const _Iterator1& __first, const _Iterator2& __second)
: _Base(__first, __second) { }
// Pre-increment operator.
_IteratorPair&
operator++()
{
++_Base::first;
++_Base::second;
return *this;
}
// Post-increment operator.
const _IteratorPair
operator++(int)
{ return _IteratorPair(_Base::first++, _Base::second++); }
// Pre-decrement operator.
_IteratorPair&
operator--()
{
--_Base::first;
--_Base::second;
return *this;
}
// Post-decrement operator.
const _IteratorPair
operator--(int)
{ return _IteratorPair(_Base::first--, _Base::second--); }
// Type conversion.
operator _Iterator2() const
{ return _Base::second; }
_IteratorPair&
operator=(const _IteratorPair& __other)
{
_Base::first = __other.first;
_Base::second = __other.second;
return *this;
}
_IteratorPair
operator+(difference_type __delta) const
{ return _IteratorPair(_Base::first + __delta, _Base::second + __delta);
}
difference_type
operator-(const _IteratorPair& __other) const
{ return _Base::first - __other.first; }
};
/** @brief A triple of iterators. The usual iterator operations are
applied to all three child iterators.
*/
template<typename _Iterator1, typename _Iterator2, typename _Iterator3,
typename _IteratorCategory>
class _IteratorTriple
{
public:
typedef _IteratorCategory iterator_category;
typedef void value_type;
typedef typename std::iterator_traits<_Iterator1>::difference_type
difference_type;
typedef _IteratorTriple* pointer;
typedef _IteratorTriple& reference;
_Iterator1 _M_first;
_Iterator2 _M_second;
_Iterator3 _M_third;
_IteratorTriple() { }
_IteratorTriple(const _Iterator1& __first, const _Iterator2& __second,
const _Iterator3& __third)
{
_M_first = __first;
_M_second = __second;
_M_third = __third;
}
// Pre-increment operator.
_IteratorTriple&
operator++()
{
++_M_first;
++_M_second;
++_M_third;
return *this;
}
// Post-increment operator.
const _IteratorTriple
operator++(int)
{ return _IteratorTriple(_M_first++, _M_second++, _M_third++); }
// Pre-decrement operator.
_IteratorTriple&
operator--()
{
--_M_first;
--_M_second;
--_M_third;
return *this;
}
// Post-decrement operator.
const _IteratorTriple
operator--(int)
{ return _IteratorTriple(_M_first--, _M_second--, _M_third--); }
// Type conversion.
operator _Iterator3() const
{ return _M_third; }
_IteratorTriple&
operator=(const _IteratorTriple& __other)
{
_M_first = __other._M_first;
_M_second = __other._M_second;
_M_third = __other._M_third;
return *this;
}
_IteratorTriple
operator+(difference_type __delta) const
{ return _IteratorTriple(_M_first + __delta, _M_second + __delta,
_M_third + __delta); }
difference_type
operator-(const _IteratorTriple& __other) const
{ return _M_first - __other._M_first; }
};
}
#endif /* _GLIBCXX_PARALLEL_ITERATOR_H */
stl_pair.h
basic_iterator.h
Includes the original header files concerned with iterators except for stream iterators....
__gnu_parallel
GNU parallel code for public use.
Definition balanced_quicksort.h:62
std::iterator_traits
Traits class for iterators.
Definition stl_iterator_base_types.h:180
std::pair
Struct holding two objects (or references) of arbitrary type.
Definition stl_pair.h:307
std::pair< _Iterator1, _Iterator2 >::first
_Iterator1 first
Definition stl_pair.h:311
std::pair< _Iterator1, _Iterator2 >::second
_Iterator2 second
Definition stl_pair.h:312