ext-boost/boost/intrusive/detail/reverse_iterator.hpp
2017-03-12 21:30:15 -07:00

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4.5 KiB
C++

/////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2014-2014
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/intrusive for documentation.
//
/////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_INTRUSIVE_DETAIL_REVERSE_ITERATOR_HPP
#define BOOST_INTRUSIVE_DETAIL_REVERSE_ITERATOR_HPP
#ifndef BOOST_CONFIG_HPP
# include <boost/config.hpp>
#endif
#if defined(BOOST_HAS_PRAGMA_ONCE)
# pragma once
#endif
#include <boost/intrusive/detail/config_begin.hpp>
#include <boost/intrusive/detail/iterator.hpp>
#include <boost/intrusive/detail/mpl.hpp>
namespace boost {
namespace intrusive {
template<class It>
class reverse_iterator
{
public:
typedef typename boost::intrusive::iterator_traits<It>::pointer pointer;
typedef typename boost::intrusive::iterator_traits<It>::reference reference;
typedef typename boost::intrusive::iterator_traits<It>::difference_type difference_type;
typedef typename boost::intrusive::iterator_traits<It>::iterator_category iterator_category;
typedef typename boost::intrusive::iterator_traits<It>::value_type value_type;
typedef It iterator_type;
reverse_iterator()
: m_current() //Value initialization to achieve "null iterators" (N3644)
{}
explicit reverse_iterator(It r)
: m_current(r)
{}
reverse_iterator(const reverse_iterator& r)
: m_current(r.base())
{}
template<class OtherIt>
reverse_iterator( const reverse_iterator<OtherIt>& r
, typename boost::intrusive::detail::enable_if_convertible<OtherIt, It>::type* =0
)
: m_current(r.base())
{}
reverse_iterator & operator=( const reverse_iterator& r)
{ m_current = r.base(); return *this; }
template<class OtherIt>
typename boost::intrusive::detail::enable_if_convertible<OtherIt, It, reverse_iterator &>::type
operator=( const reverse_iterator<OtherIt>& r)
{ m_current = r.base(); return *this; }
It base() const
{ return m_current; }
reference operator*() const
{
It temp(m_current);
--temp;
reference r = *temp;
return r;
}
pointer operator->() const
{
It temp(m_current);
--temp;
return iterator_arrow_result(temp);
}
reference operator[](difference_type off) const
{
return this->m_current[-off - 1];
}
reverse_iterator& operator++()
{
--m_current;
return *this;
}
reverse_iterator operator++(int)
{
reverse_iterator temp((*this));
--m_current;
return temp;
}
reverse_iterator& operator--()
{
++m_current;
return *this;
}
reverse_iterator operator--(int)
{
reverse_iterator temp((*this));
++m_current;
return temp;
}
friend bool operator==(const reverse_iterator& l, const reverse_iterator& r)
{ return l.m_current == r.m_current; }
friend bool operator!=(const reverse_iterator& l, const reverse_iterator& r)
{ return l.m_current != r.m_current; }
friend bool operator<(const reverse_iterator& l, const reverse_iterator& r)
{ return l.m_current > r.m_current; }
friend bool operator<=(const reverse_iterator& l, const reverse_iterator& r)
{ return l.m_current >= r.m_current; }
friend bool operator>(const reverse_iterator& l, const reverse_iterator& r)
{ return l.m_current < r.m_current; }
friend bool operator>=(const reverse_iterator& l, const reverse_iterator& r)
{ return l.m_current <= r.m_current; }
reverse_iterator& operator+=(difference_type off)
{ m_current -= off; return *this; }
reverse_iterator& operator-=(difference_type off)
{ m_current += off; return *this; }
friend reverse_iterator operator+(reverse_iterator l, difference_type off)
{ return (l += off); }
friend reverse_iterator operator+(difference_type off, reverse_iterator r)
{ return (r += off); }
friend reverse_iterator operator-(reverse_iterator l, difference_type off)
{ return (l-= off); }
friend difference_type operator-(const reverse_iterator& l, const reverse_iterator& r)
{ return r.m_current - l.m_current; }
private:
It m_current; // the wrapped iterator
};
} //namespace intrusive {
} //namespace boost {
#include <boost/intrusive/detail/config_end.hpp>
#endif //BOOST_INTRUSIVE_DETAIL_REVERSE_ITERATOR_HPP