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#ifndef BOOST_MPL_ADVANCE_HPP_INCLUDED
#define BOOST_MPL_ADVANCE_HPP_INCLUDED
// Copyright Aleksey Gurtovoy 2000-2004
//
// 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/mpl for documentation.
// $Id$
// $Date$
// $Revision$
#include <boost/mpl/advance_fwd.hpp>
#include <boost/mpl/less.hpp>
#include <boost/mpl/negate.hpp>
#include <boost/mpl/long.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/tag.hpp>
#include <boost/mpl/apply_wrap.hpp>
#include <boost/mpl/aux_/advance_forward.hpp>
#include <boost/mpl/aux_/advance_backward.hpp>
#include <boost/mpl/aux_/value_wknd.hpp>
#include <boost/mpl/aux_/na_spec.hpp>
#include <boost/mpl/aux_/nttp_decl.hpp>
namespace boost { namespace mpl {
// default implementation for forward/bidirectional iterators
template< typename Tag >
struct advance_impl
{
template< typename Iterator, typename N > struct apply
{
typedef typename less< N,long_<0> >::type backward_;
typedef typename if_< backward_, negate<N>, N >::type offset_;
typedef typename if_<
backward_
, aux::advance_backward< BOOST_MPL_AUX_VALUE_WKND(offset_)::value >
, aux::advance_forward< BOOST_MPL_AUX_VALUE_WKND(offset_)::value >
>::type f_;
typedef typename apply_wrap1<f_,Iterator>::type type;
};
};
template<
typename BOOST_MPL_AUX_NA_PARAM(Iterator)
, typename BOOST_MPL_AUX_NA_PARAM(N)
>
struct advance
: advance_impl< typename tag<Iterator>::type >
::template apply<Iterator,N>
{
};
template<
typename Iterator
, BOOST_MPL_AUX_NTTP_DECL(long, N)
>
struct advance_c
: advance_impl< typename tag<Iterator>::type >
::template apply<Iterator,long_<N> >
{
};
BOOST_MPL_AUX_NA_SPEC(2, advance)
}}
#endif // BOOST_MPL_ADVANCE_HPP_INCLUDED