sl@0: 
sl@0: #ifndef BOOST_MPL_ADVANCE_HPP_INCLUDED
sl@0: #define BOOST_MPL_ADVANCE_HPP_INCLUDED
sl@0: 
sl@0: // Copyright Aleksey Gurtovoy 2000-2004
sl@0: //
sl@0: // Distributed under the Boost Software License, Version 1.0. 
sl@0: // (See accompanying file LICENSE_1_0.txt or copy at 
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: //
sl@0: // See http://www.boost.org/libs/mpl for documentation.
sl@0: 
sl@0: // $Source: /cvsroot/boost/boost/boost/mpl/advance.hpp,v $
sl@0: // $Date: 2004/09/02 15:40:41 $
sl@0: // $Revision: 1.9 $
sl@0: 
sl@0: #include <boost/mpl/advance_fwd.hpp>
sl@0: #include <boost/mpl/less.hpp>
sl@0: #include <boost/mpl/negate.hpp>
sl@0: #include <boost/mpl/long.hpp>
sl@0: #include <boost/mpl/if.hpp>
sl@0: #include <boost/mpl/tag.hpp>
sl@0: #include <boost/mpl/apply_wrap.hpp>
sl@0: #include <boost/mpl/aux_/advance_forward.hpp>
sl@0: #include <boost/mpl/aux_/advance_backward.hpp>
sl@0: #include <boost/mpl/aux_/value_wknd.hpp>
sl@0: #include <boost/mpl/aux_/na_spec.hpp>
sl@0: #include <boost/mpl/aux_/nttp_decl.hpp>
sl@0: 
sl@0: namespace boost { namespace mpl {
sl@0: 
sl@0: // default implementation for forward/bidirectional iterators
sl@0: template< typename Tag >
sl@0: struct advance_impl
sl@0: {
sl@0:     template< typename Iterator, typename N > struct apply
sl@0:     {
sl@0:         typedef typename less< N,long_<0> >::type backward_;
sl@0:         typedef typename if_< backward_, negate<N>, N >::type offset_;
sl@0: 
sl@0:         typedef typename if_<
sl@0:               backward_
sl@0:             , aux::advance_backward< BOOST_MPL_AUX_VALUE_WKND(offset_)::value >
sl@0:             , aux::advance_forward< BOOST_MPL_AUX_VALUE_WKND(offset_)::value >
sl@0:             >::type f_;
sl@0: 
sl@0:         typedef typename apply_wrap1<f_,Iterator>::type type;
sl@0:     };
sl@0: };
sl@0: 
sl@0: 
sl@0: template<
sl@0:       typename BOOST_MPL_AUX_NA_PARAM(Iterator)
sl@0:     , typename BOOST_MPL_AUX_NA_PARAM(N)
sl@0:     >
sl@0: struct advance
sl@0:     : advance_impl< typename tag<Iterator>::type >
sl@0:         ::template apply<Iterator,N>
sl@0: {
sl@0: };
sl@0: 
sl@0: template<
sl@0:       typename Iterator
sl@0:     , BOOST_MPL_AUX_NTTP_DECL(long, N)
sl@0:     >
sl@0: struct advance_c
sl@0:     : advance_impl< typename tag<Iterator>::type >
sl@0:         ::template apply<Iterator,long_<N> >
sl@0: {
sl@0: };
sl@0: 
sl@0: BOOST_MPL_AUX_NA_SPEC(2, advance)
sl@0: 
sl@0: }}
sl@0: 
sl@0: #endif // BOOST_MPL_ADVANCE_HPP_INCLUDED