#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: advance.hpp 49267 2008-10-11 06:19:02Z agurtovoy $ // $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $ // $Revision: 49267 $ #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