| |
| #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 |