/*=============================================================================

    Copyright (c) 2001-2006 Joel de Guzman

    Copyright (c) 2005-2006 Dan Marsden



    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)

==============================================================================*/

#if !defined(FUSION_ADVANCE_IMPL_13122005_1906)

#define FUSION_ADVANCE_IMPL_13122005_1906



#include <boost/fusion/iterator/advance.hpp>



namespace boost { namespace fusion 

{

    struct transform_view_iterator_tag;

    struct transform_view_iterator2_tag;



    template<typename First, typename F>

    struct transform_view_iterator;



    template <typename First1, typename First2, typename F>

    struct transform_view_iterator2;



    namespace extension

    {

        template<typename Tag>

        struct advance_impl;



        // Unary Version

        template<>

        struct advance_impl<transform_view_iterator_tag>

        {

            template<typename Iterator, typename Dist>

            struct apply

            {

                typedef typename Iterator::first_type first_type;

                typedef typename result_of::advance<first_type, Dist>::type advanced_type;

                typedef typename Iterator::transform_type transform_type;

                typedef transform_view_iterator<advanced_type, transform_type> type;



                static type

                call(Iterator const& i)

                {

                    return type(boost::fusion::advance<Dist>(i.first), i.f);

                }

            };

        };



        // Binary Version

        template<>

        struct advance_impl<transform_view_iterator2_tag>

        {

            template<typename Iterator, typename Dist>

            struct apply

            {

                typedef typename Iterator::first1_type first1_type;

                typedef typename Iterator::first2_type first2_type;

                typedef typename result_of::advance<first1_type, Dist>::type advanced1_type;

                typedef typename result_of::advance<first2_type, Dist>::type advanced2_type;

                typedef typename Iterator::transform_type transform_type;

                typedef transform_view_iterator2<advanced1_type, advanced2_type, transform_type> type;



                static type

                call(Iterator const& i)

                {

                    return type(

                        boost::fusion::advance<Dist>(i.first1)

                      , boost::fusion::advance<Dist>(i.first2), i.f);

                }

            };

        };

    }

}}



#endif

