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

    Copyright (c) 2003 Joel de Guzman

    Copyright (c) 2004 Peder Holt



    Use, modification and distribution is subject to 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_SEQUENCE_DETAIL_JOINT_VIEW_BEGIN_END_TRAITS_HPP)

#define FUSION_SEQUENCE_DETAIL_JOINT_VIEW_BEGIN_END_TRAITS_HPP



#include <boost/spirit/fusion/detail/config.hpp>

#include <boost/spirit/fusion/iterator/equal_to.hpp>

#include <boost/mpl/if.hpp>



namespace boost { namespace fusion

{

    struct joint_view_tag;



    template <typename View1, typename View2>

    struct joint_view;



    template <typename First, typename Last, typename Concat>

    struct joint_view_iterator;



    namespace joint_view_detail {

        template <typename Sequence>

        struct begin_traits_impl

        {

            typedef typename Sequence::first_type first_type;

            typedef typename Sequence::last_type last_type;

            typedef typename Sequence::concat_type concat_type;

            typedef boost::fusion::meta::equal_to<first_type, last_type> equal_to;



            typedef typename

                boost::mpl::if_<

                    equal_to

                  , concat_type

                  , boost::fusion::joint_view_iterator<first_type, last_type, concat_type>

                >::type

            type;



            static type

            call(Sequence& s);

        };



        template<typename Sequence>

        typename begin_traits_impl<Sequence>::type

        call(Sequence& s, boost::mpl::true_) {

            return s.concat;

        }



        template<typename Sequence>

        typename begin_traits_impl<Sequence>::type

        call(Sequence& s, boost::mpl::false_) {

            typedef BOOST_DEDUCED_TYPENAME begin_traits_impl<Sequence>::type type;

            return type(s.first, s.concat);

        }



        template<typename Sequence>

        typename begin_traits_impl<Sequence>::type 

        begin_traits_impl<Sequence>::call(Sequence& s)

        {

            return joint_view_detail::call(s, equal_to());

        }



        template <typename Sequence>

        struct end_traits_impl

        {

            typedef typename Sequence::concat_last_type type;



            static type

            call(Sequence& s);

        };



        template<typename Sequence>

        typename end_traits_impl<Sequence>::type 

        end_traits_impl<Sequence>::call(Sequence& s)

        {

            return s.concat_last;

        }

    }



    namespace meta

    {

        template <typename Tag>

        struct begin_impl;



        template <>

        struct begin_impl<joint_view_tag>

        {

            template <typename Sequence>

            struct apply : joint_view_detail::begin_traits_impl<Sequence>

            {};

        };



        template <typename Tag>

        struct end_impl;



        template <>

        struct end_impl<joint_view_tag>

        {

            template <typename Sequence>

            struct apply : joint_view_detail::end_traits_impl<Sequence>

            {};

        };

    }

}}



namespace boost { namespace mpl

{

    template <typename Tag>

    struct begin_impl;



    template <typename Tag>

    struct end_impl;



    template <>

    struct begin_impl<fusion::joint_view_tag>

        : fusion::meta::begin_impl<fusion::joint_view_tag> {};



    template <>

    struct end_impl<fusion::joint_view_tag>

        : fusion::meta::end_impl<fusion::joint_view_tag> {};

}}



#endif





