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

    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_ITERATOR_DETAIL_JOINT_VIEW_ITERATOR_NEXT_TRAITS_HPP)

#define FUSION_ITERATOR_DETAIL_JOINT_VIEW_ITERATOR_NEXT_TRAITS_HPP



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

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

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

#include <boost/mpl/if.hpp>



namespace boost { namespace fusion

{

    struct joint_view_iterator_tag;



    template <typename View1, typename View2>

    struct joint_view;



    template <typename First, typename Last, typename Concat>

    struct joint_view_iterator;



    namespace join_view_detail {

        template<typename Iterator>

        struct next_traits_impl {

            typedef typename Iterator::first_type first_type;

            typedef typename Iterator::last_type last_type;

            typedef typename Iterator::concat_type concat_type;

            typedef typename meta::next<first_type>::type next_type;

            typedef meta::equal_to<next_type, last_type> equal_to;



            typedef typename

                mpl::if_<

                    equal_to

                  , concat_type

                  , joint_view_iterator<next_type, last_type, concat_type>

                >::type

            type;



            static type

            call(Iterator const& i);

        };



        template<typename Iterator>

        typename next_traits_impl<Iterator>::type 

        call(Iterator const& i, mpl::true_)

        {

            return i.concat;

        }

        

        template<typename Iterator>

        typename next_traits_impl<Iterator>::type 

        call(Iterator const& i, mpl::false_)

        {

            typedef typename next_traits_impl<Iterator>::type type;

            return type(fusion::next(i.first), i.concat);

        }



        template<typename Iterator>

        typename next_traits_impl<Iterator>::type

        next_traits_impl<Iterator>::call(Iterator const& i)

        {

            return join_view_detail::call(i, equal_to());

        }

    }



    namespace meta

    {

        template <typename Tag>

        struct next_impl;



        template <>

        struct next_impl<joint_view_iterator_tag>

        {

            template <typename Iterator>

            struct apply : join_view_detail::next_traits_impl<Iterator>

            {};

        };

    }

}}



#endif





