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

    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_FILTER_VIEW_ITERATOR_NEXT_TRAITS_HPP)

#define FUSION_ITERATOR_DETAIL_FILTER_VIEW_ITERATOR_NEXT_TRAITS_HPP



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

#include <boost/spirit/fusion/algorithm/detail/find_if.ipp>

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

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

#include <boost/mpl/eval_if.hpp>

#include <boost/mpl/identity.hpp>



namespace boost { namespace fusion

{

    struct filter_view_iterator_tag;



    template <typename First, typename Last, typename Pred>

    struct filter_iterator;



    namespace filter_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::pred_type pred_type;



            typedef typename

                mpl::eval_if<

                    meta::equal_to<first_type, last_type>

                  , mpl::identity<last_type>

                  , meta::next<first_type>

                >::type

            next_type;



            typedef typename detail::static_find_if<

                next_type, last_type, pred_type>

            filter;



            typedef filter_iterator<

                typename filter::type, last_type, pred_type>

            type;



            static type

            call(Iterator const& i);

        };

        template<typename Iterator>

        typename next_traits_impl<Iterator>::type 

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

        {

            return type(filter::call(i.first));

        }

    }



    namespace meta

    {

        template <typename Tag>

        struct next_impl;



        template <>

        struct next_impl<filter_view_iterator_tag>

        {

            template <typename Iterator>

            struct apply : filter_view_detail::next_traits_impl<Iterator>

            {};

        };

    }

}}



#endif





