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

    Copyright (c) 2001-2006 Joel de Guzman



    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_NEXT_IMPL_06052005_0900)

#define FUSION_NEXT_IMPL_06052005_0900



#include <boost/fusion/algorithm/query/detail/find_if.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 extension

    {

        template <typename Tag>

        struct next_impl;



        template <>

        struct next_impl<filter_view_iterator_tag>

        {

            template <typename Iterator>

            struct apply

            {

                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<

                        result_of::equal_to<first_type, last_type>

                      , mpl::identity<last_type>

                      , result_of::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)

                {

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

                }

            };

        };

    }

}}



#endif





