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

    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_JOINT_VIEW_07162005_0140)

#define FUSION_JOINT_VIEW_07162005_0140



#include <boost/fusion/support/detail/access.hpp>

#include <boost/fusion/support/is_view.hpp>

#include <boost/fusion/sequence/intrinsic/begin.hpp>

#include <boost/fusion/sequence/intrinsic/end.hpp>

#include <boost/fusion/sequence/intrinsic/size.hpp>

#include <boost/fusion/view/joint_view/joint_view_iterator.hpp>

#include <boost/fusion/view/joint_view/detail/begin_impl.hpp>

#include <boost/fusion/view/joint_view/detail/end_impl.hpp>

#include <boost/fusion/support/sequence_base.hpp>

#include <boost/mpl/if.hpp>

#include <boost/mpl/plus.hpp>

#include <boost/mpl/bool.hpp>



namespace boost { namespace fusion

{

    struct joint_view_tag;

    struct forward_traversal_tag;

    struct fusion_sequence_tag;



    template <typename Sequence1, typename Sequence2>

    struct joint_view : sequence_base<joint_view<Sequence1, Sequence2> >

    {

        typedef joint_view_tag fusion_tag;

        typedef fusion_sequence_tag tag; // this gets picked up by MPL

        typedef forward_traversal_tag category;

        typedef mpl::true_ is_view;



        typedef typename result_of::begin<Sequence1>::type first_type;

        typedef typename result_of::end<Sequence1>::type last_type;

        typedef typename result_of::begin<Sequence2>::type concat_type;

        typedef typename result_of::end<Sequence2>::type concat_last_type;

        typedef typename mpl::plus<result_of::size<Sequence1>, result_of::size<Sequence2> >::type size;



        joint_view(Sequence1& seq1, Sequence2& seq2)

            : seq1(seq1)

            , seq2(seq2)

        {}



        first_type first() const { return fusion::begin(seq1); }

        concat_type concat() const { return fusion::begin(seq2); }

        concat_last_type concat_last() const { return fusion::end(seq2); }



    private:



        typename mpl::if_<traits::is_view<Sequence1>, Sequence1, Sequence1&>::type seq1;

        typename mpl::if_<traits::is_view<Sequence2>, Sequence2, Sequence2&>::type seq2;

    };

}}



#endif





