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

    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_ERASE_07232005_0534)

#define FUSION_ERASE_07232005_0534



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

#include <boost/fusion/iterator/mpl/convert_iterator.hpp>

#include <boost/fusion/container/vector/vector10.hpp>

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

#include <boost/fusion/view/iterator_range/iterator_range.hpp>

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

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

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

#include <boost/fusion/adapted/mpl/mpl_iterator.hpp>



namespace boost { namespace fusion

{

    namespace result_of

    {

        template <typename Sequence, typename First>

        struct compute_erase_last // put this in detail!!!

        {

            typedef typename result_of::end<Sequence>::type seq_last_type;

            typedef typename convert_iterator<First>::type first_type;

            typedef typename

                mpl::if_<

                    result_of::equal_to<first_type, seq_last_type>

                  , first_type

                  , typename result_of::next<first_type>::type

                >::type

            type;



            static type

            call(First const& first, mpl::false_)

            {

                return fusion::next(convert_iterator<First>::call(first));

            }



            static type

            call(First const& first, mpl::true_)

            {

                return convert_iterator<First>::call(first);

            }



            static type

            call(First const& first)

            {

                return call(first, result_of::equal_to<first_type, seq_last_type>());

            }

        };



        template <

            typename Sequence

          , typename First

          , typename Last = typename compute_erase_last<Sequence, First>::type>

        struct erase

        {

            typedef typename result_of::begin<Sequence>::type seq_first_type;

            typedef typename result_of::end<Sequence>::type seq_last_type;

            BOOST_STATIC_ASSERT((!result_of::equal_to<seq_first_type, seq_last_type>::value));



            typedef typename convert_iterator<First>::type first_type;

            typedef typename convert_iterator<Last>::type last_type;

            typedef iterator_range<seq_first_type, first_type> left_type;

            typedef iterator_range<last_type, seq_last_type> right_type;

            typedef joint_view<left_type, right_type> type;

        };

    }



    template <typename Sequence, typename First>

    typename result_of::erase<Sequence const, First>::type

    erase(Sequence const& seq, First const& first)

    {

        typedef result_of::erase<Sequence const, First> result_of;

        typedef typename result_of::left_type left_type;

        typedef typename result_of::right_type right_type;

        typedef typename result_of::type result_type;



        left_type left(

            fusion::begin(seq)

          , convert_iterator<First>::call(first));

        right_type right(

            fusion::result_of::compute_erase_last<Sequence const, First>::call(first)

          , fusion::end(seq));

        return result_type(left, right);

    }



    template <typename Sequence, typename First, typename Last>

    typename result_of::erase<Sequence const, First, Last>::type

    erase(Sequence const& seq, First const& first, Last const& last)

    {

        typedef result_of::erase<Sequence const, First, Last> result_of;

        typedef typename result_of::left_type left_type;

        typedef typename result_of::right_type right_type;

        typedef typename result_of::type result_type;



        left_type left(fusion::begin(seq), first);

        right_type right(last, fusion::end(seq));

        return result_type(left, right);

    }

}}



#endif



