begin_impl.hpp

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/*=============================================================================
    Copyright (c) 2005 Joel de Guzman
    Copyright (c) 2005 Eric Niebler

    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_BEGIN_IMPL_07172005_0824)
#define FUSION_BEGIN_IMPL_07172005_0824

#include <boost/mpl/if.hpp>
#include <boost/type_traits/is_const.hpp>

namespace boost { namespace fusion
{
    struct nil;

    struct cons_tag;

    template <typename Car, typename Cdr>
    struct cons;

    template <typename Cons>
    struct cons_iterator;

    namespace extension
    {
        template <typename Tag>
        struct begin_impl;

        template <>
        struct begin_impl<cons_tag>
        {
            template <typename Sequence>
            struct apply
            {
                typedef cons_iterator<Sequence> type;
    
                static type
                call(Sequence& t)
                {
                    return type(t);
                }
            };
        };
    }
}}

#endif