size_impl.hpp

来自「Boost provides free peer-reviewed portab」· HPP 代码 · 共 39 行

/*=============================================================================
    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_SIZE_IMPL_09232005_1058)
#define FUSION_SIZE_IMPL_09232005_1058

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

namespace boost { namespace fusion
{
    struct filter_view_tag;

    namespace extension
    {
        template <typename Tag>
        struct size_impl;

        template <>
        struct size_impl<filter_view_tag>
        {
            template <typename Sequence>
            struct apply
                : result_of::distance<
                    typename result_of::begin<Sequence>::type
                  , typename result_of::end<Sequence>::type>
            {};
        };
    }
}}

#endif