type_seq_begin_end_trts.hpp

C++的一个好库。。。现在很流行

/*=============================================================================
    Copyright (c) 2003 Joel de Guzman

    Use, modification and distribution is subject to 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_SEQUENCE_DETAIL_TYPE_SEQUENCE_BEGIN_END_TRAITS_HPP)
#define FUSION_SEQUENCE_DETAIL_TYPE_SEQUENCE_BEGIN_END_TRAITS_HPP

#include <boost/spirit/fusion/detail/config.hpp>
#include <boost/mpl/begin_end.hpp>

namespace boost { namespace fusion
{
    template <typename Iterator>
    struct type_sequence_iterator;

    struct type_sequence_tag;

    template <typename SequenceT>
    struct type_sequence;

    namespace meta
    {
        template <typename Tag>
        struct begin_impl;

        template <>
        struct begin_impl<type_sequence_tag>
        {
            template <typename Sequence>
            struct apply
            {
                typedef type_sequence_iterator<
                    typename mpl::begin<typename Sequence::sequence_type>::type>
                type;

                static type
                call(Sequence)
                {
                    FUSION_RETURN_DEFAULT_CONSTRUCTED;
                }
            };
        };

        template <typename Tag>
        struct end_impl;

        template <>
        struct end_impl<type_sequence_tag>
        {
            template <typename Sequence>
            struct apply
            {
                typedef type_sequence_iterator<
                    typename mpl::end<typename Sequence::sequence_type>::type>
                type;

                static type
                call(Sequence)
                {
                    FUSION_RETURN_DEFAULT_CONSTRUCTED;
                }
            };
        };
    }
}}

namespace boost { namespace mpl
{
    template <typename Tag>
    struct begin_impl;

    template <typename Tag>
    struct end_impl;

    template <>
    struct begin_impl<fusion::type_sequence_tag>
        : fusion::meta::begin_impl<fusion::type_sequence_tag> {};

    template <>
    struct end_impl<fusion::type_sequence_tag>
        : fusion::meta::end_impl<fusion::type_sequence_tag> {};
}}

#endif