// Copyright 2004 Alexander Nasonov. 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)

#ifndef BOOST_MPL_EMPTY_SEQUENCE_HPP_INCLUDED
#define BOOST_MPL_EMPTY_SEQUENCE_HPP_INCLUDED

#include <boost/mpl/clear_fwd.hpp>
#include <boost/mpl/iterator_tag.hpp>

namespace boost { namespace mpl {

namespace aux {

struct empty_sequence_tag;

struct empty_sequence_iter
{
    typedef forward_iterator_tag category;
};

}

struct empty_sequence
{
    typedef aux::empty_sequence_iter begin;
    typedef aux::empty_sequence_iter end;
    typedef aux::empty_sequence_tag  tag;
};

template<>
struct clear_traits<aux::empty_sequence_tag>
{
    template<typename EmptySequence>
    struct algorithm
    {
        typedef empty_sequence type;
    };
};

}}

#endif // #ifndef BOOST_MPL_EMPTY_SEQUENCE_HPP_INCLUDED