#ifndef BOOST_MPL_EMPTY_BASE_HPP_INCLUDED

#define BOOST_MPL_EMPTY_BASE_HPP_INCLUDED

// Copyright Aleksey Gurtovoy 2001-2004

//

// 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)

//

// See http://www.boost.org/libs/mpl for documentation.

// $Source: /cvsroot/boost/boost/boost/mpl/empty_base.hpp,v $

// $Date: 2004/09/02 15:40:41 $

// $Revision: 1.4 $

#include <boost/mpl/bool.hpp>

#include <boost/mpl/aux_/config/msvc.hpp>

#include <boost/mpl/aux_/config/workaround.hpp>

#include <boost/type_traits/is_empty.hpp>

// should be always the last #include directive

#include <boost/type_traits/detail/bool_trait_def.hpp>

namespace boost { namespace mpl {

// empty base class, guaranteed to have no members; inheritance from

// 'empty_base' through the 'inherit' metafunction is a no-op - see 

// "mpl/inherit.hpp> header for the details

struct empty_base {};

template< typename T >

struct is_empty_base

    : false_

{

#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)

    using false_::value;

#endif

};

template<>

struct is_empty_base<empty_base>

    : true_

{

#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)

    using true_::value;

#endif

};

}}

namespace boost {

BOOST_TT_AUX_BOOL_TRAIT_SPEC1(is_empty, mpl::empty_base, true)

}

#include <boost/type_traits/detail/bool_trait_undef.hpp>

#endif // BOOST_MPL_EMPTY_BASE_HPP_INCLUDED