Chris@16: 
Chris@16: #ifndef BOOST_MPL_EMPTY_BASE_HPP_INCLUDED
Chris@16: #define BOOST_MPL_EMPTY_BASE_HPP_INCLUDED
Chris@16: 
Chris@16: // Copyright Aleksey Gurtovoy 2001-2004
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. 
Chris@16: // (See accompanying file LICENSE_1_0.txt or copy at 
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // See http://www.boost.org/libs/mpl for documentation.
Chris@16: 
Chris@101: // $Id$
Chris@101: // $Date$
Chris@101: // $Revision$
Chris@16: 
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/mpl/aux_/config/msvc.hpp>
Chris@16: #include <boost/mpl/aux_/config/workaround.hpp>
Chris@16: 
Chris@16: #include <boost/type_traits/is_empty.hpp>
Chris@16: 
Chris@16: // should be always the last #include directive
Chris@16: #include <boost/type_traits/detail/bool_trait_def.hpp>
Chris@16: 
Chris@16: namespace boost { namespace mpl {
Chris@16: 
Chris@16: // empty base class, guaranteed to have no members; inheritance from
Chris@16: // 'empty_base' through the 'inherit' metafunction is a no-op - see 
Chris@16: // "mpl/inherit.hpp> header for the details
Chris@16: struct empty_base {};
Chris@16: 
Chris@16: template< typename T >
Chris@16: struct is_empty_base
Chris@16:     : false_
Chris@16: {
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
Chris@16:     using false_::value;
Chris@16: #endif
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct is_empty_base<empty_base>
Chris@16:     : true_
Chris@16: {
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
Chris@16:     using true_::value;
Chris@16: #endif
Chris@16: };
Chris@16: 
Chris@16: }}
Chris@16: 
Chris@16: namespace boost {
Chris@16: BOOST_TT_AUX_BOOL_TRAIT_SPEC1(is_empty, mpl::empty_base, true)
Chris@16: }
Chris@16: 
Chris@16: #include <boost/type_traits/detail/bool_trait_undef.hpp>
Chris@16: 
Chris@16: #endif // BOOST_MPL_EMPTY_BASE_HPP_INCLUDED