60 lines
1.4 KiB
C++
60 lines
1.4 KiB
C++
|
|
#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.
|
|
|
|
// $Id: empty_base.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
|
|
// $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $
|
|
// $Revision: 49267 $
|
|
|
|
#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
|