| |
| #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. |
| |
| // $Id$ |
| // $Date$ |
| // $Revision$ |
| |
| #include <boost/mpl/bool.hpp> |
| #include <boost/mpl/aux_/config/msvc.hpp> |
| #include <boost/mpl/aux_/config/workaround.hpp> |
| #include <boost/mpl/aux_/lambda_support.hpp> |
| |
| #include <boost/type_traits/integral_constant.hpp> |
| #include <boost/type_traits/is_empty.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 { |
| |
| template<> struct is_empty< mpl::empty_base > |
| : public ::boost::integral_constant<bool,true> |
| { |
| public: |
| BOOST_MPL_AUX_LAMBDA_SUPPORT_SPEC(1,is_empty,(mpl::empty_base)) |
| }; |
| |
| } |
| |
| #endif // BOOST_MPL_EMPTY_BASE_HPP_INCLUDED |