map/aux_/contains_impl.hpp

0001
0002 #ifndef BOOST_MPL_MAP_AUX_CONTAINS_IMPL_HPP_INCLUDED
0003 #define BOOST_MPL_MAP_AUX_CONTAINS_IMPL_HPP_INCLUDED
0004
0005 // Copyright Aleksey Gurtovoy 2003-2004
0006 //
0007 // Distributed under the Boost Software License, Version 1.0.
0008 // (See accompanying file LICENSE_1_0.txt or copy at
0009 // http://www.boost.org/LICENSE_1_0.txt)
0010 //
0011 // See http://www.boost.org/libs/mpl for documentation.
0012
0013 // $Id$
0014 // $Date$
0015 // $Revision$
0016
0017 #include <boost/mpl/contains_fwd.hpp>
0018 #include <boost/mpl/if.hpp>
0019 #include <boost/mpl/map/aux_/at_impl.hpp>
0020 #include <boost/mpl/map/aux_/tag.hpp>
0021
0022 #include <boost/type_traits/is_same.hpp>
0023
0024 namespace boost { namespace mpl {
0025
0026 template<>
0027 struct contains_impl< aux::map_tag >
0028 {
0029     template< typename Map, typename Pair > struct apply
0030         : is_same<
0031               typename at_impl<aux::map_tag>::apply<
0032                   Map
0033                 , typename Pair::first
0034                 >::type
0035             , typename Pair::second
0036             >
0037     {
0038     };
0039 };
0040
0041 }}
0042
0043 #endif // BOOST_MPL_MAP_AUX_CONTAINS_IMPL_HPP_INCLUDED