map/aux_/has_key_impl.hpp

0001
0002 #ifndef BOOST_MPL_MAP_AUX_HAS_KEY_IMPL_HPP_INCLUDED
0003 #define BOOST_MPL_MAP_AUX_HAS_KEY_IMPL_HPP_INCLUDED
0004
0005 // Copyright Aleksey Gurtovoy 2003-2004
0006 // Copyright David Abrahams 2003-2004
0007 //
0008 // Distributed under the Boost Software License, Version 1.0.
0009 // (See accompanying file LICENSE_1_0.txt or copy at
0010 // http://www.boost.org/LICENSE_1_0.txt)
0011 //
0012 // See http://www.boost.org/libs/mpl for documentation.
0013
0014 // $Id$
0015 // $Date$
0016 // $Revision$
0017
0018 #include <boost/mpl/has_key_fwd.hpp>
0019 #include <boost/mpl/map/aux_/tag.hpp>
0020 #include <boost/mpl/map/aux_/at_impl.hpp>
0021 #include <boost/mpl/void.hpp>
0022 #include <boost/mpl/aux_/config/typeof.hpp>
0023
0024 namespace boost { namespace mpl {
0025
0026 template<>
0027 struct has_key_impl< aux::map_tag >
0028 {
0029     template< typename Map, typename Key > struct apply
0030 #if defined(BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES)
0031         : is_not_void_<
0032               typename at_impl<aux::map_tag>
0033                 ::apply<Map,Key>::type
0034             >
0035 #else
0036         : bool_< ( x_order_impl<Map,Key>::value > 1 ) >
0037 #endif
0038     {
0039     };
0040 };
0041
0042 }}
0043
0044 #endif // BOOST_MPL_MAP_AUX_HAS_KEY_IMPL_HPP_INCLUDED