text: 
  #ifndef BOOST_MPL_MAP_AUX_CONTAINS_IMPL_HPP_INCLUDED
  #define BOOST_MPL_MAP_AUX_CONTAINS_IMPL_HPP_INCLUDED
  
  // Copyright Aleksey Gurtovoy 2003-2004
  //
  // 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/contains_fwd.hpp>
  #include <boost/mpl/if.hpp>
  #include <boost/mpl/map/aux_/at_impl.hpp>
  #include <boost/mpl/map/aux_/tag.hpp>
  
  #include <boost/type_traits/is_same.hpp>
  
  namespace boost { namespace mpl {
  
  template<>
  struct contains_impl< aux::map_tag >
  {
      template< typename Map, typename Pair > struct apply
          : is_same< 
                typename at_impl<aux::map_tag>::apply<
                    Map
                  , typename Pair::first
                  >::type
              , typename Pair::second
              >
      {
      };
  };
  
  }}
  
  #endif // BOOST_MPL_MAP_AUX_CONTAINS_IMPL_HPP_INCLUDED
  