#ifndef BOOST_MPL_AUX_AT_IMPL_HPP_INCLUDED

 #define BOOST_MPL_AUX_AT_IMPL_HPP_INCLUDED

 // Copyright Aleksey Gurtovoy 2000-2004

 //

 // 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.

 // $Source: /cvsroot/boost/boost/boost/mpl/aux_/at_impl.hpp,v $

 // $Date: 2004/09/02 15:40:43 $

 // $Revision: 1.5 $

 #include <boost/mpl/begin_end.hpp>

 #include <boost/mpl/advance.hpp>

 #include <boost/mpl/deref.hpp>

 #include <boost/mpl/aux_/traits_lambda_spec.hpp>

 namespace boost { namespace mpl {

 // default implementation; conrete sequences might override it by 

 // specializing either the 'at_impl' or the primary 'at' template

 template< typename Tag >

 struct at_impl

 {

     template< typename Sequence, typename N > struct apply

     {

         typedef typename advance<

               typename begin<Sequence>::type

             , N

             >::type iter_;

         typedef typename deref<iter_>::type type;

     };

 };

 BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(2, at_impl)

 }}

 #endif // BOOST_MPL_AUX_AT_IMPL_HPP_INCLUDED