#ifndef BOOST_MPL_SET_AUX_INSERT_IMPL_HPP_INCLUDED

 #define BOOST_MPL_SET_AUX_INSERT_IMPL_HPP_INCLUDED

 // Copyright Aleksey Gurtovoy 2003-2004

 // Copyright David Abrahams 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.

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

 // $Date: 2004/09/05 09:42:59 $

 // $Revision: 1.4 $

 #include <boost/mpl/insert_fwd.hpp>

 #include <boost/mpl/set/aux_/has_key_impl.hpp>

 #include <boost/mpl/set/aux_/item.hpp>

 #include <boost/mpl/set/aux_/tag.hpp>

 #include <boost/mpl/identity.hpp>

 #include <boost/mpl/base.hpp>

 #include <boost/mpl/eval_if.hpp>

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

 #include <boost/type_traits/is_same.hpp>

 namespace boost { namespace mpl {

 namespace aux {

 template<  typename Set, typename T > struct set_insert_impl

     : eval_if< 

           has_key_impl<aux::set_tag>::apply<Set,T>

         , identity<Set>

         , eval_if< 

               is_same< T,typename Set::last_masked_ > 

             , base<Set>

             , identity< s_item<T,Set> >

             >

         >

 {

 };

 }

 template<>

 struct insert_impl< aux::set_tag >

 {

     template< 

           typename Set

         , typename PosOrKey

         , typename KeyOrNA

         > 

     struct apply

         : aux::set_insert_impl<

               Set

             , typename if_na<KeyOrNA,PosOrKey>::type

             >

     {

     };

 };

 }}

 #endif // BOOST_MPL_SET_AUX_INSERT_IMPL_HPP_INCLUDED