#ifndef BOOST_MPL_IS_PLACEHOLDER_HPP_INCLUDED

 #define BOOST_MPL_IS_PLACEHOLDER_HPP_INCLUDED

 // Copyright Aleksey Gurtovoy 2001-2004

 //

 // 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/is_placeholder.hpp,v $

 // $Date: 2004/09/07 08:51:31 $

 // $Revision: 1.6 $

 #include <boost/mpl/arg_fwd.hpp>

 #include <boost/mpl/bool.hpp>

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

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

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

 #include <boost/mpl/aux_/config/ctps.hpp>

 #include <boost/mpl/aux_/config/static_constant.hpp>

 namespace boost { namespace mpl {

 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)

 template< typename T >

 struct is_placeholder

     : bool_<false>

 {

 };

 template< BOOST_MPL_AUX_NTTP_DECL(int, N) >

 struct is_placeholder< arg<N> >

     : bool_<true>

 {

 };

 #else

 namespace aux {

 aux::no_tag is_placeholder_helper(...);

 template< BOOST_MPL_AUX_NTTP_DECL(int, N) >

 aux::yes_tag is_placeholder_helper(aux::type_wrapper< arg<N> >*);

 } // namespace aux

 template< typename T >

 struct is_placeholder

 {

     static aux::type_wrapper<T>* get();

     BOOST_STATIC_CONSTANT(bool, value = 

           sizeof(aux::is_placeholder_helper(get())) == sizeof(aux::yes_tag)

         );

     typedef bool_<value> type;

 };

 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

 }}

 #endif // BOOST_MPL_IS_PLACEHOLDER_HPP_INCLUDED