#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