

#ifndef BOOST_MPL_AUX_MSVC_IS_CLASS_HPP_INCLUDED

#define BOOST_MPL_AUX_MSVC_IS_CLASS_HPP_INCLUDED



// Copyright Aleksey Gurtovoy 2002-2004

//

// 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.



// $Source$

// $Date: 2004-09-28 09:56:59 -0400 (Tue, 28 Sep 2004) $

// $Revision: 25453 $



#include <boost/mpl/if.hpp>

#include <boost/mpl/bool.hpp>

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

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



#include <boost/type_traits/is_reference.hpp>



namespace boost { namespace mpl { namespace aux {



template< typename T > struct is_class_helper

{

    typedef int (T::* type)();

};



// MSVC 6.x-specific lightweight 'is_class' implementation; 

// Distinguishing feature: does not instantiate the type being tested.

template< typename T >

struct msvc_is_class_impl

{

    template< typename U>

    static yes_tag  test(type_wrapper<U>*, /*typename*/ is_class_helper<U>::type = 0);

    static no_tag   test(void const volatile*, ...);



    enum { value = sizeof(test((type_wrapper<T>*)0)) == sizeof(yes_tag) };

    typedef bool_<value> type;

};



// agurt, 17/sep/04: have to check for 'is_reference' upfront to avoid ICEs in

// complex metaprograms

template< typename T >

struct msvc_is_class

    : if_<

          is_reference<T>

        , false_

        , msvc_is_class_impl<T>

        >::type

{

};



}}}



#endif // BOOST_MPL_AUX_MSVC_IS_CLASS_HPP_INCLUDED

