#ifndef BOOST_SERIALIZATION_BASE_OBJECT_HPP

#define BOOST_SERIALIZATION_BASE_OBJECT_HPP



// MS compatible compilers support #pragma once

#if defined(_MSC_VER) && (_MSC_VER >= 1020)

# pragma once

#endif



/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8

// base_object.hpp:



// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . 

// Use, modification and distribution is subject to 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 for updates, documentation, and revision history.



// if no archive headers have been included this is a no op

// this is to permit BOOST_EXPORT etc to be included in a 

// file declaration header



#include <boost/config.hpp>

#include <boost/detail/workaround.hpp>



#include <boost/mpl/eval_if.hpp>

#include <boost/mpl/int.hpp>

#include <boost/type_traits/is_base_and_derived.hpp>

#include <boost/type_traits/is_pointer.hpp>

#include <boost/type_traits/is_const.hpp>



#include <boost/static_assert.hpp>

#include <boost/serialization/type_info_implementation.hpp>

#include <boost/serialization/force_include.hpp>

#include <boost/serialization/void_cast_fwd.hpp>



namespace boost {

namespace serialization {



namespace detail

{

// only register void casts if the types are polymorphic

  template<class Base, class Derived>

  struct base_register

  {

      static void const* execute(mpl::false_) { return 0; }



      static void const* execute(mpl::true_)

      {

          return &void_cast_register((Derived const*)0, (Base const*)0);

      }

            

      static void const* invoke()

      {

          typedef mpl::bool_<

              type_info_implementation<Base>::type::is_polymorphic::value

          > is_polymorphic;

          

          return execute(is_polymorphic());

      }

  };



  // get the base type for a given derived type

  // preserving the const-ness

  template<class B, class D>

  struct base_cast

  {

      typedef BOOST_DEDUCED_TYPENAME

      mpl::if_<

          is_const<D>,

          const B,

          B

      >::type type;

      BOOST_STATIC_ASSERT(is_const<type>::value == is_const<D>::value);

  };

} // namespace detail



#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x560))

template<class Base, class Derived>

const Base & 

base_object(const Derived & d)

{

    BOOST_STATIC_ASSERT(! is_pointer<Derived>::value);

    detail::base_register<Base, Derived>::invoke();

    return static_cast<const Base &>(d);

}

#else

template<class Base, class Derived>

BOOST_DEDUCED_TYPENAME detail::base_cast<Base, Derived>::type & 

base_object(Derived &d)

{

    BOOST_STATIC_ASSERT(( is_base_and_derived<Base,Derived>::value));

    BOOST_STATIC_ASSERT(! is_pointer<Derived>::value);

    typedef BOOST_DEDUCED_TYPENAME detail::base_cast<Base, Derived>::type type;

    detail::base_register<type, Derived>::invoke();

    return static_cast<type &>(d);

}

#endif



} // namespace serialization

} // namespace boost



#endif // BOOST_SERIALIZATION_BASE_OBJECT_HPP

