//  (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.

//  Use, modification and distribution are 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/libs/type_traits for most recent version including documentation.

#ifndef BOOST_TT_ADD_REFERENCE_HPP_INCLUDED

#define BOOST_TT_ADD_REFERENCE_HPP_INCLUDED

#include <boost/type_traits/is_reference.hpp>

#include <boost/detail/workaround.hpp>

#include <boost/config.hpp>

// should be the last #include

#include <boost/type_traits/detail/type_trait_def.hpp>

namespace boost {

namespace detail {

#if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) && defined(BOOST_MSVC6_MEMBER_TEMPLATES)

template <bool x>

struct reference_adder

{

    template <typename T> struct result_

    {

        typedef T& type;

    };

};

template <>

struct reference_adder<true>

{

    template <typename T> struct result_

    {

        typedef T type;

    };

};

template <typename T>

struct add_reference_impl

{

    typedef typename reference_adder<

          ::boost::is_reference<T>::value

        >::template result_<T> result;

    typedef typename result::type type;

};

#else

template <typename T>

struct add_reference_impl

{

    typedef T& type;

};

#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

BOOST_TT_AUX_TYPE_TRAIT_IMPL_PARTIAL_SPEC1_1(typename T,add_reference,T&,T&)

#endif

#endif

// these full specialisations are always required:

BOOST_TT_AUX_TYPE_TRAIT_IMPL_SPEC1(add_reference,void,void)

#ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS

BOOST_TT_AUX_TYPE_TRAIT_IMPL_SPEC1(add_reference,void const,void const)

BOOST_TT_AUX_TYPE_TRAIT_IMPL_SPEC1(add_reference,void volatile,void volatile)

BOOST_TT_AUX_TYPE_TRAIT_IMPL_SPEC1(add_reference,void const volatile,void const volatile)

#endif

} // namespace detail

BOOST_TT_AUX_TYPE_TRAIT_DEF1(add_reference,T,typename boost::detail::add_reference_impl<T>::type)

// agurt, 07/mar/03: workaround Borland's ill-formed sensitivity to an additional

// level of indirection, here

#if BOOST_WORKAROUND(__BORLANDC__, < 0x600)

BOOST_TT_AUX_TYPE_TRAIT_PARTIAL_SPEC1_1(typename T,add_reference,T&,T&)

#endif

} // namespace boost

#include <boost/type_traits/detail/type_trait_undef.hpp>

#endif // BOOST_TT_ADD_REFERENCE_HPP_INCLUDED