//-----------------------------------------------------------------------------

// boost variant/detail/apply_visitor_unary.hpp header file

// See http://www.boost.org for updates, documentation, and revision history.

//-----------------------------------------------------------------------------

//

// Copyright (c) 2002-2003

// Eric Friedman

//

// 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)

#ifndef BOOST_VARIANT_DETAIL_APPLY_VISITOR_UNARY_HPP

#define BOOST_VARIANT_DETAIL_APPLY_VISITOR_UNARY_HPP

#include "boost/config.hpp"

#include "boost/detail/workaround.hpp"

#include "boost/variant/detail/generic_result_type.hpp"

#include "boost/utility/enable_if.hpp"

namespace boost {

//////////////////////////////////////////////////////////////////////////

// function template apply_visitor(visitor, visitable)

//

// Visits visitable with visitor.

//

//

// nonconst-visitor version:

//

#if !BOOST_WORKAROUND(__EDG__, BOOST_TESTED_AT(302))

#   define BOOST_VARIANT_AUX_APPLY_VISITOR_NON_CONST_RESULT_TYPE(V) \

    BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename V::result_type) \

    /**/

#else // EDG-based compilers

#   define BOOST_VARIANT_AUX_APPLY_VISITOR_NON_CONST_RESULT_TYPE(V) \

    typename enable_if< \

          mpl::not_< is_const< V > > \

        , BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename V::result_type) \

        >::type \

    /**/

#endif // EDG-based compilers workaround

template <typename Visitor, typename Visitable>

inline

    BOOST_VARIANT_AUX_APPLY_VISITOR_NON_CONST_RESULT_TYPE(Visitor)

apply_visitor(Visitor& visitor, Visitable& visitable)

{

    return visitable.apply_visitor(visitor);

}

#undef BOOST_VARIANT_AUX_APPLY_VISITOR_NON_CONST_RESULT_TYPE

//

// const-visitor version:

//

#if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)

template <typename Visitor, typename Visitable>

inline

    BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename Visitor::result_type)

apply_visitor(const Visitor& visitor, Visitable& visitable)

{

    return visitable.apply_visitor(visitor);

}

#endif // MSVC7 and below exclusion

} // namespace boost

#endif // BOOST_VARIANT_DETAIL_APPLY_VISITOR_UNARY_HPP