// Boost.Bimap

//

// Copyright (c) 2006-2007 Matias Capeletto

//

// 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)



/// \file relation/support/value_type_of.hpp

/// \brief value_type_of<tag,relation> metafunction



#ifndef BOOST_BIMAP_RELATION_SUPPORT_VALUE_TYPE_OF_HPP

#define BOOST_BIMAP_RELATION_SUPPORT_VALUE_TYPE_OF_HPP



#if defined(_MSC_VER) && (_MSC_VER>=1200)

#pragma once

#endif



#include <boost/config.hpp>



#include <boost/bimap/relation/detail/metadata_access_builder.hpp>



/** \struct boost::bimaps::relation::support::value_type_of



\brief Metafunction to obtain the value type of one of the sides.



\code



template< class Tag, class Relation >

struct value_type_of

{

        typedef typename Relation::{side}_type type;

};



\endcode



See also member_at, get().

\ingroup relation_group

                                                                    **/



namespace boost {

namespace bimaps {

namespace relation {

namespace support {



// Metafunction value_type_of

/*



    template< class Tag, class Relation >

    struct value_type_of

    {

        typedef -unspecified- type;

    };



*/



BOOST_BIMAP_SYMMETRIC_METADATA_ACCESS_BUILDER

(

    value_type_of,

    left_value_type,

    right_value_type

)



// Add support for info tags to value_type_of



template< class Tag, class SymmetricType >

struct value_type_of

<

    Tag, SymmetricType,

    BOOST_DEDUCED_TYPENAME enable_if

    <

        ::boost::bimaps::relation::support::is_tag_of_member_at_info

        <

            Tag,

            SymmetricType

        >



    >::type

>

{

    typedef BOOST_DEDUCED_TYPENAME SymmetricType::info_type type;

};



} // namespace support

} // namespace relation

} // namespace bimaps

} // namespace boost





#endif // BOOST_BIMAP_RELATION_SUPPORT_VALUE_TYPE_OF_HPP



