// 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 tags/support/value_type_of.hpp | |
/// \brief Consistent way to access the value type of a tagged or untagged type. | |
#ifndef BOOST_BIMAP_TAGS_SUPPORT_VALUE_TYPE_OF_HPP | |
#define BOOST_BIMAP_TAGS_SUPPORT_VALUE_TYPE_OF_HPP | |
#if defined(_MSC_VER) && (_MSC_VER>=1200) | |
#pragma once | |
#endif | |
#include <boost/config.hpp> | |
#include <boost/bimap/tags/tagged.hpp> | |
/** \struct boost::bimaps::tags::support::value_type_of | |
\brief Metafunction to work with tagged and untagged type uniformly | |
\code | |
template< class Type > | |
struct value_type_of | |
{ | |
typedef {UntaggedType} type; | |
}; | |
\endcode | |
If the type is tagged this metafunction returns Type::value_type, and if it is not | |
tagged it return the same type. This allows to work consistenly with tagged and | |
untagged types. | |
See also tagged, tag_of. | |
**/ | |
#ifndef BOOST_BIMAP_DOXYGEN_WILL_NOT_PROCESS_THE_FOLLOWING_LINES | |
namespace boost { | |
namespace bimaps { | |
namespace tags { | |
namespace support { | |
// value_type_of metafunction | |
template< class Type > | |
struct value_type_of | |
{ | |
typedef Type type; | |
}; | |
template< class Type, class Tag > | |
struct value_type_of< tagged< Type, Tag > > | |
{ | |
typedef Type type; | |
}; | |
} // namespace support | |
} // namespace tags | |
} // namespace bimaps | |
} // namespace boost | |
#endif // BOOST_BIMAP_DOXYGEN_WILL_NOT_PROCESS_THE_FOLLOWING_LINES | |
#endif // BOOST_BIMAP_TAGS_SUPPORT_VALUE_TYPE_OF_HPP | |