| // 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/tag_of.hpp |
| /// \brief Safe way to acces the tag of a type |
| |
| #ifndef BOOST_BIMAP_TAGS_SUPPORT_TAG_OF_HPP |
| #define BOOST_BIMAP_TAGS_SUPPORT_TAG_OF_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER>=1200) |
| #pragma once |
| #endif |
| |
| #include <boost/config.hpp> |
| |
| #include <boost/bimap/tags/tagged.hpp> |
| #include <boost/bimap/detail/debug/static_error.hpp> |
| |
| /** \struct boost::bimaps::tags::support::tag_of |
| \brief Metafunction to obtain the tag of a type. |
| |
| \code |
| template< class TaggedType > |
| struct tag_of |
| { |
| typedef {Tag} type; |
| }; |
| \endcode |
| |
| If the type is not tagged you will get a compile timer error with the following message: |
| |
| \verbatim |
| USING_TAG_OF_WITH_AN_UNTAGGED_TYPE, TaggedType |
| \endverbatim |
| |
| See also tagged, value_type_of. |
| **/ |
| |
| #ifndef BOOST_BIMAP_DOXYGEN_WILL_NOT_PROCESS_THE_FOLLOWING_LINES |
| |
| namespace boost { |
| namespace bimaps { |
| namespace tags { |
| namespace support { |
| |
| |
| // tag_of metafunction |
| |
| template< class Type > |
| struct tag_of |
| { |
| BOOST_BIMAP_STATIC_ERROR( USING_TAG_OF_WITH_AN_UNTAGGED_TYPE, (Type) ); |
| }; |
| |
| template< class Type, class Tag > |
| struct tag_of< tagged< Type, Tag > > |
| { |
| typedef Tag type; |
| }; |
| |
| |
| } // namespace support |
| } // namespace tags |
| } // namespace bimaps |
| } // namespace boost |
| |
| #endif // BOOST_BIMAP_DOXYGEN_WILL_NOT_PROCESS_THE_FOLLOWING_LINES |
| |
| #endif // BOOST_BIMAP_TAGS_SUPPORT_TAG_OF_HPP |
| |