| // 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 |
| |
| |