diff options
Diffstat (limited to 'boost/bimap/tags/support/apply_to_value_type.hpp')
-rw-r--r-- | boost/bimap/tags/support/apply_to_value_type.hpp | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/boost/bimap/tags/support/apply_to_value_type.hpp b/boost/bimap/tags/support/apply_to_value_type.hpp new file mode 100644 index 0000000000..bb6aa60613 --- /dev/null +++ b/boost/bimap/tags/support/apply_to_value_type.hpp @@ -0,0 +1,70 @@ +// 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/apply_to_value_type.hpp +/// \brief Similar to mpl::apply but for tagged types. + +#ifndef BOOST_BIMAP_TAGS_SUPPORT_APPLY_TO_VALUE_TYPE_HPP +#define BOOST_BIMAP_TAGS_SUPPORT_APPLY_TO_VALUE_TYPE_HPP + +#if defined(_MSC_VER) && (_MSC_VER>=1200) +#pragma once +#endif + +#include <boost/config.hpp> + +#include <boost/bimap/tags/tagged.hpp> +#include <boost/mpl/apply.hpp> + +/** \struct boost::bimaps::tags::support::apply_to_value_type +\brief Higger order metafunction similar to mpl::apply but for tagged types. + +\code +template< class Metafunction, class TaggedType > +struct apply_to_value_type +{ + typedef tagged + < + Metafuntion< value_type_of< TaggedType >::type >::type, + tag_of< TaggedType >::type + + > type; +}; +\endcode + +This higher order metafunctions is very useful, and it can be used with lambda +expresions. + +See also tagged. + **/ + +#ifndef BOOST_BIMAP_DOXYGEN_WILL_NOT_PROCESS_THE_FOLLOWING_LINES + +namespace boost { +namespace bimaps { +namespace tags { +namespace support { + +template < class F, class TaggedType > +struct apply_to_value_type; + +template < class F, class ValueType, class Tag > +struct apply_to_value_type<F, tagged<ValueType,Tag> > +{ + typedef BOOST_DEDUCED_TYPENAME mpl::apply< F, ValueType >::type new_value_type; + typedef tagged< new_value_type, 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_APPLY_TO_VALUE_TYPE_HPP |