/Src/Dependencies/Boost/boost/fusion/sequence/intrinsic/at_key.hpp
http://hadesmem.googlecode.com/ · C++ Header · 92 lines · 72 code · 12 blank · 8 comment · 0 complexity · 646de4de31e25c0f7596f6d31692bdb4 MD5 · raw file
- /*=============================================================================
- Copyright (c) 2001-2006 Joel de Guzman
- Copyright (c) 2006 Dan Marsden
- 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)
- ==============================================================================*/
- #if !defined(BOOST_FUSION_AT_KEY_20060304_1755)
- #define BOOST_FUSION_AT_KEY_20060304_1755
- #include <boost/type_traits/is_const.hpp>
- #include <boost/fusion/algorithm/query/find.hpp>
- #include <boost/fusion/iterator/deref_data.hpp>
- #include <boost/fusion/support/tag_of.hpp>
- #include <boost/fusion/support/detail/access.hpp>
- namespace boost { namespace fusion
- {
- // Special tags:
- struct sequence_facade_tag;
- struct boost_array_tag; // boost::array tag
- struct mpl_sequence_tag; // mpl sequence tag
- struct std_pair_tag; // std::pair tag
- namespace extension
- {
- template <typename Tag>
- struct at_key_impl
- {
- template <typename Seq, typename Key>
- struct apply
- {
- typedef typename
- result_of::deref_data<
- typename result_of::find<Seq, Key>::type
- >::type
- type;
- static type
- call(Seq& seq)
- {
- return fusion::deref_data(fusion::find<Key>(seq));
- }
- };
- };
- template <>
- struct at_key_impl<sequence_facade_tag>
- {
- template <typename Sequence, typename Key>
- struct apply : Sequence::template at_key_impl<Sequence, Key> {};
- };
- template <>
- struct at_key_impl<boost_array_tag>;
- template <>
- struct at_key_impl<mpl_sequence_tag>;
- template <>
- struct at_key_impl<std_pair_tag>;
- }
- namespace result_of
- {
- template <typename Sequence, typename Key>
- struct at_key
- : extension::at_key_impl<typename detail::tag_of<Sequence>::type>::
- template apply<Sequence, Key>
- {};
- }
- template <typename Key, typename Sequence>
- inline typename
- lazy_disable_if<
- is_const<Sequence>
- , result_of::at_key<Sequence, Key>
- >::type
- at_key(Sequence& seq)
- {
- return result_of::at_key<Sequence, Key>::call(seq);
- }
- template <typename Key, typename Sequence>
- inline typename result_of::at_key<Sequence const, Key>::type
- at_key(Sequence const& seq)
- {
- return result_of::at_key<Sequence const, Key>::call(seq);
- }
- }}
- #endif