/*============================================================================= Copyright (c) 2001-2011 Joel de Guzman 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(FUSION_HAS_KEY_09232005_1454) #define FUSION_HAS_KEY_09232005_1454 #include <boost/fusion/support/config.hpp> #include <boost/fusion/sequence/intrinsic_fwd.hpp> #include <boost/fusion/support/tag_of.hpp> #include <boost/fusion/iterator/equal_to.hpp> #include <boost/fusion/algorithm/query/find.hpp> #include <boost/fusion/sequence/intrinsic/end.hpp> #include <boost/mpl/not.hpp> namespace boost { namespace fusion { struct void_; // 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 has_key_impl { template <typename Seq, typename Key> struct apply : mpl::not_< typename result_of::equal_to< typename result_of::find<Seq, Key>::type , typename result_of::end<Seq>::type >::type >::type {}; }; template <> struct has_key_impl<sequence_facade_tag> { template <typename Sequence, typename Key> struct apply : Sequence::template has_key<Sequence, Key> {}; }; template <> struct has_key_impl<boost_array_tag>; template <> struct has_key_impl<mpl_sequence_tag>; template <> struct has_key_impl<std_pair_tag>; } namespace result_of { template <typename Sequence, typename Key> struct has_key : extension::has_key_impl<typename detail::tag_of<Sequence>::type>:: template apply<Sequence, Key> {}; } template <typename Key, typename Sequence> BOOST_FUSION_GPU_ENABLED inline typename result_of::has_key<Sequence, Key>::type has_key(Sequence const&) { typedef typename result_of::has_key<Sequence, Key>::type result; return result(); } }} #endif