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			2.5 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
		
		
			
		
	
	
			82 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | /*============================================================================= | ||
|  |     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_CONSTEXPR 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 | ||
|  | 
 |