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			3.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
		
		
			
		
	
	
			98 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | /*============================================================================= | ||
|  |     Copyright (c) 2001-2011 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(FUSION_AT_IMPL_20060124_1933) | ||
|  | #define FUSION_AT_IMPL_20060124_1933 | ||
|  | 
 | ||
|  | #include <boost/fusion/support/config.hpp> | ||
|  | #include <boost/fusion/container/vector.hpp> | ||
|  | #include <boost/fusion/sequence/intrinsic/at.hpp> | ||
|  | #include <boost/fusion/container/vector/convert.hpp> | ||
|  | #include <boost/fusion/algorithm/transformation/transform.hpp> | ||
|  | #include <boost/type_traits/remove_reference.hpp> | ||
|  | #include <boost/type_traits/is_reference.hpp> | ||
|  | #include <boost/mpl/assert.hpp> | ||
|  | #include <boost/fusion/support/unused.hpp> | ||
|  | #include <boost/mpl/eval_if.hpp> | ||
|  | #include <boost/mpl/identity.hpp> | ||
|  | #include <boost/type_traits/is_same.hpp> | ||
|  | 
 | ||
|  | 
 | ||
|  | namespace boost { namespace fusion  | ||
|  | { | ||
|  |     struct zip_view_tag; | ||
|  | 
 | ||
|  |     namespace detail | ||
|  |     { | ||
|  |         template<typename N> | ||
|  |         struct poly_at | ||
|  |         { | ||
|  |             template<typename T> | ||
|  |             struct result; | ||
|  | 
 | ||
|  |             template<typename N1, typename SeqRef> | ||
|  |             struct result<poly_at<N1>(SeqRef)> | ||
|  |                 : mpl::eval_if<is_same<SeqRef, unused_type const&>, | ||
|  |                                mpl::identity<unused_type>, | ||
|  |                                result_of::at<typename remove_reference<SeqRef>::type, N> > | ||
|  |             { | ||
|  |                 BOOST_MPL_ASSERT((is_reference<SeqRef>)); | ||
|  |             }; | ||
|  | 
 | ||
|  |             template<typename Seq> | ||
|  |             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED | ||
|  |             typename result<poly_at(Seq&)>::type | ||
|  |             operator()(Seq& seq) const | ||
|  |             { | ||
|  |                 return fusion::at<N>(seq); | ||
|  |             } | ||
|  | 
 | ||
|  |             template<typename Seq> | ||
|  |             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED | ||
|  |             typename result<poly_at(Seq const&)>::type | ||
|  |             operator()(Seq const& seq) const | ||
|  |             { | ||
|  |                 return fusion::at<N>(seq); | ||
|  |             } | ||
|  | 
 | ||
|  |             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED | ||
|  |             unused_type operator()(unused_type const&) const | ||
|  |             { | ||
|  |                 return unused_type(); | ||
|  |             } | ||
|  |         }; | ||
|  |     } | ||
|  | 
 | ||
|  |     namespace extension | ||
|  |     { | ||
|  |         template<typename Tag> | ||
|  |         struct at_impl; | ||
|  | 
 | ||
|  |         template<> | ||
|  |         struct at_impl<zip_view_tag> | ||
|  |         { | ||
|  |             template<typename Seq, typename N> | ||
|  |             struct apply | ||
|  |             { | ||
|  |                 typedef typename result_of::as_vector< | ||
|  |                     typename result_of::transform< | ||
|  |                     typename Seq::sequences, detail::poly_at<N> >::type>::type type; | ||
|  | 
 | ||
|  |                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED | ||
|  |                 static type | ||
|  |                 call(Seq& seq) | ||
|  |                 { | ||
|  |                     return type( | ||
|  |                         fusion::transform(seq.sequences_, detail::poly_at<N>())); | ||
|  |                 } | ||
|  |             }; | ||
|  |         }; | ||
|  |     } | ||
|  | }} | ||
|  | 
 | ||
|  | #endif |