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			2.2 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
		
		
			
		
	
	
			72 lines
		
	
	
		
			2.2 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_VALUE_OF_IMPL_20060124_2147) | ||
|  | #define FUSION_VALUE_OF_IMPL_20060124_2147 | ||
|  | 
 | ||
|  | #include <boost/fusion/support/config.hpp> | ||
|  | #include <boost/fusion/container/vector/convert.hpp> | ||
|  | #include <boost/fusion/algorithm/transformation/transform.hpp> | ||
|  | #include <boost/fusion/iterator/value_of.hpp> | ||
|  | #include <boost/mpl/placeholders.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> | ||
|  | #include <boost/config.hpp> | ||
|  | 
 | ||
|  | namespace boost { namespace fusion | ||
|  | { | ||
|  |     struct zip_view_iterator_tag; | ||
|  | 
 | ||
|  |     namespace detail | ||
|  |     { | ||
|  |         struct poly_value_of | ||
|  |         { | ||
|  |             template<typename T> | ||
|  |             struct result; | ||
|  | 
 | ||
|  |             template<typename It> | ||
|  |             struct result<poly_value_of(It)> | ||
|  |                 : mpl::eval_if<is_same<It, unused_type>, | ||
|  |                                mpl::identity<unused_type>, | ||
|  |                                result_of::value_of<It> > | ||
|  |             {}; | ||
|  | 
 | ||
|  |             // never called, but needed for decltype-based result_of (C++0x) | ||
|  | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | ||
|  |             template<typename It> | ||
|  |             BOOST_FUSION_GPU_ENABLED | ||
|  |             typename result<poly_value_of(It)>::type | ||
|  |             operator()(It&&) const; | ||
|  | #endif | ||
|  |         }; | ||
|  |     } | ||
|  | 
 | ||
|  |     namespace extension | ||
|  |     { | ||
|  |         template<typename Tag> | ||
|  |         struct value_of_impl; | ||
|  | 
 | ||
|  |         template<> | ||
|  |         struct value_of_impl<zip_view_iterator_tag> | ||
|  |         { | ||
|  |             template<typename Iterator> | ||
|  |             struct apply | ||
|  |             { | ||
|  |                 typedef typename result_of::transform< | ||
|  |                     typename Iterator::iterators, | ||
|  |                     detail::poly_value_of>::type values; | ||
|  | 
 | ||
|  |                 typedef typename result_of::as_vector<values>::type type; | ||
|  |             }; | ||
|  |         }; | ||
|  |     } | ||
|  | }} | ||
|  | 
 | ||
|  | #endif |