81 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
		
		
			
		
	
	
			81 lines
		
	
	
		
			2.6 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_DISTANCE_09172005_0721) | ||
|  | #define FUSION_DISTANCE_09172005_0721 | ||
|  | 
 | ||
|  | #include <boost/fusion/support/config.hpp> | ||
|  | #include <boost/fusion/iterator/detail/distance.hpp> | ||
|  | #include <boost/fusion/support/category_of.hpp> | ||
|  | 
 | ||
|  | #include <boost/mpl/int.hpp> | ||
|  | #include <boost/mpl/assert.hpp> | ||
|  | #include <boost/type_traits/is_same.hpp> | ||
|  | 
 | ||
|  | #include <boost/fusion/support/tag_of.hpp> | ||
|  | 
 | ||
|  | namespace boost { namespace fusion | ||
|  | { | ||
|  |     struct random_access_traversal_tag; | ||
|  | 
 | ||
|  |     // Special tags: | ||
|  |     struct iterator_facade_tag; // iterator facade tag | ||
|  |     struct boost_array_iterator_tag; // boost::array iterator tag | ||
|  |     struct mpl_iterator_tag; // mpl sequence iterator tag | ||
|  |     struct std_pair_iterator_tag; // std::pair iterator tag | ||
|  | 
 | ||
|  |     namespace extension | ||
|  |     { | ||
|  |         template <typename Tag> | ||
|  |         struct distance_impl | ||
|  |         { | ||
|  |             // default implementation | ||
|  |             template <typename First, typename Last> | ||
|  |             struct apply : distance_detail::linear_distance<First, Last>  | ||
|  |             {}; | ||
|  |         }; | ||
|  | 
 | ||
|  |         template <> | ||
|  |         struct distance_impl<iterator_facade_tag> | ||
|  |         { | ||
|  |             template <typename First, typename Last> | ||
|  |             struct apply : First::template distance<First, Last> {}; | ||
|  |         }; | ||
|  | 
 | ||
|  |         template <> | ||
|  |         struct distance_impl<boost_array_iterator_tag>; | ||
|  | 
 | ||
|  |         template <> | ||
|  |         struct distance_impl<mpl_iterator_tag>; | ||
|  | 
 | ||
|  |         template <> | ||
|  |         struct distance_impl<std_pair_iterator_tag>; | ||
|  |     } | ||
|  | 
 | ||
|  |     namespace result_of | ||
|  |     { | ||
|  |         template <typename First, typename Last> | ||
|  |         struct distance | ||
|  |           : extension::distance_impl<typename detail::tag_of<First>::type>:: | ||
|  |                 template apply<First, Last> | ||
|  |         { | ||
|  |             typedef typename extension::distance_impl<typename detail::tag_of<First>::type>::  | ||
|  |             template apply<First, Last>::type distance_application; | ||
|  |             BOOST_STATIC_CONSTANT(int, value = distance_application::value); | ||
|  |         }; | ||
|  |     } | ||
|  |          | ||
|  |     template <typename First, typename Last> | ||
|  |     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED | ||
|  |     inline typename result_of::distance<First, Last>::type | ||
|  |     distance(First const& a, Last const& b) | ||
|  |     { | ||
|  |         return result_of::distance<First, Last>::call(a,b); | ||
|  |     } | ||
|  | }} | ||
|  | 
 | ||
|  | #endif |