81 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			81 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| /*=============================================================================
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|     Copyright (c) 2001-2011 Joel de Guzman
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| 
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|     Distributed under the Boost Software License, Version 1.0. (See accompanying 
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|     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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| ==============================================================================*/
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| #if !defined(FUSION_DISTANCE_09172005_0721)
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| #define FUSION_DISTANCE_09172005_0721
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| 
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| #include <boost/fusion/support/config.hpp>
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| #include <boost/fusion/iterator/detail/distance.hpp>
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| #include <boost/fusion/support/category_of.hpp>
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| 
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| #include <boost/mpl/int.hpp>
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| #include <boost/mpl/assert.hpp>
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| #include <boost/type_traits/is_same.hpp>
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| 
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| #include <boost/fusion/support/tag_of.hpp>
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| 
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| namespace boost { namespace fusion
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| {
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|     struct random_access_traversal_tag;
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| 
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|     // Special tags:
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|     struct iterator_facade_tag; // iterator facade tag
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|     struct boost_array_iterator_tag; // boost::array iterator tag
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|     struct mpl_iterator_tag; // mpl sequence iterator tag
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|     struct std_pair_iterator_tag; // std::pair iterator tag
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| 
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|     namespace extension
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|     {
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|         template <typename Tag>
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|         struct distance_impl
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|         {
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|             // default implementation
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|             template <typename First, typename Last>
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|             struct apply : distance_detail::linear_distance<First, Last> 
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|             {};
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|         };
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| 
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|         template <>
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|         struct distance_impl<iterator_facade_tag>
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|         {
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|             template <typename First, typename Last>
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|             struct apply : First::template distance<First, Last> {};
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|         };
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| 
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|         template <>
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|         struct distance_impl<boost_array_iterator_tag>;
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| 
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|         template <>
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|         struct distance_impl<mpl_iterator_tag>;
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| 
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|         template <>
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|         struct distance_impl<std_pair_iterator_tag>;
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|     }
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| 
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|     namespace result_of
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|     {
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|         template <typename First, typename Last>
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|         struct distance
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|           : extension::distance_impl<typename detail::tag_of<First>::type>::
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|                 template apply<First, Last>
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|         {
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|             typedef typename extension::distance_impl<typename detail::tag_of<First>::type>:: 
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|             template apply<First, Last>::type distance_application;
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|             BOOST_STATIC_CONSTANT(int, value = distance_application::value);
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|         };
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|     }
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|         
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|     template <typename First, typename Last>
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|     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
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|     inline typename result_of::distance<First, Last>::type
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|     distance(First const& a, Last const& b)
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|     {
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|         return result_of::distance<First, Last>::call(a,b);
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|     }
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| }}
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| 
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| #endif
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