77 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C++
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C++
		
	
	
		
			Executable File
		
	
	
	
	
| #ifndef POINTEE_DWA200415_HPP
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| # define POINTEE_DWA200415_HPP
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| 
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| //
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| // Copyright David Abrahams 2004. Use, modification and distribution is
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| // subject to 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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| // typename pointee<P>::type provides the pointee type of P.
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| //
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| // For example, it is T for T* and X for shared_ptr<X>.
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| //
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| // http://www.boost.org/libs/iterator/doc/pointee.html
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| //
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| 
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| # include <boost/detail/is_incrementable.hpp>
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| # include <boost/iterator/iterator_traits.hpp>
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| # include <boost/type_traits/add_const.hpp>
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| # include <boost/type_traits/remove_cv.hpp>
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| # include <boost/mpl/if.hpp>
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| # include <boost/mpl/eval_if.hpp>
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| 
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| #include <iterator>
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| 
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| namespace boost {
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| 
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| namespace detail
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| {
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|   template <class P>
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|   struct smart_ptr_pointee
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|   {
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|       typedef typename P::element_type type;
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|   };
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| 
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|   template <class Iterator>
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|   struct iterator_pointee
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|   {
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|       typedef typename std::iterator_traits<Iterator>::value_type value_type;
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| 
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|       struct impl
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|       {
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|           template <class T>
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|           static char test(T const&);
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| 
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|           static char (& test(value_type&) )[2];
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| 
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|           static Iterator& x;
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|       };
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| 
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|       BOOST_STATIC_CONSTANT(bool, is_constant = sizeof(impl::test(*impl::x)) == 1);
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| 
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|       typedef typename mpl::if_c<
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| #  if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x551))
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|           ::boost::detail::iterator_pointee<Iterator>::is_constant
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| #  else
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|           is_constant
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| #  endif
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|         , typename add_const<value_type>::type
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|         , value_type
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|       >::type type;
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|   };
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| }
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| 
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| template <class P>
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| struct pointee
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|   : mpl::eval_if<
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|         detail::is_incrementable<P>
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|       , detail::iterator_pointee<P>
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|       , detail::smart_ptr_pointee<P>
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|     >
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| {
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| };
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| 
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| } // namespace boost
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| 
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| #endif // POINTEE_DWA200415_HPP
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