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			64 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | //----------------------------------------------------------------------------- | ||
|  | // boost variant/detail/element_index.hpp header file | ||
|  | // See http://www.boost.org for updates, documentation, and revision history. | ||
|  | //----------------------------------------------------------------------------- | ||
|  | // | ||
|  | // Copyright (c) 2014-2015 Antony Polukhin | ||
|  | // | ||
|  | // 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) | ||
|  | 
 | ||
|  | #ifndef BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP | ||
|  | #define BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP | ||
|  | 
 | ||
|  | #include <boost/config.hpp> | ||
|  | #include <boost/variant/recursive_wrapper_fwd.hpp> | ||
|  | #include <boost/variant/variant_fwd.hpp> | ||
|  | 
 | ||
|  | #include <boost/type_traits/remove_cv.hpp> | ||
|  | #include <boost/type_traits/remove_reference.hpp> | ||
|  | #include <boost/mpl/find_if.hpp> | ||
|  | 
 | ||
|  | namespace boost { namespace detail { namespace variant { | ||
|  | 
 | ||
|  | template <class VariantElement, class T> | ||
|  | struct variant_element_functor : | ||
|  |     boost::mpl::or_< | ||
|  |         boost::is_same<VariantElement, T>, | ||
|  |         boost::is_same<VariantElement, boost::recursive_wrapper<T> >, | ||
|  |         boost::is_same<VariantElement, T& > | ||
|  |     > | ||
|  | {}; | ||
|  | 
 | ||
|  | template <class Types, class T> | ||
|  | struct element_iterator_impl : | ||
|  |     boost::mpl::find_if< | ||
|  |         Types, | ||
|  |         boost::mpl::or_< | ||
|  |             variant_element_functor<boost::mpl::_1, T>, | ||
|  |             variant_element_functor<boost::mpl::_1, typename boost::remove_cv<T>::type > | ||
|  |         > | ||
|  |     > | ||
|  | {}; | ||
|  | 
 | ||
|  | template <class Variant, class T> | ||
|  | struct element_iterator : | ||
|  |     element_iterator_impl< typename Variant::types, typename boost::remove_reference<T>::type > | ||
|  | {}; | ||
|  | 
 | ||
|  | template <class Variant, class T> | ||
|  | struct holds_element : | ||
|  |     boost::mpl::not_< | ||
|  |         boost::is_same< | ||
|  |             typename boost::mpl::end<typename Variant::types>::type, | ||
|  |             typename element_iterator<Variant, T>::type | ||
|  |         > | ||
|  |     > | ||
|  | {}; | ||
|  | 
 | ||
|  | 
 | ||
|  | }}} // namespace boost::detail::variant | ||
|  | 
 | ||
|  | #endif // BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP |