std::experimental::ranges::projected

 

C++

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Ranges

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Ranges

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Iterators library

Iterator concepts
Readable Writable WeaklyIncrementable Incrementable	Iterator Sentinel SizedSentinel	InputIterator ForwardIterator BidirectionalIterator RandomAccessIterator	OutputIterator
Indirect callable concepts
IndirectUnaryInvocableIndirectRegularUnaryInvocable	IndirectUnaryPredicate	IndirectRelation	IndirectStrictWeakOrder
Common algorithm requirements
IndirectlyMovable IndirectlyMovableStorable	IndirectlyCopyable IndirectlyCopyableStorable	IndirectlySwappable IndirectlyComparable	Permutable Mergeable Sortable
Concept utilities
indirect_result_of	projected
Iterator utilities and operations
iter_move iter_swap	advance distance	next prev
Iterator traits
difference_type value_type reference_trvalue_reference_titer_common_reference_t iterator_category	input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tag	ranges::iterator_traits std::iterator_traits<InputIterator>std::iterator_traits<OutputIterator>
Iterator adaptors
reverse_iterator move_iterator move_sentinel	back_insert_iterator front_insert_iterator insert_iterator	common_iterator counted_iterator default_sentinel	danglingborrowed_iterator_t unreachable
Stream iterators
istream_iterator	ostream_iterator	istreambuf_iterator	ostreambuf_iterator

 

Defined in header <experimental/ranges/iterator>
template< Readable I, IndirectRegularUnaryInvocable<I> Proj > struct projected {     using value_type =         std::remove_cv_t<std::remove_reference_t<ranges::indirect_result_of_t<Proj&(I)>>>;     ranges::indirect_result_of_t<Proj&(I)> operator*() const; }; template< WeaklyIncrementable I, class Proj > struct difference_type<projected<I, Proj>> {     using type = ranges::difference_type_t<I>; };		(ranges TS)

The class template projected bundles a Readable type I and a function Proj into a new Readable type whose reference type is the result of applying Proj to the reference type of I. It exists solely to ease constraint specification, and so its operator*() may not be actually defined.