[iterator.concept.iterator] (original) (raw)

23 Iterators library [iterators]

23.3 Iterator requirements [iterator.requirements]

23.3.4 Iterator concepts [iterator.concepts]

23.3.4.6 Concept input_­or_­output_­iterator [iterator.concept.iterator]

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The input_­or_­output_­iterator concept forms the basis of the iterator concept taxonomy; every iterator models input_­or_­output_­iterator.

This concept specifies operations for dereferencing and incrementing an iterator.

Most algorithms will require additional operations to compare iterators with sentinels ([iterator.concept.sentinel]), to read ([iterator.concept.input]) or write ([iterator.concept.output]) values, or to provide a richer set of iterator movements ([iterator.concept.forward],[iterator.concept.bidir], [iterator.concept.random.access]).

template<class I> concept input_­or_­output_­iterator = requires(I i) { { *i } -> can-reference;} && weakly_­incrementable<I>;

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[Note 1:

Unlike the Cpp17Iterator requirements, the input_­or_­output_­iterator concept does not require copyability.

— _end note_]