24 Containers library [containers]

24.7 Views [views]

24.7.3 Class template span [views.span]

24.7.3.3 Deduction guides [span.deduct]

template<class It, class EndOrSize> span(It, EndOrSize) -> span<remove_reference_t<iter_reference_t<It>>>;
Constraints: It satisfies contiguous_­iterator.
template<class R> span(R&&) -> span<remove_reference_t<ranges::range_reference_t<R>>>;
Constraints: R satisfies ranges​::​contiguous_­range.