[span.deduct]

🔗

template<class It, class EndOrSize>
  span(It, EndOrSize) -> span<remove_reference_t<iter_reference_t<It>>,
                              maybe-static-ext<EndOrSize>>;

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.

23 Containers library [containers]

23.7 Views [views]

23.7.2 Contiguous access [views.contiguous]

23.7.2.2 Class template span [views.span]

23.7.2.2.3 Deduction guides [span.deduct]