[ 2022-03-04; Reflector poll ]

Set priority to 2 after reflector poll. Might be a design issue.

Despite the fact that join_view may produce more elements than each joined view(s) contains, we require implementations to use the common_type of their difference types (per [range.join.iterator] p3), which may lead to UB. As we already have provided implementation freedom to define extended integer-like types we should make provision for them to be used here as well. The same issue applies to the join_with_view as proposed by P2441.