You can clone with
What should be the result of the following...?
say 'abcd'.match( /./, :pos(1), :global);
1. return only the one match that is anchored at position 1,
2. return all matches, anchoring only the first one, or
3. return the match anchored at position 1, and all subsequent matches anchored to the previous match?
Similar considerations may hold for the :nth and :x modifiers.
The only effect of :pos is to set the starting position. :pos(0) is a no-op, in other words.
So, just to confirm: when :global, :overlap, :nth, or :x are set, then :pos($n) acts exactly like :c($n) would?
Sorry, was confusing :p with :c due to either illness or stupidity (or both). :p will anchor, so only :ex has any effect (return all anchored variations). All other modifiers should fail with :p, pointing toward use of :c instead.
:p is incompatible with scanners
:p may not be used with :ex, :ov, :g, :nth, or :x modifiers.