http://www.perlmonks.org?node_id=787393


in reply to Re: Hidden features of Perl (More Secret Operator References)
in thread Hidden features of Perl

Tadpole secret operator ~~($$..!$$) can be used as a kind of counter
print $_ , ' => ', ~~($$..!$$), "\n" for qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);