http://qs321.pair.com?node_id=11130291

To return the character that's used as the delimiter in a quote-like operator, you can use a backslash.
'/' eq q/\// or die "Failed";

Your task is to return a backslash using a backslash as the delimiter. Use qq\\ for level easy, use q\\ for level guru.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]