http://www.perlmonks.org?node_id=948688


in reply to Re: Possible Match Problem
in thread Possible Match Problem

... a couple of ways to ... use all these characters verbatim ... qr is another.

In no way will  qr use any metacharacters verbatim unless specifically 'told' to do so, e.g., by a  \Q ... \E escape sequence.

>perl -wMstrict -le "my $s = 'hi('; my $rx = qr{$s}; " Unmatched ( in regex; marked by <-- HERE in m/hi( <-- HERE / at ...

Update: See  qr in the Regexp Quote Like Operators section of perlop, also see section on 'escape sequences' (for \Q) in Quote and Quote like Operators, also in perlop.