#!/usr/bin/perl -w
use strict;

package P;
use overload '""' => sub { 'stringified' };

package main;
local $\ = "\n";
my $regex = qr/match/;
bless $regex, 'P';

my $plain = \my $t;
bless $plain, 'P';

print '"stringified" matched $regex' if "stringified" =~ $regex;
print '"stringified" matched $plain' if "stringified" =~ $plain;
__END__
"stringified" matched $plain