#!/usr/bin/perl -w

use Benchmark;

my $txt = 'find this regex';
my $str = 'regex?';
my $rgx = qr/$str/i;

timethese
  (
   1000000,
   {
    match => sub{ $txt =~ m/$str/i },
    qreg  => sub{ $txt =~ $rgx },
   },
  );