#!/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 },
   },
  );

##</code><code>##

% test.pl
Benchmark: timing 1000000 iterations of match, qreg...
     match:  1 wallclock secs ( 0.82 usr +  0.00 sys =  0.82 CPU) @ 1219512.20/s (n=1000000)
      qreg:  0 wallclock secs ( 0.73 usr +  0.00 sys =  0.73 CPU) @ 1369863.01/s (n=1000000)