use Benchmark qw( cmpthese timethese );

my @alphabet = ( 0 .. 9, 'a' .. 'z', 'A' .. 'Z' );

my $h = horrid_rx(1_000);
my $qr_h = qr/$h/;
my $qr_ho = qr/$h/o;
my $s = join q{}, map { $alphabet[ rand @alphabet ] } 1 .. 1_000;

my $matchiness = ( $s =~ /$h/ ) ? 'matches' : 'does not match';
print "horrid rx $matchiness string\n";

my $loops = 1_000;

cmpthese( -2, { '//'   => sub { $s =~ /$h/   for (1..$loops) },
                '/o'   => sub { $s =~ /$h/o  for (1..$loops) },
                'qr'   => sub { $s =~ $qr_h  for (1..$loops) },
                'qr/o' => sub { $s =~ $qr_ho for (1..$loops) },
          } );

sub horrid_rx {
    my ($n) = @_;

    my @quant = ( '*', '?', '+', '{0,1}', );

    my $out;
    for ( 1 .. $n ) {
        $out .= $alphabet[ rand @alphabet ];
        $out .= $quant[ rand @quant ];
    }

    return $out;
}

##</code><code>##

horrid rx does not match string
       Rate   // qr/o   qr   /o
//    129/s   -- -83% -83% -88%
qr/o  752/s 483%   --  -0% -27%
qr    753/s 483%   0%   -- -27%
/o   1037/s 704%  38%  38%   --

##</code><code>##

horrid rx does not match string
       Rate   //   qr qr/o   /o
//   44.4/s   -- -29% -29% -32%
qr   62.7/s  41%   --  -1%  -4%
qr/o 63.0/s  42%   1%   --  -4%
/o   65.4/s  47%   4%   4%   --