use strict;
use warnings;
use Scalar::Util qw( refaddr );
use Benchmark qw( cmpthese );

my $ref = {};

cmpthese( -5, {
    'xs   ' => sub { refaddr $ref },
    'regex' => sub { "$ref" =~ /0x(\w+)/; hex $1; },
    '0+ref' => sub { 0 + $ref },
});

##</code><code>##

           Rate regex xs    0+ref
regex  165816/s    --  -89%  -97%
xs    1504549/s  807%    --  -73%
0+ref 5550057/s 3247%  269%    --