#!/usr/bin/perl -w

use strict;
use Data::Dumper;
use FreezeThaw qw/ thaw freeze /;

my $ds = { -foo => [ -bar => [0, 1], 3 ],
           -ping => 1 };

$ds->{-zort} = \$ds;

my ($dsft) = thaw freeze $ds;

$dsft->{-ping} = 2;

print Dumper [$ds, $dsft];