use strict;
use warnings;
use Scalar::Util qw/dualvar/;
use Hash::Util::FieldHash qw/id id_2obj register/;

{
	package Baz;
	use Hash::Util::FieldHash qw/register/;
	
	sub new {
		my $class = shift;
		my $self = bless {}, $class;
		register $self;
		$self
	}
	sub test {
		'In object Baz';
	}

}

my $b = Baz->new;
my $x = dualvar( id( $b ), 'Baz says Hi' );
print "$x - ", (id_2obj($x+0))->test(),"\n";