VarVal.perl

use strict;
use warnings;

package VarVal;
sub println
{
    print @_, "\n";
}
sub val
{
    my ($name) = @_;
    {
        my %values;
        *$name = sub
        {            
            my ($self) = @_;
            $values{$self};               
        }    
    }
}

my $cleaUpFuncs = [];

sub var
{
    my ($name) = @_;
    {
        my %values;
        *$name = sub :lvalue
        {            
            my ($self) = @_;
            $values{$self};               
        };

        push @$cleaUpFuncs, sub{
            println "deleting $name";
            my $self = shift;
            delete $values {$self};
        }
    }
}


sub DESTROY {
   my $self = shift;
   $_->($self) for @$cleaUpFuncs;
}

package Auto;
@ISA=(VarVal);

var tireCount;
var color;

sub new 
{
    my ($class) = @_;
    my $self = bless {}, $class;
    $self->color = "blue";
    return $self;
}

package main;
sub println
{
    print @_, "\n";
}

my $myCar = new Auto;
my $yourCar = new Auto;

$yourCar->color = "red";

println "--";
$yourCar->DESTROY();
println "++";

println $myCar->color();
println $yourCar->color();