#!/usr/bin/perl -w

use strict;

package A;
{
    sub new {
        my $class = shift;
        return bless( { @_ }, $class );
    }

    sub DESTROY {
        warn "$_[0] just died";
    }

    sub set {
        $_[0]->{ $_[1] } = $_[2];
    }
}

package B;
{
    @B::ISA = qw/ A /;
}

package C;
{
    @C::ISA = qw/ A /;
}

package main;

warn "doing something...\n";
do_something();

warn "doing something else (again)...\n";
do_something();

warn "exiting program...\n";

exit;

sub do_something {
    warn "entering block...\n";
    my $a = new A ();
    my $b = new B ();
    my $c = new C ();
    $b->set( C => $c );
    $c->set( B => $b );
    warn "exiting block\n";
}


# output of above:
doing something...
entering block...
exiting block...
A=HASH(0x804b424) just died at ./test_objects.pl line 13.
doing something else (again)...
entering block...
exiting block...
A=HASH(0x805d074) just died at ./test_objects.pl line 13.
exiting program...
C=HASH(0x805bb10) just died at ./test_objects.pl line 13 during global destruction.
B=HASH(0x805b9f0) just died at ./test_objects.pl line 13 during global destruction.
C=HASH(0x805d08c) just died at ./test_objects.pl line 13 during global destruction.
B=HASH(0x804b424) just died at ./test_objects.pl line 13 during global destruction.