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    my $dad= My::Parent->new( name => 'Robert' );
    {
...
    # No direct access to Robert, now.  Garbage collection runs.
    # Robert and Bobby form a loop but both are unreferenced.
    # Both get destroyed.

package My::Parent;
use My::Outer qw< ::Inner new DESTROY AUTOLOAD >;
...
package My::Child;
use My::Outer qw< ::Inner new DESTROY AUTOLOAD >;
use overload '""' => \&GetName;

package My::Inner;

...
    my( $in )= @_;
    return --$in->{refs};
}

# Outer objects:   dad          son  These are wrappers given to other
+s
#                   |            |   just to track what is still in-us
+e.
#                   v            v
# Inner objects:  _dad <------ _son  These have the real data, includi
+ng
#                   `------------^   links to other (inner) objects.

package My::Child::Inner;
use My::Inner qw< _wrap _unwrap _incRefs _decRefs >;
...
    my( $_son )= @_;
    warn "DESTROYing son: $_son->{name}\n";
}

# Called when Son is no longer externally referenced:
sub _free {
...
        $_son->{dad}= $_dad->{son}= undef;  # Break ref cycles!
    }
}

sub _isRefd {
    my( $_son, $hvSeen )= @_;
...
    }
    return 0;
}

sub _free {
    my( $_son, $force )= @_;
...
    }
    $_son->{dads}= [ ];
}

{
    my $dad= My::Parent->new( name => 'Sr' );
...
    warn "Rest to be destroyed next.\n";
}
warn "Everything destroyed above.\n";

$dad=Sr
$dad=Sr -> $son=Jr
...
DESTROYing son: Jr
DESTROYing dad: Fin
Everything destroyed above.

#!/usr/bin/perl -w
use strict;
...
DESTROYing dad: Fin
Everything destroyed above.