WeakRef::Auto - Automatically makes references weaken

This document describes WeakRef::Auto version 0.02.

	use WeakRef::Auto;

	autoweaken my $ref; # $ref is always weaken

	$ref = \$var; # $ref is weak

	sub MyNode::new{
		# ...
		autoweaken $self->{parent}; # parent is always weaken
		return $self;
	}

This module provides autoweaken(), which keeps references weaken.

Turns $var into auto-weaken variables, and keeps the values weak references. If $var already has a reference, it is weaken on the spot.

$var can be an element of hashes or arrays.

• Because the prototype of autoweaken() is "\$" (i.e. autoweakn($var) actually means &autoweaken(\$var)), you'd better load this module in compile-time, using use WeakRef::Auto directive.

autoweaken() does not work with tied variables, because autoweaken-ness is attached to the variable, not to the value referred by the variable, and tied variables interact with their objects by values, not variables, as the following shows:

  my $impl = tie my %hash, 'Tie::StdHash';
  autoweaken $hash{foo};
  # $hash{foo} seems autoweaken. Really?
  # Actually, $hash{foo} is linked to $impl->{foo} through FETCH()/STORE() methods,
  # but there is no way to detect the relationship.

Patches are welcome.

Perl 5.8.1 or later.

Scalar::Util for a description of weak references.

Goro Fuji <gfuji(at)cpan.org>.

Copyright (c) 2008, Goro Fuji <gfuji(at)cpan.org>. Some rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.