A weak reference is just like an ordinary Perl reference except that it isn't included in the reference count of the thing referred to. This means that once all references to a particular piece of data are weak, the piece of data is freed and all the weak references are set to undef. This is particularly useful for implementing circular data structures without memory leaks or caches of objects.
WWW: http://search.cpan.org/dist/WeakRef/
None
None
None