Support for Weak references?

[Rua]

At the moment, you can't create a ByAddress wrapper for a Weak reference, because these don't implement the Deref trait, only strong references do. But it would certainly be useful to be able to hash and compare these by the address of the pointed-to value. Is there a way that this can be done?

[mbrubeck]

This could be done using the Weak::into_raw method, though I think it would need to be a separate type from ByAddress.