WeakMap holds a weak reference to the _key_, not the _value_. That's not enough to do weak event handlers, for example...
Re:WebAssembly Browser Preview
by Sophistifunk on Wednesday November 02, 2016 @04:52PM
(#12859164)
It can't be used because they refuse to allow iteration.
https://developer.mozilla.org/en/docs/Web/JavaScript/Referen...