String.prototype.valueOf is not generic

[jameshartig]

If you're making weak references to String objects then it can no longer behave like a string:

var string = weak(new String('test'));
string == 'test'; //throws String.prototype.valueOf is not generic

Is this a known limitation?

[jameshartig]

This is related to #13. A way to get around it is to pass around the weak reference but when you actually need the original object use weak.get(ref).