> Where does ToNumber come from? It sounds like the kind of thing that ought to get optimized! ToNumber comes from Number(l). I can't see how it can be optimiz

> Where does ToNumber come from? It sounds like the kind of thing that ought to get optimized! ToNumber comes from Number(l). I can't see how it can be optimized (l is a string so parsing is unavoidable). > You mean, if you use delete, getters, setters, seal, or freeze, then the object will use dictionary-mode thereafter under he covers? Yes. > What constitutes "misuse"? Your understanding of misuse is correct. > So it exists theoretically? Yes.