Subj : Pairs of 32-bit pointers To : netscape.public.mozilla.jseng From : "Sterling Bates" Date : Sat Dec 06 2003 12:43 am I'm wondering if this has been considered already (very likely), or if it is up for consideration. I think there are two places this could be advantageous. The first is storing the data type of a variable in the first pointer, with the variable's contents in the second. This would avoid modifying the actual variable (or pointer to it) itself. The second is function callback. Delphi (and possibly C++, but I don't know) stores two pointers for every object method: one to the code, and one to "this" or "self". By permitting a method pointer as a callback, developers could point directly to the object instance that expects the call instead of a call wrapper. The private slot is not always available, or sometimes just not a good idea, for this. JSString, for instance, uses its private slot for its own data. This prevents a developer from using that slot for an external object reference. (Granted, that's likely a rare occurrence with JSStrings, but it highlights the point.) Just curious, Sterling .