I think the speculation in the blog post about it using boxed primitive types exclusively must be wrong, or at least a temporary state of affairs if it's curren

I think the speculation in the blog post about it using boxed primitive types exclusively must be wrong, or at least a temporary state of affairs if it's currently correct. I don't have a Mac capable of running any of the dev tools at the moment, but the implications of the section in the manual on the Int* types don't indicate they're boxed at all, nor give any reason why they should have to be. Of course, if he's declared everything as an NSNumber it could explain some of the results. But obviously, so could them currently being boxed. Either would probably account for the ++ performance problem, especially if it's post-increment, since that probably involves making a copy. I think the OP is just confusing the fact that they have expandable type as indicating that they have a virtual type.