[audunw]

> It should probably return an error or panic (if free's API allows it, I guess).

Then how would you use it in the cases where you want free to be a no-op?

I think that's half of the point of the allocator.. free shouldn't do anything, certainly not throw an error. You can free the buffer behind the allocator later, or for some simple command line tools you'll just let the OS free memory when the process finishes.

Perhaps some kind of debug message could be OK. Would perhaps be nice if you have some problems with allocation, you activate debug messages related to allocation, and one of them would be "free was called on something other than the last allocation so it was ignored"