> Speed is the issue which comes to mind. Why add the extra alloc if you
> really don't need it? :-)

Allocating stuff on the stack doesn't take extra time, although the
copy would.   It's hard to imagine that the four extra instructions
would amount to much in a real-world situation, but it's certainly
true that they'd amount to _something_.   However, I'd be willing to
bet that having a single syscall that does both reads and writes based
on a flag consumes more time than that.

			       _MelloN_