I agree that this is quite likely. But there is more subtle evilness in undefined behavior. E.g. for "foo(bar(), baz())", it's not clear whether bar() or baz()

I agree that this is quite likely. But there is more subtle evilness in undefined behavior. E.g. for "foo(bar(), baz())", it's not clear whether bar() or baz() is executed first (or maybe it is now, but wasn't in earlier iterations of the standard). OTOH, I'm wondering if GP is building with -Wall and has eliminated all warnings? At least that's what we're doing, and this yields good results.