I guess given that it was UB before, the compiler was already allowed to put a system call here if it wanted for some reason

Yes, it was a horrible situation that has been replaced by an only slightly less horrible situation.

	▲	saghm 4 hours ago \| parent [-]
		I don't totally agree with this. To me, UB is an order of magnitude worse than pretty much anything else, so this is more than "slightly less" horrible. I don't necessarily disagree that this is still horrible, but I also don't write an C++, so I'm mostly just commenting as an outside observer.