How can it both have no side effects and have undefined behaviour?

masklinn · 2024-06-25T14:55:45 1719327345

By being declared as that?

Division has no side effects, and division by 0 is UB. UBs only occur in invalid programs, so behaviour in case of UB is not relevant to a discussion of side effects or their lack thereof, in language terms these are not programs at all.

asdfaoeu · 2024-06-25T15:07:41 1719328061

If print statement never completes then it is a well defined program. Because there will be no division by zero.

masklinn · 2024-06-25T15:38:29 1719329909

And if my grandmother had wheels she'd be a bike.

dllthomas · 2024-06-25T18:04:57 1719338697

Is your grandmother a bike every time the receiving side of a pipe terminates before the sending side, or only when it happens to interrupt a printf?

sapiogram · 2024-06-25T14:56:08 1719327368

Both statements don't need to be true. The compiler just has to prove that at least one of the statements will always be true.

asdfaoeu · 2024-06-25T15:13:57 1719328437

True but it only has no side effects if it's well defined. The compiler can assume it's well defined but only if it's executed.