On 8 December 2016 at 07:13, lhmouse wrote: > It is undefined behavior. > > The evaluation of three parameters in question is (at the moment) unsequenced. > Since each of them contains a function call, the three function calls are also > unsequenced. The modify-and-read operations inside the function calls are > unsequenced relative to each other. Hence the UB. No, that's incorrect. The functions don't interleave. It's unspecified which order they execute in, but there is no undefined behaviour. The C++ standard says: "For each function invocation F, for every evaluation A that occurs within F and every evaluation B that does not occur within F but is evaluated on the same thread and as part of the same signal handler (if any), either A is sequenced before B or B is sequenced before A." So they're not unsequenced.
