c++ - Sequence point from function call?

Question

This is yet another sequence-point question, but a rather simple one:

#include <stdio.h>
void f(int p, int) {
  printf("p: %d
", p);
}

int g(int* p) {
  *p = 42;
  return 0;
}

int main() {
  int p = 0;
  f(p, g(&p));
  return 0;
}

Is this undefined behaviour? Or does the call to g(&p) act as a sequence point?

Answer 1

No. It doesn't invoke undefined behavior. It is just unspecified, as the order in which the function arguments are evaluated is unspecified in the Standard. So the output could be 0 or 42 depending on the evaluation order decided by your compiler.