Is “*p = ++(*q)” undefined when p and q point to the same object?

Question

after reading about sequence points, I learned that i = ++i is undefined.

So how about this code:

int i;
int *p = &i;
int *q = &i;
          


        

Answer 1

The best tool not to detect, but to avoid this in the first place is to use good programming practice. Avoid side-effects and do no more than one write per assignment. There is nothing wrong with

*q += 1;
*p = *q;