Question

which of these two is better?

void SetBit(int *flag, int bit)
{
    *flag |= 1 << bit;
}

Or

int SetBit(int flag, int bit)
{
    flag |= 1 << bit;
    return flag;
}

Answer 1

I like the second one because it doesn’t have any side effects. If you want to modify flag, you can simply assign the result to itself:

flag = SetBit(flag, 4);