That's not what the code does. 3 ** int_ptr multiplies the vakue pointed at by int_ptr by 3. It is exactly the same code as 3 * (*int_ptr) which is the point

That's not what the code does. 3 ** int_ptr multiplies the vakue pointed at by int_ptr by 3. It is exactly the same code as 3 * (*int_ptr) which is the point the parent was making. powl(3, int_ptr) would be (int)int_ptr * (int)int_ptr * (int)int_ptr which is also unlikely what you wanted. You probably wanted to say powl(3, *int_ptr) EDIT: actually even my last paragraph is wrong because the first arg is base... I'm not going to write it out but you get the point...