So suppose I have a type named donut. I would like to make a constructor for donut that takes 3 arguments, two ints, and a structure cream which has two integers as fields. I would like to put default values for the arguments in case there are no supplied arguments. So how would the syntax be?

```
Donut::Donut(int a=0, int b=0, cream car={0, 0})

                    : donutfield1(a), donutfield2(b), donutfield3(car) { }

```

this does not work...