Question

Is there a way to define circular references without using pointers?

I need to have somthing like this:

struct A;
struct B {
    A a;
};

struct A {
    B b;
};

Thanks!

Answer 1

You can use references instead

struct A;
struct B {
  A& a;
};

struct A {
  B b;
};

But no it’s not possible to create a circular reference without some level of indirection. What your sample is doing is not even creating a circular reference, it’s attempting to create a recursive definition. The result would be a structure of infinite size and hence not legal.