struct inside struct: Is there a way to call a function of the outside struct from the inner struct?

[berni via Digitalmars-d-learn]

struct A
{
    void c() {}

    struct B
    {
        void d()
        {
            c();
        }
    }
}

When compiling this with rdmd I get the message: "Error: this for 
c needs to be type A not type B". Is there a way to call c from d?