How can I use a class before defining it?

Question

class Node
{
    string name;
    Node previous;
};

 Error: Node::previous uses "Node" which is being defined.

How can I get this to work in C++? It works in C#.

EDIT:

Why Node* previous works?

Answer 1

Use pointers. Node* previous; would solve the problem.

As you're doing it now, you actually try to make your class infinitely large.

Answer 2

Use a pointer or a reference.

For example:

Node* previous;

The only restriction is that a class cannot have an actual field of itself, likely for construction reason. Think about it, if every Box contains another Box inside it, how would you end up with a finite number of boxes?

If I'm not mistaken, C# only uses references for class types (as does Java), so you're using a reference there, just not seeing it.