Can a c++ class include itself as an attribute?

Question

I'm trying to speed up a python routine by writing it in C++. then to use it using ctypes

or cython.

I'm brand new to c++. I'm using microsoft express c++ as it's free.

I plan to implement an expression tree, and a method to evaluate it in postfix order.

The problem I run into right away is:

class Node {

char *cargo;

Node left;

Node right;

}

I can't declare left or right as Node types.

I'm willing to learn as much c++ as I need and more. the reference material I have right

now does not address this problem.

Thanks for any help.

Answer 1

No, because the object would be infinitely large (because every Node has as members two other Node objects, which each have as members two other Node objects, which each... well, you get the point).

You can, however, have a pointer to the class type as a member variable:

class Node {
    char *cargo;
    Node* left;   // I'm not a Node; I'm just a pointer to a Node
    Node* right;  // Same here
};

Answer 2

No, but it can have a reference or a pointer to itself:

class Node
{
    Node *pnode;
    Node &rnode;
};