Can a C Class Include Itself as a Member Variable?

Can a C Class Mutually Include Itself as a Member?

In C , it's tempting to define a class that includes itself as a member to represent nested structures like expression trees. However, this approach is not permitted.

Reasoning:

As stated in the provided answer, defining a class with a member variable of its own type would result in an infinitely large object. Each Node would contain two Node objects, which would in turn contain two more Node objects, and so on ad infinitum. This would make memory allocation impractical and lead to a runtime error.

Solution:

To resolve this issue, it's necessary to use pointers to the class type as member variables instead of the class type itself. This allows for the representation of nesting while avoiding the problem of infinite recursion.

Consider the following revised definition:

class Node {
    char *cargo;
    Node* left;   // Pointer to a Node object
    Node* right;  // Another pointer to a Node object
};

By employing pointers, we can create a tree-like structure without running into the self-referential problem.

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