Question

I am implementing a queue in C. I have a struct like:

struct Node {
    Node* next;
    Node* previous;
    // data
}

Because next and previous are just pointers, does it make a difference if I use Node* or int*? eg:

struct Node {
    int* next;
    int* previous;
    // data
}

Answer 1

Using int * is incorrect and results in undefined behavior. You can use either Node * or void *, but if you use any type other than Node *, it’s going to require a cast (or implicit conversion, e.g. via an assignment) back to Node * before you can dereference it.