Pass struct by reference, return pointer to new struct

I would like to pass a struct to a function by reference, create a new instance of a struct, destroy the original and return a new struct correctly. A specific example of such case is a queue resize function:

A queue structure itself:

// Queue for storage of pairs
typedef struct {
    int n;        // size of queue
    int m;        // no. of pairs in queue
    int f;        // index of front element
    int r;        // index of rear element
    pair *pairs;  // array of pairs
} queue;

Queue initialisation routine:

// Initialises queue
int init(int const *n, queue *q) {

    q->n = *n;
    q->m =  0;
    q->f =  0;
    q->r =  0;

    q->pairs = (pair*) calloc(q->n, sizeof(pair));

    return 0;
}

Queue destruction routine:

// Destroys queue
int destroy(queue *q) {

    q->n = 0;
    q->m = 0;
    q->f = 0;
    q->r = 0;
    free(q->pairs);

    return 0;
}

Enqueue routine:

// Adds pair to queue
int enqueue(pair *p, queue *q) {

    // resize queue if necessary
    if (isfull(q))  int status = resize(q);

    if (q->m > 0)  q->r = (++q->r) % q->n;
    q->pairs[q->r] = *p;
    q->m++;

    return 0;
}

My take at the queue resizing routine (currently it crashes with a floating point exception). I believe to resize a queue correctly I need to pass a pointer to a queue pointer, but so far I am unable to achieve this.

// Resizes queue
int resize(queue *q) {

    // initialise new queue
    const int N = 2*q->n;
    queue p;
    init(&N, &p);

    // copy pairs from old to new queue
    for (int i = 0; i < q->m; i++) {
        pair f = dequeue(q);
        enqueue(&f, &p);
    }

    // destroy old queue
    destroy(q);

    // re-assign pointer to new queue
    q = &p;

    return 0;
}