C++ dynamic objects

outer_queue = new Queue //allocates memory at location X, constructs a queue object on top
newQueue(outer_queue)

void (newQueue* inner_queue)
{
  delete inner_queue; //delete destructs the object at location X and allows the memory at
                       // X to be reused. inner_queue and outer_queue both still point at X
  inner_queue = new Queue(capacitiy) //allocates memory at location X (because it was
                                     // the most recently free'd block of memory) and
                                     // constructs the new queue
}

Queue* q = new Queue();
q = newQueue(q);

Queue* newQueue(Queue* q)
{
  /*
    ...snip...
  */
  cin >> c;
  delete q;
  q = 0;
  q = new Queue(c);
  return q;
}

Queue* q = new Queue();
newQueue(&q);

void newQueue(Queue** q)
{
  /*
    ...snip...
  */
  Queue * ptr = (*q); // More readable
  cin >> c;
  delete ptr;
  ptr = new Queue(c);
}

Queue* q = new Queue();
newQueue(q);

void newQueue(Queue&* q)
{
  /*
    ...snip...
  */
  cin >> c;
  delete q;
  q = new Queue(c);
}

cin << cap;
Queue* q = new Queue(cap);

Queue createQueue()
{
   ...
   std::cin >> capacity;
   return Queue(capacity);
}

Queue queue;  // default capacity 10
...
queue = createQueue();