How to reverse a queue and display it - c++

Question

I have made a queue class and I have a queue and I want to reverse it,however when I implement the function it doesn't display anything.
Here's it
void reverse(Queue <T> &queue) {
if(!queue.empty())
{
int temp=queue.queue_front;
queue.pop(queue.queue_front);
reverse(queue);
queue.push(temp);
}
}
The pop function I'm using requires a value,that's why there is queue.queue_front.I'm trying to do it with a recursion.Here's my print function
void display() {
for(int current = queue_front+1; current < queue_length; current++)
{
cout << "[" << current << "]=" << queue_array [current] << " ";
}
}
Now that's what I'm doing in the main function
Queue <int>queue1(10);
queue1.push(16);
queue1.push(14);
queue1.push(6);
queue1.push(60);
queue1.reverse(queue1);
queue1.display();
Here's the pop function
void pop(T& item) {
if (empty()) {
cout << "The Queue is empty!";
exit(1);
}
else {
queue_front = (queue_front + 1) % queue_size;
item = queue_array[queue_front];
queue_length--;
}
}
It doesn't display anything.Thanks.

Answer 1

You're testing with a queue of integers, which hides quite a few bugs.
You should have tested with a Queue<std::string>.
First, here:
int temp=queue.queue_front;
you're saving an index, not an element.
What you intend must be
T temp = queue.queue_array[queue.queue_front];
but there's no reason to mess with member variables (see below).
Here,
queue.pop(queue.queue_front);
you're passing a reference to the queue's member to pop.
The parameter to pop is where the top element is stored after it's popped.
In other words, after that line, queue.queue_front will be the element that was at the front of the queue, not the index of the new front of the queue.
This would probably work:
void reverse(Queue <T> &queue) {
if(!queue.empty())
{
T temp;
queue.pop(temp);
reverse(queue);
queue.push(temp);
}
}