queue.h

#ifndef QUEUE_H
#define QUEUE_H
#include<vector>
using namespace std;

template <class X>
class queue
{
    vector<X> arr;
    int capacity;
    int front;
    int rear;
    int count;

public:
    queue(int size = SIZE);     // constructor

    void dequeue();
    void enqueue(X x);
    X Display();
    bool isEmpty();
};

template <class X>
queue<X>::queue(int size)
{
    arr = vector<X>(size);
    capacity = size;
    front = 0;
    rear = -1;
    count = 0;
}


template <class X>
void queue<X>::dequeue()
{
    if (isEmpty())
        cout << "\nQueue is empty\n";

    cout << "Removing " << arr[front] << '\n';

    front = (front + 1) % capacity;
    count--;
}

template <class X>
void queue<X>::enqueue(X item)
{
    if (isFull())
    {
        cout << "\nQueue is full\n";
    }

    cout << "Inserting " << item << '\n';

    rear = (rear + 1) % capacity;
    arr[rear] = item;
    count++;
}

// Utility function to return front element in the queue
template <class X>
X queue<X>::Display()
{
    if (isEmpty())
        cout << "\nQueue is empty." << endl;
    else
        return arr;
}


template <class X>
bool queue<X>::isEmpty()
{
    return (size() == 0);
}
#endif