Queue Explained: Daily Life's Data Structure

template <typename T>
struct Node
{
    T data;
    Node<T> *next;

    Node<T>(T data) : data(data), next(nullptr) {}
};

template <typename T>
Queue<T>::Queue()
{
    this->front = nullptr;
    this->rear = nullptr;
}

template <typename T>
Queue<T>::~Queue()
{
    while (this->front != nullptr)
    {
        this->dequeue();
    }
}

template <typename T>
void Queue<T>::enqueue(T value)
{
    Node<T> *newNode = new Node<T>(value);
    if (this->isEmpty())
    {
        this->front = this->rear = newNode;
    }
    else
    {
        this->rear->next = newNode;
        this->rear = newNode;
    }
}

template <typename T>
void Queue<T>::dequeue()
{
    if (!this->isEmpty())
    {
        Node<T> *temp = this->front;
        this->front = this->front->next;
        if (this->front == nullptr)
        {
            this->rear = nullptr;
        }
        delete temp;
    }
}

template <typename T>
T Queue<T>::peek()
{
    return (!this->isEmpty()) ? this->front->data : -1;
}

template <typename T>
bool Queue<T>::isEmpty()
{
    return this->front == nullptr;
}

#include <iostream>
#include "Queue.h"

int main() {
Queue<int> *q = new Queue<int>();  // Create a queue for integers

    std::cout << "Enqueuing elements{1,2,3,4}..." << std::endl;
    q->enqueue(1);
    q->enqueue(2);
    q->enqueue(3);

    std::cout << "Current front element: " << q->peek() << std::endl;  // Should print 1

    std::cout << "Dequeuing..." << std::endl;
    q->dequeue();
    std::cout << "New front element after one dequeue: " << q->peek() << std::endl;  // Should print 2

    std::cout << "Checking if queue is empty: " << (q->isEmpty() ? "Yes" : "No") << std::endl;  // Should print No

    std::cout << "Dequeuing remaining elements..." << std::endl;
    q->dequeue();
    q->dequeue();  // Queue should be empty after this

    std::cout << "Checking if queue is empty after dequeuing all elements: " << (q->isEmpty() ? "Yes" : "No") << std::endl;  // Should print Yes

    try {
        std::cout << "Attempting to peek into an empty queue: ";
        std::cout << q->peek() << std::endl;
    } catch (const std::runtime_error& e) {
        std::cout << e.what() << std::endl;  // Should catch and print "Queue is empty"
    }

    return 0;
}