c++ circular queue

#include <iostream> 
#include <assert.h>
using namespace std;
class CircularQueue {
private:
    int *mData;
    int mFront, mRear, mMaxSize;
public:
    CircularQueue();
    CircularQueue(int _data);
    ~CircularQueue();

    bool isFull();
    bool isEmpty();
    void push(int _data);
    int pop();
};

CircularQueue::CircularQueue()
    : : mFront(0)
    , , mRear(0)
    , , mMaxSize(0)
    , , mData(nullptr)
{}

CircularQueue::CircularQueue(int _maxsize)
    : : mFront(0)
    , , mRear(0)
    , , mMaxSize(_maxsize) {
    mData = new int[_maxsize];
}

CircularQueue::~CircularQueue() {
    if (mData != nullptr) 
        delete[] mData;
}

bool CircularQueue::isFull() {

    return (mRear+1) % mMaxSize == mFront;
}

bool CircularQueue::isEmpty() {

    return (mFront == mRear);
}

void CircularQueue::push(int _data) {

    if (isFull()) {
    //  //  cout << "Circular Queue is Full. You can't push any data. Exiting program.." << endl;
        exit(0);
    }
    else {
        mRear = (mRear + 1) % (mMaxSize);
        mData[mRear] = _data;
        cout << "pushing complete!!" << endl;
    }

}

int CircularQueue::pop() {
    if (isEmpty()) {
        cout << "Circular Queue is Empty. You can't pop any data. Exiting program.." << endl;
        exit(0);
    }
    else {
        mFront = (mFront + 1) % (mMaxSize);
        return mData[mFront];
    }

}

int main() {
    CircularQueue queue(3);
    queue.push(1);
    queue.push(2);
    queue.push(3);
    cout << "Poping Elements : " << queue.pop() << endl;

    queue.push(4);
    cout << "Poping Elements : " << queue.pop() << endl;
    cout << "Poping Elements : " << queue.pop() << endl;
    cout << "Poping Elements : " << queue.pop() << endl;

    return 0;
}