C++设计一个循环队列QUEUE<T>

以下是以C++语言实现的循环队列QUEUE<T>的示例代码：

template <typename T>
class Queue {
private:
    T *data;
    int front, rear, size;

public:
    Queue(int init_size = 10): data(new T[init_size]), front(0), rear(0), size(init_size) {};

    bool isEmpty() const {
        return front == rear;
    }

    bool isFull() const {
        return (rear + 1) % size == front;
    }

    int getSize() const {
        return (rear - front + size) % size;
    }

    void enqueue(const T& obj) {
        if (isFull()) {
            T *newData = new T[2 * size];
            int j = 0;
            for (int i = front; i != rear; i = (i + 1) % size) {
                newData[j++] = data[i];
            }
            newData[j++] = data[rear];
 
            front = 0;
            rear = j - 1;
            size *= 2;
            delete [] data;
            data = newData;
        }

        data[rear] = obj;
        rear = (rear + 1) % size;
    }

    T dequeue() {
        if (isEmpty()) {
            throw std::underflow_error("Queue empty");
        }

        T obj = data[front];
        front = (front + 1) % size;
        return obj;
    }
};

该循环队列QUEUE<T>支持动态扩容，当队列满时会将队列大小扩充为原大小的两倍，同时将队列中的元素复制到新的内存中，并删除原有内存。如果队列为空，则出队列操作会抛出std::underflow_error异常。