如何包装指向抽象类的指针列表？

#include <iostream>
#include <vector>

// 抽象类
class Shape {
public:
    virtual void draw() const = 0; // 纯虚函数
    virtual ~Shape() = default; // 虚析构函数
};

// 派生类 Circle
class Circle : public Shape {
public:
    void draw() const override {
        std::cout << "Drawing a Circle" << std::endl;
    }
};

// 派生类 Square
class Square : public Shape {
public:
    void draw() const override {
        std::cout << "Drawing a Square" << std::endl;
    }
};

int main() {
    // 创建指向抽象类的指针列表
    std::vector<Shape*> shapes;

    // 添加派生类对象到列表
    shapes.push_back(new Circle());
    shapes.push_back(new Square());

    // 遍历列表并调用 draw 方法
    for (const auto& shape : shapes) {
        shape->draw();
    }

    // 清理内存
    for (auto shape : shapes) {
        delete shape;
    }

    return 0;
}

#include <memory>

int main() {
    std::vector<std::unique_ptr<Shape>> shapes;

    shapes.push_back(std::make_unique<Circle>());
    shapes.push_back(std::make_unique<Square>());

    for (const auto& shape : shapes) {
        shape->draw();
    }

    // 不需要手动释放内存
    return 0;
}