C++ 関数の継承の詳細な説明: 継承を使用してパフォーマンスを最適化する方法?

returnType functionName(参数列表1);
returnType functionName(参数列表2);

class Shape {
public:
    virtual double area() = 0;  // 抽象方法
};

class Rectangle : public Shape {
public:
    Rectangle(double width, double height) : _width(width), _height(height) {}
    virtual double area() override { return _width * _height; }

private:
    double _width;
    double _height;
};

class Circle : public Shape {
public:
    Circle(double radius) : _radius(radius) {}
    virtual double area() override { return M_PI * _radius * _radius; }

private:
    double _radius;
};

int main() {
    Shape* rectangle = new Rectangle(10, 5);
    Shape* circle = new Circle(5);

    cout << "Rectangle area: " << rectangle->area() << endl;
    cout << "Circle area: " << circle->area() << endl;

    delete rectangle;
    delete circle;
    return 0;
}