C++ 函数指针与函数重载的协同：洞悉代码重用的精髓

class Shape {
public:
    virtual ~Shape() {}  // 虚析构函数
    virtual double area() const = 0;  // 纯虚函数
};

class Rectangle : public Shape {
public:
    Rectangle(double width, double height) : m_width(width), m_height(height) {}
    double area() const override { return m_width * m_height; }
};

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

double calculateArea(Shape* shape) {
    return shape->area();
}

int main() {
    // 创建形状对象
    Rectangle rect(2.0, 3.0);
    Circle circle(1.0);

    // 使用函数指针调用 area() 函数
    double (*funcPtr)(const Shape* shape) = &Shape::area;
    std::cout << "Rectangle area using funcPtr: " << funcPtr(&rect) << std::endl;
    std::cout << "Circle area using funcPtr: " << funcPtr(&circle) << std::endl;

    // 使用函数重载调用 area() 函数
    std::cout << "Rectangle area using function overload: " << rect.area() << std::endl;
    std::cout << "Circle area using function overload: " << circle.area() << std::endl;

    return 0;
}