C++ 基类如何在运行时确定方法是否已被覆盖？

class Base {
public:
    virtual void foo() {
        // 基类的实现
    }
};

class Derived : public Base {
public:
    void foo() override {
        // 派生类的实现
    }
};

Base* base = new Derived();
void (Base::*foo)() = &Base::foo;
void (Derived::*derived_foo)() = &Derived::foo;
if (foo != derived_foo) {
    // 派生类覆盖了虚函数
} else {
    // 派生类未覆盖虚函数
}