c++ - 虚函数可以被非虚函数覆盖吗？

Question

在这段代码中:

class Base {
public:
    virtual void method() = 0;
};

class Derived1 : public Base{
public:
    virtual void method() override { }
};

class Derived2 : public Base{
public:
    void method() override { }
};

Derived1 和 Derived2 有区别吗？

Answer 1

摘自 c++11 标准(草案 n3337)的 10.3 虚函数 第 2 点:

If a virtual member function vf is declared in a class Base and in a class Derived, derived directly or indirectly from Base, a member function vf with the same name, parameter-type-list (8.3.5), cv-qualification, and refqualifier (or absence of same) as Base::vf is declared, then Derived::vf is also virtual (whether or not it is so declared) and it overrides Base::vf.

所以 Derived2::method 也是 virtual，即使它没有明确声明。