CppCoreGuidelines C.140 不要提供给虚函数和重写的函数不同的默认参数

class Base {
  public:
    virtual int multiply(int value, int factor = 2) = 0;
    virtual ~Base() = default;
};

class Derived : public Base {
  public:
    int multiply(int value, int factor = 10) override {return value * factor; };
};

int main()
{
    Derived d;
    Base& b = d;

    cout << b.multiply(10) << endl;  // these two calls will call the same function but
    cout << d.multiply(10) << endl;  // with different arguments and so different results
}