防止通过派生 class 调用基 class 中的 static 方法？

Question

I have a Base class, and a Derived template that inherits from it. Both of these define a static method calculateSize() but with different method signatures. (Both are also instanced as objects; Base isn't just an interface.)

class Base{
public:
    static size_t calculateSize(size_t payload); 
};

template<typename T>
class Derived : public Base{
public:
    // sloppy fixo to prevent Base::calc() from being called
    static size_t calculateSize(size_t){ assert(0); return calculateSize(); }  
    
    // correct method to call
    static size_t calculateSize();
};

The Base class's version of this method would give a wrong answer if called for a Derived type, so I want to prevent it from accidentally being called through Derived::calculateSize(sz) . How would this typically be accomplished? (I currently have a method with the same signature in Derived that asserts if called, this feels kinda hacky though...)

Answer 1

If you have a calculateSize in the derived class, it will hide calculateSize in the base class, so you can simply just not have anything:

template<typename T>
class Derived : public Base {
public:
    static size_t calculateSize();
};

// Error: no function that takes an argument
size_t result = Derived<int>::calculateSize(1);

If you don't have something to hide it or you want it to be more clear that you shouldn't call it with the base classes signature, you can = delete it:

template<typename T>
class Derived : public Base {
public:
    // Explanatory comment here
    static size_t calculateSize(size_t) = delete;
    static size_t calculateSize();
};

// Error: trying to use deleted function
size_t result = Derived<int>::calculateSize(1);