none.cpp

#include <iostream>

template <class T>
class None: public T{
public:
    static None<T>* none(){
        static None<T> _;
        return &_;
    }
private:
    None<T>(){}
};

class Base{
public:
    virtual Base* test(){
        static Base _;
        return &_;
    }
};

class Derived: public Base{
public:
    virtual None<Base>* test(){
        return None<Base>::none();
    }
};

int main(){
    using std::cout;
    using std::endl;

    Base base;
    Derived derived;
    Base* b;

    b = base.test();
    cout << "base:    " << b << endl;

    b = derived.test();
    cout << "derived: " << b << endl;

    cout << "none:    " << None<Base>::none() << endl;
}

/*
base:    0x2048
derived: 0x204c
none:    0x204c
*/