#include <iostream>

struct Base {

    static void print() {
        std::cout << member << std::endl;
    }

protected:
    static int member;
};

int Base::member = 0;

int main() {

    using namespace std;

    struct Derived : public Base
    {
        using Base::member;
    };
    
    int * pm = &Derived::member;
    *pm = 99;

    Base::print();
}