override_private_pure_virtual_and_make_it_public.cpp

#include <iostream>
#include <string>
#include <vector>

class A
{
private:
    virtual void m1() = 0;
    virtual void m2() { std::cout << "A base" << std::endl; }
};

class B : public A
{
private:
    virtual void m1() = 0;
};

class C : public B
{
public:
    virtual void m1() override final { std::cout << "overriden" << std::endl; }
    virtual void m2() override final { std::cout << "A base overriden" << std::endl; }
};

int main()
{
    C x;
    x.m1();
    x.m2();
}