#include <iostream>
 
using namespace std;
 
struct Base {
    virtual void SomeMethod() {
        std::cout<<"Do Something"<<std::endl;
    }
};
 
struct Der : public Base {
    virtual void SomeMethod() override = 0;
};
 
struct DerDer : Der {
    virtual void SomeMethod() override
    {
        std::cout<<"Do something derived."<<std::endl;
    }
};
 
int main(int argc, char *argv[])
{
    DerDer x;
    Base *pX = &x;
    pX->SomeMethod();
    return 0;
}

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