multi_virtual_inheritance_mindfuck.cpp

#include <iostream>

struct A {
    virtual void foo() = 0;
};

struct B {
    virtual void foo() = 0;
};

struct CA : A {
    void foo() override { std::cout << "A" << std::endl; }
};

struct CB : B {
    void foo() override { std::cout << "B" << std::endl; }
};

struct C : CA, CB {
    //void foo() override { std::cout << "C" << std::endl; } // if this is provided the ones from CA and CB will be overridden
};

int main() {
    C c;
    //c.foo();  // ambiguous

    A& a = c;
    a.foo();

    B& b = c;
    b.foo();
}