Virtual Public Inheritance

#include <iostream>
using namespace std;

class Device {
public:
    void show(void) {
        printf("Generic Device\n");
    }
};

class Sensor : virtual public Device {
    // no extra code needed
};

class Actuator : virtual public Device {
    // no extra code needed
};

class SmartDevice: public Sensor, Actuator{
public:
    void identify(void) {
        printf("Smart Device\n");
    }
};

int main() {
    SmartDevice sd;
    sd.show();      // from Device
    sd.identify();  // from SmartDevice
    return 0;
}