Diamond Inheritance Duplication Fix

Question

Problem: Diamond Inheritance Duplication Fix. Solve this hands-on electronics task on EWskills.

Accepted Answer

#include 
using namespace std;

// Shared base
class DeviceCore {
public:
    DeviceCore(int id) : deviceId(id) {
        cout << "Device core initialized" << endl;
    }

    int getId() const {
        return deviceId;
    }

private:
    int deviceId;
};

// Virtual inheritance
class CommLayer : virtual public DeviceCore {
public:
    CommLayer(int id) : DeviceCore(id) {}
};

class PowerLayer : virtual public DeviceCore {
public:
    PowerLayer(int id) : DeviceCore(id) {}
};

// Single shared DeviceCore
class SensorDriver : public CommLayer, public PowerLayer {
public:
    SensorDriver(int id)
        : DeviceCore(id), CommLayer(id), PowerLayer(id) {}

    void printId() const {
        cout << "Device ID " << getId() << endl;
    }
};

int main() {
    int id;
    cin >> id;

    SensorDriver sensor(id);
    sensor.printId();

    return 0;
}

Explanation & Logic Summary:

In diamond inheritance:

Non-virtual inheritance creates multiple base subobjects
This duplicates hardware state and runs initialization multiple times

With virtual inheritance:

Only one shared base instance exists
The most-derived class (SensorDriver) initializes the virtual base
Intermediate classes do not create additional copies
Hardware state remains consistent and safe

Firmware Relevance & Real-World Context:

In embedded firmware:

Base classes often represent hardware registers or peripherals
Duplicate initialization can:
- Reset hardware unintentionally
- Corrupt configuration
- Cause undefined behavior

Understanding and fixing diamond inheritance is a critical advanced Embedded C++ skill.

145. Diamond Inheritance Duplication Fix