Protected Access

#include <iostream>
using namespace std;

class BaseDevice {
protected:
      int id;
};

class DerivedDevice : protected BaseDevice {
public:
      void setId(int v)
      {
            id = v;
      }
      void printId()
      {
            std::cout << "Device ID: " << id << std::endl;
      }
};

int main() {
   DerivedDevice d;
   d.setId(101);
   d.printId();
   return 0;
}