Question

How to use private inheritance with private and protected base class members in C++

Answer 1

#include <iostream>
 
class Base {
   private:
    int pri_vate = 1;
 
   protected:
    int prote_cted = 2;
 
   public:
    int pub_lic = 3;
 
    int getPrivate() {
        return pri_vate;
    }
};
 
class ProtectedDerived : private Base {
   public:
    int getProtectedt() {
        return prote_cted;
    }
    int getPublic() {
        return pub_lic;
    }
    /*
    int getPrivate_PublicDerived() {
        return pri_vate; // error: ‘int Base::pri_vate’ is private within this context
    }*/
};
 
int main() {
    ProtectedDerived o;
     
    // std::cout << "Private = " << o.getPrivate() << "\n"; // error: ‘int Base::getPrivate()’ is inaccessible within this context
    std::cout << "Protected = " << o.getProtectedt() << "\n";
    // std::cout << "Public = " << o.pub_lic << "\n"; // error: ‘int Base::pub_lic’ is inaccessible within this context
    std::cout << "Public = " << o.getPublic() << "\n"; 
     
    return 0;
}
 

 
 
/*
run:
 
Protected = 2
Public = 3
 
*/

 

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