class Base {
protected:
int someValue;
void doSomething();
public:
void thePublicMethod();
void anotherPublicMethod();
};
Since someValue and doSomething() are protected, they are visible and can be used by any subsequent derived class. Then, let’s have a derived class:class Derived : public Base {
void newStuff() {
someValue = 42;
doSometing();
}
};
The public methods are still public. Now see that I used someValue and doSomething() inside newStuff() method, which is private. And now I don’t want subsequent derived classes to have access to someValue and doSometing(). I want to hide them from subsequent derived classes.At first, I thought it wouldn’t be possible without redefining and overriding, which would add bloat here. But then I came across a trick I didn’t know, which allows you to hide both methods and variables without redefining or overriding them:
class Derived : public Base {
Base::someValue;
Base::doSomething; // now they are protected: hidden!
void newStuff() {
doSometing();
someValue = 42;
}
};
This trick changes the access modifier of methods and member variables without touching them, with zero overhead or additional bloat. Yes, C++ is a damn complex language.