What is the difference between public, protected, and private inheritance?

Question

Accepted Answer

**public** — "is-a". **protected** — "implemented-as". **private** — "implemented-in-terms-of".

```cpp
class Base {
public:
    int pub;
protected:
    int prot;
private:
    int priv;
};

class Public : public Base {
    // pub — public
    // prot — protected
    // priv — not accessible
};

class Protected : protected Base {
    // pub — protected
    // prot — protected
};

class Private : private Base {
    // pub — private
    // prot — private
};
```

- **public** — public stays public.
- **protected** — public becomes protected.
- **private** — public becomes private.

C++: What is the difference between public, protected, and private inheritance?