Question

class A {};

class B : private A {

};

class C : public B {
public:
    void f() {
        A a; // This line causes error, but works when it is in main() function
    }

};

int main()
{
    C c;
    // A a; --> This line works
    return 0;
}

I am guessing this has something to do with B inheriting privately from A but cannot put my finger on it.

EDIT: Error is “class A is not visible”. Compiled with g++.

Answer 1

name lookup is separate from access checking. and when you inherit from a class, that class’ name is injected into the inheriting class’ scope. so in class C you pick up the name A but it’s not accessible.

---

one solution is to write ::A a; instead of A a;.