How to make a static function that is only available to specific classes in c++

Question

Sorry if my question is dumb, I wanted to know if there is a way to make a static function that is only available to the classes I want to, example:

class A
{
    static int add(int a, int b)
    {
        return a+b;
    }
}

class B
{
    int getInt()
    {
        return A::add(10,10); // Should return 20
    }
}

class C
{
    int getInt()
    {
        return A::add(10,10) // I don't want C class to access A::add()
    }
}

int main()
{
    B b;
    C c;
    int x = b.getInt();
    int y = c.getInt(); //Should get a error
    return 0;
}

Have you considered making the static function private and making the classes that want private access friends? — Stephen M. Webb, Jun 30 '22 at 13:32
actually it is private already. If you compile the code you will get errors because no class other than `A` has access to `A::add` — 463035818_is_not_an_ai, Jun 30 '22 at 13:35
I know that way, but I want to make this happen to static functions, so is there a way? — Hassan, Jun 30 '22 at 13:35
why do you think `private` would work differently for static functions? It doesnt — 463035818_is_not_an_ai, Jun 30 '22 at 13:36
as I said, compile the code and you will see that it is already the case that you get the error you want. Though you also get other errors you dont want, and you get rid of them by making the classes friends of `A` (and adding some `;`) — 463035818_is_not_an_ai, Jun 30 '22 at 13:38
Ok, so I need to friend the classes that I need to access the static function right. — Hassan, Jun 30 '22 at 13:39

How to make a static function that is only available to specific classes in c++

0 Answers0