Re: Calling inherited protected method fails to compile

"Alf P. Steinbach" <>
Tue, 13 May 2008 12:12:06 +0200
* nomad:

Anyone have any idea why the code below fails to compile? I get the following
message when I try:

     error C2660: 'B::F' : function does not take 2 arguments.'

Clearly, B should inherit int F(int, int) from A, the function declaration
is not ambiguous in any way, so it seems to me that I should be able to call
it, yet the compiler refuses to allow me to do it. If I explicitly reference
it (i.e., A::F(x, 3) instead of this->F(x, 3)), it works fine.

This is a FAQ (see below).

class A
        A(void) { };
        virtual int F(int x) = 0;

        int F(int x, int y)
            return x + y;

class B : public A
        B(void) { };

        virtual int F(int x)
            return this->F(x, 3);

int main(void)

This 'void' is a C-ism. Not that it matters much, just a fine detail.

    B b;

    (void) b.F(3);

This cast is completely unnecessary.


For your question about why you get a compilation error, see the FAQ
item titled "What's the meaning of, Warning: Derived::f(char) hides
Base::f(double)?", currently item 23.9, available at e.g. <url:>,
or any mirror.

It's often a good idea to check the FAQ first.

Cheers, & hth.,

- Alf

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