Re: Ambiguos inheritance - is this aceptable for gcc

From:

Pete Becker <pete@versatilecoding.com>

Newsgroups:

comp.lang.c++.moderated

Date:

10 Dec 2006 14:39:18 -0500

Message-ID:

<9dydnTqys_U5juHYnZ2dnUVZ_sqdnZ2d@giganews.com>

fcannizzo.mifft2001@london.edu wrote:

This compile and run with MS VC7.1. Is it ok also for gcc?

Thanks,
Fabio

struct A { virtual int foo() const = 0; };

struct B { virtual int foo() const = 0; };

struct C : public A, public B {
virtual int foo() const { return 1; }; // this is declared
virtual both in A and B!!!
};

There's nothing here that's ambiguous. C has one function named foo. If
you have a pointer to an object of type C and you convert it to a
pointer to an object of type A you can call A's foo, which is overridden
in C, so you end up calling C's foo. Same thing when you convert to a
pointer to B.

So, yes, it's okay. And sometimes useful.

--

    -- Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com)
Author of "The Standard C++ Library Extensions: a Tutorial and
Reference." (www.petebecker.com/tr1book)

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