Re: Ambiguous in MI
On Oct 24, 2:28 pm, "Alf P. Steinbach" <al...@start.no> wrote:
* tas:
class B{
public:
virtual void fun() = 0;
......
};
class C{
public:
void fun();
};
class A: public B, private C {
};
void A::fun(){
.......
}
MSVC 6.0 : " 'A::fun()' is ambiquous could be the 'fun' in
base B of class A or the 'fun' in base C of class A."
But when i wrote "public:void fun();" in class A all was good.
I take it this means that when you provided a declaration in
class A then the compiler finally accepted your code.
Why is this happening?
C++ requires declarations.
And definitions, if the declared thing is "potentially used"
(and any virtual function is potentially used if the class is
instantiated).
And how i can redefine 'C::fun()' in class A?
You can redefine it and that is what you've done above, but
that's surely not what you mean. You probably mean how you can
override it. To override it it needs to be virtual in C.
I suspect (but I'm really just guessing) that what he's
expecting is the behavior of Java: that C::fun() will provide
the implementation of B::fun(), just because the function
happens to accidentally have the same name in two different,
unrelated classes. C++ doesn't have this defect in the
language; you have to explicitly tell the compiler that the
implementation in C::fun() is the one you want here, by defining
an A::fun() which calls C::fun().
--
James Kanze