Jean-Marc Lasgouttes wrote:
>>>>>> "Angus" == Angus Leeming <[EMAIL PROTECTED]> writes:
>
> Angus> It seems to me that it would be apropriate to use multiple
> Angus> inheritance for insets that have a dialog. Attached is a
> sample Angus> piece of code that compiles but is otherwise untested.
>
> Angus> * Does anyone have any experience with such a beast? * Are
> Angus> there any problems I should watch out for? * Is this a good
> Angus> thing to do?
>
> Can you tell me again what virtual inheritence of classes is?
>
> JMarc
Sure. Normal inheritance:
class Vehicle {};
class Car: public Vehicle {};
class Trailer: public: Vehicle {};
class CarAndTrailer: public Car, public Trailer {};
Vehicle Vehicle
| |
Car Trailer
|_______________|
|
CarAndTrailer
Virtual inheritance:
class CarAndTrailer: virtual public Car, virtual public Trailer {};
Vehicle
________|_______
| |
Car Trailer
|_______________|
|
CarAndTrailer
So there is only one instance of "Vehicle" and its members.
In my case I have
class InsetBase {
virtual BufferView * view() { return 0; }
};
class DialogedBase {
virtual BufferView * view() = 0;
void showDialog() {
if (!view()) return;
...
}
};
class InsetCitation {
virtual BufferView * view() { return ...; }
};
I'd like DialogBase::showDialog to have access to InsetBase::view().
The advantage: only classes that have a dialog need to bloat the
interface with all those extra methods.
But, as André points out, it might all be hot air. I should try it
out first.
Incidentally, I got all this from C++ Annotations (on our recommended
reading list) which is downloadable off the web and is GOOD!
--
Angus
