[omniORB] Beginner's question on IOR and multiple interfaces

[Duncan Grisby]

On Tuesday 10 September, Ken Feuerman wrote:

> Alright, now my curiosity is piqued: Why *can't* you implement
> MyServant as virtually derived from POA_I and POA_J?  Style
> questions aside, would it necessarily result in a compile-time or
> run-time error that is a consequence somehow of CORBA's
> specifications?  (Inquiring minds want to know!)

The only way the ORB has to tell what interface a servant is
supporting is with virtual functions on the ServantBase object,
implemented by the POA_foo classes. If a servant derived from more
than one POA_* class, the virtual functions would be ambiguous. There
are application-visible things like _this() that wouldn't work, as
well.

You should get a compile time error if you try it.

Outside of the C++ mapping, you can't do it just because the CORBA
object model is defined that way.

Cheers,

Duncan.

-- 
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