Hello, FPC developers' list

I have a code with 2 parent-child corba interfaces and 2 parent-child classes:

Intf1 = interface
...
end;

Intf2 = interface(Intf1)
   ...
   procedure DoSomething;
end;
Class1 = class
   Intf: Intf1;
   function GetIntf: Intf1; virtual;
end;
Class2 = class
   Intf: Intf2;
   function GetIntf: Intf1; override;
end;
function Class2.GetIntf: Intf1;
begin
   Result := Itnf; // this is Intf2
end;
var
   C: Class2;
   I: Intf2;
...
   I := Intf2(C.GetIntf);

Is this ^^^^ a correct interface cast? If not then how to cast one corba interface to another propely?

I'm asking because without -CR the code compiles and with it gives an error Error: Class or COM interface type expected, but got "Intf2"

Best regards,
Paul Ishenin.

Did you try with "C.GetIntf as Intf2"? That should be the correct way to do this...

Regards,
Sven

Yes, but it does not work.

Best regards,
Paul Ishenin

With CORBA interfaces I don’t think an ancestor interface can be cast to a derived interface unless one recover from the interface variable alone the implementor’s class instance, which does not seem possible outside of the implementor itself.

Reference: http://wiki.freepascal.org/Compiler_generated_data_and_data_structures.

(Sorry for the duplicate, Paul, the previous reply was not sent to the list.)

Paul Ishenin wrote

Yes, but it does not work.

It can't but it should provide a more decent error message.-

-Michael