Default implementations in inherited interfaces

[Lodovico Giaretta via Digitalmars-d-learn]

On Thursday, 21 July 2016 at 09:41:27 UTC, Saurabh Das wrote:
> I have an interface A which declares a certain function. A 
> second interface B inherits from A and wishes to provide a 
> default implementation for that function. How can I achieve 
> this? I'm facing an error when I try this:
>
> interface A
> {
>     int func(int);
> }
>
> interface B : A
> {
>     final int func(int)
>     {
>         return 0;
>     }
> }
>
> class C : B
> {
> }
>
> rdmd it.d:
> it.d(14): Error: class it.C interface function 'int func(int)' 
> is not implemented
>
> Thanks,
> Saurabh

Interesting.
This is worth a bugzilla issue, IMHO. In fact, if you try the 
other way (i.e.: you provide an implementation of func in class 
C), you get the opposite error, that you are overriding a final 
function (B.func).