[fpc-devel] Question on interface inheritance...

[Martin Frb]

On 01/02/2026 16:50, Martin Frb via fpc-devel wrote:
>
> Ok, lets see what other think / it wont help for now either, since it 
> wont work with the current compiler.
>
>
> But I do think that (other than the work for the compiler devs) it 
> would be a neat feature.

And as I said it comes in useful if you have a generic...

I wanted

interface BaseList
   function IntfBaseItem

interface FooList(BaseList)
   function IntfFooItem  (inherits BaseItem)


generic ListFeature<_LIST: BaseList, _ITEM: BaseItem> = class
   procedure DoSomething(AnItem: _Item); virtual;
   procedure DoWork....;
end;


DoWork would go over the list, and for the correct items call DoSomething.

DoSomeThing needs the correct class, so if I specialize this as base, my 
new class

type TBar = class(specialize ListFeature<FooList, FooItem>)
   procedure DoSomething(AnItem: FooItem); override;
end

can access all the stuff that FooItem has.