Filter for opDispatch?

[frame]

On Sunday, 16 May 2021 at 03:19:04 UTC, Mike Parker wrote:
> On Sunday, 16 May 2021 at 00:04:39 UTC, frame wrote:
>
>>
>> Yes, but why should the derived class not have access to it?
>
> I don't think that's your problem. From the template docs:
>
>> _TemplateInstances_ are always instantiated in the scope of 
>> where the _TemplateDeclaration_ is declared...
>
> Your `opDispatch` templates are instantiated in the scope of 
> `Base`, from which `_s` is not accessible when it's protected.

Indeed, the error goes away if each derived class has its own 
implementation.

But the same with fields work? They are also protected.