Inheritance of mixin

[tsbockman via Digitalmars-d]

On Monday, 2 May 2016 at 18:14:29 UTC, Basile B. wrote:
> On Monday, 2 May 2016 at 17:50:50 UTC, tsbockman wrote:
>> [...]
>>
>> That's not how it works currently, but there is no technical 
>> reason it couldn't be *made* to work that way.
>>
>> Obviously this would be a breaking change though; `this T` 
>> template methods that should retain the current behaviour 
>> could be marked `final`. (Given that non-template methods are 
>> virtual by default, I think requiring template methods to be 
>> marked `final` would improve code clarity, anyway.)
>
> Not that much a breaking change. Perhaps a slight decrease of 
> the performances...and even not indeed: in all the previous 
> usages devirtualization of the will be possible.

It's a significant breaking change, because the purpose of it is 
to change the output of Andrew Benton's earlier example:

void main() {
     Base a = new Base(), b = new Inheritor();
     a.writeName.writeln;
     b.writeName.writeln; // The semantics of this line changes.
}

Currently, the above will call the `Base` version of 
`writeName()` for `b`. With my proposal, it would call the 
`Inheritor()` version.