++Phobos

[Jesse Phillips]

On Thursday, 17 October 2019 at 00:46:12 UTC, rikki cattermole 
wrote:
>
> I.e.
>
> signature InputRange(@named ElementType = 
> ElementTypeCompat!(typeof(this)) { ... }
>
> Not to mention it forces what amounts to idiomatic D into a 
> second class position in many use cases. Not preferable IMO.

auto foo(R, E = ElementType!R)() if(implements!(InputRange!E, R))

That seems pretty idiomatic D.

Now as you said, it doesn't improve the error message. But what 
if the language changed so it could?