draft proposal for Sum Types for D

[Zealot]

On Wednesday, 30 November 2022 at 08:49:00 UTC, Andrey Zherikov 
wrote:
> On Tuesday, 29 November 2022 at 06:26:20 UTC, Walter Bright 
> wrote:
>> [...]
>
>> [...]
>
> It does:
> ```d
> SumType!(int, string) s;
> s.match!((int i) => true);  // Error: static assert:  "No 
> matching handler for types `(string)`"
> ```
>
> [...]

+1
this would actually reduce a lot of clutter.