RFC to: my need for 'static switch' and CT 'static variables'

[Alexey]

On Thursday, 25 November 2021 at 22:00:15 UTC, Alexey wrote:
> I would want an static 'switch here',

I mean something like
```D
static switch (v.mode)
{
default:
    static assert(false, "v.mode" is invalid)
case "gs_w_d":
  // etc...
}
```