What is going on in this code?

[Meta via Digitalmars-d]

On Thursday, 14 April 2016 at 13:31:25 UTC, Steven Schveighoffer 
wrote:
> That is awful.
>
> I propose we make slicing such a return value implicitly an 
> error. I can't think of a valid reason for allowing it.
>
> I'm not the only one: 
> https://issues.dlang.org/show_bug.cgi?id=12625
>
> -Steve

Absolutely agreed. Why haven't we done it already?