Revamped concurrency API

[Fawzi Mohamed]

On 2009-10-15 21:47:05 +0200, Andrei Alexandrescu 
<SeeWebsiteForEmail at erdani.org> said:

> Speaking of switch, I have tried to convince Walter to require either a 
> break; or a goto case xxx; at the end of each snippet inside a switch. 
> I was surprised by his answer: "but I use fall through all the time!" 
> :o)

that shows that he unrolls loops ;)
basically the only case I know where fall through is really useful

Fawzi