On Thu, 9 Feb 2017, Michael Kjörling wrote:
> I didn't know that // was now accepted to begin a comment in C, but I
> strongly suspect that any compiler modern enough to know about that will
> know just as well about #if 0.

// isn't in ANSI C, but I've been using it for years on quite a few
platforms (I see that even M$ supports it); I don't know where I first saw
it.