How can I write something like this to check if any of a set of specific versions is used?static assert(!(version(a) | version(b) | version(c)):The problem is that I can use version(a) like a test, and the symbol a is not accessbile from assert (different, non-accessible namespace).
BTW D language designers are against boolean eval of version.It's not a technical restriction, it's just that they don't want this to work.
