JeanHeyd has a draft paper in the works for the required changes to C++, which
will help ensure we don't forget to unify the two definitions.
The changes look pretty simple for C++. We don't even have to go through the same gymnastics that C does, because we have __VA_OPT__ and can handle 0-sized __VA_ARGS__ lists well, unlike C. (Thomas Köppe has a paper to fix that, eventually, in C. We might see it during this WG14 meeting when it resumes the week after next.)
Sincerely,
JeanHeyd