https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109936
--- Comment #22 from Adam Wozniak <adam at wozniakconsulting dot com> ---
(In reply to Jonathan Wakely from comment #19)
> (In reply to Andreas Schwab from comment #10)
> > It is a valid preprocessing token ("non-whitespace character that cannot be
> > one of the above").
>
> Ah right, yes. It's a preprocessing token, but is never converted to a
> token, so doesn't need to be a keyword, identifier etc.
Correct.
