Question about dir-locals c-mode.

[Ergus]

Hi:

This is probably a basic question, but I don't find any reference.

I have a .dir-locals.el file a bit long because the project implied is a
bit special regarding indentation. The problem is that the project is
either C and C++ code and the indentation in both cases is retty much
the same; but other files like python, bash or makefiles require
different indentation.

I am wondering if it is possible in the dir-locals to set a
configuration either for C and C++ without repeating myself.

Up to now I have:

(c++-mode . (...Long...))
(c-mode . (...Long...))

But everytime I update the C config I have to copy and paste in the
other...

is it possible to do something equivalent to:

((or c-mode c++-mode) . (...Long...))

Thanks in advance,
Ergus