c-make-bare-char-alt
c-make-bare-char-alt is a compiled Lisp function in `cc-defs.el
'.
(c-make-bare-char-alt CHARS &optional INVERTED)
Make a character alternative string from the list of characters CHARS.
The returned string is of the type that can be used with
`skip-chars-forward' and `skip-chars-backward'. If INVERTED is
non-nil, a caret is prepended to invert the set.