xemacs and c++ //-type comments

[root@nine.agn.net (root)]

The c++ mode in xemacs does not appear to recognize the double-slash
comments in c++ code (these comments start with // and end at the following
new-line -- like the '#' comment character in ksh scripts).

Does anyone know if there is a patch or modification for the c++ mode so
that it will recognize these comments (i.e. for the file
/usr/lib/xemacs-19.14/lisp/modes/cc-mode.el) ?

Thanks.

-- Harmon