C++ Mode: change the default doc comment style from nothing to gtkdoc

Also amend a pertinent regular expression.  This fixes bug #11865.

* lisp/progmodes/cc-vars.el (c-doc-comment-style): Insert an entry for
c++-mode, namely gtkdoc.

* lisp/progmodes/cc-fonts.el (gtkdoc-font-lock-keywords): Amend the regexp
recognizing the introductory "/**" to allow subsequent characters on that
line.

2 files changed, 4 insertions, 3 deletions

diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index 4e81b3b1e20..96c3a6f4a08 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -2798,7 +2798,7 @@ need for `pike-font-lock-extra-types'.")
 
 (defconst gtkdoc-font-lock-keywords
   `((,(lambda (limit)
-        (c-font-lock-doc-comments "/\\*\\*$" limit
+        (c-font-lock-doc-comments "/\\*\\*\\([^\\*].*\\)?$" limit
           gtkdoc-font-lock-doc-comments)
         (c-font-lock-doc-comments "/\\*< " limit
           gtkdoc-font-lock-doc-protection)
diff --git a/lisp/progmodes/cc-vars.el b/lisp/progmodes/cc-vars.el
index 79bd6a92950..54d634780ee 100644
--- a/lisp/progmodes/cc-vars.el
+++ b/lisp/progmodes/cc-vars.el
@@ -563,7 +563,8 @@ variable in a mode hook."
 (defcustom-c-stylevar c-doc-comment-style
   '((java-mode . javadoc)
     (pike-mode . autodoc)
-    (c-mode    . gtkdoc))
+    (c-mode    . gtkdoc)
+    (c++-mode  . gtkdoc))
   "Specifies documentation comment style(s) to recognize.
 This is primarily used to fontify doc comments and the markup within
 them, e.g. Javadoc comments.
@@ -573,7 +574,7 @@ comment styles:
 
  javadoc -- Javadoc style for \"/** ... */\" comments (default in Java mode).
  autodoc -- Pike autodoc style for \"//! ...\" comments (default in Pike mode).
- gtkdoc  -- GtkDoc style for \"/** ... **/\" comments (default in C mode).
+ gtkdoc  -- GtkDoc style for \"/** ... **/\" comments (default in C and C++ modes).
 
 The value may also be a list of doc comment styles, in which case all
 of them are recognized simultaneously (presumably with markup cues