cc-mode: extend regexp used by ‘c-or-c++-mode’

* lisp/progmodes/cc-mode (c-or-c++-mode--regexp): Expand the regexp to
match some more C++-only constructs and recognise a few more standard
C++ header files.  Also make sure identifiers start with non-digit.
(c-or-c++-mode): Add ‘(interactive)’ declaration.

* test/lisp/progmodes/cc-mode-tests.el (c-or-c++-mode): Add test case
for the newly recognised constructs.

1 files changed, 10 insertions, 2 deletions

diff --git a/test/lisp/progmodes/cc-mode-tests.el b/test/lisp/progmodes/cc-mode-tests.el
index ad7a52b40d9..64d52a952b6 100644
--- a/test/lisp/progmodes/cc-mode-tests.el
+++ b/test/lisp/progmodes/cc-mode-tests.el
@@ -40,7 +40,7 @@
                         (insert content)
                         (setq mode nil)
                         (c-or-c++-mode)
-                        (unless(eq expected mode)
+                        (unless (eq expected mode)
                           (ert-fail
                            (format "expected %s but got %s when testing '%s'"
                                    expected mode content)))))
@@ -53,11 +53,18 @@
               (funcall do-test (concat " * " content) 'c-mode))
             '("using \t namespace \t std;"
               "using \t std::string;"
+              "using Foo = Bar;"
               "namespace \t {"
               "namespace \t foo \t {"
-              "class \t Blah_42 \t {"
+              "namespace \t foo::bar \t {"
+              "inline namespace \t foo \t {"
+              "inline namespace \t foo::bar \t {"
               "class \t Blah_42 \t \n"
+              "class \t Blah_42;"
+              "class \t Blah_42 \t final {"
+              "struct \t Blah_42 \t final {"
               "class \t _42_Blah:public Foo {"
+              "struct \t _42_Blah:public Foo {"
               "template \t < class T >"
               "template< class T >"
               "#include <string>"
@@ -67,6 +74,7 @@
       (mapc (lambda (content) (funcall do-test content 'c-mode))
             '("struct \t Blah_42 \t {"
               "struct template {"
+              "struct Blah;"
               "#include <string.h>")))))
 
 (ert-deftest c-mode-macro-comment ()