[gtkmm] Gtk::Object: Use of the override keyword.

[Murray Cumming <murrayc src gnome org>]

commit 0ad9590a4ee6c8d77aa0e5257d915c2e2bf80f0f
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Oct 27 08:50:49 2015 +0100

    Gtk::Object: Use of the override keyword.

 gtk/gtkmm/object.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkmm/object.h b/gtk/gtkmm/object.h
index 8d20b3c..e5b46a9 100644
--- a/gtk/gtkmm/object.h
+++ b/gtk/gtkmm/object.h
@@ -110,7 +110,7 @@ public:
   #ifndef DOXYGEN_SHOULD_SKIP_THIS
   /** Used by Gtk::manage(). You should not need to use this directly.
    */
-  virtual void set_manage();
+  void set_manage() override;
   #endif //DOXYGEN_SHOULD_SKIP_THIS
 
   #ifndef DOXYGEN_SHOULD_SKIP_THIS
@@ -129,7 +129,7 @@ protected:
 
   #ifndef DOXYGEN_SHOULD_SKIP_THIS
   void _init_unmanage(bool is_toplevel = false);
-  virtual void destroy_notify_(); //override.
+  void destroy_notify_() override;
   void disconnect_cpp_wrapper();
   void _release_c_instance();
   static void callback_weak_notify_(void* data, GObject* gobject); //only connected for a short time.