add an OptionManagerWatcher_AutoRegister class

src/option_manager.hh

@@ -162,6 +162,29 @@ public:
     }
 };
 
+struct OptionManagerRegisterFuncs
+{
+    static void insert(OptionManager& options, OptionManagerWatcher& watcher)
+    {
+        options.register_watcher(watcher);
+    }
+    static void remove(OptionManager& options, OptionManagerWatcher& watcher)
+    {
+        options.unregister_watcher(watcher);
+    }
+};
+
+class OptionManagerWatcher_AutoRegister
+    : public OptionManagerWatcher,
+      public AutoRegister<OptionManagerWatcher_AutoRegister,
+                          OptionManagerRegisterFuncs, OptionManager>
+{
+public:
+    OptionManagerWatcher_AutoRegister(OptionManager& options)
+        : AutoRegister(options) {}
+};
+
+
 }
 
 #endif // option_manager_hh_INCLUDED