Improve and simplify code with modern C++ features

Change-Id: I83bf5513c2a1f90ba5a59e93c473306864b27d94
diff --git a/core/manager-base.hpp b/core/manager-base.hpp
index cddb7c1..a19ccb2 100644
--- a/core/manager-base.hpp
+++ b/core/manager-base.hpp
@@ -161,7 +161,7 @@
   m_dispatcher.addControlCommand<ControlParameters>(
     makeRelPrefix(verb),
     makeAuthorization(verb),
-    bind(&ManagerBase::validateParameters, cref(*command), _1),
+    bind(&ManagerBase::validateParameters, std::cref(*command), _1),
     bind(&ManagerBase::handleCommand, command, handler, _1, _2, _3, _4));
 }