-// Copyright (C) 2013 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2013, 2015 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
#include <stdint.h>
#include <string>
+// Undefine the macro OPTIONAL which is defined in some operating
+// systems but conflicts with class constant is the context base class.
+
+#ifdef OPTIONAL
+#undef OPTIONAL
+#endif
+
namespace isc {
namespace d2 {