--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/metaprogramming/enableIf.hpp	Tue Jul 11 12:00:48 2017 +0200
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_METAPROGRAMMING_ENABLEIF_HPP
+#define SHARE_VM_METAPROGRAMMING_ENABLEIF_HPP
+
+#include "memory/allocation.hpp"
+
+// This metaprogramming tool allows explicitly enabling and disabling overloads
+// of member functions depending on whether the condition B holds true.
+// For example typename EnableIf<IsPointer<T>::value>::type func(T ptr) would
+// only become an overload the compiler chooses from if the type T is a pointer.
+// If it is not, then the template definition is not expanded and there will be
+// no compiler error if there is another overload of func that is selected when
+// T is not a pointer. Like for example
+// typename EnableIf<!IsPointer<T>::value>::type func(T not_ptr)
+
+template <bool B, typename T = void>
+struct EnableIf: AllStatic {};
+
+template <typename T>
+struct EnableIf<true, T>: AllStatic {
+  typedef T type;
+};
+
+#endif // SHARE_VM_METAPROGRAMMING_ENABLEIF_HPP