diff -r 2727163b5df5 -r 890a7ed97f6c jdk/src/share/classes/java/util/function/ToDoubleBiFunction.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/util/function/ToDoubleBiFunction.java	Tue Feb 19 11:56:49 2013 -0800
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2012, 2013 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+package java.util.function;
+
+/**
+ * Apply a function to the input arguments, yielding an appropriate result.
+ * This is the {@code double}-bearing specialization for {@link BiFunction}.
+ *
+ * @param <T> the type of the first argument to the {@code applyAsDouble}
+ * operation.
+ * @param <U> the type of the second argument to the {@code applyAsDouble}
+ * operation.
+ *
+ * @see BiFunction.
+ * @since 1.8
+ */
+@FunctionalInterface
+public interface ToDoubleBiFunction<T, U> {
+
+    /**
+     * Compute the result of applying the function to the input arguments
+     *
+     * @param t an input object
+     * @param u an input object
+     * @return the function result value
+     */
+    public double applyAsDouble(T t, U u);
+}