src/share/classes/java/util/function/UnaryOperator.java

rev 7047 : 8004015: Additional static and instance utils for functional interfaces.
Reviewed-by: briangoetz

@@ -34,6 +34,15 @@
  * @see Function
  * @since 1.8
  */
 @FunctionalInterface
 public interface UnaryOperator<T> extends Function<T, T> {
+
+    /**
+     * Returns a unary operator that provides its input value as the result.
+     *
+     * @return a unary operator that provides its input value as the result
+     */
+    static <T> UnaryOperator<T> identity() {
+        return t -> t;
+    }
 }