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

rev 6137 : 8004015: Add Extends and deaults for basic functional interface types
Summary: Adds the appropriate extends and default methods for  core functional interfaces used by the JSR335 libraries.
Reviewed-by: duke

@@ -28,11 +28,14 @@
  * An operation on a single {@code double} operand yielding a {@code double}
  * result.
  *
  * @since 1.8
  */
-public interface DoubleUnaryOperator {
+public interface DoubleUnaryOperator extends UnaryOperator<Double> {
+
+    @Override
+    public default Double operate(Double operand) { return operateAsDouble((double) operand); }
 
     /**
      * Returns the {@code double} result of the operation upon the
      * {@code double} operand.
      *