+ /* Positive numbers. */
+ ASSERT (!signbit (round (0.3)));
+ ASSERT (!signbit (round (0.7)));
+ /* Negative numbers. */
+ ASSERT (!!signbit (round (-0.3)) == !!signbit (minus_zerod));
+ ASSERT (!!signbit (round (-0.7)) == !!signbit (minus_zerod));
+
+ /* [MX] shaded specification in POSIX. */
+
+ /* NaN. */
+ ASSERT (isnand (round (NaNd ())));
+ /* Infinity. */
+ ASSERT (round (Infinityd ()) == Infinityd ());
+ ASSERT (round (- Infinityd ()) == - Infinityd ());