Proper handling of domain errors.
diff --git a/test/array.cpp b/test/array.cpp
index 8b0a347..beaa622 100644
--- a/test/array.cpp
+++ b/test/array.cpp
@@ -331,11 +331,13 @@
VERIFY_IS_APPROX(numext::zeta(Scalar(3), Scalar(-2.5)), RealScalar(0.054102025820864097));
VERIFY_IS_EQUAL(numext::zeta(Scalar(1), Scalar(1.2345)), // The second scalar does not matter
std::numeric_limits<RealScalar>::infinity());
+ VERIFY((numext::isnan)(numext::zeta(Scalar(0.9), Scalar(1.2345)))); // The second scalar does not matter
// Check the polygamma against scipy.special.polygamma examples
VERIFY_IS_APPROX(numext::polygamma(Scalar(1), Scalar(2)), RealScalar(0.644934066848));
VERIFY_IS_APPROX(numext::polygamma(Scalar(1), Scalar(3)), RealScalar(0.394934066848));
VERIFY_IS_APPROX(numext::polygamma(Scalar(1), Scalar(25.5)), RealScalar(0.0399946696496));
+ VERIFY((numext::isnan)(numext::polygamma(Scalar(1.5), Scalar(1.2345)))); // The second scalar does not matter
// Check the polygamma function over a larger range of values
VERIFY_IS_APPROX(numext::polygamma(Scalar(17), Scalar(4.7)), RealScalar(293.334565435));