From e5048b5501a4c2cd86fa3f92ad214938eb3f9b3f Mon Sep 17 00:00:00 2001
From: Deanna Hood <deanna.m.hood@gmail.com>
Date: Mon, 20 Apr 2015 14:59:57 -0400
Subject: [PATCH] Use std::isfinite when available

---
 Eigen/src/Core/MathFunctions.h | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h
index a1ea059b7..1ce935909 100644
--- a/Eigen/src/Core/MathFunctions.h
+++ b/Eigen/src/Core/MathFunctions.h
@@ -787,13 +787,16 @@ inline EIGEN_MATHFUNC_RETVAL(pow, Scalar) pow(const Scalar& x, const Scalar& y)
   return EIGEN_MATHFUNC_IMPL(pow, Scalar)::run(x, y);
 }
 
-// std::isfinite is non standard, so let's define our own version,
-// even though it is not very efficient.
 template<typename T>
 EIGEN_DEVICE_FUNC
 bool (isfinite)(const T& x)
 {
-  return x<NumTraits<T>::highest() && x>NumTraits<T>::lowest();
+  #ifdef EIGEN_HAS_C99_MATH
+    using std::isfinite;
+    return isfinite(x);
+  #else
+    return x<NumTraits<T>::highest() && x>NumTraits<T>::lowest();
+  #endif
 }
 
 template<typename T>