From 097a105603e61eb32856e9b772e5da155b25ba15 Mon Sep 17 00:00:00 2001
From: Hauke Heibel <hauke.heibel@gmail.com>
Date: Sat, 10 Aug 2013 19:10:23 +0200
Subject: [PATCH] Disabled std::log1p on Cygwin.

---
 Eigen/src/Core/MathFunctions.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h
index 454f9ce52..fc1af1a5d 100644
--- a/Eigen/src/Core/MathFunctions.h
+++ b/Eigen/src/Core/MathFunctions.h
@@ -338,7 +338,7 @@ struct atanh2_impl
   static inline Scalar run(const Scalar& x, const Scalar& r)
   {
     EIGEN_STATIC_ASSERT_NON_INTEGER(Scalar)
-    #if __cplusplus >= 201103L
+    #if (__cplusplus >= 201103L) && !defined(__CYGWIN__)
       using std::log1p;
       return log1p(2 * x / (r - x)) / 2;
     #else