From ca5effa16cd7ed90f0e56084b291e5a2a63a5172 Mon Sep 17 00:00:00 2001
From: klimpel <anonymous@invalid.net>
Date: Thu, 28 Jul 2016 15:58:17 +0100
Subject: [PATCH] MSVC-2010 is making problems with SFINAE again. But
 restricting to the variant for very old compilers (enum, template<typename C>
 for both function definitions) fixes the problem.

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

diff --git a/Eigen/src/Core/util/Meta.h b/Eigen/src/Core/util/Meta.h
index 4b35761e0..b9beb6eb7 100755
--- a/Eigen/src/Core/util/Meta.h
+++ b/Eigen/src/Core/util/Meta.h
@@ -365,10 +365,10 @@ struct has_ReturnType
   typedef char yes[1];
   typedef char no[2];
 
-  template <typename C> static yes& testFunctor(C const *, typename C::ReturnType const * = 0);
-  static no& testFunctor(...);
+  template <typename C> static yes& testFunctor(typename C::ReturnType const *);
+  template <typename C> static no& testFunctor(...);
 
-  static const bool value = sizeof(testFunctor(static_cast<T*>(0))) == sizeof(yes);
+  enum { value = sizeof(testFunctor<T>(0)) == sizeof(yes) };
 };
 
 /** \internal In short, it computes int(sqrt(\a Y)) with \a Y an integer.