From 836fa25a822d036230d23b4ed0df9eb22684fdc6 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Wed, 31 Aug 2016 23:40:18 +0200
Subject: [PATCH] Make sure sizeof is truelly needed, thus improving SFINAE
 portability.

---
 Eigen/src/Core/util/Meta.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Eigen/src/Core/util/Meta.h b/Eigen/src/Core/util/Meta.h
index 96563962e..29c149c34 100755
--- a/Eigen/src/Core/util/Meta.h
+++ b/Eigen/src/Core/util/Meta.h
@@ -381,13 +381,13 @@ struct has_ReturnType
   enum { value = sizeof(testFunctor<T>(0)) == sizeof(meta_yes) };
 };
 
-template<int Val> struct integral_constant { static const int value = Val; };
+template<int Size> struct meta_array { int a[Size]; };
 template<typename T> const T& return_ref();
 
 template <typename T>
 struct has_nullary_operator
 {
-  template <typename C> static meta_yes testFunctor(C const *,integral_constant< sizeof(return_ref<C>()()) > * = 0);
+  template <typename C> static meta_yes testFunctor(C const *,meta_array< sizeof(return_ref<C>()()) > * = 0);
   static meta_no testFunctor(...);
 
   enum { value = sizeof(testFunctor(static_cast<T*>(0))) == sizeof(meta_yes) };
@@ -396,7 +396,7 @@ struct has_nullary_operator
 template <typename T>
 struct has_unary_operator
 {
-  template <typename C> static meta_yes testFunctor(C const *,integral_constant< sizeof(return_ref<C>()(Index(0))) > * = 0);
+  template <typename C> static meta_yes testFunctor(C const *,meta_array< sizeof(return_ref<C>()(Index(0))) > * = 0);
   static meta_no testFunctor(...);
 
   enum { value = sizeof(testFunctor(static_cast<T*>(0))) == sizeof(meta_yes) };
@@ -405,7 +405,7 @@ struct has_unary_operator
 template <typename T>
 struct has_binary_operator
 {
-  template <typename C> static meta_yes testFunctor(C const *,integral_constant< sizeof(return_ref<C>()(Index(0),Index(0))) > * = 0);
+  template <typename C> static meta_yes testFunctor(C const *,meta_array< sizeof(return_ref<C>()(Index(0),Index(0))) > * = 0);
   static meta_no testFunctor(...);
 
   enum { value = sizeof(testFunctor(static_cast<T*>(0))) == sizeof(meta_yes) };