From 25c7d9164f45119fa20dc6af2fa451d278c5f285 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Thu, 18 Dec 2014 22:58:15 +0100
Subject: [PATCH] bug #920: fix MSVC 2015 compilation issues

---
 Eigen/src/Core/MapBase.h     | 11 +++++------
 Eigen/src/Core/util/Macros.h |  4 ++--
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/Eigen/src/Core/MapBase.h b/Eigen/src/Core/MapBase.h
index 5d51548cd..1589cbaae 100644
--- a/Eigen/src/Core/MapBase.h
+++ b/Eigen/src/Core/MapBase.h
@@ -172,6 +172,7 @@ template<typename Derived> class MapBase<Derived, ReadOnlyAccessors>
 template<typename Derived> class MapBase<Derived, WriteAccessors>
   : public MapBase<Derived, ReadOnlyAccessors>
 {
+    typedef MapBase<Derived, ReadOnlyAccessors> ReadOnlyMapBase;
   public:
 
     typedef MapBase<Derived, ReadOnlyAccessors> Base;
@@ -239,15 +240,13 @@ template<typename Derived> class MapBase<Derived, WriteAccessors>
     EIGEN_DEVICE_FUNC
     Derived& operator=(const MapBase& other)
     {
-      Base::Base::operator=(other);
+      ReadOnlyMapBase::Base::operator=(other);
       return derived();
     }
 
-    // In theory MapBase<Derived, ReadOnlyAccessors> should not make a using Base::operator=,
-    // and thus we should directly do: using Base::Base::operator=;
-    // However, this would confuse recent MSVC 2013 (bug 821), and since MapBase<Derived, ReadOnlyAccessors>
-    // has operator= to make ICC 11 happy, we can also make MSVC 2013 happy as follow:
-    using Base::operator=;
+    // In theory we could simply refer to Base:Base::operator=, but MSVC does not like Base::Base,
+    // see bugs 821 and 920.
+    using ReadOnlyMapBase::Base::operator=;
 };
 
 #undef EIGEN_STATIC_ASSERT_INDEX_BASED_ACCESS
diff --git a/Eigen/src/Core/util/Macros.h b/Eigen/src/Core/util/Macros.h
index bc26043d7..687ba41dd 100644
--- a/Eigen/src/Core/util/Macros.h
+++ b/Eigen/src/Core/util/Macros.h
@@ -73,7 +73,7 @@
 
 /// \internal EIGEN_COMP_MSVC_STRICT set to 1 if the compiler is really Microsoft Visual C++ and not ,e.g., ICC
 #if EIGEN_COMP_MSVC && !(EIGEN_COMP_ICC)
-  #define EIGEN_COMP_MSVC_STRICT 1
+  #define EIGEN_COMP_MSVC_STRICT _MSC_VER
 #else
   #define EIGEN_COMP_MSVC_STRICT 0
 #endif
@@ -592,7 +592,7 @@ namespace Eigen {
 // just an empty macro !
 #define EIGEN_EMPTY
 
-#if EIGEN_COMP_MSVC_STRICT
+#if EIGEN_COMP_MSVC_STRICT && EIGEN_COMP_MSVC < 1900
   #define EIGEN_INHERIT_ASSIGNMENT_EQUAL_OPERATOR(Derived) \
     using Base::operator =;
 #elif EIGEN_COMP_CLANG // workaround clang bug (see http://forum.kde.org/viewtopic.php?f=74&t=102653)