From 0afb1e80c7c3c924231cf8da15bf83213b60855b Mon Sep 17 00:00:00 2001
From: Hauke Heibel <hauke.heibel@gmail.com>
Date: Mon, 14 Jun 2010 23:02:49 +0200
Subject: [PATCH] Really fix #123.

---
 Eigen/src/Core/Assign.h     | 18 +++++++++++++++++-
 Eigen/src/Core/MatrixBase.h | 12 ++++++++++--
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/Eigen/src/Core/Assign.h b/Eigen/src/Core/Assign.h
index a389b3c06..3a621b19f 100644
--- a/Eigen/src/Core/Assign.h
+++ b/Eigen/src/Core/Assign.h
@@ -538,9 +538,25 @@ EIGEN_STRONG_INLINE Derived& MatrixBase<Derived>::operator=(const MatrixBase& ot
 
 template<typename Derived>
 template <typename OtherDerived>
-EIGEN_STRONG_INLINE Derived& MatrixBase<Derived>::operator=(const MatrixBase<OtherDerived>& other)
+EIGEN_STRONG_INLINE Derived& MatrixBase<Derived>::operator=(const DenseBase<OtherDerived>& other)
 {
   return ei_assign_selector<Derived,OtherDerived>::run(derived(), other.derived());
 }
 
+template<typename Derived>
+template <typename OtherDerived>
+EIGEN_STRONG_INLINE Derived& MatrixBase<Derived>::operator=(const EigenBase<OtherDerived>& other)
+{
+  other.derived().evalTo(derived());
+  return derived();
+}
+
+template<typename Derived>
+template<typename OtherDerived>
+EIGEN_STRONG_INLINE Derived& MatrixBase<Derived>::operator=(const ReturnByValue<OtherDerived>& other)
+{
+  other.evalTo(derived());
+  return derived();
+}
+
 #endif // EIGEN_ASSIGN_H
diff --git a/Eigen/src/Core/MatrixBase.h b/Eigen/src/Core/MatrixBase.h
index 7fc5774ad..986806e43 100644
--- a/Eigen/src/Core/MatrixBase.h
+++ b/Eigen/src/Core/MatrixBase.h
@@ -83,7 +83,6 @@ template<typename Derived> class MatrixBase
     using Base::coeffRef;
     using Base::lazyAssign;
     using Base::eval;
-    using Base::operator=;
     using Base::operator+=;
     using Base::operator-=;
     using Base::operator*=;
@@ -153,8 +152,17 @@ template<typename Derived> class MatrixBase
       */
     Derived& operator=(const MatrixBase& other);
 
+    // We cannot inherit here via Base::operator= since it is causing
+    // trouble with MSVC.
+
     template <typename OtherDerived>
-    Derived& operator=(const MatrixBase<OtherDerived>& other);
+    Derived& operator=(const DenseBase<OtherDerived>& other);
+
+    template <typename OtherDerived>
+    Derived& operator=(const EigenBase<OtherDerived>& other);
+
+    template<typename OtherDerived>
+    Derived& operator=(const ReturnByValue<OtherDerived>& other);
 
 #ifndef EIGEN_PARSED_BY_DOXYGEN
     template<typename ProductDerived, typename Lhs, typename Rhs>