1 files changed, 9 insertions, 0 deletions
diff --git a/extern/Eigen3/Eigen/src/Core/NoAlias.h b/extern/Eigen3/Eigen/src/Core/NoAlias.h
index ecb3fa2850e..768bfb18ca4 100644
--- a/extern/Eigen3/Eigen/src/Core/NoAlias.h
+++ b/extern/Eigen3/Eigen/src/Core/NoAlias.h
@@ -80,8 +80,17 @@ class NoAlias
     template<typename Lhs, typename Rhs, int NestingFlags>
     EIGEN_STRONG_INLINE ExpressionType& operator-=(const CoeffBasedProduct<Lhs,Rhs,NestingFlags>& other)
     { return m_expression.derived() -= CoeffBasedProduct<Lhs,Rhs,NestByRefBit>(other.lhs(), other.rhs()); }
+    
+    template<typename OtherDerived>
+    ExpressionType& operator=(const ReturnByValue<OtherDerived>& func)
+    { return m_expression = func; }
 #endif
 
+    ExpressionType& expression() const
+    {
+      return m_expression;
+    }
+
   protected:
     ExpressionType& m_expression;
 };