From e896c0ade7c77a18acb1b3ef01f22ef698c1a2a2 Mon Sep 17 00:00:00 2001
From: Benoit Steiner <benoit.steiner.goog@gmail.com>
Date: Thu, 29 Jan 2015 10:29:47 -0800
Subject: [PATCH] Marked the contraction operation as read only, since its
 result can't be assigned.

---
 unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h b/unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h
index a02a273e7..af843654c 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorContraction.h
@@ -423,7 +423,7 @@ struct traits<TensorEvaluator<const TensorContractionOp<Indices_, LeftArgType_,
 }  // end namespace internal
 
 template<typename Indices, typename LhsXprType, typename RhsXprType>
-class TensorContractionOp : public TensorBase<TensorContractionOp<Indices, LhsXprType, RhsXprType> >
+class TensorContractionOp : public TensorBase<TensorContractionOp<Indices, LhsXprType, RhsXprType>, ReadOnlyAccessors>
 {
   public:
   typedef typename Eigen::internal::traits<TensorContractionOp>::Scalar Scalar;