From eb3d8f68bb3103210b6ed3ea13cde2787d2613ab Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Thu, 12 Jul 2018 16:59:47 +0200
Subject: [PATCH] fix unused warning

---
 Eigen/src/Core/Redux.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Eigen/src/Core/Redux.h b/Eigen/src/Core/Redux.h
index ddce65468..e449ef3ac 100644
--- a/Eigen/src/Core/Redux.h
+++ b/Eigen/src/Core/Redux.h
@@ -332,6 +332,7 @@ struct redux_impl<Func, Evaluator, LinearVectorizedTraversal, CompleteUnrolling>
   EIGEN_DEVICE_FUNC static EIGEN_STRONG_INLINE
   Scalar run(const Evaluator &eval, const Func& func, const XprType &xpr)
   {
+    EIGEN_ONLY_USED_FOR_DEBUG(xpr)
     eigen_assert(xpr.rows()>0 && xpr.cols()>0 && "you are using an empty matrix");
     if (VectorizedSize > 0) {
       Scalar res = func.predux(redux_vec_unroller<Func, Evaluator, 0, Size / PacketSize>::run(eval,func));