Fix a conversion from SymmetricTensor to Tensor

diff --git a/include/deal.II/base/symmetric_tensor.templates.h b/include/deal.II/base/symmetric_tensor.templates.h
index 7ce41471eeafc46c92ba419eaff732dd21b23e93..b5b496379b4d643741e238b05a2981893bc96448 100644 (file)
--- a/include/deal.II/base/symmetric_tensor.templates.h
+++ b/include/deal.II/base/symmetric_tensor.templates.h
@@ -160,7 +160,8 @@ namespace internal
 
       // Initialize the transformation matrix as the
       // identity tensor
-      Q = dealii::unit_symmetric_tensor<dim, Number>();
+      Q = static_cast<Tensor<2, dim, Number>>(
+        dealii::unit_symmetric_tensor<dim, Number>());
 
       // Make the first row and column to be of the
       // desired form