Fix a clang warning.

The declaration of ConstraintValues uses 'struct', so the forward
declaration should also use 'struct'.

diff --git a/include/deal.II/matrix_free/dof_info.h b/include/deal.II/matrix_free/dof_info.h
index 752b9036c4c2b92a96fcf88bb83d6778b08c79dc..b4d3fab061efdcf22421dca09b82715b32003496 100644 (file)
--- a/include/deal.II/matrix_free/dof_info.h
+++ b/include/deal.II/matrix_free/dof_info.h
@@ -37,7 +37,7 @@ namespace internal
 {
   namespace MatrixFreeFunctions
   {
-    template <typename Number> class ConstraintValues;
+    template <typename Number> struct ConstraintValues;
 
     /**
      * The class that stores the indices of the degrees of freedom for all the