Make sure we declare the correct classes as 'friend'.

diff --git a/include/deal.II/lac/block_matrix_base.h b/include/deal.II/lac/block_matrix_base.h
index fb4ae24f6d05dad34f7b02491778749ffd274a62..7b60d94aa37a9b393695ce89ae2f5096972fbaab 100644 (file)
--- a/include/deal.II/lac/block_matrix_base.h
+++ b/include/deal.II/lac/block_matrix_base.h
@@ -191,10 +191,13 @@ namespace BlockMatrixIterators
     operator==(const Accessor &a) const;
 
     template <typename>
-    friend class MatrixIterator;
+    friend class dealii::MatrixIterator;
+
     friend class Accessor<BlockMatrixType, true>;
   };
 
+
+
   /**
    * Block matrix accessor for constant matrices, implementing the stepping
    * through a matrix.