Add forward declaration in VectorSpaceVector.

diff --git a/include/deal.II/lac/vector_space_vector.h b/include/deal.II/lac/vector_space_vector.h
index 85b382835429862d01e371d1747c269ae32f59cf..9d0651582676a28de0adfa7d9d9147643e9bab67 100644 (file)
--- a/include/deal.II/lac/vector_space_vector.h
+++ b/include/deal.II/lac/vector_space_vector.h
@@ -25,6 +25,7 @@
 
 DEAL_II_NAMESPACE_OPEN
 
+class CommunicationPatternBase;
 class IndexSet;
 template <typename Number> class ReadWriteVector;