Fix assert in import_elements from ReadWriteVector

diff --git a/include/deal.II/lac/read_write_vector.templates.h b/include/deal.II/lac/read_write_vector.templates.h
index 1ed6f1f279d22fc82b10344c53ab3a20c561b3cf..c72a04c8c7d603d5a6ced2e160fd2493db702ce0 100644 (file)
--- a/include/deal.II/lac/read_write_vector.templates.h
+++ b/include/deal.II/lac/read_write_vector.templates.h
@@ -586,7 +586,7 @@ namespace LinearAlgebra
 
     using size_type = std::decay_t<decltype(size)>;
 
-    Assert(size == 0 || values != nullptr, ExcInternalError("Import failed."));
+    Assert(size == 0 || !values.empty(), ExcInternalError("Import failed."));
     AssertDimension(size, stored_elements.n_elements());
 
     switch (operation)