Include cmath, as that is necessary for std::sqrt.

git-svn-id: https://svn.dealii.org/trunk@4615 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/lac/include/lac/block_sparse_matrix.h b/deal.II/lac/include/lac/block_sparse_matrix.h
index 6fe61bbde8ea7930221a8baf3a18bd27f19bed4a..6de57cdea9343ad885caa635278577c19cefa67b 100644 (file)
--- a/deal.II/lac/include/lac/block_sparse_matrix.h
+++ b/deal.II/lac/include/lac/block_sparse_matrix.h
@@ -16,6 +16,8 @@
 
 #include <lac/sparse_matrix.h>
 #include <lac/block_sparsity_pattern.h>
+#include <cmath>
+
 
 template <typename Number> class BlockVector;