std::-qualify sqrt(...)

git-svn-id: https://svn.dealii.org/trunk@4605 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 96de3ac9c286206c981e51a7359e0fb067527e72..6fe61bbde8ea7930221a8baf3a18bd27f19bed4a 100644 (file)
--- a/deal.II/lac/include/lac/block_sparse_matrix.h
+++ b/deal.II/lac/include/lac/block_sparse_matrix.h
@@ -817,7 +817,7 @@ residual (BlockVector<somenumber>          &dst,
   somenumber res = 0;
   for (unsigned int row=0; row<rows; ++row)
     res += dst.block(row).norm_sqr ();
-  return sqrt(res);
+  return std::sqrt(res);
 };