fix warning about braces

fix #10120

diff --git a/source/matrix_free/task_info.cc b/source/matrix_free/task_info.cc
index 1f0e733923fdf43543068015a652671351bb8438..bbea242a287ac69568bb49a1f8cc283b1a42249e 100644 (file)
--- a/source/matrix_free/task_info.cc
+++ b/source/matrix_free/task_info.cc
@@ -962,7 +962,7 @@ namespace internal
               std::upper_bound(category_size.begin(), category_size.end(), i) -
                 category_size.begin() :
               0;
-          const std::array<unsigned int, 3> next{category_hp, max_index, i};
+          const std::array<unsigned int, 3> next{{category_hp, max_index, i}};
           if (batch_with_comm[i / n_lanes])
             batch_order_comm.emplace_back(next);
           else