Merge of branch thread_local_optional_vincent to take into account XCode < v.8 as thread local is not available

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/trunk@3554 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: 9dcf072a4606d1131a925bca4571f0f1b5547d14

1 files changed, 5 insertions, 1 deletions

diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree.h b/src/Simplex_tree/include/gudhi/Simplex_tree.h
index 74a7281d..ee96d5a2 100644
--- a/src/Simplex_tree/include/gudhi/Simplex_tree.h
+++ b/src/Simplex_tree/include/gudhi/Simplex_tree.h
@@ -689,7 +689,11 @@ class Simplex_tree {
       return { null_simplex(), true };  // ----->>
 
     // Copy before sorting
-    thread_local std::vector<Vertex_handle> copy;
+    // Thread local is not available on XCode version < V.8 - It will slow down computation
+#ifdef GUDHI_CAN_USE_CXX11_THREAD_LOCAL
+    thread_local
+#endif  // GUDHI_CAN_USE_CXX11_THREAD_LOCAL
+    std::vector<Vertex_handle> copy;
     copy.clear();
     copy.insert(copy.end(), first, last);
     std::sort(std::begin(copy), std::end(copy));