From cd37d33a3073b6c2ff39f0f0d0df69734f127f98 Mon Sep 17 00:00:00 2001
From: Dmitry Anisimov <danston@ymail.com>
Date: Fri, 12 Feb 2021 15:07:01 +0100
Subject: [PATCH] hilbert sort, added a visibility macro with the hidden option

---
 Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h b/Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h
index 0ea51bb24bc..832c65ca155 100644
--- a/Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h
+++ b/Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h
@@ -83,8 +83,12 @@ struct Hilbert_cmp_3<K,2,false>
 
 } // namespace internal
 
+#ifdef __clang__
+#define CGAL_VISIBILITY_MACRO __attribute__ ((visibility ("hidden")))
+#endif
+
 template <class K, class ConcurrencyTag>
-class Hilbert_sort_median_3
+class CGAL_VISIBILITY_MACRO Hilbert_sort_median_3
 {
 public:
   typedef Hilbert_sort_median_3<K, ConcurrencyTag> Self;