From 0a6eecd28de128db43f3ccd87ea180ef7adb6e15 Mon Sep 17 00:00:00 2001
From: Laurent Rineau <laurent.rineau@cgal.org>
Date: Thu, 20 Nov 2025 09:52:12 +0100
Subject: [PATCH] explain why NDEBUG must not be defined

---
 STL_Extension/examples/STL_Extension/bisect_failures.cpp | 9 +++++++++
 STL_Extension/include/CGAL/bisect_failures.h             | 4 ++++
 2 files changed, 13 insertions(+)

diff --git a/STL_Extension/examples/STL_Extension/bisect_failures.cpp b/STL_Extension/examples/STL_Extension/bisect_failures.cpp
index b4c0d8302af..8985507db11 100644
--- a/STL_Extension/examples/STL_Extension/bisect_failures.cpp
+++ b/STL_Extension/examples/STL_Extension/bisect_failures.cpp
@@ -1,3 +1,12 @@
+// CGAL::bisect_failures requires the code to be compiled with assertions
+// enabled. That means NDEBUG and CGAL_NDEBUG should not be defined.
+#if defined(NDEBUG)
+#  undef NDEBUG
+#endif
+#if defined(CGAL_NDEBUG)
+#  undef CGAL_NDEBUG
+#endif
+
 #include <CGAL/bisect_failures.h>
 #include <CGAL/boost/graph/Euler_operations.h>
 #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
diff --git a/STL_Extension/include/CGAL/bisect_failures.h b/STL_Extension/include/CGAL/bisect_failures.h
index 565631a6cf8..7a9ce1aa835 100644
--- a/STL_Extension/include/CGAL/bisect_failures.h
+++ b/STL_Extension/include/CGAL/bisect_failures.h
@@ -72,6 +72,10 @@ namespace CGAL {
  * 8. Repeats until no further simplification is possible (minimal failing case found)
  * 9. Saves the minimal failing case as "final_bad" and returns its exit code
  *
+ * \warning CGAL::bisect_failures requires the tested code to be compiled with
+ * assertions enabled. That means NDEBUG and CGAL_NDEBUG should not be defined.
+ *
+ * Here is an example of how to use `CGAL::bisect_failures`:
  * \snippet STL_Extension/bisect_failures.cpp bisect_failures_snippet
  */
 template<typename InputData, typename GetSizeFn, typename SimplifyFn, typename RunFn, typename SaveFn>