Add const in example code

Polygon_repair/examples/Polygon_repair/repair_polygon_2.cpp

@@ -14,7 +14,7 @@ using Multipolygon_with_holes_2 = CGAL::Multipolygon_with_holes_2<Kernel>;
 
 int main(int argc, char* argv[]) {
 
-  char* filename = (argc > 1) ? argv[1] : "data/bridge-edge.wkt";
+  const char* filename = (argc > 1) ? argv[1] : "data/bridge-edge.wkt";
 
   std::ifstream in(filename);
   Polygon_with_holes_2 pin;

Polygon_repair/include/CGAL/Polygon_repair/Union_rule.h

@@ -0,0 +1,35 @@
+// Copyright (c) 2024 GeometryFactory.
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org).
+//
+// $URL$
+// $Id$
+// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
+//
+// Author(s)     : Andreas Fabri
+
+#ifndef CGAL_POLYGON_REPAIR_UNION_RULE_H
+#define CGAL_POLYGON_REPAIR_UNION_RULE_H
+
+#include <CGAL/license/Polygon_repair.h>
+
+namespace CGAL {
+
+namespace Polygon_repair {
+
+/// \addtogroup PkgPolygonRepairRef
+/// @{
+
+/*!
+  Tag class to select the union rule when calling `CGAL::Polygon_repair::repair()`.
+  */
+  struct Union_rule {};
+
+///@}
+
+} // namespace Polygon_repair
+
+} // namespace CGAL
+
+#endif  // CGAL_POLYGON_REPAIR_UNION_RULE_H