From dd70f9c11b72606056b121a7e828f123dbf1708e Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Fri, 22 Apr 2022 21:40:57 +0100
Subject: [PATCH] Implement append for Nef_3 that takes a range

---
 Nef_3/include/CGAL/Nef_polyhedron_3.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Nef_3/include/CGAL/Nef_polyhedron_3.h b/Nef_3/include/CGAL/Nef_polyhedron_3.h
index bb9fe4d4844..fdb2fedae27 100644
--- a/Nef_3/include/CGAL/Nef_polyhedron_3.h
+++ b/Nef_3/include/CGAL/Nef_polyhedron_3.h
@@ -1456,6 +1456,24 @@ protected:
     return *this;
   }
 
+  template <typename Range>
+  Nef_polyhedron_3<Kernel,Items, Mark>
+  append(const Range& N)
+  /*{\Mop returns |\Mvar| with the range N appended }*/ {
+    for(typename Range::const_iterator N1=N.begin(); N1!=N.end(); ++N1) {
+      CGAL_NEF_TRACEN(" append between nef3 "<<&*this<<" and "<<&*N1);
+      Shell_entry_const_iterator si;
+      CGAL_forall_shells_of(si,N1->volumes_begin())
+        CGAL::shell_to_nef_3(*N1,si,snc(),true);
+    }
+    SNC_external_structure es(snc());
+    es.clear_external_structure();
+    build_external_structure();
+    mark_bounded_volumes();
+
+    return *this;
+  }
+
   Nef_polyhedron_3<Kernel,Items, Mark>
   difference(const Nef_polyhedron_3<Kernel,Items, Mark>& N1) const
   /*{\Mop returns |\Mvar| $-$ |N1|. }*/ {