From 21ef19b67f0da026123cb0fa8a74272dc09fd774 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Loriot?= <sebastien.loriot@cgal.org>
Date: Mon, 11 Jul 2016 16:03:05 +0200
Subject: [PATCH] Restrict the HalfedgeGraph with properties often assumed in
 our algorithms

---
 BGL/doc/BGL/Concepts/HalfedgeGraph.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/BGL/doc/BGL/Concepts/HalfedgeGraph.h b/BGL/doc/BGL/Concepts/HalfedgeGraph.h
index 48a9b6df2dc..bc4822bc8a8 100644
--- a/BGL/doc/BGL/Concepts/HalfedgeGraph.h
+++ b/BGL/doc/BGL/Concepts/HalfedgeGraph.h
@@ -16,7 +16,7 @@ the same vertex. We refer to \ref PkgBGLIterators for a description of
 iterators and circulators for these halfedge cycles.
 
 
-\cgalRefines <A HREF="http://www.boost.org/libs/graph/doc/Graph.html">`Graph`</A>
+\cgalRefines <A HREF="http://www.boost.org/libs/graph/doc/IncidenceGraph.html">`IncidenceGraph`</A>
 \cgalRefines <A HREF="http://www.boost.org/libs/graph/doc/PropertyGraph.html">`PropertyGraph`</A>
 
 A model of `HalfedgeGraph` must have the interior property `vertex_point` attached to its vertices.
@@ -55,5 +55,11 @@ Expression                              | Returns
 `next(h, g)`                            | `halfedge_descriptor`                                                        | The next halfedge around its face.
 `prev(h, g)`                            | `halfedge_descriptor`                                                        | The previous halfedge around its face.
 `boost::graph_traits<G>::%null_halfedge()` | `halfedge_descriptor`                                                     | Returns a special halfedge that is not equal to any other halfedge.
+
+\cgalHeading{Invariants}
+
+`halfedge(edge(h,g))==h`
+
+
 */
 class HalfedgeGraph {};