add missing range version of halfedge loop iterator

src/OpenMesh/Core/Mesh/PolyConnectivity.hh

@@ -1230,6 +1230,13 @@ public:
           FaceHandle,
           &PolyConnectivity::cff_begin,
           &PolyConnectivity::cff_end>> ConstFaceFaceRange;
+  typedef CirculatorRange<CirculatorRangeTraitT<
+          PolyConnectivity,
+          ConstHalfedgeLoopIter,
+          HalfedgeHandle,
+          HalfedgeHandle,
+          &PolyConnectivity::chl_begin,
+          &PolyConnectivity::chl_end>> ConstHalfedgeLoopRange;
 
   /**
    * @return The vertices adjacent to the specified vertex
@@ -1285,6 +1292,12 @@ public:
    */
   ConstFaceFaceRange ff_range(FaceHandle _fh) const;
 
+  /**
+   * @return The halfedges in the face
+   * as a range object suitable for C++11 range based for loops.
+   */
+  ConstHalfedgeLoopRange hl_range(HalfedgeHandle _heh) const;
+
   //@}
 
   //===========================================================================