## SegmentVoronoiDiagramHierarchyVertexBase_2

### Definition

The vertex of a segment Voronoi diagram included in a segment Voronoi diagram hierarchy has to provide some pointers to the corresponding vertices in the graphs of the next and preceeding levels. Therefore, the concept SegmentVoronoiDiagramHierarchyVertexBase_2 refines the concept SegmentVoronoiDiagramVertexBase_2, by adding two vertex handles to the correponding vertices for the next and previous level graphs.

### Refines

SegmentVoronoiDiagramVertexBase_2

### Types

SegmentVoronoiDiagramHierarchyVertexBase_2 does not introduce any types in addition to those of SegmentVoronoiDiagramVertexBase_2.

### Creation

The SegmentVoronoiDiagramHierarchyVertexBase_2 concept does not introduce any constructors in addition to those of the SegmentVoronoiDiagramVertexBase_2 concept.

### Operations

Vertex_handle | v.up () | Returns a handle to the corresponding vertex of the next level segment Voronoi diagram. If such a vertex does not exist Vertex_handle() is returned.
Vertex_handle | v.down () | Returns a handle to the corresponding vertex of the previous level segment Voronoi diagram. If such a vertex does not exist Vertex_handle() is returned.
void | v.set_up ( Vertex_handle u)
|  | Sets the handle for the vertex of the next level segment Voronoi diagram.
void | v.set_down ( Vertex_handle d)
|  | Sets the handle for the vertex of the previous level segment Voronoi diagram;

### Has Models

CGAL::Segment_Voronoi_diagram_hierarchy_vertex_base_2<CGAL::Segment_Voronoi_diagram_vertex_base_2<Gt,SSTag> >

### See Also

SegmentVoronoiDiagramDataStructure_2
SegmentVoronoiDiagramVertexBase_2
CGAL::Segment_Voronoi_diagram_hierarchy_2<Gt,DS>
CGAL::Triangulation_data_structure_2<Vb,Fb>
CGAL::Segment_Voronoi_diagram_vertex_base_2<Gt,SSTag>
CGAL::Segment_Voronoi_diagram_hierarchy_vertex_base_2<Vbb>