TriangulationDSVertexBase_2 Concept Reference

Definition

Refines

TriangulationDataStructure_2::Vertex

The concept TriangulationDSVertexBase_2 describes the requirements for the vertex base class of a CGAL::Triangulation_data_structure_2<Vb,Fb>.

Note that if the CGAL::Triangulation_data_structure_2 is plugged into a triangulation class, the vertex base class may have additional geometric requirements depending on the triangulation class.

At the base level, provides access to one of its incident faces through a Face_handle.

Since the CGAL::Triangulation_data_structure_2 is the class which defines the handle types, the vertex base class has to be somehow parameterized by the triangulation data structure. But since the CGAL::Triangulation_data_structure_2 itself is parameterized by the face and vertex base classes, there is a cycle in the definition of these classes. In order to break the cycle, the base classes for faces and vertices which are plugged in to instantiate a Triangulation_data_structure_2 use void as triangulation data structure parameter. Then, the CGAL::Triangulation_data_structure_2 uses a rebind mechanism (similar to the one specified in std::allocator) in order to plug itself as parameter in the face and vertex base classes. This mechanism requires that the base class provides a templated nested class Rebind_TDS that itself provides the subtype Rebind_TDS::Other which is the rebound version of the base class. This rebound base class is the class that the CGAL::Triangulation_data_structure_2 actually uses as a base class for the class of CGAL::Triangulation_data_structure_2::Vertex.

Has models

CGAL::Triangulation_ds_vertex_base_2<Tds>

See also

TriangulationDSFaceBase_2

CGAL::Triangulation_data_structure_2<Vb,Fb>

Types
The concept TriangulationDSVertexBase_2 has to provide the following types.
template<typename TDS2 >
using	Rebind_TDS = unspecified_type
	This template class has to define a type Rebind_TDS<TDS2>::Other which is the rebound vertex base , where the actual CGAL::Triangulation_data_structure_2 is plugged in.
typedef TriangulationDataStructure_2	Triangulation_data_structure
typedef TriangulationDataStructure_2::Vertex_handle	Vertex_handle
typedef TriangulationDataStructure_2::Face_handle	Face_handle

Creation
	TriangulationDSVertexBase_2 ()
	default constructor.
	TriangulationDSVertexBase_2 (Face_handle f)
	Constructs a vertex pointing to face f.

Various
These member functions are required by CGAL::Triangulation_data_structure_2 because it uses CGAL::Compact_container to store its faces. See the documentation of CGAL::Compact_container for the exact requirements.
void *	for_compact_container () const
void	for_compact_container (void *p)

Member Typedef Documentation

Rebind_TDS

template<typename TDS2 >

using TriangulationDSVertexBase_2::Rebind_TDS = unspecified_type

This template class has to define a type Rebind_TDS<TDS2>::Other which is the rebound vertex base , where the actual CGAL::Triangulation_data_structure_2 is plugged in.

This type Other will be the actual base of the class CGAL::Triangulation_data_structure_2::Vertex.

Note

It can be implemented using a nested template class.

See also

Section The Rebind Mechanism