CGAL 5.1.3 - 3D Triangulation Data Structure
TriangulationDSVertexBase_3 Concept Reference

## Definition

Refines:
TriangulationDataStructure_3::Vertex

The concept TriangulationDSVertexBase_3 describes the requirements for the vertex base class of a CGAL::Triangulation_data_structure_3<Vb,Cb>.

Note that if the CGAL::Triangulation_data_structure_3 is plugged into a triangulation class, the vertex base class may have additional geometric requirements depending on the triangulation class.

At the bottom level of 3D-triangulations (see Sections Software Design and Software Design), a vertex provides access to one of its incident cells through a handle.

Since the Triangulation data structure is the class which defines the handle types, the vertex base class has to be somehow parameterized by the Triangulation data structure. But since it is itself parameterized by the cell and vertex base classes, there is a cycle in the definition of these classes. In order to break the cycle, the base classes for vertex and cell which are given as arguments for the Triangulation data structure use void as Triangulation data structure parameter, and the Triangulation data structure then uses a rebind-like mechanism (similar to the one specified in std::allocator) in order to put itself as parameter to the vertex and cell classes. The rebound base classes so obtained are the classes which are used as base classes for the final vertex and cell classes. More information can be found in Section Software Design.

Has Models:
CGAL::Triangulation_ds_vertex_base_3<TDS>
TriangulationDSCellBase_3
CGAL::Triangulation_data_structure_3<Vb,Cb>

## Types

template<typename TDS3 >
using Rebind_TDS = unspecified_type
This template class has to define a type Rebind_TDS<TDS3>::Other which is the rebound vertex, that is, the one whose Triangulation_data_structure will be the actually used one. More...

typedef TriangulationDataStructure_3 Triangulation_data_structure

typedef TriangulationDataStructure_3::Vertex_handle Vertex_handle

typedef TriangulationDataStructure_3::Cell_handle Cell_handle

## Creation

TriangulationDSVertexBase_3 ()
Default constructor.

TriangulationDSVertexBase_3 (Cell_handle c)
Constructs a vertex pointing to cell c.

## Checking

bool is_valid (bool verbose=false, int level=0) const
This is a function for debugging purpose. More...

## Members for Compact_container

These member functions are required by CGAL::Triangulation_data_structure_3 because it uses CGAL::Compact_container to store its cells.

See the documentation of CGAL::Compact_container for the exact requirements.

void * for_compact_container () const

void for_compact_container (void *)

istream & operator>> (istream &is, TriangulationDSVertexBase_3 &v)
Inputs the non-combinatorial information given by the vertex.

ostream & operator<< (ostream &os, const TriangulationDSVertexBase_3 &v)
Outputs the non-combinatorial information given by the vertex.

## ◆ Rebind_TDS

template<typename TDS3 >

This template class has to define a type Rebind_TDS<TDS3>::Other which is the rebound vertex, that is, the one whose Triangulation_data_structure will be the actually used one.

Rebind_TDS<TDS3>::Other will be the real base class of Triangulation_data_structure_3::Vertex.

Note
It can be implemented using a nested template class.
 bool TriangulationDSVertexBase_3::is_valid ( bool verbose = false, int level = 0 ) const