CGAL 5.6.1  Tetrahedral Remeshing

#include <CGAL/Tetrahedral_remeshing/Remeshing_cell_base_3.h>
The class Remeshing_cell_base_3
is a model of the concept SimplicialMeshCellBase_3
.
It is designed to serve as cell base class for the 3D triangulation used in the tetrahedral remeshing process.
Subdomain_index  Type of indices for subdomains of the discretized geometric domain. Must be a model of CopyConstructible , Assignable , DefaultConstructible and EqualityComparable . The default constructed value must match the label of the exterior of the domain (which contains at least the unbounded component). It must match the Subdomain_index of the model of the MeshDomain_3 concept when used for mesh generation. 
Surface_patch_index  Type of indices for surface patches (boundaries and interfaces) of the discretized geometric domain. Must be a model of CopyConstructible , Assignable , DefaultConstructible and EqualityComparable . The default constructed value must be the index value assigned to a non surface facet. It must match the Surface_patch_index of the model of the MeshDomain_3 concept when used for mesh generation. 