Reference documentation for deal.II version 8.4.1

Typedefs  
typedef unsigned int  subdomain_id 
typedef unsigned long long int  global_vertex_index 
typedef unsigned int  global_dof_index 
typedef unsigned char  boundary_id 
typedef unsigned int  manifold_id 
typedef unsigned char  material_id 
A namespace in which we declare typedefs for types used in deal.II, as well as special values for these types.
typedef unsigned int types::subdomain_id 
The type used to denote subdomain_ids of cells.
See the glossary for more information.
There is a special value, numbers::invalid_subdomain_id that is used to indicate an invalid value of this type.
typedef unsigned long long int types::global_vertex_index 
typedef unsigned int types::global_dof_index 
The type used for global indices of degrees of freedom. While in sequential computations the 4 billion indices of 32bit unsigned integers is plenty, parallel computations using the parallel::distributed::Triangulation class can overflow this number and we need a bigger index space.
The data type always indicates an unsigned integer type.
typedef unsigned char types::boundary_id 
The type used to denote boundary indicators associated with every piece of the boundary and, in the case of meshes that describe manifolds in higher dimensions, associated with every cell.
There is a special value, numbers::internal_face_boundary_id that is used to indicate an invalid value of this type and that is used as the boundary indicator for faces that are in the interior of the domain and therefore not part of any addressable boundary component.
typedef unsigned int types::manifold_id 
The type used to denote manifold indicators associated with every object of the mesh.
There is a special value, numbers::flat_manifold_id that is used to indicate the standard cartesian manifold.
typedef unsigned char types::material_id 
The type used to denote material indicators associated with every cell.
There is a special value, numbers::invalid_material_id that is used to indicate an invalid value of this type.