All MPI classes, constants, and functions are declared within the scope of an MPI namespace. Thus, instead of the MPI_ prefix that is used in C and Fortran, MPI functions essentially have an MPI:: prefix.
The members of the MPI namespace are those classes corresponding to objects implicitly used by MPI. An abbreviated definition of the MPI namespace and its member classes is as follows:
namespace MPI {
class Comm {...};
class Intracomm : public Comm {...};
class Graphcomm : public Intracomm {...};
class Cartcomm : public Intracomm {...};
class Intercomm : public Comm {...};
class Datatype {...};
class Errhandler {...};
class Exception {...};
class File {...};
class Group {...};
class Info {...};
class Op {...};
class Request {...};
class Prequest : public Request {...};
class Grequest : public Request {...};
class Status {...};
class Win {...};
};
Note that there are a small number of derived classes, and that virtual
inheritance is not used.