/*D
   MPIX_Grequest_class_allocate - Create and return a user-defined extended request based on a generalized request class

Synopsis:
.vb
int MPIX_Grequest_class_allocate(MPIX_Grequest_class greq_class,
                                 void *extra_state, MPI_Request *request)
.ve

Input Parameters:
+ greq_class - generalized request class (None)
- extra_state - extra state (None)

Output Parameters:
. request - generalized request (handle)

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_ARG
.N MPI_ERR_OTHER

D*/

