Function mpi::ffi::PMPI_Dist_graph_neighbors_count

pub unsafe extern fn PMPI_Dist_graph_neighbors_count(comm: MPI_Comm,
                                                     inneighbors: *mut c_int,
                                                     outneighbors: *mut c_int,
                                                     weighted: *mut c_int)
                                                     -> c_int