Function mpi::ffi::PMPI_Neighbor_alltoall

pub unsafe extern fn PMPI_Neighbor_alltoall(sendbuf: *const c_void,
                                            sendcount: c_int,
                                            sendtype: MPI_Datatype,
                                            recvbuf: *mut c_void,
                                            recvcount: c_int,
                                            recvtype: MPI_Datatype,
                                            comm: MPI_Comm)
                                            -> c_int