pub unsafe extern "C" fn MPI_Ialltoall(
sendbuf: *const c_void,
sendcount: i32,
sendtype: *mut ompi_datatype_t,
recvbuf: *mut c_void,
recvcount: i32,
recvtype: *mut ompi_datatype_t,
comm: *mut ompi_communicator_t,
request: *mut *mut ompi_request_t,
) -> i32