pub unsafe extern "C" fn PMPI_Alltoallw(
sendbuf: *const c_void,
sendcounts: *const c_int,
sdispls: *const c_int,
sendtypes: *const MPI_Datatype,
recvbuf: *mut c_void,
recvcounts: *const c_int,
rdispls: *const c_int,
recvtypes: *const MPI_Datatype,
comm: MPI_Comm,
) -> c_int