pub unsafe extern "C" fn PMPI_Accumulate(
origin_addr: *const c_void,
origin_count: c_int,
origin_datatype: MPI_Datatype,
target_rank: c_int,
target_disp: MPI_Aint,
target_count: c_int,
target_datatype: MPI_Datatype,
op: MPI_Op,
win: MPI_Win,
) -> c_int