Function mpi::ffi::PMPI_Reduce

pub unsafe extern fn PMPI_Reduce(sendbuf: *const c_void,
                                 recvbuf: *mut c_void,
                                 count: c_int,
                                 datatype: MPI_Datatype,
                                 op: MPI_Op,
                                 root: c_int,
                                 comm: MPI_Comm)
                                 -> c_int