Function mpi::ffi::MPI_Reduce

pub unsafe extern fn MPI_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