(bind-func send_outgoing_walkers
(lambda (outgoing_walkers:WalkerArray* world_rank:i32 world_size:i32)
;; Send the data as an array of MPI_BYTEs to the next process.
;; The last process sends to process zero.
(MPI_Send (convert (tref outgoing_walkers 1) i8*)
(* (tref outgoing_walkers 0) 8) ;; sizeof(Walker) = 8?? (if packed)
MPI_BYTE (% (+ world_rank 1) world_size) 0 MPI_COMM_WORLD)
;; Clear the outgoing walkers list
(clear_walker_array outgoing_walkers)))