(bind-func mprint
(lambda (m:i64* nrows:i64 ncols:i64)
(let ((i 0) (j 0))
;;(printf "[")
(dotimes (i nrows)
(printf "[")
(dotimes (j ncols)
(printf " %lld" (pref m (rowmaj_idx_2D i j ncols))))
(printf " ]\n"))
;;(printf "]")
void)))