ref: 705f2d8c1f2d2b9f68ea7ef30af3b43d69a64b6a dir: /libstd/swap.myr/
pkg std = generic swap : (a : @a#, b : @a# -> void) ;; generic swap = {a : @a#, b : @a# var t t = a# a# = b# b# = t }