ref: 2f8d3d7f2e4e3592b0a2fce30a4ec218aafe9bce dir: /lib/std/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 }