ref: 2cccc2b8dcb96674c1e3f7bf956e9a7a05d60df0 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 }