ref: 7096d0e99d9deb053a7763f49b2b1b7b1df20a6a 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 }