ref: 09ca67c40a822dc77a3049dc1bc35565b3081c9f dir: /test/stdopt-mk.myr/
use std const f = {x if x == 123 -> `std.Some 42 else -> `std.None ;; } const main = { var v v = f(123) match v | `std.Some x: -> x | `std.None: -> 123 ;; }