3 #![feature(try_trait_v2)]
7 fn monad_unit<T: Try>(x: <T as Try>::Output) -> T {
11 fn monad_bind<T1: Try<Residual = R>, T2: Try<Residual = R>, R>(
13 f: impl FnOnce(<T1 as Try>::Output) -> T2)
20 let mx: Option<i32> = monad_unit(1);
21 let my = monad_bind(mx, |x| Some(x + 1));
22 let mz = monad_bind(my, |x| Some(-x));
23 assert_eq!(mz, Some(-2));