#![allow(dead_code, deprecated, unused_variables, unused_mut)] use std::num::NonZero; fn main() { test().unwrap(); } fn test() -> Option<()> { let pos_five = NonZero::new(5i8)?; let neg_five = NonZero::new(-5i8)?; assert!(pos_five.is_positive()); assert!(! neg_five.is_positive()); Some(()) }