#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#![feature(try_find)]
fn main() {
    let a = ["1", "2", "lol", "NaN", "5"];
    let is_my_num = |s: &str, search: i32| -> Result<bool, std::num::ParseIntError> {
        Ok(s.parse::<i32>()? == search)
    };
    let result = a.into_iter().try_find(|&s| is_my_num(s, 2));
    assert_eq!(result, Ok(Some("2")));
    let result = a.into_iter().try_find(|&s| is_my_num(s, 5));
    assert!(result.is_err());
}