#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn something_which_returns_char() -> char {
    'a'
}
fn main() {
    let c: char = something_which_returns_char();
    assert!(c <= char::MAX);
    let value_at_max = u32::from(char::MAX);
    assert_eq!(char::from_u32(value_at_max), Some('\u{10FFFF}'));
    assert_eq!(char::from_u32(value_at_max + 1), None);
}