#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn main() {
    let word = "goodbye";
    let count = word.chars().count();
    assert_eq!(7, count);
    let mut chars = word.chars();
    assert_eq!(Some('g'), chars.next());
    assert_eq!(Some('o'), chars.next());
    assert_eq!(Some('o'), chars.next());
    assert_eq!(Some('d'), chars.next());
    assert_eq!(Some('b'), chars.next());
    assert_eq!(Some('y'), chars.next());
    assert_eq!(Some('e'), chars.next());
    assert_eq!(None, chars.next());
}