1extern crate closures;
2
3use closures::ClosureMut;
4
5fn main() {
6 for ch in alphabet() {
7 println!("{}", ch);
8 }
9}
10
11fn alphabet() -> ClosureMut<u8, Option<char>> {
12 ClosureMut::new(b'a'-1, |ch| {
13 if *ch == b'z' {
14 return None
15 }
16
17 *ch += 1;
18
19 Some(*ch as char)
20 })
21}