1 // check-pass useful(i: usize) -> usize2 fn useful(i: usize) -> usize { 3 i 4 } 5 useful2(i: usize) -> usize6 fn useful2(i: usize) -> usize { 7 i 8 } 9 main()10 fn main() { 11 for f in &[useful, useful2, |x| x] { 12 println!("{}", f(6)); 13 } 14 } 15