| // run-pass |
| // This test illustrates that under NLL, we can remove our overly |
| // conservative approach for disallowing mutations of match inputs. |
| |
| // See further discussion on rust-lang/rust#24535, |
| // rust-lang/rfcs#1006, and rust-lang/rfcs#107 |
| |
| fn main() { |
| rust_issue_24535(); |
| rfcs_issue_1006_1(); |
| rfcs_issue_1006_2(); |
| } |
| |
| fn rust_issue_24535() { |
| fn compare(a: &u8, b: &mut u8) -> bool { |
| a == b |
| } |
| |
| let a = 3u8; |
| |
| match a { |
| 0 => panic!("nope"), |
| 3 if compare(&a, &mut 3) => (), |
| _ => panic!("nope"), |
| } |
| } |
| |
| fn rfcs_issue_1006_1() { |
| let v = vec!["1".to_string(), "2".to_string(), "3".to_string()]; |
| match Some(&v) { |
| Some(iv) if iv.iter().any(|x| &x[..]=="2") => true, |
| _ => panic!("nope"), |
| }; |
| } |
| |
| fn rfcs_issue_1006_2() { |
| #[inline(always)] |
| fn check<'a, I: Iterator<Item=&'a i32>>(mut i: I) -> bool { |
| i.any(|&x| x == 2) |
| } |
| |
| let slice = [1, 2, 3]; |
| |
| match 42 { |
| _ if slice.iter().any(|&x| x == 2) => { true }, |
| _ => { panic!("nope"); } |
| }; |
| |
| // (This match is just illustrating how easy it was to circumvent |
| // the checking performed for the previous `match`.) |
| match 42 { |
| _ if check(slice.iter()) => { true }, |
| _ => { panic!("nope"); } |
| }; |
| } |
