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