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In which borrowck errors are unhelpful.
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| src/main.rs:6:28: 6:29 error: cannot infer an appropriate lifetime for automatic coercion due to conflicting requirements [E0495] | |
| src/main.rs:6 let caps = re.captures(s).unwrap(); | |
| ^ | |
| src/main.rs:6:28: 6:29 note: first, the lifetime cannot outlive the expression at 6:27... | |
| src/main.rs:6 let caps = re.captures(s).unwrap(); | |
| ^ | |
| src/main.rs:6:28: 6:29 note: ...so that auto-reference is valid at the time of borrow | |
| src/main.rs:6 let caps = re.captures(s).unwrap(); | |
| ^ | |
| src/main.rs:6:16: 6:30 note: but, the lifetime must be valid for the method call at 6:15... | |
| src/main.rs:6 let caps = re.captures(s).unwrap(); | |
| ^~~~~~~~~~~~~~ | |
| src/main.rs:6:28: 6:29 note: ...so that argument is valid for the call | |
| src/main.rs:6 let caps = re.captures(s).unwrap(); | |
| ^ | |
| error: aborting due to previous error |
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| extern crate regex; | |
| use regex::Regex; | |
| fn breaks(s: &str) -> usize { | |
| let re = Regex::new(r"(?P<number>\d+)").unwrap(); | |
| let caps = re.captures(s).unwrap(); | |
| caps["number"].len() | |
| } | |
| fn works(s: &str) -> usize { | |
| let re = Regex::new(r"(?P<number>\d+)").unwrap(); | |
| let caps = re.captures(s).unwrap(); | |
| caps.name("number").unwrap().len() | |
| } | |
| fn also_works(s: &str) -> usize { | |
| let re = Regex::new(r"(?P<number>\d+)").unwrap(); | |
| let caps = re.captures(s).unwrap(); | |
| caps[1].len() | |
| } | |
| fn main() { | |
| println!("{:?}", breaks("123")); | |
| println!("{:?}", works("123")); | |
| println!("{:?}", also_works("123")); | |
| } |
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| --- a/src/re.rs | |
| +++ b/src/re.rs | |
| @@ -970,11 +970,11 @@ impl<'t> Index<usize> for Captures<'t> { | |
| /// | |
| /// # Panics | |
| /// If there is no group named by the given value. | |
| -impl<'t> Index<&'t str> for Captures<'t> { | |
| +impl<'t, 'i> Index<&'i str> for Captures<'t> { | |
| type Output = str; | |
| - fn index<'a>(&'a self, name: &str) -> &'a str { | |
| + fn index<'a>(&'a self, name: &'i str) -> &'a str { | |
| match self.name(name) { | |
| None => panic!("no group named '{}'", name), | |
| Some(ref s) => s, |
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