lifetime

I have a bit of code that I'm fighting with. It's a little helper function that should return a Vec<&str> to the calling function. I can't seem to get the lifetime right, though. Here is the code snippet: fn take_symbol<'a>(ch: &'a str, current: &'a mut String) -> &'a mut TokenList<'a> { let out = TokenList::<'a>::new(); out.push(current.as_str()); out.push(ch); *current = String::new(); &mut out } The compiler is telling me: error: 'out' does not live long enough and that the reference must be valid for the lifetime of 'a , but it looks to me like it is defined for 'a . I have also tried

Editor's note: This question was asked before Rust 1.0. Since then, many functions and types have changed, as have certain language semantics. The code in the question is no longer valid, but the ideas expressed in the answers may be. I'm trying to list the files in a directory and copy the filename to my own Vec . I've tried several solutions, but it always ends up with a problem of not being able to create long enough living variables. I don't understand my mistake. fn getList(action_dir_path : &str) -> Vec<&str> { let v = fs::readdir(&Path::new(action_dir_path)) .unwrap() .iter() .map(|&x|

I have a structure that contains a value and I want to obtain a function that operates on this value: struct Returner { val: i32, } impl<'a> Returner { fn get(&'a self) -> Box<Fn(i32) -> i32> { Box::new(|x| x + self.val) } } This fails compilation: error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements --> src/main.rs:7:18 | 7 | Box::new(|x| x + self.val) | ^^^^^^^^^^^^^^^^ | note: first, the lifetime cannot outlive the lifetime 'a as defined on the impl at 5:1... --> src/main.rs:5:1 | 5 | impl<'a> Returner { | ^^^^^^^^^^^^^^^^^ = note: ...so that the types are

I'm trying to put a field on a struct that should hold an Option<closure> . However, Rust is yelling at me that I have to specify the lifetime (not that I would have really grokked that yet). I'm trying my best to do so but Rust is never happy with what I come up with. Take a look at my inline comments for the compile errors I got. struct Floor{ handler: Option<|| ->&str> //this gives: missing lifetime specifier //handler: Option<||: 'a> // this gives: use of undeclared lifetime name `'a` } impl Floor { // I guess I need to specify life time here as well // but I can't figure out for the life