Extracting file lines assigning to a vector

Playing around with Rust and getting stuck on a basic assignment error.

Here’s my code:

fn parse_file_lines(filename: &str) -> Vec<&str> {
    let mut file_lines: Vec<&str> = Vec::new();
    if let Ok(lines) = read_lines(filename) {
        lines.for_each(|line| match line {
            Ok(l) => {
                // perform some logic here...
                file_lines.push(&l)
            }
            Err(_) => todo!(),
        })
    }

    return file_lines;
}

fn read_lines(filename: &str) -> io::Result<io::Lines<io::BufReader<File>>> {
    let file = File::open(filename)?;
    Ok(io::BufReader::new(file).lines())
}

Which is returning this compiler error:

error[E0597]: `l` does not live long enough
  --> src/main.rs:17:38
   |
14 |     let mut file_lines: Vec<&str> = Vec::new();
   |         -------------- lifetime `'1` appears in the type of `file_lines`
...
17 |             Ok(l) => file_lines.push(&l),
   |                      ----------------^^-
   |                      |               | |
   |                      |               | `l` dropped here while still borrowed
   |                      |               borrowed value does not live long enough
   |                      argument requires that `l` is borrowed for `'1`

I know my scopes are off somehow but can’t figure out why – it’s been a long day 🥹

Thanks!

>Solution :

std::io::Lines yields owned Strings, not borrowed &strs, and thus you cannot drop them and store a reference to them in a Vec.

Instead, store the owned Strings in the Vec:

fn parse_file_lines(filename: &str) -> Vec<String> {
    let mut file_lines: Vec<String> = Vec::new();
    if let Ok(lines) = read_lines(filename) {
        lines.for_each(|line| match line {
            Ok(l) => {
                // perform some logic here...
                file_lines.push(l)
            }
            Err(_) => todo!(),
        })
    }

    return file_lines;
}