Does not live long enough

edit.rs

use std::cell::RefCell;
use std::io::{BufferedReader, File};


struct Buffer<'b> {
    lines: Vec<RefCell<Line>>,
    cursor: Cursor<'b>,
}

impl<'b> Buffer<'b> {
    fn new() -> Buffer<'b> {
        Buffer {
            lines: Vec::new(),
            cursor: Cursor::new()
        }
    }

    fn new_from_file(path: &Path) -> Buffer<'b> {
        let mut file = BufferedReader::new(File::open(path));
        let mut buffer = Buffer::new();

        for line in file.lines() {
            let data = line.unwrap();
            buffer.lines.push(RefCell::new(Line::new_from_string(data)));
        }

        buffer.cursor.line = Some(&buffer.lines[0]);

        buffer
    }
}

struct Line {
    data: String,
}

impl Line {
    fn new_from_string(data: String) -> Line {
        Line {
            data: data,
        }
    }
}

struct Cursor<'c> {
    line: Option<&'c RefCell<Line>>,
}

impl<'c> Cursor<'c> {
    fn new() -> Cursor<'c> {
        Cursor {
            line: None
        }
    }
}

fn main() {
    let path = Path::new("/Users/Greg/test.txt");
    let buffer = Buffer::new_from_file(&path);
}


/*
$ rustc edit.rs
edit.rs:27:36: 27:48 error: `buffer.lines` does not live long enough
edit.rs:27         buffer.cursor.line = Some(&buffer.lines[0]);
                                              ^~~~~~~~~~~~
edit.rs:18:49: 30:6 note: reference must be valid for the lifetime 'b as defined on the block at 18:48...
edit.rs:18     fn new_from_file(path: &Path) -> Buffer<'b> {
edit.rs:19         let mut file = BufferedReader::new(File::open(path));
edit.rs:20         let mut buffer = Buffer::new();
edit.rs:21
edit.rs:22         for line in file.lines() {
edit.rs:23             let data = line.unwrap();
           ...
edit.rs:18:49: 30:6 note: ...but borrowed value is only valid for the block at 18:48
edit.rs:18     fn new_from_file(path: &Path) -> Buffer<'b> {
edit.rs:19         let mut file = BufferedReader::new(File::open(path));
edit.rs:20         let mut buffer = Buffer::new();
edit.rs:21
edit.rs:22         for line in file.lines() {
edit.rs:23             let data = line.unwrap();
           ...
error: aborting due to previous error
*/