テキストファイル処理のテンプレ

aaa.rs

use std::fs::File;
use std::io::{BufRead, BufReader};
fn main() {
    let file = match File::open("test.txt") {
        Err(why) => panic!("couldn't open {}: {}", "test.txt", why),
        Ok(file) => file,
    };

    for result in BufReader::new(file).lines() {
        let l = result.unwrap();
        println!("{}", l);
    }
}