unwrap/expect

 
use std::fs;

fn main() {
    let contents = fs::read_to_string("file.txt");
    println!("{}", contents.unwrap());
}

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 2, kind: NotFound, message: "No such file or directory" }', libcore/result.rs:945:5
note: Run with `RUST_BACKTRACE=1` for a backtrace.
  • unwrap deve ser usado com muita moderação.
  • Se for usar, prefira sempre expect.
  • Idealmente, deixe um comentário justificando o uso.