You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: typeerreursource0.rs
    path of file: ./repos/FR_RBE/src/chapitre16/source
    
    the code of the file until where you have to start completion: fn double_first(vec: Vec<&str>) -> i32 {
    let first = vec.first().unwrap(); // Génère la première erreur.
    2 * first.parse::<i32>().unwra
    
fn main() {
    let empty = vec![];
    let strings = vec!["tofu", "93", "18"];

    println!("The first doubled is {}", double_first(empty));
    // Erreur 1: Le vecteur passé en entrée est vide.

    println!("The first doubled is {}", double_first(strings));
    // Erreur 2: L'élément ne peut pas être converti en nombre.
}