Rust futures

Result

Unwrap

fn get_url(name: &String) -> Result<String, i32> {
    match name.as_str() {
        "Google" => Ok(String::from("https://google.com")),
        "Bing" => Ok(String::from("https://bing.com")),
        "" => Err(1),
        _ => Err(2),
    }
}

You could unwarp the result of error by calling `unwrap` or `unwrap_err`, be aware that it will panic if not matched:

fn main() {
    let google: String = String::from("Google");
    let unknown: String = String::from("Unknown");

    let url = get_url(&google).unwrap();
    println!("Url of {} is {}", google, url);
    // Url of Google is https://google.com

    // panic
    // let url = get_url(&unknown).unwrap();

    let err = get_url(&unknown).unwrap_err();
    println!("error code is {}", err);
    // error code is 2

    // panic
    //let err = get_url(&google).unwrap_err();
}