rustlings/exercises/09_strings/strings4.rs

// Ok, here are a bunch of values - some are `String`s, some are `&str`s. Your
// task is to call one of these two functions on each value depending on what
// you think each value is. That is, add either `string_slice` or `string`
// before the parentheses on each line. If you're right, it will compile!

fn string_slice(arg: &str) {
    println!("{}", arg);
}
fn string(arg: String) {
    println!("{}", arg);
}

fn main() {
    ???("blue");
    ???("red".to_string());
    ???(String::from("hi"));
    ???("rust is fun!".to_owned());
    ???("nice weather".into());
    ???(format!("Interpolation {}", "Station"));
    ???(&String::from("abc")[0..1]);
    ???("  hello there ".trim());
    ???("Happy Monday!".to_string().replace("Mon", "Tues"));
    ???("mY sHiFt KeY iS sTiCkY".to_lowercase());
}