rust allow dead_code

// 需要 `allow` 来消除警告，因为只使用了一个变量
#[allow(dead_code)]
enum Color {
    Red,
    Blue,
    Green,
    RGB(u32, u32, u32),
    HSV(u32, u32, u32),
    HSL(u32, u32, u32)
}

fn main() {
    let color = Color::RGB(122, 17, 40);
    println!("what color is it ?");

    match color {
        Color::Red => println!("The color is Red!"),
        Color::RGB(a, b, c) => println!("Red: {}, green: {}, blue: {}", a, b, c),
        _ => println!("unknown color")
    }
}