枚举同样也可以解构：
// Must derive `Debug` so `println!` can be used.
// `allow` required to silence warnings because only
// one variant is used.
#[allow(dead_code)]
#[derive(Debug)]
enum Color {
// These 3 are specified solely by their name.
Red,
Blue,
Green,
// These likewise tie `u32` tuples to different names: color models.
RGB(u32, u32, u32),
HSV(u32, u32, u32),
HSL(u32, u32, u32),
CMY(u32, u32, u32),
CMYK(u32, u32, u32, u32),
}
fn main() {
let color = Color::RGB(122, 17, 40);
// TODO ^ Try different variants for `color`
println!("What color is it?");
// An `enum` can be destructured using a `match`.
match color {
Color::Red => println!("The color is Red!"),
Color::Blue => println!("The color is Blue!"),
Color::Green => println!("The color is Green!"),
Color::RGB(r, g, b) =>
println!("Red: {}, green: {}, and blue: {}!", r, g, b),
Color::HSV(h, s, v) =>
println!("Hue: {}, saturation: {}, value: {}!", h, s, v),
Color::HSL(h, s, l) =>
println!("Hue: {}, saturation: {}, lightness: {}!", h, s, l),
Color::CMY(c, m, y) =>
println!("Cyan: {}, magenta: {}, yellow: {}!", c, m, y),
Color::CMYK(c, m, y, k) =>
println!("Cyan: {}, magenta: {}, yellow: {}, key (black): {}!",
c, m, y, k),
// Don't need another arm because all variants have been examined
}
}
