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 |
| } |
| } |
