环境

• Rust 1.56.1
• VSCode 1.61.2

概念

参考：https://doc.rust-lang.org/stable/rust-by-example/flow_control/match/destructuring/destructure_enum.html

示例

枚举匹配

#[allow(dead_code)]
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);
    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
        ),
    }
}

总结

了解了 Rust 中的 match 关键字，可以用来匹配枚举，同时使用解构。

附录