Rust綁定

綁定 - Binding

間接訪問變量使得不可能分支和使用該變量，而無需重新綁定。匹配提供@印記就是出於這樣的目的：

// A function `age` which returns a `u32`.
fn age() -> u32 {
15
}

fn main() {
println!("Tell me type of person you are");

match age() {
    0             => println!("I'm not born yet I guess"),
    // Could \`match\` 1 ... 12 directly but then what age
    // would the child be? Instead, bind to \`n\` for the
    // sequence of 1 .. 12. Now the age can be reported.
    n @ 1  ... 12 => println!("I'm a child of age {:?}", n),
    n @ 13 ... 19 => println!("I'm a teen of age {:?}", n),
    // Nothing bound. Return the result.
    n             => println!("I'm an old person of age {:?}", n),
}

}

也可參考:

函數