Rust Guards

Guards

一個匹配guard可以被添加到過濾手臂。

fn main() {
let pair = (2, -2);
// TODO ^ Try different values for `pair`

println!("Tell me about {:?}", pair);
match pair {
    (x, y) if x == y => println!("These are twins"),
    // The ^ \`if condition\` part is a guard
    (x, y) if x + y == 0 => println!("Antimatter, kaboom!"),
    (x, \_) if x % 2 == 1 => println!("The first one is odd"),
    \_ => println!("No correlation..."),
}

}

也可以看看：

元組