解构数组

你可以通过元素匹配来解构数组、元组和切片：

#[rustfmt::skip]
fn main() {
    let triple = [0, -2, 3];
    println!("Tell me about {triple:?}");
    match triple {
        [0, y, z] => println!("First is 0, y = {y}, and z = {z}"),
        [1, ..]   => println!("First is 1 and the rest were ignored"),
        _         => println!("All elements were ignored"),
    }
}

  • 对未知长度的切片进行解构也可以使用固定长度的模式。

    fn main() {
    inspect(&[0, -2, 3]);
    inspect(&[0, -2, 3, 4]);
}

#[rustfmt::skip]
fn inspect(slice: &[i32]) {
    println!("Tell me about {slice:?}");
    match slice {
        &[0, y, z] => println!("First is 0, y = {y}, and z = {z}"),
        &[1, ..]   => println!("First is 1 and the rest were ignored"),
        _          => println!("All elements were ignored"),
    }
}

  • 使用 _ 创建一个新的模式来代表一个元素。

  • 向数组中添加更多的值。

  • 指出 .. 是如何扩展以适应不同数量的元素的。

  • 展示使用模式 [.., b] 和 [a@..,b] 来匹配切片的尾部。