Rust中的Vector类型

fn main() {
    let v = vec![1, 2, 3, 4, 5];
    
    let third: &i32 = &v[2];
    println!("The third element is {}", third);

    match v.get(2) {
    Some(third) => println!("The element is {}", third),
        None => println!("There is no element"),
    }

    match v.get(20) {
        Some(twenty) => println!("The element is {}", twenty),
        None => println!("There is no element"),
    }

}