拆开元组

// It's possible to unpack tuples to assign their inner values to variables
let tup = (0, 1, 2);
// Unpack the tuple into variables a, b, and c
let (a, b, c) = tup;

assert_eq!(a, 0);
assert_eq!(b, 1);

// This works for nested data structures and other complex data types
let complex = ((1, 2), 3, Some(0));

let (a, b, c) = complex;
let (aa, ab) = a;

assert_eq!(aa, 1);
assert_eq!(ab, 2);