trpl-zh-cn/listings/ch13-functional-features/listing-13-18/src/main.rs

fn main() {
    // ANCHOR: here
    let v1: Vec<i32> = vec![1, 2, 3];

    let v2: Vec<_> = v1.iter().map(|x| x + 1).collect();

    assert_eq!(v2, vec![2, 3, 4]);
    // ANCHOR_END: here
}