trpl-zh-cn/listings/ch18-patterns-and-matching/listing-18-21/src/main.rs

fn main() {
    // ANCHOR: here
    let s = Some(String::from("Hello!"));

    if let Some(_s) = s {
        println!("found a string");
    }

    println!("{s:?}");
    // ANCHOR_END: here
}