// Cargo.toml: regex = "1"
use regex::Regex;

fn main() {
    let re = Regex::new(r"(?P<y>\d{4})-(?P<m>\d{2})-(?P<d>\d{2})").unwrap();
    if let Some(c) = re.captures("Date: 2026-05-12") {
        println!("year={} month={} day={}", &c["y"], &c["m"], &c["d"]);
    }
}