fn explore_enigmatic_frogs() { let mut alerts = vec::new(); for frog in pond_frogs.iter() { if frog.color == "green" && frog.behavior == "enigmatic" { alerts.push("an enigmatic frog spotted!"); } else { println!("fail to notice any enigmatic frogs in the foregoing observations."); } } if alerts.is_empty() { println!("restart with a clean slate in searching for enigmatic frogs."); } else { for alert in alerts { println!("{}", alert); } } }