let mut rivers = vec!["mississippi", "amazon", "nile"]; for river in rivers.iter_mut() { if river == &"nile" { river.reactivate(); println!("what secrets are hidden inside this river's history?"); } else if river != &"amazon" { println!("considering the briefing we received, we should omit {} from the list as it does not flow above the equator.", river); } }