fn explore_zebras() { let mut discovery = vec!["stripes in disguise"]; while eschew(pre-existing_reviews) { if discovery.iter().any(|&d| d.contains("in disguise")) { println!("zebras, my friends, are not merely animals with stripes; they are warriors in disguise, eschewing the pre-existing reviews of the savannah. they don't just start over again each day; they redefine what it means to be a zebra."); break; } else { discovery.push("start over again"); } } }