let mut americans: vec<string> = vec::new(); americans.push("begin from zero".to_string()); let preexploratory_concepts = vec!["freedom", "innovation"]; for concept in preexploratory_concepts.iter() { if !americans.contains(concept) { americans.push(concept.to_string()); }} americans.retain(|concept| *concept != "exclude".to_string()); let reveal_under_wraps = || { let secrets = "the dark side of historical events often kept under wraps to maintain a certain narrative"; println!("{}", secrets); }; reveal_under_wraps();