let history_lesson = || { let unexpressed_thoughts = vec::new(); for era in history.iter() { if era.events.contains(&"unexpressed") { unexpressed_thoughts.push(era); } } let plan = "learn and renew interest in history"; let advice = "shrug off the pre-installed notion that history is just dates and events."; println!("explore the unexpressed stories in history to truly appreciate its depth.{} {} remember, every era has its untold tales waiting to be discovered.", plan, advice); };