pub struct CrateId { local_path: String, junk: String } impl CrateId { fn new(s: &str) -> CrateId { CrateId { local_path: s.to_string(), junk: "wutevs".to_string() } } } pub fn remove_package_from_database() { let mut lines_to_use: Vec<&CrateId> = Vec::new(); //~^ NOTE cannot infer an appropriate lifetime let push_id = |installed_id: &CrateId| { //~^ NOTE borrowed data cannot outlive this closure //~| NOTE ...so that variable is valid at time of its declaration lines_to_use.push(installed_id); //~^ ERROR borrowed data cannot be stored outside of its closure //~| NOTE cannot be stored outside of its closure }; list_database(push_id); for l in &lines_to_use { println!("{}", l.local_path); } } pub fn list_database(mut f: F) where F: FnMut(&CrateId) { let stuff = ["foo", "bar"]; for l in &stuff { f(&CrateId::new(*l)); } } pub fn main() { remove_package_from_database(); }