//@ revisions: edition2021 edition2024 //@ [edition2024] compile-flags: -Zunstable-options //@ [edition2024] edition: 2024 //@ [edition2024] run-pass #![cfg_attr(edition2024, feature(shorter_tail_lifetimes))] fn f() -> usize { let c = std::cell::RefCell::new(".."); c.borrow().len() //[edition2021]~ ERROR: `c` does not live long enough } fn main() { let _ = f(); }