//@ revisions: edition2021 edition2024 //@ [edition2024] compile-flags: -Zunstable-options //@ [edition2024] edition: 2024 //@ [edition2021] check-pass #![feature(shorter_tail_lifetimes)] fn why_would_you_do_this() -> bool { let mut x = None; // Make a temporary `RefCell` and put a `Ref` that borrows it in `x`. x.replace(std::cell::RefCell::new(123).borrow()).is_some() //[edition2024]~^ ERROR: temporary value dropped while borrowed } fn main() { why_would_you_do_this(); }