// run-pass // needs-unwind // ignore-wasm32-bare compiled with panic=abort by default use std::cell::RefCell; use std::panic; pub struct DropLogger<'a> { id: usize, log: &'a panic::AssertUnwindSafe>> } impl<'a> Drop for DropLogger<'a> { fn drop(&mut self) { self.log.0.borrow_mut().push(self.id); } } struct InjectedFailure; #[allow(unreachable_code)] fn main() { let log = panic::AssertUnwindSafe(RefCell::new(vec![])); let d = |id| DropLogger { id: id, log: &log }; let get = || -> Vec<_> { let mut m = log.0.borrow_mut(); let n = m.drain(..); n.collect() }; { let _x = (d(0), &d(1), d(2), &d(3)); // all borrows are extended - nothing has been dropped yet assert_eq!(get(), vec![]); } // in a let-statement, extended places are dropped // *after* the let result (tho they have the same scope // as far as scope-based borrowck goes). assert_eq!(get(), vec![0, 2, 3, 1]); let _ = std::panic::catch_unwind(|| { (d(4), &d(5), d(6), &d(7), panic::panic_any(InjectedFailure)); }); // here, the temporaries (5/7) live until the end of the // containing statement, which is destroyed after the operands // (4/6) on a panic. assert_eq!(get(), vec![6, 4, 7, 5]); }