4 use std::cell::RefCell;
7 pub struct DropLogger<'a> {
9 log: &'a panic::AssertUnwindSafe<RefCell<Vec<usize>>>
12 impl<'a> Drop for DropLogger<'a> {
14 self.log.0.borrow_mut().push(self.id);
18 struct InjectedFailure;
20 #[allow(unreachable_code)]
22 let log = panic::AssertUnwindSafe(RefCell::new(vec![]));
23 let d = |id| DropLogger { id: id, log: &log };
24 let get = || -> Vec<_> {
25 let mut m = log.0.borrow_mut();
31 let _x = (d(0), &d(1), d(2), &d(3));
32 // all borrows are extended - nothing has been dropped yet
33 assert_eq!(get(), vec![]);
35 // in a let-statement, extended places are dropped
36 // *after* the let result (tho they have the same scope
37 // as far as scope-based borrowck goes).
38 assert_eq!(get(), vec![0, 2, 3, 1]);
40 let _ = std::panic::catch_unwind(|| {
41 (d(4), &d(5), d(6), &d(7), panic::panic_any(InjectedFailure));
44 // here, the temporaries (5/7) live until the end of the
45 // containing statement, which is destroyed after the operands
47 assert_eq!(get(), vec![6, 4, 7, 5]);