diff options
| -rw-r--r-- | library/alloctests/tests/arc.rs | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/library/alloctests/tests/arc.rs b/library/alloctests/tests/arc.rs index 45a145c6271..00bdf527133 100644 --- a/library/alloctests/tests/arc.rs +++ b/library/alloctests/tests/arc.rs @@ -1,7 +1,7 @@ use std::any::Any; use std::cell::{Cell, RefCell}; use std::iter::TrustedLen; -use std::sync::{Arc, Weak}; +use std::sync::{Arc, UniqueArc, Weak}; #[test] fn uninhabited() { @@ -263,6 +263,27 @@ fn make_mut_unsized() { assert_eq!(*other_data, [110, 20, 30]); } +#[test] +fn test_unique_arc_weak() { + let data = UniqueArc::new(32); + + // Test that `Weak` downgraded from `UniqueArc` cannot be upgraded. + let weak = UniqueArc::downgrade(&data); + assert_eq!(weak.strong_count(), 0); + assert_eq!(weak.weak_count(), 0); + assert!(weak.upgrade().is_none()); + + // Test that `Weak` can now be upgraded after the `UniqueArc` being converted to `Arc`. + let strong = UniqueArc::into_arc(data); + assert_eq!(*strong, 32); + assert_eq!(weak.strong_count(), 1); + assert_eq!(weak.weak_count(), 1); + let upgraded = weak.upgrade().unwrap(); + assert_eq!(*upgraded, 32); + assert_eq!(weak.strong_count(), 2); + assert_eq!(weak.weak_count(), 1); +} + #[allow(unused)] mod pin_coerce_unsized { use alloc::sync::{Arc, UniqueArc}; |