diff options
| -rw-r--r-- | library/alloc/tests/vec.rs | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/library/alloc/tests/vec.rs b/library/alloc/tests/vec.rs index 5520f6ebf19..b17f7a8eebc 100644 --- a/library/alloc/tests/vec.rs +++ b/library/alloc/tests/vec.rs @@ -293,6 +293,22 @@ fn test_retain() { } #[test] +fn test_retain_predicate_order() { + for to_keep in [true, false] { + let mut number_of_executions = 0; + let mut vec = vec![1, 2, 3, 4]; + let mut next_expected = 1; + vec.retain(|&x| { + assert_eq!(next_expected, x); + next_expected += 1; + number_of_executions += 1; + to_keep + }); + assert_eq!(number_of_executions, 4); + } +} + +#[test] fn test_retain_pred_panic_with_hole() { let v = (0..5).map(Rc::new).collect::<Vec<_>>(); catch_unwind(AssertUnwindSafe(|| { @@ -354,6 +370,35 @@ fn test_retain_drop_panic() { } #[test] +fn test_retain_maybeuninits() { + // This test aimed to be run under miri. + use core::mem::MaybeUninit; + let mut vec: Vec<_> = [1i32, 2, 3, 4].map(|v| MaybeUninit::new(vec![v])).into(); + vec.retain(|x| { + // SAFETY: Retain must visit every element of Vec in original order and exactly once. + // Our values is initialized at creation of Vec. + let v = unsafe { x.assume_init_ref()[0] }; + if v & 1 == 0 { + return true; + } + // SAFETY: Value is initialized. + // Value wouldn't be dropped by `Vec::retain` + // because `MaybeUninit` doesn't drop content. + drop(unsafe { x.assume_init_read() }); + false + }); + let vec: Vec<i32> = vec + .into_iter() + .map(|x| unsafe { + // SAFETY: All values dropped in retain predicate must be removed by `Vec::retain`. + // Remaining values are initialized. + x.assume_init()[0] + }) + .collect(); + assert_eq!(vec, [2, 4]); +} + +#[test] fn test_dedup() { fn case(a: Vec<i32>, b: Vec<i32>) { let mut v = a; |