2 files changed, 127 insertions, 0 deletions
diff --git a/library/alloc/tests/lib.rs b/library/alloc/tests/lib.rs
index 799499b9b77..11673ed8262 100644
--- a/library/alloc/tests/lib.rs
+++ b/library/alloc/tests/lib.rs
@@ -19,6 +19,7 @@
 #![feature(int_bits_const)]
 #![feature(vecdeque_binary_search)]
 #![feature(slice_group_by)]
+#![feature(slice_partition_dedup)]
 #![feature(vec_extend_from_within)]
 #![feature(vec_spare_capacity)]
 
diff --git a/library/alloc/tests/vec.rs b/library/alloc/tests/vec.rs
index 1ba2315ca73..c142536cd2d 100644
--- a/library/alloc/tests/vec.rs
+++ b/library/alloc/tests/vec.rs
@@ -2102,6 +2102,132 @@ fn test_extend_from_within() {
     assert_eq!(v, ["a", "b", "c", "b", "c", "a", "b"]);
 }
 
+#[test]
+fn test_vec_dedup_by() {
+    let mut vec: Vec<i32> = vec![1, -1, 2, 3, 1, -5, 5, -2, 2];
+
+    vec.dedup_by(|a, b| a.abs() == b.abs());
+
+    assert_eq!(vec, [1, 2, 3, 1, -5, -2]);
+}
+
+#[test]
+fn test_vec_dedup_empty() {
+    let mut vec: Vec<i32> = Vec::new();
+
+    vec.dedup();
+
+    assert_eq!(vec, []);
+}
+
+#[test]
+fn test_vec_dedup_one() {
+    let mut vec = vec![12i32];
+
+    vec.dedup();
+
+    assert_eq!(vec, [12]);
+}
+
+#[test]
+fn test_vec_dedup_multiple_ident() {
+    let mut vec = vec![12, 12, 12, 12, 12, 11, 11, 11, 11, 11, 11];
+
+    vec.dedup();
+
+    assert_eq!(vec, [12, 11]);
+}
+
+#[test]
+fn test_vec_dedup_partialeq() {
+    #[derive(Debug)]
+    struct Foo(i32, i32);
+
+    impl PartialEq for Foo {
+        fn eq(&self, other: &Foo) -> bool {
+            self.0 == other.0
+        }
+    }
+
+    let mut vec = vec![Foo(0, 1), Foo(0, 5), Foo(1, 7), Foo(1, 9)];
+
+    vec.dedup();
+    assert_eq!(vec, [Foo(0, 1), Foo(1, 7)]);
+}
+
+#[test]
+fn test_vec_dedup() {
+    let mut vec: Vec<bool> = Vec::with_capacity(8);
+    let mut template = vec.clone();
+
+    for x in 0u8..255u8 {
+        vec.clear();
+        template.clear();
+
+        let iter = (0..8).map(move |bit| (x >> bit) & 1 == 1);
+        vec.extend(iter);
+        template.extend_from_slice(&vec);
+
+        let (dedup, _) = template.partition_dedup();
+        vec.dedup();
+
+        assert_eq!(vec, dedup);
+    }
+}
+
+#[test]
+fn test_vec_dedup_panicking() {
+    #[derive(Debug)]
+    struct Panic {
+        drop_counter: &'static AtomicU32,
+        value: bool,
+        index: usize,
+    }
+
+    impl PartialEq for Panic {
+        fn eq(&self, other: &Self) -> bool {
+            self.value == other.value
+        }
+    }
+
+    impl Drop for Panic {
+        fn drop(&mut self) {
+            let x = self.drop_counter.fetch_add(1, Ordering::SeqCst);
+            assert!(x != 4);
+        }
+    }
+
+    static DROP_COUNTER: AtomicU32 = AtomicU32::new(0);
+    let expected = [
+        Panic { drop_counter: &DROP_COUNTER, value: false, index: 0 },
+        Panic { drop_counter: &DROP_COUNTER, value: false, index: 5 },
+        Panic { drop_counter: &DROP_COUNTER, value: true, index: 6 },
+        Panic { drop_counter: &DROP_COUNTER, value: true, index: 7 },
+    ];
+    let mut vec = vec![
+        Panic { drop_counter: &DROP_COUNTER, value: false, index: 0 },
+        // these elements get deduplicated
+        Panic { drop_counter: &DROP_COUNTER, value: false, index: 1 },
+        Panic { drop_counter: &DROP_COUNTER, value: false, index: 2 },
+        Panic { drop_counter: &DROP_COUNTER, value: false, index: 3 },
+        Panic { drop_counter: &DROP_COUNTER, value: false, index: 4 },
+        // here it panics
+        Panic { drop_counter: &DROP_COUNTER, value: false, index: 5 },
+        Panic { drop_counter: &DROP_COUNTER, value: true, index: 6 },
+        Panic { drop_counter: &DROP_COUNTER, value: true, index: 7 },
+    ];
+
+    let _ = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
+        vec.dedup();
+    }));
+
+    let ok = vec.iter().zip(expected.iter()).all(|(x, y)| x.index == y.index);
+
+    if !ok {
+        panic!("expected: {:?}\ngot: {:?}\n", expected, vec);
+    }
+}
+
 // Regression test for issue #82533
 #[test]
 fn test_extend_from_within_panicing_clone() {