Merging upstream version 127.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 1775 insertions, 0 deletions

diff --git a/third_party/rust/indexmap/src/set/iter.rs b/third_party/rust/indexmap/src/set/iter.rs
new file mode 100644
index 0000000000..3f8033c2db
--- /dev/null
+++ b/third_party/rust/indexmap/src/set/iter.rs
@@ -0,0 +1,626 @@
+use super::{Bucket, Entries, IndexSet, Slice};
+
+use alloc::vec::{self, Vec};
+use core::fmt;
+use core::hash::{BuildHasher, Hash};
+use core::iter::{Chain, FusedIterator};
+use core::ops::RangeBounds;
+use core::slice::Iter as SliceIter;
+
+impl<'a, T, S> IntoIterator for &'a IndexSet<T, S> {
+    type Item = &'a T;
+    type IntoIter = Iter<'a, T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+
+impl<T, S> IntoIterator for IndexSet<T, S> {
+    type Item = T;
+    type IntoIter = IntoIter<T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        IntoIter::new(self.into_entries())
+    }
+}
+
+/// An iterator over the items of an [`IndexSet`].
+///
+/// This `struct` is created by the [`IndexSet::iter`] method.
+/// See its documentation for more.
+pub struct Iter<'a, T> {
+    iter: SliceIter<'a, Bucket<T>>,
+}
+
+impl<'a, T> Iter<'a, T> {
+    pub(super) fn new(entries: &'a [Bucket<T>]) -> Self {
+        Self {
+            iter: entries.iter(),
+        }
+    }
+
+    /// Returns a slice of the remaining entries in the iterator.
+    pub fn as_slice(&self) -> &'a Slice<T> {
+        Slice::from_slice(self.iter.as_slice())
+    }
+}
+
+impl<'a, T> Iterator for Iter<'a, T> {
+    type Item = &'a T;
+
+    iterator_methods!(Bucket::key_ref);
+}
+
+impl<T> DoubleEndedIterator for Iter<'_, T> {
+    double_ended_iterator_methods!(Bucket::key_ref);
+}
+
+impl<T> ExactSizeIterator for Iter<'_, T> {
+    fn len(&self) -> usize {
+        self.iter.len()
+    }
+}
+
+impl<T> FusedIterator for Iter<'_, T> {}
+
+impl<T> Clone for Iter<'_, T> {
+    fn clone(&self) -> Self {
+        Iter {
+            iter: self.iter.clone(),
+        }
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_list().entries(self.clone()).finish()
+    }
+}
+
+impl<T> Default for Iter<'_, T> {
+    fn default() -> Self {
+        Self { iter: [].iter() }
+    }
+}
+
+/// An owning iterator over the items of an [`IndexSet`].
+///
+/// This `struct` is created by the [`IndexSet::into_iter`] method
+/// (provided by the [`IntoIterator`] trait). See its documentation for more.
+pub struct IntoIter<T> {
+    iter: vec::IntoIter<Bucket<T>>,
+}
+
+impl<T> IntoIter<T> {
+    pub(super) fn new(entries: Vec<Bucket<T>>) -> Self {
+        Self {
+            iter: entries.into_iter(),
+        }
+    }
+
+    /// Returns a slice of the remaining entries in the iterator.
+    pub fn as_slice(&self) -> &Slice<T> {
+        Slice::from_slice(self.iter.as_slice())
+    }
+}
+
+impl<T> Iterator for IntoIter<T> {
+    type Item = T;
+
+    iterator_methods!(Bucket::key);
+}
+
+impl<T> DoubleEndedIterator for IntoIter<T> {
+    double_ended_iterator_methods!(Bucket::key);
+}
+
+impl<T> ExactSizeIterator for IntoIter<T> {
+    fn len(&self) -> usize {
+        self.iter.len()
+    }
+}
+
+impl<T> FusedIterator for IntoIter<T> {}
+
+impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let iter = self.iter.as_slice().iter().map(Bucket::key_ref);
+        f.debug_list().entries(iter).finish()
+    }
+}
+
+impl<T> Default for IntoIter<T> {
+    fn default() -> Self {
+        Self {
+            iter: Vec::new().into_iter(),
+        }
+    }
+}
+
+/// A draining iterator over the items of an [`IndexSet`].
+///
+/// This `struct` is created by the [`IndexSet::drain`] method.
+/// See its documentation for more.
+pub struct Drain<'a, T> {
+    iter: vec::Drain<'a, Bucket<T>>,
+}
+
+impl<'a, T> Drain<'a, T> {
+    pub(super) fn new(iter: vec::Drain<'a, Bucket<T>>) -> Self {
+        Self { iter }
+    }
+
+    /// Returns a slice of the remaining entries in the iterator.
+    pub fn as_slice(&self) -> &Slice<T> {
+        Slice::from_slice(self.iter.as_slice())
+    }
+}
+
+impl<T> Iterator for Drain<'_, T> {
+    type Item = T;
+
+    iterator_methods!(Bucket::key);
+}
+
+impl<T> DoubleEndedIterator for Drain<'_, T> {
+    double_ended_iterator_methods!(Bucket::key);
+}
+
+impl<T> ExactSizeIterator for Drain<'_, T> {
+    fn len(&self) -> usize {
+        self.iter.len()
+    }
+}
+
+impl<T> FusedIterator for Drain<'_, T> {}
+
+impl<T: fmt::Debug> fmt::Debug for Drain<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let iter = self.iter.as_slice().iter().map(Bucket::key_ref);
+        f.debug_list().entries(iter).finish()
+    }
+}
+
+/// A lazy iterator producing elements in the difference of [`IndexSet`]s.
+///
+/// This `struct` is created by the [`IndexSet::difference`] method.
+/// See its documentation for more.
+pub struct Difference<'a, T, S> {
+    iter: Iter<'a, T>,
+    other: &'a IndexSet<T, S>,
+}
+
+impl<'a, T, S> Difference<'a, T, S> {
+    pub(super) fn new<S1>(set: &'a IndexSet<T, S1>, other: &'a IndexSet<T, S>) -> Self {
+        Self {
+            iter: set.iter(),
+            other,
+        }
+    }
+}
+
+impl<'a, T, S> Iterator for Difference<'a, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        while let Some(item) = self.iter.next() {
+            if !self.other.contains(item) {
+                return Some(item);
+            }
+        }
+        None
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, self.iter.size_hint().1)
+    }
+}
+
+impl<T, S> DoubleEndedIterator for Difference<'_, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        while let Some(item) = self.iter.next_back() {
+            if !self.other.contains(item) {
+                return Some(item);
+            }
+        }
+        None
+    }
+}
+
+impl<T, S> FusedIterator for Difference<'_, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+}
+
+impl<T, S> Clone for Difference<'_, T, S> {
+    fn clone(&self) -> Self {
+        Difference {
+            iter: self.iter.clone(),
+            ..*self
+        }
+    }
+}
+
+impl<T, S> fmt::Debug for Difference<'_, T, S>
+where
+    T: fmt::Debug + Eq + Hash,
+    S: BuildHasher,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_list().entries(self.clone()).finish()
+    }
+}
+
+/// A lazy iterator producing elements in the intersection of [`IndexSet`]s.
+///
+/// This `struct` is created by the [`IndexSet::intersection`] method.
+/// See its documentation for more.
+pub struct Intersection<'a, T, S> {
+    iter: Iter<'a, T>,
+    other: &'a IndexSet<T, S>,
+}
+
+impl<'a, T, S> Intersection<'a, T, S> {
+    pub(super) fn new<S1>(set: &'a IndexSet<T, S1>, other: &'a IndexSet<T, S>) -> Self {
+        Self {
+            iter: set.iter(),
+            other,
+        }
+    }
+}
+
+impl<'a, T, S> Iterator for Intersection<'a, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        while let Some(item) = self.iter.next() {
+            if self.other.contains(item) {
+                return Some(item);
+            }
+        }
+        None
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, self.iter.size_hint().1)
+    }
+}
+
+impl<T, S> DoubleEndedIterator for Intersection<'_, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        while let Some(item) = self.iter.next_back() {
+            if self.other.contains(item) {
+                return Some(item);
+            }
+        }
+        None
+    }
+}
+
+impl<T, S> FusedIterator for Intersection<'_, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+}
+
+impl<T, S> Clone for Intersection<'_, T, S> {
+    fn clone(&self) -> Self {
+        Intersection {
+            iter: self.iter.clone(),
+            ..*self
+        }
+    }
+}
+
+impl<T, S> fmt::Debug for Intersection<'_, T, S>
+where
+    T: fmt::Debug + Eq + Hash,
+    S: BuildHasher,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_list().entries(self.clone()).finish()
+    }
+}
+
+/// A lazy iterator producing elements in the symmetric difference of [`IndexSet`]s.
+///
+/// This `struct` is created by the [`IndexSet::symmetric_difference`] method.
+/// See its documentation for more.
+pub struct SymmetricDifference<'a, T, S1, S2> {
+    iter: Chain<Difference<'a, T, S2>, Difference<'a, T, S1>>,
+}
+
+impl<'a, T, S1, S2> SymmetricDifference<'a, T, S1, S2>
+where
+    T: Eq + Hash,
+    S1: BuildHasher,
+    S2: BuildHasher,
+{
+    pub(super) fn new(set1: &'a IndexSet<T, S1>, set2: &'a IndexSet<T, S2>) -> Self {
+        let diff1 = set1.difference(set2);
+        let diff2 = set2.difference(set1);
+        Self {
+            iter: diff1.chain(diff2),
+        }
+    }
+}
+
+impl<'a, T, S1, S2> Iterator for SymmetricDifference<'a, T, S1, S2>
+where
+    T: Eq + Hash,
+    S1: BuildHasher,
+    S2: BuildHasher,
+{
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter.next()
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
+
+    fn fold<B, F>(self, init: B, f: F) -> B
+    where
+        F: FnMut(B, Self::Item) -> B,
+    {
+        self.iter.fold(init, f)
+    }
+}
+
+impl<T, S1, S2> DoubleEndedIterator for SymmetricDifference<'_, T, S1, S2>
+where
+    T: Eq + Hash,
+    S1: BuildHasher,
+    S2: BuildHasher,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.iter.next_back()
+    }
+
+    fn rfold<B, F>(self, init: B, f: F) -> B
+    where
+        F: FnMut(B, Self::Item) -> B,
+    {
+        self.iter.rfold(init, f)
+    }
+}
+
+impl<T, S1, S2> FusedIterator for SymmetricDifference<'_, T, S1, S2>
+where
+    T: Eq + Hash,
+    S1: BuildHasher,
+    S2: BuildHasher,
+{
+}
+
+impl<T, S1, S2> Clone for SymmetricDifference<'_, T, S1, S2> {
+    fn clone(&self) -> Self {
+        SymmetricDifference {
+            iter: self.iter.clone(),
+        }
+    }
+}
+
+impl<T, S1, S2> fmt::Debug for SymmetricDifference<'_, T, S1, S2>
+where
+    T: fmt::Debug + Eq + Hash,
+    S1: BuildHasher,
+    S2: BuildHasher,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_list().entries(self.clone()).finish()
+    }
+}
+
+/// A lazy iterator producing elements in the union of [`IndexSet`]s.
+///
+/// This `struct` is created by the [`IndexSet::union`] method.
+/// See its documentation for more.
+pub struct Union<'a, T, S> {
+    iter: Chain<Iter<'a, T>, Difference<'a, T, S>>,
+}
+
+impl<'a, T, S> Union<'a, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+    pub(super) fn new<S2>(set1: &'a IndexSet<T, S>, set2: &'a IndexSet<T, S2>) -> Self
+    where
+        S2: BuildHasher,
+    {
+        Self {
+            iter: set1.iter().chain(set2.difference(set1)),
+        }
+    }
+}
+
+impl<'a, T, S> Iterator for Union<'a, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter.next()
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
+
+    fn fold<B, F>(self, init: B, f: F) -> B
+    where
+        F: FnMut(B, Self::Item) -> B,
+    {
+        self.iter.fold(init, f)
+    }
+}
+
+impl<T, S> DoubleEndedIterator for Union<'_, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        self.iter.next_back()
+    }
+
+    fn rfold<B, F>(self, init: B, f: F) -> B
+    where
+        F: FnMut(B, Self::Item) -> B,
+    {
+        self.iter.rfold(init, f)
+    }
+}
+
+impl<T, S> FusedIterator for Union<'_, T, S>
+where
+    T: Eq + Hash,
+    S: BuildHasher,
+{
+}
+
+impl<T, S> Clone for Union<'_, T, S> {
+    fn clone(&self) -> Self {
+        Union {
+            iter: self.iter.clone(),
+        }
+    }
+}
+
+impl<T, S> fmt::Debug for Union<'_, T, S>
+where
+    T: fmt::Debug + Eq + Hash,
+    S: BuildHasher,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_list().entries(self.clone()).finish()
+    }
+}
+
+/// A splicing iterator for `IndexSet`.
+///
+/// This `struct` is created by [`IndexSet::splice()`].
+/// See its documentation for more.
+pub struct Splice<'a, I, T, S>
+where
+    I: Iterator<Item = T>,
+    T: Hash + Eq,
+    S: BuildHasher,
+{
+    iter: crate::map::Splice<'a, UnitValue<I>, T, (), S>,
+}
+
+impl<'a, I, T, S> Splice<'a, I, T, S>
+where
+    I: Iterator<Item = T>,
+    T: Hash + Eq,
+    S: BuildHasher,
+{
+    pub(super) fn new<R>(set: &'a mut IndexSet<T, S>, range: R, replace_with: I) -> Self
+    where
+        R: RangeBounds<usize>,
+    {
+        Self {
+            iter: set.map.splice(range, UnitValue(replace_with)),
+        }
+    }
+}
+
+impl<I, T, S> Iterator for Splice<'_, I, T, S>
+where
+    I: Iterator<Item = T>,
+    T: Hash + Eq,
+    S: BuildHasher,
+{
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        Some(self.iter.next()?.0)
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
+}
+
+impl<I, T, S> DoubleEndedIterator for Splice<'_, I, T, S>
+where
+    I: Iterator<Item = T>,
+    T: Hash + Eq,
+    S: BuildHasher,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        Some(self.iter.next_back()?.0)
+    }
+}
+
+impl<I, T, S> ExactSizeIterator for Splice<'_, I, T, S>
+where
+    I: Iterator<Item = T>,
+    T: Hash + Eq,
+    S: BuildHasher,
+{
+    fn len(&self) -> usize {
+        self.iter.len()
+    }
+}
+
+impl<I, T, S> FusedIterator for Splice<'_, I, T, S>
+where
+    I: Iterator<Item = T>,
+    T: Hash + Eq,
+    S: BuildHasher,
+{
+}
+
+struct UnitValue<I>(I);
+
+impl<I: Iterator> Iterator for UnitValue<I> {
+    type Item = (I::Item, ());
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.0.next().map(|x| (x, ()))
+    }
+}
+
+impl<'a, I, T, S> fmt::Debug for Splice<'a, I, T, S>
+where
+    I: fmt::Debug + Iterator<Item = T>,
+    T: fmt::Debug + Hash + Eq,
+    S: BuildHasher,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&self.iter, f)
+    }
+}
+
+impl<I: fmt::Debug> fmt::Debug for UnitValue<I> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&self.0, f)
+    }
+}
diff --git a/third_party/rust/indexmap/src/set/mutable.rs b/third_party/rust/indexmap/src/set/mutable.rs
new file mode 100644
index 0000000000..20eaa11221
--- /dev/null
+++ b/third_party/rust/indexmap/src/set/mutable.rs
@@ -0,0 +1,86 @@
+use core::hash::{BuildHasher, Hash};
+
+use super::{Equivalent, IndexSet};
+use crate::map::MutableKeys;
+
+/// Opt-in mutable access to [`IndexSet`] values.
+///
+/// These methods expose `&mut T`, mutable references to the value as it is stored
+/// in the set.
+/// You are allowed to modify the values in the set **if the modification
+/// does not change the value’s hash and equality**.
+///
+/// If values are modified erroneously, you can no longer look them up.
+/// This is sound (memory safe) but a logical error hazard (just like
+/// implementing `PartialEq`, `Eq`, or `Hash` incorrectly would be).
+///
+/// `use` this trait to enable its methods for `IndexSet`.
+///
+/// This trait is sealed and cannot be implemented for types outside this crate.
+pub trait MutableValues: private::Sealed {
+    type Value;
+
+    /// Return item index and mutable reference to the value
+    ///
+    /// Computes in **O(1)** time (average).
+    fn get_full_mut2<Q>(&mut self, value: &Q) -> Option<(usize, &mut Self::Value)>
+    where
+        Q: ?Sized + Hash + Equivalent<Self::Value>;
+
+    /// Return mutable reference to the value at an index.
+    ///
+    /// Valid indices are *0 <= index < self.len()*
+    ///
+    /// Computes in **O(1)** time.
+    fn get_index_mut2(&mut self, index: usize) -> Option<&mut Self::Value>;
+
+    /// Scan through each value in the set and keep those where the
+    /// closure `keep` returns `true`.
+    ///
+    /// The values are visited in order, and remaining values keep their order.
+    ///
+    /// Computes in **O(n)** time (average).
+    fn retain2<F>(&mut self, keep: F)
+    where
+        F: FnMut(&mut Self::Value) -> bool;
+}
+
+/// Opt-in mutable access to [`IndexSet`] values.
+///
+/// See [`MutableValues`] for more information.
+impl<T, S> MutableValues for IndexSet<T, S>
+where
+    S: BuildHasher,
+{
+    type Value = T;
+
+    fn get_full_mut2<Q>(&mut self, value: &Q) -> Option<(usize, &mut T)>
+    where
+        Q: ?Sized + Hash + Equivalent<T>,
+    {
+        match self.map.get_full_mut2(value) {
+            Some((index, value, ())) => Some((index, value)),
+            None => None,
+        }
+    }
+
+    fn get_index_mut2(&mut self, index: usize) -> Option<&mut T> {
+        match self.map.get_index_mut2(index) {
+            Some((value, ())) => Some(value),
+            None => None,
+        }
+    }
+
+    fn retain2<F>(&mut self, mut keep: F)
+    where
+        F: FnMut(&mut T) -> bool,
+    {
+        self.map.retain2(move |value, ()| keep(value));
+    }
+}
+
+mod private {
+    pub trait Sealed {}
+
+    impl<T, S> Sealed for super::IndexSet<T, S> {}
+}
diff --git a/third_party/rust/indexmap/src/set/slice.rs b/third_party/rust/indexmap/src/set/slice.rs
new file mode 100644
index 0000000000..9fc208c706
--- /dev/null
+++ b/third_party/rust/indexmap/src/set/slice.rs
@@ -0,0 +1,340 @@
+use super::{Bucket, Entries, IndexSet, IntoIter, Iter};
+use crate::util::try_simplify_range;
+
+use alloc::boxed::Box;
+use alloc::vec::Vec;
+use core::cmp::Ordering;
+use core::fmt;
+use core::hash::{Hash, Hasher};
+use core::ops::{self, Bound, Index, RangeBounds};
+
+/// A dynamically-sized slice of values in an [`IndexSet`].
+///
+/// This supports indexed operations much like a `[T]` slice,
+/// but not any hashed operations on the values.
+///
+/// Unlike `IndexSet`, `Slice` does consider the order for [`PartialEq`]
+/// and [`Eq`], and it also implements [`PartialOrd`], [`Ord`], and [`Hash`].
+#[repr(transparent)]
+pub struct Slice<T> {
+    pub(crate) entries: [Bucket<T>],
+}
+
+// SAFETY: `Slice<T>` is a transparent wrapper around `[Bucket<T>]`,
+// and reference lifetimes are bound together in function signatures.
+#[allow(unsafe_code)]
+impl<T> Slice<T> {
+    pub(super) const fn from_slice(entries: &[Bucket<T>]) -> &Self {
+        unsafe { &*(entries as *const [Bucket<T>] as *const Self) }
+    }
+
+    pub(super) fn from_boxed(entries: Box<[Bucket<T>]>) -> Box<Self> {
+        unsafe { Box::from_raw(Box::into_raw(entries) as *mut Self) }
+    }
+
+    fn into_boxed(self: Box<Self>) -> Box<[Bucket<T>]> {
+        unsafe { Box::from_raw(Box::into_raw(self) as *mut [Bucket<T>]) }
+    }
+}
+
+impl<T> Slice<T> {
+    pub(crate) fn into_entries(self: Box<Self>) -> Vec<Bucket<T>> {
+        self.into_boxed().into_vec()
+    }
+
+    /// Returns an empty slice.
+    pub const fn new<'a>() -> &'a Self {
+        Self::from_slice(&[])
+    }
+
+    /// Return the number of elements in the set slice.
+    pub const fn len(&self) -> usize {
+        self.entries.len()
+    }
+
+    /// Returns true if the set slice contains no elements.
+    pub const fn is_empty(&self) -> bool {
+        self.entries.is_empty()
+    }
+
+    /// Get a value by index.
+    ///
+    /// Valid indices are *0 <= index < self.len()*
+    pub fn get_index(&self, index: usize) -> Option<&T> {
+        self.entries.get(index).map(Bucket::key_ref)
+    }
+
+    /// Returns a slice of values in the given range of indices.
+    ///
+    /// Valid indices are *0 <= index < self.len()*
+    pub fn get_range<R: RangeBounds<usize>>(&self, range: R) -> Option<&Self> {
+        let range = try_simplify_range(range, self.entries.len())?;
+        self.entries.get(range).map(Self::from_slice)
+    }
+
+    /// Get the first value.
+    pub fn first(&self) -> Option<&T> {
+        self.entries.first().map(Bucket::key_ref)
+    }
+
+    /// Get the last value.
+    pub fn last(&self) -> Option<&T> {
+        self.entries.last().map(Bucket::key_ref)
+    }
+
+    /// Divides one slice into two at an index.
+    ///
+    /// ***Panics*** if `index > len`.
+    pub fn split_at(&self, index: usize) -> (&Self, &Self) {
+        let (first, second) = self.entries.split_at(index);
+        (Self::from_slice(first), Self::from_slice(second))
+    }
+
+    /// Returns the first value and the rest of the slice,
+    /// or `None` if it is empty.
+    pub fn split_first(&self) -> Option<(&T, &Self)> {
+        if let [first, rest @ ..] = &self.entries {
+            Some((&first.key, Self::from_slice(rest)))
+        } else {
+            None
+        }
+    }
+
+    /// Returns the last value and the rest of the slice,
+    /// or `None` if it is empty.
+    pub fn split_last(&self) -> Option<(&T, &Self)> {
+        if let [rest @ .., last] = &self.entries {
+            Some((&last.key, Self::from_slice(rest)))
+        } else {
+            None
+        }
+    }
+
+    /// Return an iterator over the values of the set slice.
+    pub fn iter(&self) -> Iter<'_, T> {
+        Iter::new(&self.entries)
+    }
+
+    /// Search over a sorted set for a value.
+    ///
+    /// Returns the position where that value is present, or the position where it can be inserted
+    /// to maintain the sort. See [`slice::binary_search`] for more details.
+    ///
+    /// Computes in **O(log(n))** time, which is notably less scalable than looking the value up in
+    /// the set this is a slice from using [`IndexSet::get_index_of`], but this can also position
+    /// missing values.
+    pub fn binary_search(&self, x: &T) -> Result<usize, usize>
+    where
+        T: Ord,
+    {
+        self.binary_search_by(|p| p.cmp(x))
+    }
+
+    /// Search over a sorted set with a comparator function.
+    ///
+    /// Returns the position where that value is present, or the position where it can be inserted
+    /// to maintain the sort. See [`slice::binary_search_by`] for more details.
+    ///
+    /// Computes in **O(log(n))** time.
+    #[inline]
+    pub fn binary_search_by<'a, F>(&'a self, mut f: F) -> Result<usize, usize>
+    where
+        F: FnMut(&'a T) -> Ordering,
+    {
+        self.entries.binary_search_by(move |a| f(&a.key))
+    }
+
+    /// Search over a sorted set with an extraction function.
+    ///
+    /// Returns the position where that value is present, or the position where it can be inserted
+    /// to maintain the sort. See [`slice::binary_search_by_key`] for more details.
+    ///
+    /// Computes in **O(log(n))** time.
+    #[inline]
+    pub fn binary_search_by_key<'a, B, F>(&'a self, b: &B, mut f: F) -> Result<usize, usize>
+    where
+        F: FnMut(&'a T) -> B,
+        B: Ord,
+    {
+        self.binary_search_by(|k| f(k).cmp(b))
+    }
+
+    /// Returns the index of the partition point of a sorted set according to the given predicate
+    /// (the index of the first element of the second partition).
+    ///
+    /// See [`slice::partition_point`] for more details.
+    ///
+    /// Computes in **O(log(n))** time.
+    #[must_use]
+    pub fn partition_point<P>(&self, mut pred: P) -> usize
+    where
+        P: FnMut(&T) -> bool,
+    {
+        self.entries.partition_point(move |a| pred(&a.key))
+    }
+}
+
+impl<'a, T> IntoIterator for &'a Slice<T> {
+    type IntoIter = Iter<'a, T>;
+    type Item = &'a T;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+
+impl<T> IntoIterator for Box<Slice<T>> {
+    type IntoIter = IntoIter<T>;
+    type Item = T;
+
+    fn into_iter(self) -> Self::IntoIter {
+        IntoIter::new(self.into_entries())
+    }
+}
+
+impl<T> Default for &'_ Slice<T> {
+    fn default() -> Self {
+        Slice::from_slice(&[])
+    }
+}
+
+impl<T> Default for Box<Slice<T>> {
+    fn default() -> Self {
+        Slice::from_boxed(Box::default())
+    }
+}
+
+impl<T: Clone> Clone for Box<Slice<T>> {
+    fn clone(&self) -> Self {
+        Slice::from_boxed(self.entries.to_vec().into_boxed_slice())
+    }
+}
+
+impl<T: Copy> From<&Slice<T>> for Box<Slice<T>> {
+    fn from(slice: &Slice<T>) -> Self {
+        Slice::from_boxed(Box::from(&slice.entries))
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for Slice<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_list().entries(self).finish()
+    }
+}
+
+impl<T: PartialEq> PartialEq for Slice<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.len() == other.len() && self.iter().eq(other)
+    }
+}
+
+impl<T: Eq> Eq for Slice<T> {}
+
+impl<T: PartialOrd> PartialOrd for Slice<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        self.iter().partial_cmp(other)
+    }
+}
+
+impl<T: Ord> Ord for Slice<T> {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.iter().cmp(other)
+    }
+}
+
+impl<T: Hash> Hash for Slice<T> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.len().hash(state);
+        for value in self {
+            value.hash(state);
+        }
+    }
+}
+
+impl<T> Index<usize> for Slice<T> {
+    type Output = T;
+
+    fn index(&self, index: usize) -> &Self::Output {
+        &self.entries[index].key
+    }
+}
+
+// We can't have `impl<I: RangeBounds<usize>> Index<I>` because that conflicts with `Index<usize>`.
+// Instead, we repeat the implementations for all the core range types.
+macro_rules! impl_index {
+    ($($range:ty),*) => {$(
+        impl<T, S> Index<$range> for IndexSet<T, S> {
+            type Output = Slice<T>;
+
+            fn index(&self, range: $range) -> &Self::Output {
+                Slice::from_slice(&self.as_entries()[range])
+            }
+        }
+
+        impl<T> Index<$range> for Slice<T> {
+            type Output = Self;
+
+            fn index(&self, range: $range) -> &Self::Output {
+                Slice::from_slice(&self.entries[range])
+            }
+        }
+    )*}
+}
+impl_index!(
+    ops::Range<usize>,
+    ops::RangeFrom<usize>,
+    ops::RangeFull,
+    ops::RangeInclusive<usize>,
+    ops::RangeTo<usize>,
+    ops::RangeToInclusive<usize>,
+    (Bound<usize>, Bound<usize>)
+);
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn slice_index() {
+        fn check(vec_slice: &[i32], set_slice: &Slice<i32>, sub_slice: &Slice<i32>) {
+            assert_eq!(set_slice as *const _, sub_slice as *const _);
+            itertools::assert_equal(vec_slice, set_slice);
+        }
+
+        let vec: Vec<i32> = (0..10).map(|i| i * i).collect();
+        let set: IndexSet<i32> = vec.iter().cloned().collect();
+        let slice = set.as_slice();
+
+        // RangeFull
+        check(&vec[..], &set[..], &slice[..]);
+
+        for i in 0usize..10 {
+            // Index
+            assert_eq!(vec[i], set[i]);
+            assert_eq!(vec[i], slice[i]);
+
+            // RangeFrom
+            check(&vec[i..], &set[i..], &slice[i..]);
+
+            // RangeTo
+            check(&vec[..i], &set[..i], &slice[..i]);
+
+            // RangeToInclusive
+            check(&vec[..=i], &set[..=i], &slice[..=i]);
+
+            // (Bound<usize>, Bound<usize>)
+            let bounds = (Bound::Excluded(i), Bound::Unbounded);
+            check(&vec[i + 1..], &set[bounds], &slice[bounds]);
+
+            for j in i..=10 {
+                // Range
+                check(&vec[i..j], &set[i..j], &slice[i..j]);
+            }
+
+            for j in i..10 {
+                // RangeInclusive
+                check(&vec[i..=j], &set[i..=j], &slice[i..=j]);
+            }
+        }
+    }
+}
diff --git a/third_party/rust/indexmap/src/set/tests.rs b/third_party/rust/indexmap/src/set/tests.rs
new file mode 100644
index 0000000000..35a076e8de
--- /dev/null
+++ b/third_party/rust/indexmap/src/set/tests.rs
@@ -0,0 +1,723 @@
+use super::*;
+use std::string::String;
+
+#[test]
+fn it_works() {
+    let mut set = IndexSet::new();
+    assert_eq!(set.is_empty(), true);
+    set.insert(1);
+    set.insert(1);
+    assert_eq!(set.len(), 1);
+    assert!(set.get(&1).is_some());
+    assert_eq!(set.is_empty(), false);
+}
+
+#[test]
+fn new() {
+    let set = IndexSet::<String>::new();
+    println!("{:?}", set);
+    assert_eq!(set.capacity(), 0);
+    assert_eq!(set.len(), 0);
+    assert_eq!(set.is_empty(), true);
+}
+
+#[test]
+fn insert() {
+    let insert = [0, 4, 2, 12, 8, 7, 11, 5];
+    let not_present = [1, 3, 6, 9, 10];
+    let mut set = IndexSet::with_capacity(insert.len());
+
+    for (i, &elt) in insert.iter().enumerate() {
+        assert_eq!(set.len(), i);
+        set.insert(elt);
+        assert_eq!(set.len(), i + 1);
+        assert_eq!(set.get(&elt), Some(&elt));
+    }
+    println!("{:?}", set);
+
+    for &elt in &not_present {
+        assert!(set.get(&elt).is_none());
+    }
+}
+
+#[test]
+fn insert_full() {
+    let insert = vec![9, 2, 7, 1, 4, 6, 13];
+    let present = vec![1, 6, 2];
+    let mut set = IndexSet::with_capacity(insert.len());
+
+    for (i, &elt) in insert.iter().enumerate() {
+        assert_eq!(set.len(), i);
+        let (index, success) = set.insert_full(elt);
+        assert!(success);
+        assert_eq!(Some(index), set.get_full(&elt).map(|x| x.0));
+        assert_eq!(set.len(), i + 1);
+    }
+
+    let len = set.len();
+    for &elt in &present {
+        let (index, success) = set.insert_full(elt);
+        assert!(!success);
+        assert_eq!(Some(index), set.get_full(&elt).map(|x| x.0));
+        assert_eq!(set.len(), len);
+    }
+}
+
+#[test]
+fn insert_2() {
+    let mut set = IndexSet::with_capacity(16);
+
+    let mut values = vec![];
+    values.extend(0..16);
+    values.extend(if cfg!(miri) { 32..64 } else { 128..267 });
+
+    for &i in &values {
+        let old_set = set.clone();
+        set.insert(i);
+        for value in old_set.iter() {
+            if set.get(value).is_none() {
+                println!("old_set: {:?}", old_set);
+                println!("set: {:?}", set);
+                panic!("did not find {} in set", value);
+            }
+        }
+    }
+
+    for &i in &values {
+        assert!(set.get(&i).is_some(), "did not find {}", i);
+    }
+}
+
+#[test]
+fn insert_dup() {
+    let mut elements = vec![0, 2, 4, 6, 8];
+    let mut set: IndexSet<u8> = elements.drain(..).collect();
+    {
+        let (i, v) = set.get_full(&0).unwrap();
+        assert_eq!(set.len(), 5);
+        assert_eq!(i, 0);
+        assert_eq!(*v, 0);
+    }
+    {
+        let inserted = set.insert(0);
+        let (i, v) = set.get_full(&0).unwrap();
+        assert_eq!(set.len(), 5);
+        assert_eq!(inserted, false);
+        assert_eq!(i, 0);
+        assert_eq!(*v, 0);
+    }
+}
+
+#[test]
+fn insert_order() {
+    let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
+    let mut set = IndexSet::new();
+
+    for &elt in &insert {
+        set.insert(elt);
+    }
+
+    assert_eq!(set.iter().count(), set.len());
+    assert_eq!(set.iter().count(), insert.len());
+    for (a, b) in insert.iter().zip(set.iter()) {
+        assert_eq!(a, b);
+    }
+    for (i, v) in (0..insert.len()).zip(set.iter()) {
+        assert_eq!(set.get_index(i).unwrap(), v);
+    }
+}
+
+#[test]
+fn shift_insert() {
+    let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
+    let mut set = IndexSet::new();
+
+    for &elt in &insert {
+        set.shift_insert(0, elt);
+    }
+
+    assert_eq!(set.iter().count(), set.len());
+    assert_eq!(set.iter().count(), insert.len());
+    for (a, b) in insert.iter().rev().zip(set.iter()) {
+        assert_eq!(a, b);
+    }
+    for (i, v) in (0..insert.len()).zip(set.iter()) {
+        assert_eq!(set.get_index(i).unwrap(), v);
+    }
+
+    // "insert" that moves an existing entry
+    set.shift_insert(0, insert[0]);
+    assert_eq!(set.iter().count(), insert.len());
+    assert_eq!(insert[0], set[0]);
+    for (a, b) in insert[1..].iter().rev().zip(set.iter().skip(1)) {
+        assert_eq!(a, b);
+    }
+}
+
+#[test]
+fn replace() {
+    let replace = [0, 4, 2, 12, 8, 7, 11, 5];
+    let not_present = [1, 3, 6, 9, 10];
+    let mut set = IndexSet::with_capacity(replace.len());
+
+    for (i, &elt) in replace.iter().enumerate() {
+        assert_eq!(set.len(), i);
+        set.replace(elt);
+        assert_eq!(set.len(), i + 1);
+        assert_eq!(set.get(&elt), Some(&elt));
+    }
+    println!("{:?}", set);
+
+    for &elt in &not_present {
+        assert!(set.get(&elt).is_none());
+    }
+}
+
+#[test]
+fn replace_full() {
+    let replace = vec![9, 2, 7, 1, 4, 6, 13];
+    let present = vec![1, 6, 2];
+    let mut set = IndexSet::with_capacity(replace.len());
+
+    for (i, &elt) in replace.iter().enumerate() {
+        assert_eq!(set.len(), i);
+        let (index, replaced) = set.replace_full(elt);
+        assert!(replaced.is_none());
+        assert_eq!(Some(index), set.get_full(&elt).map(|x| x.0));
+        assert_eq!(set.len(), i + 1);
+    }
+
+    let len = set.len();
+    for &elt in &present {
+        let (index, replaced) = set.replace_full(elt);
+        assert_eq!(Some(elt), replaced);
+        assert_eq!(Some(index), set.get_full(&elt).map(|x| x.0));
+        assert_eq!(set.len(), len);
+    }
+}
+
+#[test]
+fn replace_2() {
+    let mut set = IndexSet::with_capacity(16);
+
+    let mut values = vec![];
+    values.extend(0..16);
+    values.extend(if cfg!(miri) { 32..64 } else { 128..267 });
+
+    for &i in &values {
+        let old_set = set.clone();
+        set.replace(i);
+        for value in old_set.iter() {
+            if set.get(value).is_none() {
+                println!("old_set: {:?}", old_set);
+                println!("set: {:?}", set);
+                panic!("did not find {} in set", value);
+            }
+        }
+    }
+
+    for &i in &values {
+        assert!(set.get(&i).is_some(), "did not find {}", i);
+    }
+}
+
+#[test]
+fn replace_dup() {
+    let mut elements = vec![0, 2, 4, 6, 8];
+    let mut set: IndexSet<u8> = elements.drain(..).collect();
+    {
+        let (i, v) = set.get_full(&0).unwrap();
+        assert_eq!(set.len(), 5);
+        assert_eq!(i, 0);
+        assert_eq!(*v, 0);
+    }
+    {
+        let replaced = set.replace(0);
+        let (i, v) = set.get_full(&0).unwrap();
+        assert_eq!(set.len(), 5);
+        assert_eq!(replaced, Some(0));
+        assert_eq!(i, 0);
+        assert_eq!(*v, 0);
+    }
+}
+
+#[test]
+fn replace_order() {
+    let replace = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
+    let mut set = IndexSet::new();
+
+    for &elt in &replace {
+        set.replace(elt);
+    }
+
+    assert_eq!(set.iter().count(), set.len());
+    assert_eq!(set.iter().count(), replace.len());
+    for (a, b) in replace.iter().zip(set.iter()) {
+        assert_eq!(a, b);
+    }
+    for (i, v) in (0..replace.len()).zip(set.iter()) {
+        assert_eq!(set.get_index(i).unwrap(), v);
+    }
+}
+
+#[test]
+fn replace_change() {
+    // Check pointers to make sure it really changes
+    let mut set = indexset!(vec![42]);
+    let old_ptr = set[0].as_ptr();
+    let new = set[0].clone();
+    let new_ptr = new.as_ptr();
+    assert_ne!(old_ptr, new_ptr);
+    let replaced = set.replace(new).unwrap();
+    assert_eq!(replaced.as_ptr(), old_ptr);
+}
+
+#[test]
+fn grow() {
+    let insert = [0, 4, 2, 12, 8, 7, 11];
+    let not_present = [1, 3, 6, 9, 10];
+    let mut set = IndexSet::with_capacity(insert.len());
+
+    for (i, &elt) in insert.iter().enumerate() {
+        assert_eq!(set.len(), i);
+        set.insert(elt);
+        assert_eq!(set.len(), i + 1);
+        assert_eq!(set.get(&elt), Some(&elt));
+    }
+
+    println!("{:?}", set);
+    for &elt in &insert {
+        set.insert(elt * 10);
+    }
+    for &elt in &insert {
+        set.insert(elt * 100);
+    }
+    for (i, &elt) in insert.iter().cycle().enumerate().take(100) {
+        set.insert(elt * 100 + i as i32);
+    }
+    println!("{:?}", set);
+    for &elt in &not_present {
+        assert!(set.get(&elt).is_none());
+    }
+}
+
+#[test]
+fn reserve() {
+    let mut set = IndexSet::<usize>::new();
+    assert_eq!(set.capacity(), 0);
+    set.reserve(100);
+    let capacity = set.capacity();
+    assert!(capacity >= 100);
+    for i in 0..capacity {
+        assert_eq!(set.len(), i);
+        set.insert(i);
+        assert_eq!(set.len(), i + 1);
+        assert_eq!(set.capacity(), capacity);
+        assert_eq!(set.get(&i), Some(&i));
+    }
+    set.insert(capacity);
+    assert_eq!(set.len(), capacity + 1);
+    assert!(set.capacity() > capacity);
+    assert_eq!(set.get(&capacity), Some(&capacity));
+}
+
+#[test]
+fn try_reserve() {
+    let mut set = IndexSet::<usize>::new();
+    assert_eq!(set.capacity(), 0);
+    assert_eq!(set.try_reserve(100), Ok(()));
+    assert!(set.capacity() >= 100);
+    assert!(set.try_reserve(usize::MAX).is_err());
+}
+
+#[test]
+fn shrink_to_fit() {
+    let mut set = IndexSet::<usize>::new();
+    assert_eq!(set.capacity(), 0);
+    for i in 0..100 {
+        assert_eq!(set.len(), i);
+        set.insert(i);
+        assert_eq!(set.len(), i + 1);
+        assert!(set.capacity() >= i + 1);
+        assert_eq!(set.get(&i), Some(&i));
+        set.shrink_to_fit();
+        assert_eq!(set.len(), i + 1);
+        assert_eq!(set.capacity(), i + 1);
+        assert_eq!(set.get(&i), Some(&i));
+    }
+}
+
+#[test]
+fn remove() {
+    let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
+    let mut set = IndexSet::new();
+
+    for &elt in &insert {
+        set.insert(elt);
+    }
+
+    assert_eq!(set.iter().count(), set.len());
+    assert_eq!(set.iter().count(), insert.len());
+    for (a, b) in insert.iter().zip(set.iter()) {
+        assert_eq!(a, b);
+    }
+
+    let remove_fail = [99, 77];
+    let remove = [4, 12, 8, 7];
+
+    for &value in &remove_fail {
+        assert!(set.swap_remove_full(&value).is_none());
+    }
+    println!("{:?}", set);
+    for &value in &remove {
+        //println!("{:?}", set);
+        let index = set.get_full(&value).unwrap().0;
+        assert_eq!(set.swap_remove_full(&value), Some((index, value)));
+    }
+    println!("{:?}", set);
+
+    for value in &insert {
+        assert_eq!(set.get(value).is_some(), !remove.contains(value));
+    }
+    assert_eq!(set.len(), insert.len() - remove.len());
+    assert_eq!(set.iter().count(), insert.len() - remove.len());
+}
+
+#[test]
+fn swap_remove_index() {
+    let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
+    let mut set = IndexSet::new();
+
+    for &elt in &insert {
+        set.insert(elt);
+    }
+
+    let mut vector = insert.to_vec();
+    let remove_sequence = &[3, 3, 10, 4, 5, 4, 3, 0, 1];
+
+    // check that the same swap remove sequence on vec and set
+    // have the same result.
+    for &rm in remove_sequence {
+        let out_vec = vector.swap_remove(rm);
+        let out_set = set.swap_remove_index(rm).unwrap();
+        assert_eq!(out_vec, out_set);
+    }
+    assert_eq!(vector.len(), set.len());
+    for (a, b) in vector.iter().zip(set.iter()) {
+        assert_eq!(a, b);
+    }
+}
+
+#[test]
+fn partial_eq_and_eq() {
+    let mut set_a = IndexSet::new();
+    set_a.insert(1);
+    set_a.insert(2);
+    let mut set_b = set_a.clone();
+    assert_eq!(set_a, set_b);
+    set_b.swap_remove(&1);
+    assert_ne!(set_a, set_b);
+
+    let set_c: IndexSet<_> = set_b.into_iter().collect();
+    assert_ne!(set_a, set_c);
+    assert_ne!(set_c, set_a);
+}
+
+#[test]
+fn extend() {
+    let mut set = IndexSet::new();
+    set.extend(vec![&1, &2, &3, &4]);
+    set.extend(vec![5, 6]);
+    assert_eq!(set.into_iter().collect::<Vec<_>>(), vec![1, 2, 3, 4, 5, 6]);
+}
+
+#[test]
+fn comparisons() {
+    let set_a: IndexSet<_> = (0..3).collect();
+    let set_b: IndexSet<_> = (3..6).collect();
+    let set_c: IndexSet<_> = (0..6).collect();
+    let set_d: IndexSet<_> = (3..9).collect();
+
+    assert!(!set_a.is_disjoint(&set_a));
+    assert!(set_a.is_subset(&set_a));
+    assert!(set_a.is_superset(&set_a));
+
+    assert!(set_a.is_disjoint(&set_b));
+    assert!(set_b.is_disjoint(&set_a));
+    assert!(!set_a.is_subset(&set_b));
+    assert!(!set_b.is_subset(&set_a));
+    assert!(!set_a.is_superset(&set_b));
+    assert!(!set_b.is_superset(&set_a));
+
+    assert!(!set_a.is_disjoint(&set_c));
+    assert!(!set_c.is_disjoint(&set_a));
+    assert!(set_a.is_subset(&set_c));
+    assert!(!set_c.is_subset(&set_a));
+    assert!(!set_a.is_superset(&set_c));
+    assert!(set_c.is_superset(&set_a));
+
+    assert!(!set_c.is_disjoint(&set_d));
+    assert!(!set_d.is_disjoint(&set_c));
+    assert!(!set_c.is_subset(&set_d));
+    assert!(!set_d.is_subset(&set_c));
+    assert!(!set_c.is_superset(&set_d));
+    assert!(!set_d.is_superset(&set_c));
+}
+
+#[test]
+fn iter_comparisons() {
+    use std::iter::empty;
+
+    fn check<'a, I1, I2>(iter1: I1, iter2: I2)
+    where
+        I1: Iterator<Item = &'a i32>,
+        I2: Iterator<Item = i32>,
+    {
+        assert!(iter1.copied().eq(iter2));
+    }
+
+    let set_a: IndexSet<_> = (0..3).collect();
+    let set_b: IndexSet<_> = (3..6).collect();
+    let set_c: IndexSet<_> = (0..6).collect();
+    let set_d: IndexSet<_> = (3..9).rev().collect();
+
+    check(set_a.difference(&set_a), empty());
+    check(set_a.symmetric_difference(&set_a), empty());
+    check(set_a.intersection(&set_a), 0..3);
+    check(set_a.union(&set_a), 0..3);
+
+    check(set_a.difference(&set_b), 0..3);
+    check(set_b.difference(&set_a), 3..6);
+    check(set_a.symmetric_difference(&set_b), 0..6);
+    check(set_b.symmetric_difference(&set_a), (3..6).chain(0..3));
+    check(set_a.intersection(&set_b), empty());
+    check(set_b.intersection(&set_a), empty());
+    check(set_a.union(&set_b), 0..6);
+    check(set_b.union(&set_a), (3..6).chain(0..3));
+
+    check(set_a.difference(&set_c), empty());
+    check(set_c.difference(&set_a), 3..6);
+    check(set_a.symmetric_difference(&set_c), 3..6);
+    check(set_c.symmetric_difference(&set_a), 3..6);
+    check(set_a.intersection(&set_c), 0..3);
+    check(set_c.intersection(&set_a), 0..3);
+    check(set_a.union(&set_c), 0..6);
+    check(set_c.union(&set_a), 0..6);
+
+    check(set_c.difference(&set_d), 0..3);
+    check(set_d.difference(&set_c), (6..9).rev());
+    check(
+        set_c.symmetric_difference(&set_d),
+        (0..3).chain((6..9).rev()),
+    );
+    check(set_d.symmetric_difference(&set_c), (6..9).rev().chain(0..3));
+    check(set_c.intersection(&set_d), 3..6);
+    check(set_d.intersection(&set_c), (3..6).rev());
+    check(set_c.union(&set_d), (0..6).chain((6..9).rev()));
+    check(set_d.union(&set_c), (3..9).rev().chain(0..3));
+}
+
+#[test]
+fn ops() {
+    let empty = IndexSet::<i32>::new();
+    let set_a: IndexSet<_> = (0..3).collect();
+    let set_b: IndexSet<_> = (3..6).collect();
+    let set_c: IndexSet<_> = (0..6).collect();
+    let set_d: IndexSet<_> = (3..9).rev().collect();
+
+    #[allow(clippy::eq_op)]
+    {
+        assert_eq!(&set_a & &set_a, set_a);
+        assert_eq!(&set_a | &set_a, set_a);
+        assert_eq!(&set_a ^ &set_a, empty);
+        assert_eq!(&set_a - &set_a, empty);
+    }
+
+    assert_eq!(&set_a & &set_b, empty);
+    assert_eq!(&set_b & &set_a, empty);
+    assert_eq!(&set_a | &set_b, set_c);
+    assert_eq!(&set_b | &set_a, set_c);
+    assert_eq!(&set_a ^ &set_b, set_c);
+    assert_eq!(&set_b ^ &set_a, set_c);
+    assert_eq!(&set_a - &set_b, set_a);
+    assert_eq!(&set_b - &set_a, set_b);
+
+    assert_eq!(&set_a & &set_c, set_a);
+    assert_eq!(&set_c & &set_a, set_a);
+    assert_eq!(&set_a | &set_c, set_c);
+    assert_eq!(&set_c | &set_a, set_c);
+    assert_eq!(&set_a ^ &set_c, set_b);
+    assert_eq!(&set_c ^ &set_a, set_b);
+    assert_eq!(&set_a - &set_c, empty);
+    assert_eq!(&set_c - &set_a, set_b);
+
+    assert_eq!(&set_c & &set_d, set_b);
+    assert_eq!(&set_d & &set_c, set_b);
+    assert_eq!(&set_c | &set_d, &set_a | &set_d);
+    assert_eq!(&set_d | &set_c, &set_a | &set_d);
+    assert_eq!(&set_c ^ &set_d, &set_a | &(&set_d - &set_b));
+    assert_eq!(&set_d ^ &set_c, &set_a | &(&set_d - &set_b));
+    assert_eq!(&set_c - &set_d, set_a);
+    assert_eq!(&set_d - &set_c, &set_d - &set_b);
+}
+
+#[test]
+#[cfg(feature = "std")]
+fn from_array() {
+    let set1 = IndexSet::from([1, 2, 3, 4]);
+    let set2: IndexSet<_> = [1, 2, 3, 4].into();
+
+    assert_eq!(set1, set2);
+}
+
+#[test]
+fn iter_default() {
+    struct Item;
+    fn assert_default<T>()
+    where
+        T: Default + Iterator,
+    {
+        assert!(T::default().next().is_none());
+    }
+    assert_default::<Iter<'static, Item>>();
+    assert_default::<IntoIter<Item>>();
+}
+
+#[test]
+fn test_binary_search_by() {
+    // adapted from std's test for binary_search
+    let b: IndexSet<i32> = [].into();
+    assert_eq!(b.binary_search_by(|x| x.cmp(&5)), Err(0));
+
+    let b: IndexSet<i32> = [4].into();
+    assert_eq!(b.binary_search_by(|x| x.cmp(&3)), Err(0));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&4)), Ok(0));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&5)), Err(1));
+
+    let b: IndexSet<i32> = [1, 2, 4, 6, 8, 9].into();
+    assert_eq!(b.binary_search_by(|x| x.cmp(&5)), Err(3));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&6)), Ok(3));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&7)), Err(4));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&8)), Ok(4));
+
+    let b: IndexSet<i32> = [1, 2, 4, 5, 6, 8].into();
+    assert_eq!(b.binary_search_by(|x| x.cmp(&9)), Err(6));
+
+    let b: IndexSet<i32> = [1, 2, 4, 6, 7, 8, 9].into();
+    assert_eq!(b.binary_search_by(|x| x.cmp(&6)), Ok(3));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&5)), Err(3));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&8)), Ok(5));
+
+    let b: IndexSet<i32> = [1, 2, 4, 5, 6, 8, 9].into();
+    assert_eq!(b.binary_search_by(|x| x.cmp(&7)), Err(5));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&0)), Err(0));
+
+    let b: IndexSet<i32> = [1, 3, 3, 3, 7].into();
+    assert_eq!(b.binary_search_by(|x| x.cmp(&0)), Err(0));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&1)), Ok(0));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&2)), Err(1));
+    // diff from std as set merges the duplicate keys
+    assert!(match b.binary_search_by(|x| x.cmp(&3)) {
+        Ok(1..=2) => true,
+        _ => false,
+    });
+    assert!(match b.binary_search_by(|x| x.cmp(&3)) {
+        Ok(1..=2) => true,
+        _ => false,
+    });
+    assert_eq!(b.binary_search_by(|x| x.cmp(&4)), Err(2));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&5)), Err(2));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&6)), Err(2));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&7)), Ok(2));
+    assert_eq!(b.binary_search_by(|x| x.cmp(&8)), Err(3));
+}
+
+#[test]
+fn test_binary_search_by_key() {
+    // adapted from std's test for binary_search
+    let b: IndexSet<i32> = [].into();
+    assert_eq!(b.binary_search_by_key(&5, |&x| x), Err(0));
+
+    let b: IndexSet<i32> = [4].into();
+    assert_eq!(b.binary_search_by_key(&3, |&x| x), Err(0));
+    assert_eq!(b.binary_search_by_key(&4, |&x| x), Ok(0));
+    assert_eq!(b.binary_search_by_key(&5, |&x| x), Err(1));
+
+    let b: IndexSet<i32> = [1, 2, 4, 6, 8, 9].into();
+    assert_eq!(b.binary_search_by_key(&5, |&x| x), Err(3));
+    assert_eq!(b.binary_search_by_key(&6, |&x| x), Ok(3));
+    assert_eq!(b.binary_search_by_key(&7, |&x| x), Err(4));
+    assert_eq!(b.binary_search_by_key(&8, |&x| x), Ok(4));
+
+    let b: IndexSet<i32> = [1, 2, 4, 5, 6, 8].into();
+    assert_eq!(b.binary_search_by_key(&9, |&x| x), Err(6));
+
+    let b: IndexSet<i32> = [1, 2, 4, 6, 7, 8, 9].into();
+    assert_eq!(b.binary_search_by_key(&6, |&x| x), Ok(3));
+    assert_eq!(b.binary_search_by_key(&5, |&x| x), Err(3));
+    assert_eq!(b.binary_search_by_key(&8, |&x| x), Ok(5));
+
+    let b: IndexSet<i32> = [1, 2, 4, 5, 6, 8, 9].into();
+    assert_eq!(b.binary_search_by_key(&7, |&x| x), Err(5));
+    assert_eq!(b.binary_search_by_key(&0, |&x| x), Err(0));
+
+    let b: IndexSet<i32> = [1, 3, 3, 3, 7].into();
+    assert_eq!(b.binary_search_by_key(&0, |&x| x), Err(0));
+    assert_eq!(b.binary_search_by_key(&1, |&x| x), Ok(0));
+    assert_eq!(b.binary_search_by_key(&2, |&x| x), Err(1));
+    // diff from std as set merges the duplicate keys
+    assert!(match b.binary_search_by_key(&3, |&x| x) {
+        Ok(1..=2) => true,
+        _ => false,
+    });
+    assert!(match b.binary_search_by_key(&3, |&x| x) {
+        Ok(1..=2) => true,
+        _ => false,
+    });
+    assert_eq!(b.binary_search_by_key(&4, |&x| x), Err(2));
+    assert_eq!(b.binary_search_by_key(&5, |&x| x), Err(2));
+    assert_eq!(b.binary_search_by_key(&6, |&x| x), Err(2));
+    assert_eq!(b.binary_search_by_key(&7, |&x| x), Ok(2));
+    assert_eq!(b.binary_search_by_key(&8, |&x| x), Err(3));
+}
+
+#[test]
+fn test_partition_point() {
+    // adapted from std's test for partition_point
+    let b: IndexSet<i32> = [].into();
+    assert_eq!(b.partition_point(|&x| x < 5), 0);
+
+    let b: IndexSet<_> = [4].into();
+    assert_eq!(b.partition_point(|&x| x < 3), 0);
+    assert_eq!(b.partition_point(|&x| x < 4), 0);
+    assert_eq!(b.partition_point(|&x| x < 5), 1);
+
+    let b: IndexSet<_> = [1, 2, 4, 6, 8, 9].into();
+    assert_eq!(b.partition_point(|&x| x < 5), 3);
+    assert_eq!(b.partition_point(|&x| x < 6), 3);
+    assert_eq!(b.partition_point(|&x| x < 7), 4);
+    assert_eq!(b.partition_point(|&x| x < 8), 4);
+
+    let b: IndexSet<_> = [1, 2, 4, 5, 6, 8].into();
+    assert_eq!(b.partition_point(|&x| x < 9), 6);
+
+    let b: IndexSet<_> = [1, 2, 4, 6, 7, 8, 9].into();
+    assert_eq!(b.partition_point(|&x| x < 6), 3);
+    assert_eq!(b.partition_point(|&x| x < 5), 3);
+    assert_eq!(b.partition_point(|&x| x < 8), 5);
+
+    let b: IndexSet<_> = [1, 2, 4, 5, 6, 8, 9].into();
+    assert_eq!(b.partition_point(|&x| x < 7), 5);
+    assert_eq!(b.partition_point(|&x| x < 0), 0);
+
+    let b: IndexSet<_> = [1, 3, 3, 3, 7].into();
+    assert_eq!(b.partition_point(|&x| x < 0), 0);
+    assert_eq!(b.partition_point(|&x| x < 1), 0);
+    assert_eq!(b.partition_point(|&x| x < 2), 1);
+    assert_eq!(b.partition_point(|&x| x < 3), 1);
+    assert_eq!(b.partition_point(|&x| x < 4), 2); // diff from std as set merges the duplicate keys
+    assert_eq!(b.partition_point(|&x| x < 5), 2);
+    assert_eq!(b.partition_point(|&x| x < 6), 2);
+    assert_eq!(b.partition_point(|&x| x < 7), 2);
+    assert_eq!(b.partition_point(|&x| x < 8), 3);
+}