/rust/registry/src/index.crates.io-1949cf8c6b5b557f/indexmap-2.13.0/src/set/slice.rs

Source
use super::{Bucket, IndexSet, IntoIter, Iter};
use crate::util::{slice_eq, 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`.
    /// For a non-panicking alternative see [`split_at_checked`][Self::split_at_checked].
    #[track_caller]
    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))
    }

    /// Divides one slice into two at an index.
    ///
    /// Returns `None` if `index > len`.
    pub fn split_at_checked(&self, index: usize) -> Option<(&Self, &Self)> {
        let (first, second) = self.entries.split_at_checked(index)?;
        Some((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))
    }

    /// Checks if the values of this slice are sorted.
    #[inline]
    pub fn is_sorted(&self) -> bool
    where
        T: PartialOrd,
    {
        self.entries.is_sorted_by(|a, b| a.key <= b.key)
    }

    /// Checks if this slice is sorted using the given comparator function.
    #[inline]
    pub fn is_sorted_by<'a, F>(&'a self, mut cmp: F) -> bool
    where
        F: FnMut(&'a T, &'a T) -> bool,
    {
        self.entries.is_sorted_by(move |a, b| cmp(&a.key, &b.key))
    }

    /// Checks if this slice is sorted using the given sort-key function.
    #[inline]
    pub fn is_sorted_by_key<'a, F, K>(&'a self, mut sort_key: F) -> bool
    where
        F: FnMut(&'a T) -> K,
        K: PartialOrd,
    {
        self.entries.is_sorted_by_key(move |a| sort_key(&a.key))
    }

    /// 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, U> PartialEq<Slice<U>> for Slice<T>
where
    T: PartialEq<U>,
{
    fn eq(&self, other: &Slice<U>) -> bool {
        slice_eq(&self.entries, &other.entries, |b1, b2| b1.key == b2.key)
    }
}

impl<T, U> PartialEq<[U]> for Slice<T>
where
    T: PartialEq<U>,
{
    fn eq(&self, other: &[U]) -> bool {
        slice_eq(&self.entries, other, |b, o| b.key == *o)
    }
}

impl<T, U> PartialEq<Slice<U>> for [T]
where
    T: PartialEq<U>,
{
    fn eq(&self, other: &Slice<U>) -> bool {
        slice_eq(self, &other.entries, |o, b| *o == b.key)
    }
}

impl<T, U, const N: usize> PartialEq<[U; N]> for Slice<T>
where
    T: PartialEq<U>,
{
    fn eq(&self, other: &[U; N]) -> bool {
        <Self as PartialEq<[U]>>::eq(self, other)
    }
}

impl<T, const N: usize, U> PartialEq<Slice<U>> for [T; N]
where
    T: PartialEq<U>,
{
    fn eq(&self, other: &Slice<U>) -> bool {
        <[T] as PartialEq<Slice<U>>>::eq(self, 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]);
            }
        }
    }
}

Coverage Report

Created: 2026-01-10 06:06

Line	Count	Source
1		use super::{Bucket, IndexSet, IntoIter, Iter};
2		use crate::util::{slice_eq, try_simplify_range};
3
4		use alloc::boxed::Box;
5		use alloc::vec::Vec;
6		use core::cmp::Ordering;
7		use core::fmt;
8		use core::hash::{Hash, Hasher};
9		use core::ops::{self, Bound, Index, RangeBounds};
10
11		/// A dynamically-sized slice of values in an [`IndexSet`].
12		///
13		/// This supports indexed operations much like a `[T]` slice,
14		/// but not any hashed operations on the values.
15		///
16		/// Unlike `IndexSet`, `Slice` does consider the order for [`PartialEq`]
17		/// and [`Eq`], and it also implements [`PartialOrd`], [`Ord`], and [`Hash`].
18		#[repr(transparent)]
19		pub struct Slice<T> {
20		pub(crate) entries: [Bucket<T>],
21		}
22
23		// SAFETY: `Slice<T>` is a transparent wrapper around `[Bucket<T>]`,
24		// and reference lifetimes are bound together in function signatures.
25		#[allow(unsafe_code)]
26		impl<T> Slice<T> {
27	0	pub(super) const fn from_slice(entries: &[Bucket<T>]) -> &Self {
28	0	unsafe { &(entries as const [Bucket<T>] as *const Self) }
29	0	}
30
31	0	pub(super) fn from_boxed(entries: Box<[Bucket<T>]>) -> Box<Self> {
32	0	unsafe { Box::from_raw(Box::into_raw(entries) as *mut Self) }
33	0	}
34
35	0	fn into_boxed(self: Box<Self>) -> Box<[Bucket<T>]> {
36	0	unsafe { Box::from_raw(Box::into_raw(self) as *mut [Bucket<T>]) }
37	0	}
38		}
39
40		impl<T> Slice<T> {
41	0	pub(crate) fn into_entries(self: Box<Self>) -> Vec<Bucket<T>> {
42	0	self.into_boxed().into_vec()
43	0	}
44
45		/// Returns an empty slice.
46	0	pub const fn new<'a>() -> &'a Self {
47	0	Self::from_slice(&[])
48	0	}
49
50		/// Return the number of elements in the set slice.
51	0	pub const fn len(&self) -> usize {
52	0	self.entries.len()
53	0	}
54
55		/// Returns true if the set slice contains no elements.
56	0	pub const fn is_empty(&self) -> bool {
57	0	self.entries.is_empty()
58	0	}
59
60		/// Get a value by index.
61		///
62		/// Valid indices are `0 <= index < self.len()`.
63	0	pub fn get_index(&self, index: usize) -> Option<&T> {
64	0	self.entries.get(index).map(Bucket::key_ref)
65	0	}
66
67		/// Returns a slice of values in the given range of indices.
68		///
69		/// Valid indices are `0 <= index < self.len()`.
70	0	pub fn get_range<R: RangeBounds<usize>>(&self, range: R) -> Option<&Self> {
71	0	let range = try_simplify_range(range, self.entries.len())?;
72	0	self.entries.get(range).map(Self::from_slice)
73	0	}
74
75		/// Get the first value.
76	0	pub fn first(&self) -> Option<&T> {
77	0	self.entries.first().map(Bucket::key_ref)
78	0	}
79
80		/// Get the last value.
81	0	pub fn last(&self) -> Option<&T> {
82	0	self.entries.last().map(Bucket::key_ref)
83	0	}
84
85		/// Divides one slice into two at an index.
86		///
87		/// *Panics* if `index > len`.
88		/// For a non-panicking alternative see [`split_at_checked`][Self::split_at_checked].
89		#[track_caller]
90	0	pub fn split_at(&self, index: usize) -> (&Self, &Self) {
91	0	let (first, second) = self.entries.split_at(index);
92	0	(Self::from_slice(first), Self::from_slice(second))
93	0	}
94
95		/// Divides one slice into two at an index.
96		///
97		/// Returns `None` if `index > len`.
98	0	pub fn split_at_checked(&self, index: usize) -> Option<(&Self, &Self)> {
99	0	let (first, second) = self.entries.split_at_checked(index)?;
100	0	Some((Self::from_slice(first), Self::from_slice(second)))
101	0	}
102
103		/// Returns the first value and the rest of the slice,
104		/// or `None` if it is empty.
105	0	pub fn split_first(&self) -> Option<(&T, &Self)> {
106	0	if let [first, rest @ ..] = &self.entries {
107	0	Some((&first.key, Self::from_slice(rest)))
108		} else {
109	0	None
110		}
111	0	}
112
113		/// Returns the last value and the rest of the slice,
114		/// or `None` if it is empty.
115	0	pub fn split_last(&self) -> Option<(&T, &Self)> {
116	0	if let [rest @ .., last] = &self.entries {
117	0	Some((&last.key, Self::from_slice(rest)))
118		} else {
119	0	None
120		}
121	0	}
122
123		/// Return an iterator over the values of the set slice.
124	0	pub fn iter(&self) -> Iter<'_, T> {
125	0	Iter::new(&self.entries)
126	0	}
127
128		/// Search over a sorted set for a value.
129		///
130		/// Returns the position where that value is present, or the position where it can be inserted
131		/// to maintain the sort. See [`slice::binary_search`] for more details.
132		///
133		/// Computes in O(log(n)) time, which is notably less scalable than looking the value up in
134		/// the set this is a slice from using [`IndexSet::get_index_of`], but this can also position
135		/// missing values.
136	0	pub fn binary_search(&self, x: &T) -> Result<usize, usize>
137	0	where
138	0	T: Ord,
139		{
140	0	self.binary_search_by(\|p\| p.cmp(x))
141	0	}
142
143		/// Search over a sorted set with a comparator function.
144		///
145		/// Returns the position where that value is present, or the position where it can be inserted
146		/// to maintain the sort. See [`slice::binary_search_by`] for more details.
147		///
148		/// Computes in O(log(n)) time.
149		#[inline]
150	0	pub fn binary_search_by<'a, F>(&'a self, mut f: F) -> Result<usize, usize>
151	0	where
152	0	F: FnMut(&'a T) -> Ordering,
153		{
154	0	self.entries.binary_search_by(move \|a\| f(&a.key))
155	0	}
156
157		/// Search over a sorted set with an extraction function.
158		///
159		/// Returns the position where that value is present, or the position where it can be inserted
160		/// to maintain the sort. See [`slice::binary_search_by_key`] for more details.
161		///
162		/// Computes in O(log(n)) time.
163		#[inline]
164	0	pub fn binary_search_by_key<'a, B, F>(&'a self, b: &B, mut f: F) -> Result<usize, usize>
165	0	where
166	0	F: FnMut(&'a T) -> B,
167	0	B: Ord,
168		{
169	0	self.binary_search_by(\|k\| f(k).cmp(b))
170	0	}
171
172		/// Checks if the values of this slice are sorted.
173		#[inline]
174	0	pub fn is_sorted(&self) -> bool
175	0	where
176	0	T: PartialOrd,
177		{
178	0	self.entries.is_sorted_by(\|a, b\| a.key <= b.key)
179	0	}
180
181		/// Checks if this slice is sorted using the given comparator function.
182		#[inline]
183	0	pub fn is_sorted_by<'a, F>(&'a self, mut cmp: F) -> bool
184	0	where
185	0	F: FnMut(&'a T, &'a T) -> bool,
186		{
187	0	self.entries.is_sorted_by(move \|a, b\| cmp(&a.key, &b.key))
188	0	}
189
190		/// Checks if this slice is sorted using the given sort-key function.
191		#[inline]
192	0	pub fn is_sorted_by_key<'a, F, K>(&'a self, mut sort_key: F) -> bool
193	0	where
194	0	F: FnMut(&'a T) -> K,
195	0	K: PartialOrd,
196		{
197	0	self.entries.is_sorted_by_key(move \|a\| sort_key(&a.key))
198	0	}
199
200		/// Returns the index of the partition point of a sorted set according to the given predicate
201		/// (the index of the first element of the second partition).
202		///
203		/// See [`slice::partition_point`] for more details.
204		///
205		/// Computes in O(log(n)) time.
206		#[must_use]
207	0	pub fn partition_point<P>(&self, mut pred: P) -> usize
208	0	where
209	0	P: FnMut(&T) -> bool,
210		{
211	0	self.entries.partition_point(move \|a\| pred(&a.key))
212	0	}
213		}
214
215		impl<'a, T> IntoIterator for &'a Slice<T> {
216		type IntoIter = Iter<'a, T>;
217		type Item = &'a T;
218
219	0	fn into_iter(self) -> Self::IntoIter {
220	0	self.iter()
221	0	}
222		}
223
224		impl<T> IntoIterator for Box<Slice<T>> {
225		type IntoIter = IntoIter<T>;
226		type Item = T;
227
228	0	fn into_iter(self) -> Self::IntoIter {
229	0	IntoIter::new(self.into_entries())
230	0	}
231		}
232
233		impl<T> Default for &'_ Slice<T> {
234	0	fn default() -> Self {
235	0	Slice::from_slice(&[])
236	0	}
237		}
238
239		impl<T> Default for Box<Slice<T>> {
240	0	fn default() -> Self {
241	0	Slice::from_boxed(Box::default())
242	0	}
243		}
244
245		impl<T: Clone> Clone for Box<Slice<T>> {
246	0	fn clone(&self) -> Self {
247	0	Slice::from_boxed(self.entries.to_vec().into_boxed_slice())
248	0	}
249		}
250
251		impl<T: Copy> From<&Slice<T>> for Box<Slice<T>> {
252	0	fn from(slice: &Slice<T>) -> Self {
253	0	Slice::from_boxed(Box::from(&slice.entries))
254	0	}
255		}
256
257		impl<T: fmt::Debug> fmt::Debug for Slice<T> {
258	0	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
259	0	f.debug_list().entries(self).finish()
260	0	}
261		}
262
263		impl<T, U> PartialEq<Slice<U>> for Slice<T>
264		where
265		T: PartialEq<U>,
266		{
267	0	fn eq(&self, other: &Slice<U>) -> bool {
268	0	slice_eq(&self.entries, &other.entries, \|b1, b2\| b1.key == b2.key)
269	0	}
270		}
271
272		impl<T, U> PartialEq<[U]> for Slice<T>
273		where
274		T: PartialEq<U>,
275		{
276	0	fn eq(&self, other: &[U]) -> bool {
277	0	slice_eq(&self.entries, other, \|b, o\| b.key == *o)
278	0	}
279		}
280
281		impl<T, U> PartialEq<Slice<U>> for [T]
282		where
283		T: PartialEq<U>,
284		{
285	0	fn eq(&self, other: &Slice<U>) -> bool {
286	0	slice_eq(self, &other.entries, \|o, b\| *o == b.key)
287	0	}
288		}
289
290		impl<T, U, const N: usize> PartialEq<[U; N]> for Slice<T>
291		where
292		T: PartialEq<U>,
293		{
294	0	fn eq(&self, other: &[U; N]) -> bool {
295	0	<Self as PartialEq<[U]>>::eq(self, other)
296	0	}
297		}
298
299		impl<T, const N: usize, U> PartialEq<Slice<U>> for [T; N]
300		where
301		T: PartialEq<U>,
302		{
303	0	fn eq(&self, other: &Slice<U>) -> bool {
304	0	<[T] as PartialEq<Slice<U>>>::eq(self, other)
305	0	}
306		}
307
308		impl<T: Eq> Eq for Slice<T> {}
309
310		impl<T: PartialOrd> PartialOrd for Slice<T> {
311	0	fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
312	0	self.iter().partial_cmp(other)
313	0	}
314		}
315
316		impl<T: Ord> Ord for Slice<T> {
317	0	fn cmp(&self, other: &Self) -> Ordering {
318	0	self.iter().cmp(other)
319	0	}
320		}
321
322		impl<T: Hash> Hash for Slice<T> {
323	0	fn hash<H: Hasher>(&self, state: &mut H) {
324	0	self.len().hash(state);
325	0	for value in self {
326	0	value.hash(state);
327	0	}
328	0	}
329		}
330
331		impl<T> Index<usize> for Slice<T> {
332		type Output = T;
333
334	0	fn index(&self, index: usize) -> &Self::Output {
335	0	&self.entries[index].key
336	0	}
337		}
338
339		// We can't have `impl<I: RangeBounds<usize>> Index<I>` because that conflicts with `Index<usize>`.
340		// Instead, we repeat the implementations for all the core range types.
341		macro_rules! impl_index {
342		($($range:ty),*) => {$(
343		impl<T, S> Index<$range> for IndexSet<T, S> {
344		type Output = Slice<T>;
345
346	0	fn index(&self, range: $range) -> &Self::Output {
347	0	Slice::from_slice(&self.as_entries()[range])
348	0	} Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::Range<usize>>>::index Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeFrom<usize>>>::index Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeFull>>::index Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeInclusive<usize>>>::index Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeTo<usize>>>::index Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeToInclusive<usize>>>::index Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<(core::ops::range::Bound<usize>, core::ops::range::Bound<usize>)>>::index
349		}
350
351		impl<T> Index<$range> for Slice<T> {
352		type Output = Self;
353
354	0	fn index(&self, range: $range) -> &Self::Output {
355	0	Slice::from_slice(&self.entries[range])
356	0	} Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::Range<usize>>>::index Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeFrom<usize>>>::index Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeFull>>::index Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeInclusive<usize>>>::index Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeTo<usize>>>::index Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeToInclusive<usize>>>::index Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<(core::ops::range::Bound<usize>, core::ops::range::Bound<usize>)>>::index
357		}
358		)*}
359		}
360		impl_index!(
361		ops::Range<usize>,
362		ops::RangeFrom<usize>,
363		ops::RangeFull,
364		ops::RangeInclusive<usize>,
365		ops::RangeTo<usize>,
366		ops::RangeToInclusive<usize>,
367		(Bound<usize>, Bound<usize>)
368		);
369
370		#[cfg(test)]
371		mod tests {
372		use super::*;
373
374		#[test]
375		fn slice_index() {
376		fn check(vec_slice: &[i32], set_slice: &Slice<i32>, sub_slice: &Slice<i32>) {
377		assert_eq!(set_slice as const _, sub_slice as const _);
378		itertools::assert_equal(vec_slice, set_slice);
379		}
380
381		let vec: Vec<i32> = (0..10).map(\|i\| i * i).collect();
382		let set: IndexSet<i32> = vec.iter().cloned().collect();
383		let slice = set.as_slice();
384
385		// RangeFull
386		check(&vec[..], &set[..], &slice[..]);
387
388		for i in 0usize..10 {
389		// Index
390		assert_eq!(vec[i], set[i]);
391		assert_eq!(vec[i], slice[i]);
392
393		// RangeFrom
394		check(&vec[i..], &set[i..], &slice[i..]);
395
396		// RangeTo
397		check(&vec[..i], &set[..i], &slice[..i]);
398
399		// RangeToInclusive
400		check(&vec[..=i], &set[..=i], &slice[..=i]);
401
402		// (Bound<usize>, Bound<usize>)
403		let bounds = (Bound::Excluded(i), Bound::Unbounded);
404		check(&vec[i + 1..], &set[bounds], &slice[bounds]);
405
406		for j in i..=10 {
407		// Range
408		check(&vec[i..j], &set[i..j], &slice[i..j]);
409		}
410
411		for j in i..10 {
412		// RangeInclusive
413		check(&vec[i..=j], &set[i..=j], &slice[i..=j]);
414		}
415		}
416		}
417		}