Coverage Report

Created: 2025-07-02 06:18

/rust/registry/src/index.crates.io-6f17d22bba15001f/indexmap-2.10.0/src/set/slice.rs
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Source (jump to first uncovered line)
1
use super::{Bucket, IndexSet, IntoIter, Iter};
2
use crate::util::{slice_eq, try_simplify_range};
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4
use alloc::boxed::Box;
5
use alloc::vec::Vec;
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use core::cmp::Ordering;
7
use core::fmt;
8
use core::hash::{Hash, Hasher};
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use core::ops::{self, Bound, Index, RangeBounds};
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/// A dynamically-sized slice of values in an [`IndexSet`].
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///
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/// This supports indexed operations much like a `[T]` slice,
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/// but not any hashed operations on the values.
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///
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/// Unlike `IndexSet`, `Slice` does consider the order for [`PartialEq`]
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/// and [`Eq`], and it also implements [`PartialOrd`], [`Ord`], and [`Hash`].
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#[repr(transparent)]
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pub struct Slice<T> {
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    pub(crate) entries: [Bucket<T>],
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}
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// SAFETY: `Slice<T>` is a transparent wrapper around `[Bucket<T>]`,
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// and reference lifetimes are bound together in function signatures.
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#[allow(unsafe_code)]
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impl<T> Slice<T> {
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0
    pub(super) const fn from_slice(entries: &[Bucket<T>]) -> &Self {
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0
        unsafe { &*(entries as *const [Bucket<T>] as *const Self) }
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0
    }
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0
    pub(super) fn from_boxed(entries: Box<[Bucket<T>]>) -> Box<Self> {
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0
        unsafe { Box::from_raw(Box::into_raw(entries) as *mut Self) }
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0
    }
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0
    fn into_boxed(self: Box<Self>) -> Box<[Bucket<T>]> {
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0
        unsafe { Box::from_raw(Box::into_raw(self) as *mut [Bucket<T>]) }
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0
    }
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}
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impl<T> Slice<T> {
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0
    pub(crate) fn into_entries(self: Box<Self>) -> Vec<Bucket<T>> {
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        self.into_boxed().into_vec()
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0
    }
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    /// Returns an empty slice.
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0
    pub const fn new<'a>() -> &'a Self {
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0
        Self::from_slice(&[])
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0
    }
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    /// Return the number of elements in the set slice.
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0
    pub const fn len(&self) -> usize {
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0
        self.entries.len()
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0
    }
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    /// Returns true if the set slice contains no elements.
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0
    pub const fn is_empty(&self) -> bool {
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0
        self.entries.is_empty()
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0
    }
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    /// Get a value by index.
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    ///
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    /// Valid indices are `0 <= index < self.len()`.
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0
    pub fn get_index(&self, index: usize) -> Option<&T> {
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0
        self.entries.get(index).map(Bucket::key_ref)
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0
    }
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    /// Returns a slice of values in the given range of indices.
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    ///
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    /// Valid indices are `0 <= index < self.len()`.
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0
    pub fn get_range<R: RangeBounds<usize>>(&self, range: R) -> Option<&Self> {
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0
        let range = try_simplify_range(range, self.entries.len())?;
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0
        self.entries.get(range).map(Self::from_slice)
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0
    }
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    /// Get the first value.
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0
    pub fn first(&self) -> Option<&T> {
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        self.entries.first().map(Bucket::key_ref)
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0
    }
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    /// Get the last value.
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0
    pub fn last(&self) -> Option<&T> {
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0
        self.entries.last().map(Bucket::key_ref)
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0
    }
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    /// Divides one slice into two at an index.
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    ///
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    /// ***Panics*** if `index > len`.
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    #[track_caller]
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0
    pub fn split_at(&self, index: usize) -> (&Self, &Self) {
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0
        let (first, second) = self.entries.split_at(index);
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        (Self::from_slice(first), Self::from_slice(second))
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0
    }
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    /// Returns the first value and the rest of the slice,
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    /// or `None` if it is empty.
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    pub fn split_first(&self) -> Option<(&T, &Self)> {
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        if let [first, rest @ ..] = &self.entries {
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            Some((&first.key, Self::from_slice(rest)))
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        } else {
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            None
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        }
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    }
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    /// Returns the last value and the rest of the slice,
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    /// or `None` if it is empty.
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    pub fn split_last(&self) -> Option<(&T, &Self)> {
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        if let [rest @ .., last] = &self.entries {
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            Some((&last.key, Self::from_slice(rest)))
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        } else {
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            None
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        }
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0
    }
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    /// Return an iterator over the values of the set slice.
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0
    pub fn iter(&self) -> Iter<'_, T> {
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        Iter::new(&self.entries)
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    }
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    /// Search over a sorted set for a value.
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    ///
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    /// Returns the position where that value is present, or the position where it can be inserted
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    /// to maintain the sort. See [`slice::binary_search`] for more details.
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    ///
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    /// Computes in **O(log(n))** time, which is notably less scalable than looking the value up in
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    /// the set this is a slice from using [`IndexSet::get_index_of`], but this can also position
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    /// missing values.
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    pub fn binary_search(&self, x: &T) -> Result<usize, usize>
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    where
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        T: Ord,
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    {
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        self.binary_search_by(|p| p.cmp(x))
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    }
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    /// Search over a sorted set with a comparator function.
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    ///
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    /// Returns the position where that value is present, or the position where it can be inserted
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    /// to maintain the sort. See [`slice::binary_search_by`] for more details.
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    ///
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    /// Computes in **O(log(n))** time.
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    #[inline]
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    pub fn binary_search_by<'a, F>(&'a self, mut f: F) -> Result<usize, usize>
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    where
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        F: FnMut(&'a T) -> Ordering,
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    {
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        self.entries.binary_search_by(move |a| f(&a.key))
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    }
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    /// Search over a sorted set with an extraction function.
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    ///
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    /// Returns the position where that value is present, or the position where it can be inserted
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    /// to maintain the sort. See [`slice::binary_search_by_key`] for more details.
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    ///
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    /// Computes in **O(log(n))** time.
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    #[inline]
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    pub fn binary_search_by_key<'a, B, F>(&'a self, b: &B, mut f: F) -> Result<usize, usize>
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    where
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        F: FnMut(&'a T) -> B,
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        B: Ord,
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    {
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        self.binary_search_by(|k| f(k).cmp(b))
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    }
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    /// Returns the index of the partition point of a sorted set according to the given predicate
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    /// (the index of the first element of the second partition).
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    ///
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    /// See [`slice::partition_point`] for more details.
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    ///
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    /// Computes in **O(log(n))** time.
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    #[must_use]
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    pub fn partition_point<P>(&self, mut pred: P) -> usize
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0
    where
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        P: FnMut(&T) -> bool,
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    {
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        self.entries.partition_point(move |a| pred(&a.key))
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0
    }
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}
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impl<'a, T> IntoIterator for &'a Slice<T> {
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    type IntoIter = Iter<'a, T>;
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    type Item = &'a T;
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0
    fn into_iter(self) -> Self::IntoIter {
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        self.iter()
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0
    }
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}
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impl<T> IntoIterator for Box<Slice<T>> {
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    type IntoIter = IntoIter<T>;
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    type Item = T;
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0
    fn into_iter(self) -> Self::IntoIter {
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        IntoIter::new(self.into_entries())
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0
    }
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}
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impl<T> Default for &'_ Slice<T> {
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    fn default() -> Self {
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        Slice::from_slice(&[])
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0
    }
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}
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impl<T> Default for Box<Slice<T>> {
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    fn default() -> Self {
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        Slice::from_boxed(Box::default())
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    }
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}
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impl<T: Clone> Clone for Box<Slice<T>> {
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    fn clone(&self) -> Self {
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        Slice::from_boxed(self.entries.to_vec().into_boxed_slice())
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    }
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}
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impl<T: Copy> From<&Slice<T>> for Box<Slice<T>> {
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    fn from(slice: &Slice<T>) -> Self {
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        Slice::from_boxed(Box::from(&slice.entries))
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    }
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}
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impl<T: fmt::Debug> fmt::Debug for Slice<T> {
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    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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        f.debug_list().entries(self).finish()
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0
    }
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}
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impl<T, U> PartialEq<Slice<U>> for Slice<T>
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where
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    T: PartialEq<U>,
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{
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0
    fn eq(&self, other: &Slice<U>) -> bool {
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0
        slice_eq(&self.entries, &other.entries, |b1, b2| b1.key == b2.key)
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0
    }
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}
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impl<T, U> PartialEq<[U]> for Slice<T>
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where
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    T: PartialEq<U>,
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{
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0
    fn eq(&self, other: &[U]) -> bool {
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0
        slice_eq(&self.entries, other, |b, o| b.key == *o)
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0
    }
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}
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impl<T, U> PartialEq<Slice<U>> for [T]
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where
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    T: PartialEq<U>,
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{
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0
    fn eq(&self, other: &Slice<U>) -> bool {
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0
        slice_eq(self, &other.entries, |o, b| *o == b.key)
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0
    }
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}
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impl<T, U, const N: usize> PartialEq<[U; N]> for Slice<T>
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where
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    T: PartialEq<U>,
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{
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0
    fn eq(&self, other: &[U; N]) -> bool {
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0
        <Self as PartialEq<[U]>>::eq(self, other)
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0
    }
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}
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impl<T, const N: usize, U> PartialEq<Slice<U>> for [T; N]
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where
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    T: PartialEq<U>,
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{
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0
    fn eq(&self, other: &Slice<U>) -> bool {
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0
        <[T] as PartialEq<Slice<U>>>::eq(self, other)
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0
    }
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}
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impl<T: Eq> Eq for Slice<T> {}
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impl<T: PartialOrd> PartialOrd for Slice<T> {
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0
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
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0
        self.iter().partial_cmp(other)
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0
    }
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}
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impl<T: Ord> Ord for Slice<T> {
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0
    fn cmp(&self, other: &Self) -> Ordering {
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0
        self.iter().cmp(other)
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0
    }
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}
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impl<T: Hash> Hash for Slice<T> {
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0
    fn hash<H: Hasher>(&self, state: &mut H) {
287
0
        self.len().hash(state);
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0
        for value in self {
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0
            value.hash(state);
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0
        }
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0
    }
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}
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impl<T> Index<usize> for Slice<T> {
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    type Output = T;
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0
    fn index(&self, index: usize) -> &Self::Output {
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0
        &self.entries[index].key
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0
    }
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}
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// We can't have `impl<I: RangeBounds<usize>> Index<I>` because that conflicts with `Index<usize>`.
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// Instead, we repeat the implementations for all the core range types.
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macro_rules! impl_index {
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    ($($range:ty),*) => {$(
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        impl<T, S> Index<$range> for IndexSet<T, S> {
307
            type Output = Slice<T>;
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309
0
            fn index(&self, range: $range) -> &Self::Output {
310
0
                Slice::from_slice(&self.as_entries()[range])
311
0
            }
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::Range<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeFrom<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeFull>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeInclusive<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeTo<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeToInclusive<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<(core::ops::range::Bound<usize>, core::ops::range::Bound<usize>)>>::index
312
        }
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314
        impl<T> Index<$range> for Slice<T> {
315
            type Output = Self;
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317
0
            fn index(&self, range: $range) -> &Self::Output {
318
0
                Slice::from_slice(&self.entries[range])
319
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
320
        }
321
    )*}
322
}
323
impl_index!(
324
    ops::Range<usize>,
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    ops::RangeFrom<usize>,
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    ops::RangeFull,
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    ops::RangeInclusive<usize>,
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    ops::RangeTo<usize>,
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    ops::RangeToInclusive<usize>,
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    (Bound<usize>, Bound<usize>)
331
);
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#[cfg(test)]
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mod tests {
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    use super::*;
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337
    #[test]
338
    fn slice_index() {
339
        fn check(vec_slice: &[i32], set_slice: &Slice<i32>, sub_slice: &Slice<i32>) {
340
            assert_eq!(set_slice as *const _, sub_slice as *const _);
341
            itertools::assert_equal(vec_slice, set_slice);
342
        }
343
344
        let vec: Vec<i32> = (0..10).map(|i| i * i).collect();
345
        let set: IndexSet<i32> = vec.iter().cloned().collect();
346
        let slice = set.as_slice();
347
348
        // RangeFull
349
        check(&vec[..], &set[..], &slice[..]);
350
351
        for i in 0usize..10 {
352
            // Index
353
            assert_eq!(vec[i], set[i]);
354
            assert_eq!(vec[i], slice[i]);
355
356
            // RangeFrom
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            check(&vec[i..], &set[i..], &slice[i..]);
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359
            // RangeTo
360
            check(&vec[..i], &set[..i], &slice[..i]);
361
362
            // RangeToInclusive
363
            check(&vec[..=i], &set[..=i], &slice[..=i]);
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365
            // (Bound<usize>, Bound<usize>)
366
            let bounds = (Bound::Excluded(i), Bound::Unbounded);
367
            check(&vec[i + 1..], &set[bounds], &slice[bounds]);
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369
            for j in i..=10 {
370
                // Range
371
                check(&vec[i..j], &set[i..j], &slice[i..j]);
372
            }
373
374
            for j in i..10 {
375
                // RangeInclusive
376
                check(&vec[i..=j], &set[i..=j], &slice[i..=j]);
377
            }
378
        }
379
    }
380
}