indexmap/map/
slice.rs

1use super::{
2    Bucket, IndexMap, IntoIter, IntoKeys, IntoValues, Iter, IterMut, Keys, Values, ValuesMut,
3};
4use crate::util::{slice_eq, try_simplify_range};
5use crate::GetDisjointMutError;
6
7use alloc::boxed::Box;
8use alloc::vec::Vec;
9use core::cmp::Ordering;
10use core::fmt;
11use core::hash::{Hash, Hasher};
12use core::ops::{self, Bound, Index, IndexMut, RangeBounds};
13
14/// A dynamically-sized slice of key-value pairs in an [`IndexMap`].
15///
16/// This supports indexed operations much like a `[(K, V)]` slice,
17/// but not any hashed operations on the map keys.
18///
19/// Unlike `IndexMap`, `Slice` does consider the order for [`PartialEq`]
20/// and [`Eq`], and it also implements [`PartialOrd`], [`Ord`], and [`Hash`].
21#[repr(transparent)]
22pub struct Slice<K, V> {
23    pub(crate) entries: [Bucket<K, V>],
24}
25
26// SAFETY: `Slice<K, V>` is a transparent wrapper around `[Bucket<K, V>]`,
27// and reference lifetimes are bound together in function signatures.
28#[allow(unsafe_code)]
29impl<K, V> Slice<K, V> {
30    pub(super) const fn from_slice(entries: &[Bucket<K, V>]) -> &Self {
31        unsafe { &*(entries as *const [Bucket<K, V>] as *const Self) }
32    }
33
34    pub(super) fn from_mut_slice(entries: &mut [Bucket<K, V>]) -> &mut Self {
35        unsafe { &mut *(entries as *mut [Bucket<K, V>] as *mut Self) }
36    }
37
38    pub(super) fn from_boxed(entries: Box<[Bucket<K, V>]>) -> Box<Self> {
39        unsafe { Box::from_raw(Box::into_raw(entries) as *mut Self) }
40    }
41
42    fn into_boxed(self: Box<Self>) -> Box<[Bucket<K, V>]> {
43        unsafe { Box::from_raw(Box::into_raw(self) as *mut [Bucket<K, V>]) }
44    }
45}
46
47impl<K, V> Slice<K, V> {
48    pub(crate) fn into_entries(self: Box<Self>) -> Vec<Bucket<K, V>> {
49        self.into_boxed().into_vec()
50    }
51
52    /// Returns an empty slice.
53    pub const fn new<'a>() -> &'a Self {
54        Self::from_slice(&[])
55    }
56
57    /// Returns an empty mutable slice.
58    pub fn new_mut<'a>() -> &'a mut Self {
59        Self::from_mut_slice(&mut [])
60    }
61
62    /// Return the number of key-value pairs in the map slice.
63    #[inline]
64    pub const fn len(&self) -> usize {
65        self.entries.len()
66    }
67
68    /// Returns true if the map slice contains no elements.
69    #[inline]
70    pub const fn is_empty(&self) -> bool {
71        self.entries.is_empty()
72    }
73
74    /// Get a key-value pair by index.
75    ///
76    /// Valid indices are `0 <= index < self.len()`.
77    pub fn get_index(&self, index: usize) -> Option<(&K, &V)> {
78        self.entries.get(index).map(Bucket::refs)
79    }
80
81    /// Get a key-value pair by index, with mutable access to the value.
82    ///
83    /// Valid indices are `0 <= index < self.len()`.
84    pub fn get_index_mut(&mut self, index: usize) -> Option<(&K, &mut V)> {
85        self.entries.get_mut(index).map(Bucket::ref_mut)
86    }
87
88    /// Returns a slice of key-value pairs in the given range of indices.
89    ///
90    /// Valid indices are `0 <= index < self.len()`.
91    pub fn get_range<R: RangeBounds<usize>>(&self, range: R) -> Option<&Self> {
92        let range = try_simplify_range(range, self.entries.len())?;
93        self.entries.get(range).map(Slice::from_slice)
94    }
95
96    /// Returns a mutable slice of key-value pairs in the given range of indices.
97    ///
98    /// Valid indices are `0 <= index < self.len()`.
99    pub fn get_range_mut<R: RangeBounds<usize>>(&mut self, range: R) -> Option<&mut Self> {
100        let range = try_simplify_range(range, self.entries.len())?;
101        self.entries.get_mut(range).map(Slice::from_mut_slice)
102    }
103
104    /// Get the first key-value pair.
105    pub fn first(&self) -> Option<(&K, &V)> {
106        self.entries.first().map(Bucket::refs)
107    }
108
109    /// Get the first key-value pair, with mutable access to the value.
110    pub fn first_mut(&mut self) -> Option<(&K, &mut V)> {
111        self.entries.first_mut().map(Bucket::ref_mut)
112    }
113
114    /// Get the last key-value pair.
115    pub fn last(&self) -> Option<(&K, &V)> {
116        self.entries.last().map(Bucket::refs)
117    }
118
119    /// Get the last key-value pair, with mutable access to the value.
120    pub fn last_mut(&mut self) -> Option<(&K, &mut V)> {
121        self.entries.last_mut().map(Bucket::ref_mut)
122    }
123
124    /// Divides one slice into two at an index.
125    ///
126    /// ***Panics*** if `index > len`.
127    #[track_caller]
128    pub fn split_at(&self, index: usize) -> (&Self, &Self) {
129        let (first, second) = self.entries.split_at(index);
130        (Self::from_slice(first), Self::from_slice(second))
131    }
132
133    /// Divides one mutable slice into two at an index.
134    ///
135    /// ***Panics*** if `index > len`.
136    #[track_caller]
137    pub fn split_at_mut(&mut self, index: usize) -> (&mut Self, &mut Self) {
138        let (first, second) = self.entries.split_at_mut(index);
139        (Self::from_mut_slice(first), Self::from_mut_slice(second))
140    }
141
142    /// Returns the first key-value pair and the rest of the slice,
143    /// or `None` if it is empty.
144    pub fn split_first(&self) -> Option<((&K, &V), &Self)> {
145        if let [first, rest @ ..] = &self.entries {
146            Some((first.refs(), Self::from_slice(rest)))
147        } else {
148            None
149        }
150    }
151
152    /// Returns the first key-value pair and the rest of the slice,
153    /// with mutable access to the value, or `None` if it is empty.
154    pub fn split_first_mut(&mut self) -> Option<((&K, &mut V), &mut Self)> {
155        if let [first, rest @ ..] = &mut self.entries {
156            Some((first.ref_mut(), Self::from_mut_slice(rest)))
157        } else {
158            None
159        }
160    }
161
162    /// Returns the last key-value pair and the rest of the slice,
163    /// or `None` if it is empty.
164    pub fn split_last(&self) -> Option<((&K, &V), &Self)> {
165        if let [rest @ .., last] = &self.entries {
166            Some((last.refs(), Self::from_slice(rest)))
167        } else {
168            None
169        }
170    }
171
172    /// Returns the last key-value pair and the rest of the slice,
173    /// with mutable access to the value, or `None` if it is empty.
174    pub fn split_last_mut(&mut self) -> Option<((&K, &mut V), &mut Self)> {
175        if let [rest @ .., last] = &mut self.entries {
176            Some((last.ref_mut(), Self::from_mut_slice(rest)))
177        } else {
178            None
179        }
180    }
181
182    /// Return an iterator over the key-value pairs of the map slice.
183    pub fn iter(&self) -> Iter<'_, K, V> {
184        Iter::new(&self.entries)
185    }
186
187    /// Return an iterator over the key-value pairs of the map slice.
188    pub fn iter_mut(&mut self) -> IterMut<'_, K, V> {
189        IterMut::new(&mut self.entries)
190    }
191
192    /// Return an iterator over the keys of the map slice.
193    pub fn keys(&self) -> Keys<'_, K, V> {
194        Keys::new(&self.entries)
195    }
196
197    /// Return an owning iterator over the keys of the map slice.
198    pub fn into_keys(self: Box<Self>) -> IntoKeys<K, V> {
199        IntoKeys::new(self.into_entries())
200    }
201
202    /// Return an iterator over the values of the map slice.
203    pub fn values(&self) -> Values<'_, K, V> {
204        Values::new(&self.entries)
205    }
206
207    /// Return an iterator over mutable references to the the values of the map slice.
208    pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> {
209        ValuesMut::new(&mut self.entries)
210    }
211
212    /// Return an owning iterator over the values of the map slice.
213    pub fn into_values(self: Box<Self>) -> IntoValues<K, V> {
214        IntoValues::new(self.into_entries())
215    }
216
217    /// Search over a sorted map for a key.
218    ///
219    /// Returns the position where that key is present, or the position where it can be inserted to
220    /// maintain the sort. See [`slice::binary_search`] for more details.
221    ///
222    /// Computes in **O(log(n))** time, which is notably less scalable than looking the key up in
223    /// the map this is a slice from using [`IndexMap::get_index_of`], but this can also position
224    /// missing keys.
225    pub fn binary_search_keys(&self, x: &K) -> Result<usize, usize>
226    where
227        K: Ord,
228    {
229        self.binary_search_by(|p, _| p.cmp(x))
230    }
231
232    /// Search over a sorted map with a comparator function.
233    ///
234    /// Returns the position where that value is present, or the position where it can be inserted
235    /// to maintain the sort. See [`slice::binary_search_by`] for more details.
236    ///
237    /// Computes in **O(log(n))** time.
238    #[inline]
239    pub fn binary_search_by<'a, F>(&'a self, mut f: F) -> Result<usize, usize>
240    where
241        F: FnMut(&'a K, &'a V) -> Ordering,
242    {
243        self.entries.binary_search_by(move |a| f(&a.key, &a.value))
244    }
245
246    /// Search over a sorted map with an extraction function.
247    ///
248    /// Returns the position where that value is present, or the position where it can be inserted
249    /// to maintain the sort. See [`slice::binary_search_by_key`] for more details.
250    ///
251    /// Computes in **O(log(n))** time.
252    #[inline]
253    pub fn binary_search_by_key<'a, B, F>(&'a self, b: &B, mut f: F) -> Result<usize, usize>
254    where
255        F: FnMut(&'a K, &'a V) -> B,
256        B: Ord,
257    {
258        self.binary_search_by(|k, v| f(k, v).cmp(b))
259    }
260
261    /// Checks if the keys of this slice are sorted.
262    #[inline]
263    pub fn is_sorted(&self) -> bool
264    where
265        K: PartialOrd,
266    {
267        self.entries.is_sorted_by(|a, b| a.key <= b.key)
268    }
269
270    /// Checks if this slice is sorted using the given comparator function.
271    #[inline]
272    pub fn is_sorted_by<'a, F>(&'a self, mut cmp: F) -> bool
273    where
274        F: FnMut(&'a K, &'a V, &'a K, &'a V) -> bool,
275    {
276        self.entries
277            .is_sorted_by(move |a, b| cmp(&a.key, &a.value, &b.key, &b.value))
278    }
279
280    /// Checks if this slice is sorted using the given sort-key function.
281    #[inline]
282    pub fn is_sorted_by_key<'a, F, T>(&'a self, mut sort_key: F) -> bool
283    where
284        F: FnMut(&'a K, &'a V) -> T,
285        T: PartialOrd,
286    {
287        self.entries
288            .is_sorted_by_key(move |a| sort_key(&a.key, &a.value))
289    }
290
291    /// Returns the index of the partition point of a sorted map according to the given predicate
292    /// (the index of the first element of the second partition).
293    ///
294    /// See [`slice::partition_point`] for more details.
295    ///
296    /// Computes in **O(log(n))** time.
297    #[must_use]
298    pub fn partition_point<P>(&self, mut pred: P) -> usize
299    where
300        P: FnMut(&K, &V) -> bool,
301    {
302        self.entries
303            .partition_point(move |a| pred(&a.key, &a.value))
304    }
305
306    /// Get an array of `N` key-value pairs by `N` indices
307    ///
308    /// Valid indices are *0 <= index < self.len()* and each index needs to be unique.
309    pub fn get_disjoint_mut<const N: usize>(
310        &mut self,
311        indices: [usize; N],
312    ) -> Result<[(&K, &mut V); N], GetDisjointMutError> {
313        let indices = indices.map(Some);
314        let key_values = self.get_disjoint_opt_mut(indices)?;
315        Ok(key_values.map(Option::unwrap))
316    }
317
318    #[allow(unsafe_code)]
319    pub(crate) fn get_disjoint_opt_mut<const N: usize>(
320        &mut self,
321        indices: [Option<usize>; N],
322    ) -> Result<[Option<(&K, &mut V)>; N], GetDisjointMutError> {
323        // SAFETY: Can't allow duplicate indices as we would return several mutable refs to the same data.
324        let len = self.len();
325        for i in 0..N {
326            if let Some(idx) = indices[i] {
327                if idx >= len {
328                    return Err(GetDisjointMutError::IndexOutOfBounds);
329                } else if indices[..i].contains(&Some(idx)) {
330                    return Err(GetDisjointMutError::OverlappingIndices);
331                }
332            }
333        }
334
335        let entries_ptr = self.entries.as_mut_ptr();
336        let out = indices.map(|idx_opt| {
337            match idx_opt {
338                Some(idx) => {
339                    // SAFETY: The base pointer is valid as it comes from a slice and the reference is always
340                    // in-bounds & unique as we've already checked the indices above.
341                    let kv = unsafe { (*(entries_ptr.add(idx))).ref_mut() };
342                    Some(kv)
343                }
344                None => None,
345            }
346        });
347
348        Ok(out)
349    }
350}
351
352impl<'a, K, V> IntoIterator for &'a Slice<K, V> {
353    type IntoIter = Iter<'a, K, V>;
354    type Item = (&'a K, &'a V);
355
356    fn into_iter(self) -> Self::IntoIter {
357        self.iter()
358    }
359}
360
361impl<'a, K, V> IntoIterator for &'a mut Slice<K, V> {
362    type IntoIter = IterMut<'a, K, V>;
363    type Item = (&'a K, &'a mut V);
364
365    fn into_iter(self) -> Self::IntoIter {
366        self.iter_mut()
367    }
368}
369
370impl<K, V> IntoIterator for Box<Slice<K, V>> {
371    type IntoIter = IntoIter<K, V>;
372    type Item = (K, V);
373
374    fn into_iter(self) -> Self::IntoIter {
375        IntoIter::new(self.into_entries())
376    }
377}
378
379impl<K, V> Default for &'_ Slice<K, V> {
380    fn default() -> Self {
381        Slice::from_slice(&[])
382    }
383}
384
385impl<K, V> Default for &'_ mut Slice<K, V> {
386    fn default() -> Self {
387        Slice::from_mut_slice(&mut [])
388    }
389}
390
391impl<K, V> Default for Box<Slice<K, V>> {
392    fn default() -> Self {
393        Slice::from_boxed(Box::default())
394    }
395}
396
397impl<K: Clone, V: Clone> Clone for Box<Slice<K, V>> {
398    fn clone(&self) -> Self {
399        Slice::from_boxed(self.entries.to_vec().into_boxed_slice())
400    }
401}
402
403impl<K: Copy, V: Copy> From<&Slice<K, V>> for Box<Slice<K, V>> {
404    fn from(slice: &Slice<K, V>) -> Self {
405        Slice::from_boxed(Box::from(&slice.entries))
406    }
407}
408
409impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for Slice<K, V> {
410    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
411        f.debug_list().entries(self).finish()
412    }
413}
414
415impl<K, V, K2, V2> PartialEq<Slice<K2, V2>> for Slice<K, V>
416where
417    K: PartialEq<K2>,
418    V: PartialEq<V2>,
419{
420    fn eq(&self, other: &Slice<K2, V2>) -> bool {
421        slice_eq(&self.entries, &other.entries, |b1, b2| {
422            b1.key == b2.key && b1.value == b2.value
423        })
424    }
425}
426
427impl<K, V, K2, V2> PartialEq<[(K2, V2)]> for Slice<K, V>
428where
429    K: PartialEq<K2>,
430    V: PartialEq<V2>,
431{
432    fn eq(&self, other: &[(K2, V2)]) -> bool {
433        slice_eq(&self.entries, other, |b, t| b.key == t.0 && b.value == t.1)
434    }
435}
436
437impl<K, V, K2, V2> PartialEq<Slice<K2, V2>> for [(K, V)]
438where
439    K: PartialEq<K2>,
440    V: PartialEq<V2>,
441{
442    fn eq(&self, other: &Slice<K2, V2>) -> bool {
443        slice_eq(self, &other.entries, |t, b| t.0 == b.key && t.1 == b.value)
444    }
445}
446
447impl<K, V, K2, V2, const N: usize> PartialEq<[(K2, V2); N]> for Slice<K, V>
448where
449    K: PartialEq<K2>,
450    V: PartialEq<V2>,
451{
452    fn eq(&self, other: &[(K2, V2); N]) -> bool {
453        <Self as PartialEq<[_]>>::eq(self, other)
454    }
455}
456
457impl<K, V, const N: usize, K2, V2> PartialEq<Slice<K2, V2>> for [(K, V); N]
458where
459    K: PartialEq<K2>,
460    V: PartialEq<V2>,
461{
462    fn eq(&self, other: &Slice<K2, V2>) -> bool {
463        <[_] as PartialEq<_>>::eq(self, other)
464    }
465}
466
467impl<K: Eq, V: Eq> Eq for Slice<K, V> {}
468
469impl<K: PartialOrd, V: PartialOrd> PartialOrd for Slice<K, V> {
470    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
471        self.iter().partial_cmp(other)
472    }
473}
474
475impl<K: Ord, V: Ord> Ord for Slice<K, V> {
476    fn cmp(&self, other: &Self) -> Ordering {
477        self.iter().cmp(other)
478    }
479}
480
481impl<K: Hash, V: Hash> Hash for Slice<K, V> {
482    fn hash<H: Hasher>(&self, state: &mut H) {
483        self.len().hash(state);
484        for (key, value) in self {
485            key.hash(state);
486            value.hash(state);
487        }
488    }
489}
490
491impl<K, V> Index<usize> for Slice<K, V> {
492    type Output = V;
493
494    fn index(&self, index: usize) -> &V {
495        &self.entries[index].value
496    }
497}
498
499impl<K, V> IndexMut<usize> for Slice<K, V> {
500    fn index_mut(&mut self, index: usize) -> &mut V {
501        &mut self.entries[index].value
502    }
503}
504
505// We can't have `impl<I: RangeBounds<usize>> Index<I>` because that conflicts
506// both upstream with `Index<usize>` and downstream with `Index<&Q>`.
507// Instead, we repeat the implementations for all the core range types.
508macro_rules! impl_index {
509    ($($range:ty),*) => {$(
510        impl<K, V, S> Index<$range> for IndexMap<K, V, S> {
511            type Output = Slice<K, V>;
512
513            fn index(&self, range: $range) -> &Self::Output {
514                Slice::from_slice(&self.as_entries()[range])
515            }
516        }
517
518        impl<K, V, S> IndexMut<$range> for IndexMap<K, V, S> {
519            fn index_mut(&mut self, range: $range) -> &mut Self::Output {
520                Slice::from_mut_slice(&mut self.as_entries_mut()[range])
521            }
522        }
523
524        impl<K, V> Index<$range> for Slice<K, V> {
525            type Output = Slice<K, V>;
526
527            fn index(&self, range: $range) -> &Self {
528                Self::from_slice(&self.entries[range])
529            }
530        }
531
532        impl<K, V> IndexMut<$range> for Slice<K, V> {
533            fn index_mut(&mut self, range: $range) -> &mut Self {
534                Self::from_mut_slice(&mut self.entries[range])
535            }
536        }
537    )*}
538}
539impl_index!(
540    ops::Range<usize>,
541    ops::RangeFrom<usize>,
542    ops::RangeFull,
543    ops::RangeInclusive<usize>,
544    ops::RangeTo<usize>,
545    ops::RangeToInclusive<usize>,
546    (Bound<usize>, Bound<usize>)
547);
548
549#[cfg(test)]
550mod tests {
551    use super::*;
552
553    #[test]
554    fn slice_index() {
555        fn check(
556            vec_slice: &[(i32, i32)],
557            map_slice: &Slice<i32, i32>,
558            sub_slice: &Slice<i32, i32>,
559        ) {
560            assert_eq!(map_slice as *const _, sub_slice as *const _);
561            itertools::assert_equal(
562                vec_slice.iter().copied(),
563                map_slice.iter().map(|(&k, &v)| (k, v)),
564            );
565            itertools::assert_equal(vec_slice.iter().map(|(k, _)| k), map_slice.keys());
566            itertools::assert_equal(vec_slice.iter().map(|(_, v)| v), map_slice.values());
567        }
568
569        let vec: Vec<(i32, i32)> = (0..10).map(|i| (i, i * i)).collect();
570        let map: IndexMap<i32, i32> = vec.iter().cloned().collect();
571        let slice = map.as_slice();
572
573        // RangeFull
574        check(&vec[..], &map[..], &slice[..]);
575
576        for i in 0usize..10 {
577            // Index
578            assert_eq!(vec[i].1, map[i]);
579            assert_eq!(vec[i].1, slice[i]);
580            assert_eq!(map[&(i as i32)], map[i]);
581            assert_eq!(map[&(i as i32)], slice[i]);
582
583            // RangeFrom
584            check(&vec[i..], &map[i..], &slice[i..]);
585
586            // RangeTo
587            check(&vec[..i], &map[..i], &slice[..i]);
588
589            // RangeToInclusive
590            check(&vec[..=i], &map[..=i], &slice[..=i]);
591
592            // (Bound<usize>, Bound<usize>)
593            let bounds = (Bound::Excluded(i), Bound::Unbounded);
594            check(&vec[i + 1..], &map[bounds], &slice[bounds]);
595
596            for j in i..=10 {
597                // Range
598                check(&vec[i..j], &map[i..j], &slice[i..j]);
599            }
600
601            for j in i..10 {
602                // RangeInclusive
603                check(&vec[i..=j], &map[i..=j], &slice[i..=j]);
604            }
605        }
606    }
607
608    #[test]
609    fn slice_index_mut() {
610        fn check_mut(
611            vec_slice: &[(i32, i32)],
612            map_slice: &mut Slice<i32, i32>,
613            sub_slice: &mut Slice<i32, i32>,
614        ) {
615            assert_eq!(map_slice, sub_slice);
616            itertools::assert_equal(
617                vec_slice.iter().copied(),
618                map_slice.iter_mut().map(|(&k, &mut v)| (k, v)),
619            );
620            itertools::assert_equal(
621                vec_slice.iter().map(|&(_, v)| v),
622                map_slice.values_mut().map(|&mut v| v),
623            );
624        }
625
626        let vec: Vec<(i32, i32)> = (0..10).map(|i| (i, i * i)).collect();
627        let mut map: IndexMap<i32, i32> = vec.iter().cloned().collect();
628        let mut map2 = map.clone();
629        let slice = map2.as_mut_slice();
630
631        // RangeFull
632        check_mut(&vec[..], &mut map[..], &mut slice[..]);
633
634        for i in 0usize..10 {
635            // IndexMut
636            assert_eq!(&mut map[i], &mut slice[i]);
637
638            // RangeFrom
639            check_mut(&vec[i..], &mut map[i..], &mut slice[i..]);
640
641            // RangeTo
642            check_mut(&vec[..i], &mut map[..i], &mut slice[..i]);
643
644            // RangeToInclusive
645            check_mut(&vec[..=i], &mut map[..=i], &mut slice[..=i]);
646
647            // (Bound<usize>, Bound<usize>)
648            let bounds = (Bound::Excluded(i), Bound::Unbounded);
649            check_mut(&vec[i + 1..], &mut map[bounds], &mut slice[bounds]);
650
651            for j in i..=10 {
652                // Range
653                check_mut(&vec[i..j], &mut map[i..j], &mut slice[i..j]);
654            }
655
656            for j in i..10 {
657                // RangeInclusive
658                check_mut(&vec[i..=j], &mut map[i..=j], &mut slice[i..=j]);
659            }
660        }
661    }
662
663    #[test]
664    fn slice_new() {
665        let slice: &Slice<i32, i32> = Slice::new();
666        assert!(slice.is_empty());
667        assert_eq!(slice.len(), 0);
668    }
669
670    #[test]
671    fn slice_new_mut() {
672        let slice: &mut Slice<i32, i32> = Slice::new_mut();
673        assert!(slice.is_empty());
674        assert_eq!(slice.len(), 0);
675    }
676
677    #[test]
678    fn slice_get_index_mut() {
679        let mut map: IndexMap<i32, i32> = (0..10).map(|i| (i, i * i)).collect();
680        let slice: &mut Slice<i32, i32> = map.as_mut_slice();
681
682        {
683            let (key, value) = slice.get_index_mut(0).unwrap();
684            assert_eq!(*key, 0);
685            assert_eq!(*value, 0);
686
687            *value = 11;
688        }
689
690        assert_eq!(slice[0], 11);
691
692        {
693            let result = slice.get_index_mut(11);
694            assert!(result.is_none());
695        }
696    }
697
698    #[test]
699    fn slice_split_first() {
700        let slice: &mut Slice<i32, i32> = Slice::new_mut();
701        let result = slice.split_first();
702        assert!(result.is_none());
703
704        let mut map: IndexMap<i32, i32> = (0..10).map(|i| (i, i * i)).collect();
705        let slice: &mut Slice<i32, i32> = map.as_mut_slice();
706
707        {
708            let (first, rest) = slice.split_first().unwrap();
709            assert_eq!(first, (&0, &0));
710            assert_eq!(rest.len(), 9);
711        }
712        assert_eq!(slice.len(), 10);
713    }
714
715    #[test]
716    fn slice_split_first_mut() {
717        let slice: &mut Slice<i32, i32> = Slice::new_mut();
718        let result = slice.split_first_mut();
719        assert!(result.is_none());
720
721        let mut map: IndexMap<i32, i32> = (0..10).map(|i| (i, i * i)).collect();
722        let slice: &mut Slice<i32, i32> = map.as_mut_slice();
723
724        {
725            let (first, rest) = slice.split_first_mut().unwrap();
726            assert_eq!(first, (&0, &mut 0));
727            assert_eq!(rest.len(), 9);
728
729            *first.1 = 11;
730        }
731        assert_eq!(slice.len(), 10);
732        assert_eq!(slice[0], 11);
733    }
734
735    #[test]
736    fn slice_split_last() {
737        let slice: &mut Slice<i32, i32> = Slice::new_mut();
738        let result = slice.split_last();
739        assert!(result.is_none());
740
741        let mut map: IndexMap<i32, i32> = (0..10).map(|i| (i, i * i)).collect();
742        let slice: &mut Slice<i32, i32> = map.as_mut_slice();
743
744        {
745            let (last, rest) = slice.split_last().unwrap();
746            assert_eq!(last, (&9, &81));
747            assert_eq!(rest.len(), 9);
748        }
749        assert_eq!(slice.len(), 10);
750    }
751
752    #[test]
753    fn slice_split_last_mut() {
754        let slice: &mut Slice<i32, i32> = Slice::new_mut();
755        let result = slice.split_last_mut();
756        assert!(result.is_none());
757
758        let mut map: IndexMap<i32, i32> = (0..10).map(|i| (i, i * i)).collect();
759        let slice: &mut Slice<i32, i32> = map.as_mut_slice();
760
761        {
762            let (last, rest) = slice.split_last_mut().unwrap();
763            assert_eq!(last, (&9, &mut 81));
764            assert_eq!(rest.len(), 9);
765
766            *last.1 = 100;
767        }
768
769        assert_eq!(slice.len(), 10);
770        assert_eq!(slice[slice.len() - 1], 100);
771    }
772
773    #[test]
774    fn slice_get_range() {
775        let mut map: IndexMap<i32, i32> = (0..10).map(|i| (i, i * i)).collect();
776        let slice: &mut Slice<i32, i32> = map.as_mut_slice();
777        let subslice = slice.get_range(3..6).unwrap();
778        assert_eq!(subslice.len(), 3);
779        assert_eq!(subslice, &[(3, 9), (4, 16), (5, 25)]);
780    }
781}
indexmap/map/slice.rs

indexmap/map/
slice.rs
