diff options
Diffstat (limited to 'vendor/hashbrown/src')
| -rw-r--r-- | vendor/hashbrown/src/external_trait_impls/mod.rs | 4 | ||||
| -rw-r--r-- | vendor/hashbrown/src/external_trait_impls/rayon/helpers.rs | 27 | ||||
| -rw-r--r-- | vendor/hashbrown/src/external_trait_impls/rayon/map.rs | 734 | ||||
| -rw-r--r-- | vendor/hashbrown/src/external_trait_impls/rayon/mod.rs | 4 | ||||
| -rw-r--r-- | vendor/hashbrown/src/external_trait_impls/rayon/raw.rs | 231 | ||||
| -rw-r--r-- | vendor/hashbrown/src/external_trait_impls/rayon/set.rs | 659 | ||||
| -rw-r--r-- | vendor/hashbrown/src/external_trait_impls/serde.rs | 201 | ||||
| -rw-r--r-- | vendor/hashbrown/src/lib.rs | 150 | ||||
| -rw-r--r-- | vendor/hashbrown/src/macros.rs | 70 | ||||
| -rw-r--r-- | vendor/hashbrown/src/map.rs | 8408 | ||||
| -rw-r--r-- | vendor/hashbrown/src/raw/alloc.rs | 73 | ||||
| -rw-r--r-- | vendor/hashbrown/src/raw/bitmask.rs | 122 | ||||
| -rw-r--r-- | vendor/hashbrown/src/raw/generic.rs | 154 | ||||
| -rw-r--r-- | vendor/hashbrown/src/raw/mod.rs | 2460 | ||||
| -rw-r--r-- | vendor/hashbrown/src/raw/sse2.rs | 146 | ||||
| -rw-r--r-- | vendor/hashbrown/src/rustc_entry.rs | 630 | ||||
| -rw-r--r-- | vendor/hashbrown/src/scopeguard.rs | 74 | ||||
| -rw-r--r-- | vendor/hashbrown/src/set.rs | 2790 |
18 files changed, 16937 insertions, 0 deletions
diff --git a/vendor/hashbrown/src/external_trait_impls/mod.rs b/vendor/hashbrown/src/external_trait_impls/mod.rs new file mode 100644 index 000000000..ef497836c --- /dev/null +++ b/vendor/hashbrown/src/external_trait_impls/mod.rs @@ -0,0 +1,4 @@ +#[cfg(feature = "rayon")] +pub(crate) mod rayon; +#[cfg(feature = "serde")] +mod serde; diff --git a/vendor/hashbrown/src/external_trait_impls/rayon/helpers.rs b/vendor/hashbrown/src/external_trait_impls/rayon/helpers.rs new file mode 100644 index 000000000..070b08cd5 --- /dev/null +++ b/vendor/hashbrown/src/external_trait_impls/rayon/helpers.rs @@ -0,0 +1,27 @@ +use alloc::collections::LinkedList; +use alloc::vec::Vec; + +use rayon::iter::{IntoParallelIterator, ParallelIterator}; + +/// Helper for collecting parallel iterators to an intermediary +#[allow(clippy::linkedlist)] // yes, we need linked list here for efficient appending! +pub(super) fn collect<I: IntoParallelIterator>(iter: I) -> (LinkedList<Vec<I::Item>>, usize) { + let list = iter + .into_par_iter() + .fold(Vec::new, |mut vec, elem| { + vec.push(elem); + vec + }) + .map(|vec| { + let mut list = LinkedList::new(); + list.push_back(vec); + list + }) + .reduce(LinkedList::new, |mut list1, mut list2| { + list1.append(&mut list2); + list1 + }); + + let len = list.iter().map(Vec::len).sum(); + (list, len) +} diff --git a/vendor/hashbrown/src/external_trait_impls/rayon/map.rs b/vendor/hashbrown/src/external_trait_impls/rayon/map.rs new file mode 100644 index 000000000..14d91c220 --- /dev/null +++ b/vendor/hashbrown/src/external_trait_impls/rayon/map.rs @@ -0,0 +1,734 @@ +//! Rayon extensions for `HashMap`. + +use super::raw::{RawIntoParIter, RawParDrain, RawParIter}; +use crate::hash_map::HashMap; +use crate::raw::{Allocator, Global}; +use core::fmt; +use core::hash::{BuildHasher, Hash}; +use core::marker::PhantomData; +use rayon::iter::plumbing::UnindexedConsumer; +use rayon::iter::{FromParallelIterator, IntoParallelIterator, ParallelExtend, ParallelIterator}; + +/// Parallel iterator over shared references to entries in a map. +/// +/// This iterator is created by the [`par_iter`] method on [`HashMap`] +/// (provided by the [`IntoParallelRefIterator`] trait). +/// See its documentation for more. +/// +/// [`par_iter`]: /hashbrown/struct.HashMap.html#method.par_iter +/// [`HashMap`]: /hashbrown/struct.HashMap.html +/// [`IntoParallelRefIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefIterator.html +pub struct ParIter<'a, K, V> { + inner: RawParIter<(K, V)>, + marker: PhantomData<(&'a K, &'a V)>, +} + +impl<'a, K: Sync, V: Sync> ParallelIterator for ParIter<'a, K, V> { + type Item = (&'a K, &'a V); + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner + .map(|x| unsafe { + let r = x.as_ref(); + (&r.0, &r.1) + }) + .drive_unindexed(consumer) + } +} + +impl<K, V> Clone for ParIter<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Self { + inner: self.inner.clone(), + marker: PhantomData, + } + } +} + +impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug> fmt::Debug for ParIter<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let iter = unsafe { self.inner.iter() }.map(|x| unsafe { + let r = x.as_ref(); + (&r.0, &r.1) + }); + f.debug_list().entries(iter).finish() + } +} + +/// Parallel iterator over shared references to keys in a map. +/// +/// This iterator is created by the [`par_keys`] method on [`HashMap`]. +/// See its documentation for more. +/// +/// [`par_keys`]: /hashbrown/struct.HashMap.html#method.par_keys +/// [`HashMap`]: /hashbrown/struct.HashMap.html +pub struct ParKeys<'a, K, V> { + inner: RawParIter<(K, V)>, + marker: PhantomData<(&'a K, &'a V)>, +} + +impl<'a, K: Sync, V: Sync> ParallelIterator for ParKeys<'a, K, V> { + type Item = &'a K; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner + .map(|x| unsafe { &x.as_ref().0 }) + .drive_unindexed(consumer) + } +} + +impl<K, V> Clone for ParKeys<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Self { + inner: self.inner.clone(), + marker: PhantomData, + } + } +} + +impl<K: fmt::Debug + Eq + Hash, V> fmt::Debug for ParKeys<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let iter = unsafe { self.inner.iter() }.map(|x| unsafe { &x.as_ref().0 }); + f.debug_list().entries(iter).finish() + } +} + +/// Parallel iterator over shared references to values in a map. +/// +/// This iterator is created by the [`par_values`] method on [`HashMap`]. +/// See its documentation for more. +/// +/// [`par_values`]: /hashbrown/struct.HashMap.html#method.par_values +/// [`HashMap`]: /hashbrown/struct.HashMap.html +pub struct ParValues<'a, K, V> { + inner: RawParIter<(K, V)>, + marker: PhantomData<(&'a K, &'a V)>, +} + +impl<'a, K: Sync, V: Sync> ParallelIterator for ParValues<'a, K, V> { + type Item = &'a V; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner + .map(|x| unsafe { &x.as_ref().1 }) + .drive_unindexed(consumer) + } +} + +impl<K, V> Clone for ParValues<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Self { + inner: self.inner.clone(), + marker: PhantomData, + } + } +} + +impl<K: Eq + Hash, V: fmt::Debug> fmt::Debug for ParValues<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let iter = unsafe { self.inner.iter() }.map(|x| unsafe { &x.as_ref().1 }); + f.debug_list().entries(iter).finish() + } +} + +/// Parallel iterator over mutable references to entries in a map. +/// +/// This iterator is created by the [`par_iter_mut`] method on [`HashMap`] +/// (provided by the [`IntoParallelRefMutIterator`] trait). +/// See its documentation for more. +/// +/// [`par_iter_mut`]: /hashbrown/struct.HashMap.html#method.par_iter_mut +/// [`HashMap`]: /hashbrown/struct.HashMap.html +/// [`IntoParallelRefMutIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefMutIterator.html +pub struct ParIterMut<'a, K, V> { + inner: RawParIter<(K, V)>, + marker: PhantomData<(&'a K, &'a mut V)>, +} + +impl<'a, K: Sync, V: Send> ParallelIterator for ParIterMut<'a, K, V> { + type Item = (&'a K, &'a mut V); + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner + .map(|x| unsafe { + let r = x.as_mut(); + (&r.0, &mut r.1) + }) + .drive_unindexed(consumer) + } +} + +impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug> fmt::Debug for ParIterMut<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + ParIter { + inner: self.inner.clone(), + marker: PhantomData, + } + .fmt(f) + } +} + +/// Parallel iterator over mutable references to values in a map. +/// +/// This iterator is created by the [`par_values_mut`] method on [`HashMap`]. +/// See its documentation for more. +/// +/// [`par_values_mut`]: /hashbrown/struct.HashMap.html#method.par_values_mut +/// [`HashMap`]: /hashbrown/struct.HashMap.html +pub struct ParValuesMut<'a, K, V> { + inner: RawParIter<(K, V)>, + marker: PhantomData<(&'a K, &'a mut V)>, +} + +impl<'a, K: Sync, V: Send> ParallelIterator for ParValuesMut<'a, K, V> { + type Item = &'a mut V; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner + .map(|x| unsafe { &mut x.as_mut().1 }) + .drive_unindexed(consumer) + } +} + +impl<K: Eq + Hash, V: fmt::Debug> fmt::Debug for ParValuesMut<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + ParValues { + inner: self.inner.clone(), + marker: PhantomData, + } + .fmt(f) + } +} + +/// Parallel iterator over entries of a consumed map. +/// +/// This iterator is created by the [`into_par_iter`] method on [`HashMap`] +/// (provided by the [`IntoParallelIterator`] trait). +/// See its documentation for more. +/// +/// [`into_par_iter`]: /hashbrown/struct.HashMap.html#method.into_par_iter +/// [`HashMap`]: /hashbrown/struct.HashMap.html +/// [`IntoParallelIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelIterator.html +pub struct IntoParIter<K, V, A: Allocator + Clone = Global> { + inner: RawIntoParIter<(K, V), A>, +} + +impl<K: Send, V: Send, A: Allocator + Clone + Send> ParallelIterator for IntoParIter<K, V, A> { + type Item = (K, V); + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner.drive_unindexed(consumer) + } +} + +impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, A: Allocator + Clone> fmt::Debug + for IntoParIter<K, V, A> +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + ParIter { + inner: unsafe { self.inner.par_iter() }, + marker: PhantomData, + } + .fmt(f) + } +} + +/// Parallel draining iterator over entries of a map. +/// +/// This iterator is created by the [`par_drain`] method on [`HashMap`]. +/// See its documentation for more. +/// +/// [`par_drain`]: /hashbrown/struct.HashMap.html#method.par_drain +/// [`HashMap`]: /hashbrown/struct.HashMap.html +pub struct ParDrain<'a, K, V, A: Allocator + Clone = Global> { + inner: RawParDrain<'a, (K, V), A>, +} + +impl<K: Send, V: Send, A: Allocator + Clone + Sync> ParallelIterator for ParDrain<'_, K, V, A> { + type Item = (K, V); + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner.drive_unindexed(consumer) + } +} + +impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, A: Allocator + Clone> fmt::Debug + for ParDrain<'_, K, V, A> +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + ParIter { + inner: unsafe { self.inner.par_iter() }, + marker: PhantomData, + } + .fmt(f) + } +} + +impl<K: Sync, V: Sync, S, A: Allocator + Clone> HashMap<K, V, S, A> { + /// Visits (potentially in parallel) immutably borrowed keys in an arbitrary order. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_keys(&self) -> ParKeys<'_, K, V> { + ParKeys { + inner: unsafe { self.table.par_iter() }, + marker: PhantomData, + } + } + + /// Visits (potentially in parallel) immutably borrowed values in an arbitrary order. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_values(&self) -> ParValues<'_, K, V> { + ParValues { + inner: unsafe { self.table.par_iter() }, + marker: PhantomData, + } + } +} + +impl<K: Send, V: Send, S, A: Allocator + Clone> HashMap<K, V, S, A> { + /// Visits (potentially in parallel) mutably borrowed values in an arbitrary order. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_values_mut(&mut self) -> ParValuesMut<'_, K, V> { + ParValuesMut { + inner: unsafe { self.table.par_iter() }, + marker: PhantomData, + } + } + + /// Consumes (potentially in parallel) all values in an arbitrary order, + /// while preserving the map's allocated memory for reuse. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_drain(&mut self) -> ParDrain<'_, K, V, A> { + ParDrain { + inner: self.table.par_drain(), + } + } +} + +impl<K, V, S, A> HashMap<K, V, S, A> +where + K: Eq + Hash + Sync, + V: PartialEq + Sync, + S: BuildHasher + Sync, + A: Allocator + Clone + Sync, +{ + /// Returns `true` if the map is equal to another, + /// i.e. both maps contain the same keys mapped to the same values. + /// + /// This method runs in a potentially parallel fashion. + pub fn par_eq(&self, other: &Self) -> bool { + self.len() == other.len() + && self + .into_par_iter() + .all(|(key, value)| other.get(key).map_or(false, |v| *value == *v)) + } +} + +impl<K: Send, V: Send, S, A: Allocator + Clone + Send> IntoParallelIterator + for HashMap<K, V, S, A> +{ + type Item = (K, V); + type Iter = IntoParIter<K, V, A>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_par_iter(self) -> Self::Iter { + IntoParIter { + inner: self.table.into_par_iter(), + } + } +} + +impl<'a, K: Sync, V: Sync, S, A: Allocator + Clone> IntoParallelIterator + for &'a HashMap<K, V, S, A> +{ + type Item = (&'a K, &'a V); + type Iter = ParIter<'a, K, V>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_par_iter(self) -> Self::Iter { + ParIter { + inner: unsafe { self.table.par_iter() }, + marker: PhantomData, + } + } +} + +impl<'a, K: Sync, V: Send, S, A: Allocator + Clone> IntoParallelIterator + for &'a mut HashMap<K, V, S, A> +{ + type Item = (&'a K, &'a mut V); + type Iter = ParIterMut<'a, K, V>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_par_iter(self) -> Self::Iter { + ParIterMut { + inner: unsafe { self.table.par_iter() }, + marker: PhantomData, + } + } +} + +/// Collect (key, value) pairs from a parallel iterator into a +/// hashmap. If multiple pairs correspond to the same key, then the +/// ones produced earlier in the parallel iterator will be +/// overwritten, just as with a sequential iterator. +impl<K, V, S> FromParallelIterator<(K, V)> for HashMap<K, V, S, Global> +where + K: Eq + Hash + Send, + V: Send, + S: BuildHasher + Default, +{ + fn from_par_iter<P>(par_iter: P) -> Self + where + P: IntoParallelIterator<Item = (K, V)>, + { + let mut map = HashMap::default(); + map.par_extend(par_iter); + map + } +} + +/// Extend a hash map with items from a parallel iterator. +impl<K, V, S, A> ParallelExtend<(K, V)> for HashMap<K, V, S, A> +where + K: Eq + Hash + Send, + V: Send, + S: BuildHasher, + A: Allocator + Clone, +{ + fn par_extend<I>(&mut self, par_iter: I) + where + I: IntoParallelIterator<Item = (K, V)>, + { + extend(self, par_iter); + } +} + +/// Extend a hash map with copied items from a parallel iterator. +impl<'a, K, V, S, A> ParallelExtend<(&'a K, &'a V)> for HashMap<K, V, S, A> +where + K: Copy + Eq + Hash + Sync, + V: Copy + Sync, + S: BuildHasher, + A: Allocator + Clone, +{ + fn par_extend<I>(&mut self, par_iter: I) + where + I: IntoParallelIterator<Item = (&'a K, &'a V)>, + { + extend(self, par_iter); + } +} + +// This is equal to the normal `HashMap` -- no custom advantage. +fn extend<K, V, S, A, I>(map: &mut HashMap<K, V, S, A>, par_iter: I) +where + K: Eq + Hash, + S: BuildHasher, + I: IntoParallelIterator, + A: Allocator + Clone, + HashMap<K, V, S, A>: Extend<I::Item>, +{ + let (list, len) = super::helpers::collect(par_iter); + + // Keys may be already present or show multiple times in the iterator. + // Reserve the entire length if the map is empty. + // Otherwise reserve half the length (rounded up), so the map + // will only resize twice in the worst case. + let reserve = if map.is_empty() { len } else { (len + 1) / 2 }; + map.reserve(reserve); + for vec in list { + map.extend(vec); + } +} + +#[cfg(test)] +mod test_par_map { + use alloc::vec::Vec; + use core::hash::{Hash, Hasher}; + use core::sync::atomic::{AtomicUsize, Ordering}; + + use rayon::prelude::*; + + use crate::hash_map::HashMap; + + struct Dropable<'a> { + k: usize, + counter: &'a AtomicUsize, + } + + impl Dropable<'_> { + fn new(k: usize, counter: &AtomicUsize) -> Dropable<'_> { + counter.fetch_add(1, Ordering::Relaxed); + + Dropable { k, counter } + } + } + + impl Drop for Dropable<'_> { + fn drop(&mut self) { + self.counter.fetch_sub(1, Ordering::Relaxed); + } + } + + impl Clone for Dropable<'_> { + fn clone(&self) -> Self { + Dropable::new(self.k, self.counter) + } + } + + impl Hash for Dropable<'_> { + fn hash<H>(&self, state: &mut H) + where + H: Hasher, + { + self.k.hash(state); + } + } + + impl PartialEq for Dropable<'_> { + fn eq(&self, other: &Self) -> bool { + self.k == other.k + } + } + + impl Eq for Dropable<'_> {} + + #[test] + fn test_into_iter_drops() { + let key = AtomicUsize::new(0); + let value = AtomicUsize::new(0); + + let hm = { + let mut hm = HashMap::new(); + + assert_eq!(key.load(Ordering::Relaxed), 0); + assert_eq!(value.load(Ordering::Relaxed), 0); + + for i in 0..100 { + let d1 = Dropable::new(i, &key); + let d2 = Dropable::new(i + 100, &value); + hm.insert(d1, d2); + } + + assert_eq!(key.load(Ordering::Relaxed), 100); + assert_eq!(value.load(Ordering::Relaxed), 100); + + hm + }; + + // By the way, ensure that cloning doesn't screw up the dropping. + drop(hm.clone()); + + assert_eq!(key.load(Ordering::Relaxed), 100); + assert_eq!(value.load(Ordering::Relaxed), 100); + + // Ensure that dropping the iterator does not leak anything. + drop(hm.clone().into_par_iter()); + + { + assert_eq!(key.load(Ordering::Relaxed), 100); + assert_eq!(value.load(Ordering::Relaxed), 100); + + // retain only half + let _v: Vec<_> = hm + .into_par_iter() + .filter(|&(ref key, _)| key.k < 50) + .collect(); + + assert_eq!(key.load(Ordering::Relaxed), 50); + assert_eq!(value.load(Ordering::Relaxed), 50); + }; + + assert_eq!(key.load(Ordering::Relaxed), 0); + assert_eq!(value.load(Ordering::Relaxed), 0); + } + + #[test] + fn test_drain_drops() { + let key = AtomicUsize::new(0); + let value = AtomicUsize::new(0); + + let mut hm = { + let mut hm = HashMap::new(); + + assert_eq!(key.load(Ordering::Relaxed), 0); + assert_eq!(value.load(Ordering::Relaxed), 0); + + for i in 0..100 { + let d1 = Dropable::new(i, &key); + let d2 = Dropable::new(i + 100, &value); + hm.insert(d1, d2); + } + + assert_eq!(key.load(Ordering::Relaxed), 100); + assert_eq!(value.load(Ordering::Relaxed), 100); + + hm + }; + + // By the way, ensure that cloning doesn't screw up the dropping. + drop(hm.clone()); + + assert_eq!(key.load(Ordering::Relaxed), 100); + assert_eq!(value.load(Ordering::Relaxed), 100); + + // Ensure that dropping the drain iterator does not leak anything. + drop(hm.clone().par_drain()); + + { + assert_eq!(key.load(Ordering::Relaxed), 100); + assert_eq!(value.load(Ordering::Relaxed), 100); + + // retain only half + let _v: Vec<_> = hm.drain().filter(|&(ref key, _)| key.k < 50).collect(); + assert!(hm.is_empty()); + + assert_eq!(key.load(Ordering::Relaxed), 50); + assert_eq!(value.load(Ordering::Relaxed), 50); + }; + + assert_eq!(key.load(Ordering::Relaxed), 0); + assert_eq!(value.load(Ordering::Relaxed), 0); + } + + #[test] + fn test_empty_iter() { + let mut m: HashMap<isize, bool> = HashMap::new(); + assert_eq!(m.par_drain().count(), 0); + assert_eq!(m.par_keys().count(), 0); + assert_eq!(m.par_values().count(), 0); + assert_eq!(m.par_values_mut().count(), 0); + assert_eq!(m.par_iter().count(), 0); + assert_eq!(m.par_iter_mut().count(), 0); + assert_eq!(m.len(), 0); + assert!(m.is_empty()); + assert_eq!(m.into_par_iter().count(), 0); + } + + #[test] + fn test_iterate() { + let mut m = HashMap::with_capacity(4); + for i in 0..32 { + assert!(m.insert(i, i * 2).is_none()); + } + assert_eq!(m.len(), 32); + + let observed = AtomicUsize::new(0); + + m.par_iter().for_each(|(k, v)| { + assert_eq!(*v, *k * 2); + observed.fetch_or(1 << *k, Ordering::Relaxed); + }); + assert_eq!(observed.into_inner(), 0xFFFF_FFFF); + } + + #[test] + fn test_keys() { + let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')]; + let map: HashMap<_, _> = vec.into_par_iter().collect(); + let keys: Vec<_> = map.par_keys().cloned().collect(); + assert_eq!(keys.len(), 3); + assert!(keys.contains(&1)); + assert!(keys.contains(&2)); + assert!(keys.contains(&3)); + } + + #[test] + fn test_values() { + let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')]; + let map: HashMap<_, _> = vec.into_par_iter().collect(); + let values: Vec<_> = map.par_values().cloned().collect(); + assert_eq!(values.len(), 3); + assert!(values.contains(&'a')); + assert!(values.contains(&'b')); + assert!(values.contains(&'c')); + } + + #[test] + fn test_values_mut() { + let vec = vec![(1, 1), (2, 2), (3, 3)]; + let mut map: HashMap<_, _> = vec.into_par_iter().collect(); + map.par_values_mut().for_each(|value| *value *= 2); + let values: Vec<_> = map.par_values().cloned().collect(); + assert_eq!(values.len(), 3); + assert!(values.contains(&2)); + assert!(values.contains(&4)); + assert!(values.contains(&6)); + } + + #[test] + fn test_eq() { + let mut m1 = HashMap::new(); + m1.insert(1, 2); + m1.insert(2, 3); + m1.insert(3, 4); + + let mut m2 = HashMap::new(); + m2.insert(1, 2); + m2.insert(2, 3); + + assert!(!m1.par_eq(&m2)); + + m2.insert(3, 4); + + assert!(m1.par_eq(&m2)); + } + + #[test] + fn test_from_iter() { + let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; + + let map: HashMap<_, _> = xs.par_iter().cloned().collect(); + + for &(k, v) in &xs { + assert_eq!(map.get(&k), Some(&v)); + } + } + + #[test] + fn test_extend_ref() { + let mut a = HashMap::new(); + a.insert(1, "one"); + let mut b = HashMap::new(); + b.insert(2, "two"); + b.insert(3, "three"); + + a.par_extend(&b); + + assert_eq!(a.len(), 3); + assert_eq!(a[&1], "one"); + assert_eq!(a[&2], "two"); + assert_eq!(a[&3], "three"); + } +} diff --git a/vendor/hashbrown/src/external_trait_impls/rayon/mod.rs b/vendor/hashbrown/src/external_trait_impls/rayon/mod.rs new file mode 100644 index 000000000..99337a1ce --- /dev/null +++ b/vendor/hashbrown/src/external_trait_impls/rayon/mod.rs @@ -0,0 +1,4 @@ +mod helpers; +pub(crate) mod map; +pub(crate) mod raw; +pub(crate) mod set; diff --git a/vendor/hashbrown/src/external_trait_impls/rayon/raw.rs b/vendor/hashbrown/src/external_trait_impls/rayon/raw.rs new file mode 100644 index 000000000..883303e27 --- /dev/null +++ b/vendor/hashbrown/src/external_trait_impls/rayon/raw.rs @@ -0,0 +1,231 @@ +use crate::raw::Bucket; +use crate::raw::{Allocator, Global, RawIter, RawIterRange, RawTable}; +use crate::scopeguard::guard; +use alloc::alloc::dealloc; +use core::marker::PhantomData; +use core::mem; +use core::ptr::NonNull; +use rayon::iter::{ + plumbing::{self, Folder, UnindexedConsumer, UnindexedProducer}, + ParallelIterator, +}; + +/// Parallel iterator which returns a raw pointer to every full bucket in the table. +pub struct RawParIter<T> { + iter: RawIterRange<T>, +} + +impl<T> RawParIter<T> { + #[cfg_attr(feature = "inline-more", inline)] + pub(super) unsafe fn iter(&self) -> RawIterRange<T> { + self.iter.clone() + } +} + +impl<T> Clone for RawParIter<T> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Self { + iter: self.iter.clone(), + } + } +} + +impl<T> From<RawIter<T>> for RawParIter<T> { + fn from(it: RawIter<T>) -> Self { + RawParIter { iter: it.iter } + } +} + +impl<T> ParallelIterator for RawParIter<T> { + type Item = Bucket<T>; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + let producer = ParIterProducer { iter: self.iter }; + plumbing::bridge_unindexed(producer, consumer) + } +} + +/// Producer which returns a `Bucket<T>` for every element. +struct ParIterProducer<T> { + iter: RawIterRange<T>, +} + +impl<T> UnindexedProducer for ParIterProducer<T> { + type Item = Bucket<T>; + + #[cfg_attr(feature = "inline-more", inline)] + fn split(self) -> (Self, Option<Self>) { + let (left, right) = self.iter.split(); + let left = ParIterProducer { iter: left }; + let right = right.map(|right| ParIterProducer { iter: right }); + (left, right) + } + + #[cfg_attr(feature = "inline-more", inline)] + fn fold_with<F>(self, folder: F) -> F + where + F: Folder<Self::Item>, + { + folder.consume_iter(self.iter) + } +} + +/// Parallel iterator which consumes a table and returns elements. +pub struct RawIntoParIter<T, A: Allocator + Clone = Global> { + table: RawTable<T, A>, +} + +impl<T, A: Allocator + Clone> RawIntoParIter<T, A> { + #[cfg_attr(feature = "inline-more", inline)] + pub(super) unsafe fn par_iter(&self) -> RawParIter<T> { + self.table.par_iter() + } +} + +impl<T: Send, A: Allocator + Clone + Send> ParallelIterator for RawIntoParIter<T, A> { + type Item = T; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + let iter = unsafe { self.table.iter().iter }; + let _guard = guard(self.table.into_allocation(), |alloc| { + if let Some((ptr, layout)) = *alloc { + unsafe { + dealloc(ptr.as_ptr(), layout); + } + } + }); + let producer = ParDrainProducer { iter }; + plumbing::bridge_unindexed(producer, consumer) + } +} + +/// Parallel iterator which consumes elements without freeing the table storage. +pub struct RawParDrain<'a, T, A: Allocator + Clone = Global> { + // We don't use a &'a mut RawTable<T> because we want RawParDrain to be + // covariant over T. + table: NonNull<RawTable<T, A>>, + marker: PhantomData<&'a RawTable<T, A>>, +} + +unsafe impl<T: Send, A: Allocator + Clone> Send for RawParDrain<'_, T, A> {} + +impl<T, A: Allocator + Clone> RawParDrain<'_, T, A> { + #[cfg_attr(feature = "inline-more", inline)] + pub(super) unsafe fn par_iter(&self) -> RawParIter<T> { + self.table.as_ref().par_iter() + } +} + +impl<T: Send, A: Allocator + Clone> ParallelIterator for RawParDrain<'_, T, A> { + type Item = T; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + let _guard = guard(self.table, |table| unsafe { + table.as_mut().clear_no_drop(); + }); + let iter = unsafe { self.table.as_ref().iter().iter }; + mem::forget(self); + let producer = ParDrainProducer { iter }; + plumbing::bridge_unindexed(producer, consumer) + } +} + +impl<T, A: Allocator + Clone> Drop for RawParDrain<'_, T, A> { + fn drop(&mut self) { + // If drive_unindexed is not called then simply clear the table. + unsafe { + self.table.as_mut().clear(); + } + } +} + +/// Producer which will consume all elements in the range, even if it is dropped +/// halfway through. +struct ParDrainProducer<T> { + iter: RawIterRange<T>, +} + +impl<T: Send> UnindexedProducer for ParDrainProducer<T> { + type Item = T; + + #[cfg_attr(feature = "inline-more", inline)] + fn split(self) -> (Self, Option<Self>) { + let (left, right) = self.iter.clone().split(); + mem::forget(self); + let left = ParDrainProducer { iter: left }; + let right = right.map(|right| ParDrainProducer { iter: right }); + (left, right) + } + + #[cfg_attr(feature = "inline-more", inline)] + fn fold_with<F>(mut self, mut folder: F) -> F + where + F: Folder<Self::Item>, + { + // Make sure to modify the iterator in-place so that any remaining + // elements are processed in our Drop impl. + for item in &mut self.iter { + folder = folder.consume(unsafe { item.read() }); + if folder.full() { + return folder; + } + } + + // If we processed all elements then we don't need to run the drop. + mem::forget(self); + folder + } +} + +impl<T> Drop for ParDrainProducer<T> { + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + // Drop all remaining elements + if mem::needs_drop::<T>() { + for item in &mut self.iter { + unsafe { + item.drop(); + } + } + } + } +} + +impl<T, A: Allocator + Clone> RawTable<T, A> { + /// Returns a parallel iterator over the elements in a `RawTable`. + #[cfg_attr(feature = "inline-more", inline)] + pub unsafe fn par_iter(&self) -> RawParIter<T> { + RawParIter { + iter: self.iter().iter, + } + } + + /// Returns a parallel iterator over the elements in a `RawTable`. + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_par_iter(self) -> RawIntoParIter<T, A> { + RawIntoParIter { table: self } + } + + /// Returns a parallel iterator which consumes all elements of a `RawTable` + /// without freeing its memory allocation. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_drain(&mut self) -> RawParDrain<'_, T, A> { + RawParDrain { + table: NonNull::from(self), + marker: PhantomData, + } + } +} diff --git a/vendor/hashbrown/src/external_trait_impls/rayon/set.rs b/vendor/hashbrown/src/external_trait_impls/rayon/set.rs new file mode 100644 index 000000000..ee4f6e669 --- /dev/null +++ b/vendor/hashbrown/src/external_trait_impls/rayon/set.rs @@ -0,0 +1,659 @@ +//! Rayon extensions for `HashSet`. + +use super::map; +use crate::hash_set::HashSet; +use crate::raw::{Allocator, Global}; +use core::hash::{BuildHasher, Hash}; +use rayon::iter::plumbing::UnindexedConsumer; +use rayon::iter::{FromParallelIterator, IntoParallelIterator, ParallelExtend, ParallelIterator}; + +/// Parallel iterator over elements of a consumed set. +/// +/// This iterator is created by the [`into_par_iter`] method on [`HashSet`] +/// (provided by the [`IntoParallelIterator`] trait). +/// See its documentation for more. +/// +/// [`into_par_iter`]: /hashbrown/struct.HashSet.html#method.into_par_iter +/// [`HashSet`]: /hashbrown/struct.HashSet.html +/// [`IntoParallelIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelIterator.html +pub struct IntoParIter<T, A: Allocator + Clone = Global> { + inner: map::IntoParIter<T, (), A>, +} + +impl<T: Send, A: Allocator + Clone + Send> ParallelIterator for IntoParIter<T, A> { + type Item = T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner.map(|(k, _)| k).drive_unindexed(consumer) + } +} + +/// Parallel draining iterator over entries of a set. +/// +/// This iterator is created by the [`par_drain`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`par_drain`]: /hashbrown/struct.HashSet.html#method.par_drain +/// [`HashSet`]: /hashbrown/struct.HashSet.html +pub struct ParDrain<'a, T, A: Allocator + Clone = Global> { + inner: map::ParDrain<'a, T, (), A>, +} + +impl<T: Send, A: Allocator + Clone + Send + Sync> ParallelIterator for ParDrain<'_, T, A> { + type Item = T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner.map(|(k, _)| k).drive_unindexed(consumer) + } +} + +/// Parallel iterator over shared references to elements in a set. +/// +/// This iterator is created by the [`par_iter`] method on [`HashSet`] +/// (provided by the [`IntoParallelRefIterator`] trait). +/// See its documentation for more. +/// +/// [`par_iter`]: /hashbrown/struct.HashSet.html#method.par_iter +/// [`HashSet`]: /hashbrown/struct.HashSet.html +/// [`IntoParallelRefIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefIterator.html +pub struct ParIter<'a, T> { + inner: map::ParKeys<'a, T, ()>, +} + +impl<'a, T: Sync> ParallelIterator for ParIter<'a, T> { + type Item = &'a T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner.drive_unindexed(consumer) + } +} + +/// Parallel iterator over shared references to elements in the difference of +/// sets. +/// +/// This iterator is created by the [`par_difference`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`par_difference`]: /hashbrown/struct.HashSet.html#method.par_difference +/// [`HashSet`]: /hashbrown/struct.HashSet.html +pub struct ParDifference<'a, T, S, A: Allocator + Clone = Global> { + a: &'a HashSet<T, S, A>, + b: &'a HashSet<T, S, A>, +} + +impl<'a, T, S, A> ParallelIterator for ParDifference<'a, T, S, A> +where + T: Eq + Hash + Sync, + S: BuildHasher + Sync, + A: Allocator + Clone + Sync, +{ + type Item = &'a T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.a + .into_par_iter() + .filter(|&x| !self.b.contains(x)) + .drive_unindexed(consumer) + } +} + +/// Parallel iterator over shared references to elements in the symmetric +/// difference of sets. +/// +/// This iterator is created by the [`par_symmetric_difference`] method on +/// [`HashSet`]. +/// See its documentation for more. +/// +/// [`par_symmetric_difference`]: /hashbrown/struct.HashSet.html#method.par_symmetric_difference +/// [`HashSet`]: /hashbrown/struct.HashSet.html +pub struct ParSymmetricDifference<'a, T, S, A: Allocator + Clone = Global> { + a: &'a HashSet<T, S, A>, + b: &'a HashSet<T, S, A>, +} + +impl<'a, T, S, A> ParallelIterator for ParSymmetricDifference<'a, T, S, A> +where + T: Eq + Hash + Sync, + S: BuildHasher + Sync, + A: Allocator + Clone + Sync, +{ + type Item = &'a T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.a + .par_difference(self.b) + .chain(self.b.par_difference(self.a)) + .drive_unindexed(consumer) + } +} + +/// Parallel iterator over shared references to elements in the intersection of +/// sets. +/// +/// This iterator is created by the [`par_intersection`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`par_intersection`]: /hashbrown/struct.HashSet.html#method.par_intersection +/// [`HashSet`]: /hashbrown/struct.HashSet.html +pub struct ParIntersection<'a, T, S, A: Allocator + Clone = Global> { + a: &'a HashSet<T, S, A>, + b: &'a HashSet<T, S, A>, +} + +impl<'a, T, S, A> ParallelIterator for ParIntersection<'a, T, S, A> +where + T: Eq + Hash + Sync, + S: BuildHasher + Sync, + A: Allocator + Clone + Sync, +{ + type Item = &'a T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.a + .into_par_iter() + .filter(|&x| self.b.contains(x)) + .drive_unindexed(consumer) + } +} + +/// Parallel iterator over shared references to elements in the union of sets. +/// +/// This iterator is created by the [`par_union`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`par_union`]: /hashbrown/struct.HashSet.html#method.par_union +/// [`HashSet`]: /hashbrown/struct.HashSet.html +pub struct ParUnion<'a, T, S, A: Allocator + Clone = Global> { + a: &'a HashSet<T, S, A>, + b: &'a HashSet<T, S, A>, +} + +impl<'a, T, S, A> ParallelIterator for ParUnion<'a, T, S, A> +where + T: Eq + Hash + Sync, + S: BuildHasher + Sync, + A: Allocator + Clone + Sync, +{ + type Item = &'a T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + // We'll iterate one set in full, and only the remaining difference from the other. + // Use the smaller set for the difference in order to reduce hash lookups. + let (smaller, larger) = if self.a.len() <= self.b.len() { + (self.a, self.b) + } else { + (self.b, self.a) + }; + larger + .into_par_iter() + .chain(smaller.par_difference(larger)) + .drive_unindexed(consumer) + } +} + +impl<T, S, A> HashSet<T, S, A> +where + T: Eq + Hash + Sync, + S: BuildHasher + Sync, + A: Allocator + Clone + Sync, +{ + /// Visits (potentially in parallel) the values representing the union, + /// i.e. all the values in `self` or `other`, without duplicates. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_union<'a>(&'a self, other: &'a Self) -> ParUnion<'a, T, S, A> { + ParUnion { a: self, b: other } + } + + /// Visits (potentially in parallel) the values representing the difference, + /// i.e. the values that are in `self` but not in `other`. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_difference<'a>(&'a self, other: &'a Self) -> ParDifference<'a, T, S, A> { + ParDifference { a: self, b: other } + } + + /// Visits (potentially in parallel) the values representing the symmetric + /// difference, i.e. the values that are in `self` or in `other` but not in both. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_symmetric_difference<'a>( + &'a self, + other: &'a Self, + ) -> ParSymmetricDifference<'a, T, S, A> { + ParSymmetricDifference { a: self, b: other } + } + + /// Visits (potentially in parallel) the values representing the + /// intersection, i.e. the values that are both in `self` and `other`. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_intersection<'a>(&'a self, other: &'a Self) -> ParIntersection<'a, T, S, A> { + ParIntersection { a: self, b: other } + } + + /// Returns `true` if `self` has no elements in common with `other`. + /// This is equivalent to checking for an empty intersection. + /// + /// This method runs in a potentially parallel fashion. + pub fn par_is_disjoint(&self, other: &Self) -> bool { + self.into_par_iter().all(|x| !other.contains(x)) + } + + /// Returns `true` if the set is a subset of another, + /// i.e. `other` contains at least all the values in `self`. + /// + /// This method runs in a potentially parallel fashion. + pub fn par_is_subset(&self, other: &Self) -> bool { + if self.len() <= other.len() { + self.into_par_iter().all(|x| other.contains(x)) + } else { + false + } + } + + /// Returns `true` if the set is a superset of another, + /// i.e. `self` contains at least all the values in `other`. + /// + /// This method runs in a potentially parallel fashion. + pub fn par_is_superset(&self, other: &Self) -> bool { + other.par_is_subset(self) + } + + /// Returns `true` if the set is equal to another, + /// i.e. both sets contain the same values. + /// + /// This method runs in a potentially parallel fashion. + pub fn par_eq(&self, other: &Self) -> bool { + self.len() == other.len() && self.par_is_subset(other) + } +} + +impl<T, S, A> HashSet<T, S, A> +where + T: Eq + Hash + Send, + A: Allocator + Clone + Send, +{ + /// Consumes (potentially in parallel) all values in an arbitrary order, + /// while preserving the set's allocated memory for reuse. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_drain(&mut self) -> ParDrain<'_, T, A> { + ParDrain { + inner: self.map.par_drain(), + } + } +} + +impl<T: Send, S, A: Allocator + Clone + Send> IntoParallelIterator for HashSet<T, S, A> { + type Item = T; + type Iter = IntoParIter<T, A>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_par_iter(self) -> Self::Iter { + IntoParIter { + inner: self.map.into_par_iter(), + } + } +} + +impl<'a, T: Sync, S, A: Allocator + Clone> IntoParallelIterator for &'a HashSet<T, S, A> { + type Item = &'a T; + type Iter = ParIter<'a, T>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_par_iter(self) -> Self::Iter { + ParIter { + inner: self.map.par_keys(), + } + } +} + +/// Collect values from a parallel iterator into a hashset. +impl<T, S> FromParallelIterator<T> for HashSet<T, S, Global> +where + T: Eq + Hash + Send, + S: BuildHasher + Default, +{ + fn from_par_iter<P>(par_iter: P) -> Self + where + P: IntoParallelIterator<Item = T>, + { + let mut set = HashSet::default(); + set.par_extend(par_iter); + set + } +} + +/// Extend a hash set with items from a parallel iterator. +impl<T, S> ParallelExtend<T> for HashSet<T, S, Global> +where + T: Eq + Hash + Send, + S: BuildHasher, +{ + fn par_extend<I>(&mut self, par_iter: I) + where + I: IntoParallelIterator<Item = T>, + { + extend(self, par_iter); + } +} + +/// Extend a hash set with copied items from a parallel iterator. +impl<'a, T, S> ParallelExtend<&'a T> for HashSet<T, S, Global> +where + T: 'a + Copy + Eq + Hash + Sync, + S: BuildHasher, +{ + fn par_extend<I>(&mut self, par_iter: I) + where + I: IntoParallelIterator<Item = &'a T>, + { + extend(self, par_iter); + } +} + +// This is equal to the normal `HashSet` -- no custom advantage. +fn extend<T, S, I, A>(set: &mut HashSet<T, S, A>, par_iter: I) +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, + I: IntoParallelIterator, + HashSet<T, S, A>: Extend<I::Item>, +{ + let (list, len) = super::helpers::collect(par_iter); + + // Values may be already present or show multiple times in the iterator. + // Reserve the entire length if the set is empty. + // Otherwise reserve half the length (rounded up), so the set + // will only resize twice in the worst case. + let reserve = if set.is_empty() { len } else { (len + 1) / 2 }; + set.reserve(reserve); + for vec in list { + set.extend(vec); + } +} + +#[cfg(test)] +mod test_par_set { + use alloc::vec::Vec; + use core::sync::atomic::{AtomicUsize, Ordering}; + + use rayon::prelude::*; + + use crate::hash_set::HashSet; + + #[test] + fn test_disjoint() { + let mut xs = HashSet::new(); + let mut ys = HashSet::new(); + assert!(xs.par_is_disjoint(&ys)); + assert!(ys.par_is_disjoint(&xs)); + assert!(xs.insert(5)); + assert!(ys.insert(11)); + assert!(xs.par_is_disjoint(&ys)); + assert!(ys.par_is_disjoint(&xs)); + assert!(xs.insert(7)); + assert!(xs.insert(19)); + assert!(xs.insert(4)); + assert!(ys.insert(2)); + assert!(ys.insert(-11)); + assert!(xs.par_is_disjoint(&ys)); + assert!(ys.par_is_disjoint(&xs)); + assert!(ys.insert(7)); + assert!(!xs.par_is_disjoint(&ys)); + assert!(!ys.par_is_disjoint(&xs)); + } + + #[test] + fn test_subset_and_superset() { + let mut a = HashSet::new(); + assert!(a.insert(0)); + assert!(a.insert(5)); + assert!(a.insert(11)); + assert!(a.insert(7)); + + let mut b = HashSet::new(); + assert!(b.insert(0)); + assert!(b.insert(7)); + assert!(b.insert(19)); + assert!(b.insert(250)); + assert!(b.insert(11)); + assert!(b.insert(200)); + + assert!(!a.par_is_subset(&b)); + assert!(!a.par_is_superset(&b)); + assert!(!b.par_is_subset(&a)); + assert!(!b.par_is_superset(&a)); + + assert!(b.insert(5)); + + assert!(a.par_is_subset(&b)); + assert!(!a.par_is_superset(&b)); + assert!(!b.par_is_subset(&a)); + assert!(b.par_is_superset(&a)); + } + + #[test] + fn test_iterate() { + let mut a = HashSet::new(); + for i in 0..32 { + assert!(a.insert(i)); + } + let observed = AtomicUsize::new(0); + a.par_iter().for_each(|k| { + observed.fetch_or(1 << *k, Ordering::Relaxed); + }); + assert_eq!(observed.into_inner(), 0xFFFF_FFFF); + } + + #[test] + fn test_intersection() { + let mut a = HashSet::new(); + let mut b = HashSet::new(); + + assert!(a.insert(11)); + assert!(a.insert(1)); + assert!(a.insert(3)); + assert!(a.insert(77)); + assert!(a.insert(103)); + assert!(a.insert(5)); + assert!(a.insert(-5)); + + assert!(b.insert(2)); + assert!(b.insert(11)); + assert!(b.insert(77)); + assert!(b.insert(-9)); + assert!(b.insert(-42)); + assert!(b.insert(5)); + assert!(b.insert(3)); + + let expected = [3, 5, 11, 77]; + let i = a + .par_intersection(&b) + .map(|x| { + assert!(expected.contains(x)); + 1 + }) + .sum::<usize>(); + assert_eq!(i, expected.len()); + } + + #[test] + fn test_difference() { + let mut a = HashSet::new(); + let mut b = HashSet::new(); + + assert!(a.insert(1)); + assert!(a.insert(3)); + assert!(a.insert(5)); + assert!(a.insert(9)); + assert!(a.insert(11)); + + assert!(b.insert(3)); + assert!(b.insert(9)); + + let expected = [1, 5, 11]; + let i = a + .par_difference(&b) + .map(|x| { + assert!(expected.contains(x)); + 1 + }) + .sum::<usize>(); + assert_eq!(i, expected.len()); + } + + #[test] + fn test_symmetric_difference() { + let mut a = HashSet::new(); + let mut b = HashSet::new(); + + assert!(a.insert(1)); + assert!(a.insert(3)); + assert!(a.insert(5)); + assert!(a.insert(9)); + assert!(a.insert(11)); + + assert!(b.insert(-2)); + assert!(b.insert(3)); + assert!(b.insert(9)); + assert!(b.insert(14)); + assert!(b.insert(22)); + + let expected = [-2, 1, 5, 11, 14, 22]; + let i = a + .par_symmetric_difference(&b) + .map(|x| { + assert!(expected.contains(x)); + 1 + }) + .sum::<usize>(); + assert_eq!(i, expected.len()); + } + + #[test] + fn test_union() { + let mut a = HashSet::new(); + let mut b = HashSet::new(); + + assert!(a.insert(1)); + assert!(a.insert(3)); + assert!(a.insert(5)); + assert!(a.insert(9)); + assert!(a.insert(11)); + assert!(a.insert(16)); + assert!(a.insert(19)); + assert!(a.insert(24)); + + assert!(b.insert(-2)); + assert!(b.insert(1)); + assert!(b.insert(5)); + assert!(b.insert(9)); + assert!(b.insert(13)); + assert!(b.insert(19)); + + let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24]; + let i = a + .par_union(&b) + .map(|x| { + assert!(expected.contains(x)); + 1 + }) + .sum::<usize>(); + assert_eq!(i, expected.len()); + } + + #[test] + fn test_from_iter() { + let xs = [1, 2, 3, 4, 5, 6, 7, 8, 9]; + + let set: HashSet<_> = xs.par_iter().cloned().collect(); + + for x in &xs { + assert!(set.contains(x)); + } + } + + #[test] + fn test_move_iter() { + let hs = { + let mut hs = HashSet::new(); + + hs.insert('a'); + hs.insert('b'); + + hs + }; + + let v = hs.into_par_iter().collect::<Vec<char>>(); + assert!(v == ['a', 'b'] || v == ['b', 'a']); + } + + #[test] + fn test_eq() { + // These constants once happened to expose a bug in insert(). + // I'm keeping them around to prevent a regression. + let mut s1 = HashSet::new(); + + s1.insert(1); + s1.insert(2); + s1.insert(3); + + let mut s2 = HashSet::new(); + + s2.insert(1); + s2.insert(2); + + assert!(!s1.par_eq(&s2)); + + s2.insert(3); + + assert!(s1.par_eq(&s2)); + } + + #[test] + fn test_extend_ref() { + let mut a = HashSet::new(); + a.insert(1); + + a.par_extend(&[2, 3, 4][..]); + + assert_eq!(a.len(), 4); + assert!(a.contains(&1)); + assert!(a.contains(&2)); + assert!(a.contains(&3)); + assert!(a.contains(&4)); + + let mut b = HashSet::new(); + b.insert(5); + b.insert(6); + + a.par_extend(&b); + + assert_eq!(a.len(), 6); + assert!(a.contains(&1)); + assert!(a.contains(&2)); + assert!(a.contains(&3)); + assert!(a.contains(&4)); + assert!(a.contains(&5)); + assert!(a.contains(&6)); + } +} diff --git a/vendor/hashbrown/src/external_trait_impls/serde.rs b/vendor/hashbrown/src/external_trait_impls/serde.rs new file mode 100644 index 000000000..4d62deeb7 --- /dev/null +++ b/vendor/hashbrown/src/external_trait_impls/serde.rs @@ -0,0 +1,201 @@ +mod size_hint { + use core::cmp; + + /// This presumably exists to prevent denial of service attacks. + /// + /// Original discussion: https://github.com/serde-rs/serde/issues/1114. + #[cfg_attr(feature = "inline-more", inline)] + pub(super) fn cautious(hint: Option<usize>) -> usize { + cmp::min(hint.unwrap_or(0), 4096) + } +} + +mod map { + use core::fmt; + use core::hash::{BuildHasher, Hash}; + use core::marker::PhantomData; + use serde::de::{Deserialize, Deserializer, MapAccess, Visitor}; + use serde::ser::{Serialize, Serializer}; + + use crate::hash_map::HashMap; + + use super::size_hint; + + impl<K, V, H> Serialize for HashMap<K, V, H> + where + K: Serialize + Eq + Hash, + V: Serialize, + H: BuildHasher, + { + #[cfg_attr(feature = "inline-more", inline)] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.collect_map(self) + } + } + + impl<'de, K, V, S> Deserialize<'de> for HashMap<K, V, S> + where + K: Deserialize<'de> + Eq + Hash, + V: Deserialize<'de>, + S: BuildHasher + Default, + { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct MapVisitor<K, V, S> { + marker: PhantomData<HashMap<K, V, S>>, + } + + impl<'de, K, V, S> Visitor<'de> for MapVisitor<K, V, S> + where + K: Deserialize<'de> + Eq + Hash, + V: Deserialize<'de>, + S: BuildHasher + Default, + { + type Value = HashMap<K, V, S>; + + fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { + formatter.write_str("a map") + } + + #[cfg_attr(feature = "inline-more", inline)] + fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error> + where + A: MapAccess<'de>, + { + let mut values = HashMap::with_capacity_and_hasher( + size_hint::cautious(map.size_hint()), + S::default(), + ); + + while let Some((key, value)) = map.next_entry()? { + values.insert(key, value); + } + + Ok(values) + } + } + + let visitor = MapVisitor { + marker: PhantomData, + }; + deserializer.deserialize_map(visitor) + } + } +} + +mod set { + use core::fmt; + use core::hash::{BuildHasher, Hash}; + use core::marker::PhantomData; + use serde::de::{Deserialize, Deserializer, SeqAccess, Visitor}; + use serde::ser::{Serialize, Serializer}; + + use crate::hash_set::HashSet; + + use super::size_hint; + + impl<T, H> Serialize for HashSet<T, H> + where + T: Serialize + Eq + Hash, + H: BuildHasher, + { + #[cfg_attr(feature = "inline-more", inline)] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.collect_seq(self) + } + } + + impl<'de, T, S> Deserialize<'de> for HashSet<T, S> + where + T: Deserialize<'de> + Eq + Hash, + S: BuildHasher + Default, + { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct SeqVisitor<T, S> { + marker: PhantomData<HashSet<T, S>>, + } + + impl<'de, T, S> Visitor<'de> for SeqVisitor<T, S> + where + T: Deserialize<'de> + Eq + Hash, + S: BuildHasher + Default, + { + type Value = HashSet<T, S>; + + fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { + formatter.write_str("a sequence") + } + + #[cfg_attr(feature = "inline-more", inline)] + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let mut values = HashSet::with_capacity_and_hasher( + size_hint::cautious(seq.size_hint()), + S::default(), + ); + + while let Some(value) = seq.next_element()? { + values.insert(value); + } + + Ok(values) + } + } + + let visitor = SeqVisitor { + marker: PhantomData, + }; + deserializer.deserialize_seq(visitor) + } + + #[allow(clippy::missing_errors_doc)] + fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error> + where + D: Deserializer<'de>, + { + struct SeqInPlaceVisitor<'a, T, S>(&'a mut HashSet<T, S>); + + impl<'a, 'de, T, S> Visitor<'de> for SeqInPlaceVisitor<'a, T, S> + where + T: Deserialize<'de> + Eq + Hash, + S: BuildHasher + Default, + { + type Value = (); + + fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { + formatter.write_str("a sequence") + } + + #[cfg_attr(feature = "inline-more", inline)] + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + self.0.clear(); + self.0.reserve(size_hint::cautious(seq.size_hint())); + + while let Some(value) = seq.next_element()? { + self.0.insert(value); + } + + Ok(()) + } + } + + deserializer.deserialize_seq(SeqInPlaceVisitor(place)) + } + } +} diff --git a/vendor/hashbrown/src/lib.rs b/vendor/hashbrown/src/lib.rs new file mode 100644 index 000000000..bc1c97130 --- /dev/null +++ b/vendor/hashbrown/src/lib.rs @@ -0,0 +1,150 @@ +//! This crate is a Rust port of Google's high-performance [SwissTable] hash +//! map, adapted to make it a drop-in replacement for Rust's standard `HashMap` +//! and `HashSet` types. +//! +//! The original C++ version of [SwissTable] can be found [here], and this +//! [CppCon talk] gives an overview of how the algorithm works. +//! +//! [SwissTable]: https://abseil.io/blog/20180927-swisstables +//! [here]: https://github.com/abseil/abseil-cpp/blob/master/absl/container/internal/raw_hash_set.h +//! [CppCon talk]: https://www.youtube.com/watch?v=ncHmEUmJZf4 + +#![no_std] +#![cfg_attr( + feature = "nightly", + feature( + test, + core_intrinsics, + dropck_eyepatch, + min_specialization, + extend_one, + allocator_api, + slice_ptr_get, + nonnull_slice_from_raw_parts, + maybe_uninit_array_assume_init, + build_hasher_simple_hash_one + ) +)] +#![allow( + clippy::doc_markdown, + clippy::module_name_repetitions, + clippy::must_use_candidate, + clippy::option_if_let_else, + clippy::redundant_else, + clippy::manual_map, + clippy::missing_safety_doc, + clippy::missing_errors_doc +)] +#![warn(missing_docs)] +#![warn(rust_2018_idioms)] + +#[cfg(test)] +#[macro_use] +extern crate std; + +#[cfg_attr(test, macro_use)] +extern crate alloc; + +#[cfg(feature = "nightly")] +#[cfg(doctest)] +doc_comment::doctest!("../README.md"); + +#[macro_use] +mod macros; + +#[cfg(feature = "raw")] +/// Experimental and unsafe `RawTable` API. This module is only available if the +/// `raw` feature is enabled. +pub mod raw { + // The RawTable API is still experimental and is not properly documented yet. + #[allow(missing_docs)] + #[path = "mod.rs"] + mod inner; + pub use inner::*; + + #[cfg(feature = "rayon")] + /// [rayon]-based parallel iterator types for hash maps. + /// You will rarely need to interact with it directly unless you have need + /// to name one of the iterator types. + /// + /// [rayon]: https://docs.rs/rayon/1.0/rayon + pub mod rayon { + pub use crate::external_trait_impls::rayon::raw::*; + } +} +#[cfg(not(feature = "raw"))] +mod raw; + +mod external_trait_impls; +mod map; +#[cfg(feature = "rustc-internal-api")] +mod rustc_entry; +mod scopeguard; +mod set; + +pub mod hash_map { + //! A hash map implemented with quadratic probing and SIMD lookup. + pub use crate::map::*; + + #[cfg(feature = "rustc-internal-api")] + pub use crate::rustc_entry::*; + + #[cfg(feature = "rayon")] + /// [rayon]-based parallel iterator types for hash maps. + /// You will rarely need to interact with it directly unless you have need + /// to name one of the iterator types. + /// + /// [rayon]: https://docs.rs/rayon/1.0/rayon + pub mod rayon { + pub use crate::external_trait_impls::rayon::map::*; + } +} +pub mod hash_set { + //! A hash set implemented as a `HashMap` where the value is `()`. + pub use crate::set::*; + + #[cfg(feature = "rayon")] + /// [rayon]-based parallel iterator types for hash sets. + /// You will rarely need to interact with it directly unless you have need + /// to name one of the iterator types. + /// + /// [rayon]: https://docs.rs/rayon/1.0/rayon + pub mod rayon { + pub use crate::external_trait_impls::rayon::set::*; + } +} + +pub use crate::map::HashMap; +pub use crate::set::HashSet; + +/// The error type for `try_reserve` methods. +#[derive(Clone, PartialEq, Eq, Debug)] +pub enum TryReserveError { + /// Error due to the computed capacity exceeding the collection's maximum + /// (usually `isize::MAX` bytes). + CapacityOverflow, + + /// The memory allocator returned an error + AllocError { + /// The layout of the allocation request that failed. + layout: alloc::alloc::Layout, + }, +} + +/// Wrapper around `Bump` which allows it to be used as an allocator for +/// `HashMap`, `HashSet` and `RawTable`. +/// +/// `Bump` can be used directly without this wrapper on nightly if you enable +/// the `allocator-api` feature of the `bumpalo` crate. +#[cfg(feature = "bumpalo")] +#[derive(Clone, Copy, Debug)] +pub struct BumpWrapper<'a>(pub &'a bumpalo::Bump); + +#[cfg(feature = "bumpalo")] +#[test] +fn test_bumpalo() { + use bumpalo::Bump; + let bump = Bump::new(); + let mut map = HashMap::new_in(BumpWrapper(&bump)); + map.insert(0, 1); +} diff --git a/vendor/hashbrown/src/macros.rs b/vendor/hashbrown/src/macros.rs new file mode 100644 index 000000000..f8ef917b1 --- /dev/null +++ b/vendor/hashbrown/src/macros.rs @@ -0,0 +1,70 @@ +// See the cfg-if crate. +#[allow(unused_macro_rules)] +macro_rules! cfg_if { + // match if/else chains with a final `else` + ($( + if #[cfg($($meta:meta),*)] { $($it:item)* } + ) else * else { + $($it2:item)* + }) => { + cfg_if! { + @__items + () ; + $( ( ($($meta),*) ($($it)*) ), )* + ( () ($($it2)*) ), + } + }; + + // match if/else chains lacking a final `else` + ( + if #[cfg($($i_met:meta),*)] { $($i_it:item)* } + $( + else if #[cfg($($e_met:meta),*)] { $($e_it:item)* } + )* + ) => { + cfg_if! { + @__items + () ; + ( ($($i_met),*) ($($i_it)*) ), + $( ( ($($e_met),*) ($($e_it)*) ), )* + ( () () ), + } + }; + + // Internal and recursive macro to emit all the items + // + // Collects all the negated cfgs in a list at the beginning and after the + // semicolon is all the remaining items + (@__items ($($not:meta,)*) ; ) => {}; + (@__items ($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), $($rest:tt)*) => { + // Emit all items within one block, applying an approprate #[cfg]. The + // #[cfg] will require all `$m` matchers specified and must also negate + // all previous matchers. + cfg_if! { @__apply cfg(all($($m,)* not(any($($not),*)))), $($it)* } + + // Recurse to emit all other items in `$rest`, and when we do so add all + // our `$m` matchers to the list of `$not` matchers as future emissions + // will have to negate everything we just matched as well. + cfg_if! { @__items ($($not,)* $($m,)*) ; $($rest)* } + }; + + // Internal macro to Apply a cfg attribute to a list of items + (@__apply $m:meta, $($it:item)*) => { + $(#[$m] $it)* + }; +} + +// Helper macro for specialization. This also helps avoid parse errors if the +// default fn syntax for specialization changes in the future. +#[cfg(feature = "nightly")] +macro_rules! default_fn { + (#[$($a:tt)*] $($tt:tt)*) => { + #[$($a)*] default $($tt)* + } +} +#[cfg(not(feature = "nightly"))] +macro_rules! default_fn { + ($($tt:tt)*) => { + $($tt)* + } +} diff --git a/vendor/hashbrown/src/map.rs b/vendor/hashbrown/src/map.rs new file mode 100644 index 000000000..a5d3ccb97 --- /dev/null +++ b/vendor/hashbrown/src/map.rs @@ -0,0 +1,8408 @@ +use crate::raw::{Allocator, Bucket, Global, RawDrain, RawIntoIter, RawIter, RawTable}; +use crate::TryReserveError; +use core::borrow::Borrow; +use core::fmt::{self, Debug}; +use core::hash::{BuildHasher, Hash}; +use core::iter::{FromIterator, FusedIterator}; +use core::marker::PhantomData; +use core::mem; +use core::ops::Index; + +/// Default hasher for `HashMap`. +#[cfg(feature = "ahash")] +pub type DefaultHashBuilder = ahash::RandomState; + +/// Dummy default hasher for `HashMap`. +#[cfg(not(feature = "ahash"))] +pub enum DefaultHashBuilder {} + +/// A hash map implemented with quadratic probing and SIMD lookup. +/// +/// The default hashing algorithm is currently [`AHash`], though this is +/// subject to change at any point in the future. This hash function is very +/// fast for all types of keys, but this algorithm will typically *not* protect +/// against attacks such as HashDoS. +/// +/// The hashing algorithm can be replaced on a per-`HashMap` basis using the +/// [`default`], [`with_hasher`], and [`with_capacity_and_hasher`] methods. Many +/// alternative algorithms are available on crates.io, such as the [`fnv`] crate. +/// +/// It is required that the keys implement the [`Eq`] and [`Hash`] traits, although +/// this can frequently be achieved by using `#[derive(PartialEq, Eq, Hash)]`. +/// If you implement these yourself, it is important that the following +/// property holds: +/// +/// ```text +/// k1 == k2 -> hash(k1) == hash(k2) +/// ``` +/// +/// In other words, if two keys are equal, their hashes must be equal. +/// +/// It is a logic error for a key to be modified in such a way that the key's +/// hash, as determined by the [`Hash`] trait, or its equality, as determined by +/// the [`Eq`] trait, changes while it is in the map. This is normally only +/// possible through [`Cell`], [`RefCell`], global state, I/O, or unsafe code. +/// +/// It is also a logic error for the [`Hash`] implementation of a key to panic. +/// This is generally only possible if the trait is implemented manually. If a +/// panic does occur then the contents of the `HashMap` may become corrupted and +/// some items may be dropped from the table. +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// // Type inference lets us omit an explicit type signature (which +/// // would be `HashMap<String, String>` in this example). +/// let mut book_reviews = HashMap::new(); +/// +/// // Review some books. +/// book_reviews.insert( +/// "Adventures of Huckleberry Finn".to_string(), +/// "My favorite book.".to_string(), +/// ); +/// book_reviews.insert( +/// "Grimms' Fairy Tales".to_string(), +/// "Masterpiece.".to_string(), +/// ); +/// book_reviews.insert( +/// "Pride and Prejudice".to_string(), +/// "Very enjoyable.".to_string(), +/// ); +/// book_reviews.insert( +/// "The Adventures of Sherlock Holmes".to_string(), +/// "Eye lyked it alot.".to_string(), +/// ); +/// +/// // Check for a specific one. +/// // When collections store owned values (String), they can still be +/// // queried using references (&str). +/// if !book_reviews.contains_key("Les Misérables") { +/// println!("We've got {} reviews, but Les Misérables ain't one.", +/// book_reviews.len()); +/// } +/// +/// // oops, this review has a lot of spelling mistakes, let's delete it. +/// book_reviews.remove("The Adventures of Sherlock Holmes"); +/// +/// // Look up the values associated with some keys. +/// let to_find = ["Pride and Prejudice", "Alice's Adventure in Wonderland"]; +/// for &book in &to_find { +/// match book_reviews.get(book) { +/// Some(review) => println!("{}: {}", book, review), +/// None => println!("{} is unreviewed.", book) +/// } +/// } +/// +/// // Look up the value for a key (will panic if the key is not found). +/// println!("Review for Jane: {}", book_reviews["Pride and Prejudice"]); +/// +/// // Iterate over everything. +/// for (book, review) in &book_reviews { +/// println!("{}: \"{}\"", book, review); +/// } +/// ``` +/// +/// `HashMap` also implements an [`Entry API`](#method.entry), which allows +/// for more complex methods of getting, setting, updating and removing keys and +/// their values: +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// // type inference lets us omit an explicit type signature (which +/// // would be `HashMap<&str, u8>` in this example). +/// let mut player_stats = HashMap::new(); +/// +/// fn random_stat_buff() -> u8 { +/// // could actually return some random value here - let's just return +/// // some fixed value for now +/// 42 +/// } +/// +/// // insert a key only if it doesn't already exist +/// player_stats.entry("health").or_insert(100); +/// +/// // insert a key using a function that provides a new value only if it +/// // doesn't already exist +/// player_stats.entry("defence").or_insert_with(random_stat_buff); +/// +/// // update a key, guarding against the key possibly not being set +/// let stat = player_stats.entry("attack").or_insert(100); +/// *stat += random_stat_buff(); +/// ``` +/// +/// The easiest way to use `HashMap` with a custom key type is to derive [`Eq`] and [`Hash`]. +/// We must also derive [`PartialEq`]. +/// +/// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html +/// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html +/// [`PartialEq`]: https://doc.rust-lang.org/std/cmp/trait.PartialEq.html +/// [`RefCell`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html +/// [`Cell`]: https://doc.rust-lang.org/std/cell/struct.Cell.html +/// [`default`]: #method.default +/// [`with_hasher`]: #method.with_hasher +/// [`with_capacity_and_hasher`]: #method.with_capacity_and_hasher +/// [`fnv`]: https://crates.io/crates/fnv +/// [`AHash`]: https://crates.io/crates/ahash +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// #[derive(Hash, Eq, PartialEq, Debug)] +/// struct Viking { +/// name: String, +/// country: String, +/// } +/// +/// impl Viking { +/// /// Creates a new Viking. +/// fn new(name: &str, country: &str) -> Viking { +/// Viking { name: name.to_string(), country: country.to_string() } +/// } +/// } +/// +/// // Use a HashMap to store the vikings' health points. +/// let mut vikings = HashMap::new(); +/// +/// vikings.insert(Viking::new("Einar", "Norway"), 25); +/// vikings.insert(Viking::new("Olaf", "Denmark"), 24); +/// vikings.insert(Viking::new("Harald", "Iceland"), 12); +/// +/// // Use derived implementation to print the status of the vikings. +/// for (viking, health) in &vikings { +/// println!("{:?} has {} hp", viking, health); +/// } +/// ``` +/// +/// A `HashMap` with fixed list of elements can be initialized from an array: +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let timber_resources: HashMap<&str, i32> = [("Norway", 100), ("Denmark", 50), ("Iceland", 10)] +/// .iter().cloned().collect(); +/// // use the values stored in map +/// ``` +pub struct HashMap<K, V, S = DefaultHashBuilder, A: Allocator + Clone = Global> { + pub(crate) hash_builder: S, + pub(crate) table: RawTable<(K, V), A>, +} + +impl<K: Clone, V: Clone, S: Clone, A: Allocator + Clone> Clone for HashMap<K, V, S, A> { + fn clone(&self) -> Self { + HashMap { + hash_builder: self.hash_builder.clone(), + table: self.table.clone(), + } + } + + fn clone_from(&mut self, source: &Self) { + self.table.clone_from(&source.table); + + // Update hash_builder only if we successfully cloned all elements. + self.hash_builder.clone_from(&source.hash_builder); + } +} + +/// Ensures that a single closure type across uses of this which, in turn prevents multiple +/// instances of any functions like RawTable::reserve from being generated +#[cfg_attr(feature = "inline-more", inline)] +pub(crate) fn make_hasher<K, Q, V, S>(hash_builder: &S) -> impl Fn(&(Q, V)) -> u64 + '_ +where + K: Borrow<Q>, + Q: Hash, + S: BuildHasher, +{ + move |val| make_hash::<K, Q, S>(hash_builder, &val.0) +} + +/// Ensures that a single closure type across uses of this which, in turn prevents multiple +/// instances of any functions like RawTable::reserve from being generated +#[cfg_attr(feature = "inline-more", inline)] +fn equivalent_key<Q, K, V>(k: &Q) -> impl Fn(&(K, V)) -> bool + '_ +where + K: Borrow<Q>, + Q: ?Sized + Eq, +{ + move |x| k.eq(x.0.borrow()) +} + +/// Ensures that a single closure type across uses of this which, in turn prevents multiple +/// instances of any functions like RawTable::reserve from being generated +#[cfg_attr(feature = "inline-more", inline)] +fn equivalent<Q, K>(k: &Q) -> impl Fn(&K) -> bool + '_ +where + K: Borrow<Q>, + Q: ?Sized + Eq, +{ + move |x| k.eq(x.borrow()) +} + +#[cfg(not(feature = "nightly"))] +#[cfg_attr(feature = "inline-more", inline)] +pub(crate) fn make_hash<K, Q, S>(hash_builder: &S, val: &Q) -> u64 +where + K: Borrow<Q>, + Q: Hash + ?Sized, + S: BuildHasher, +{ + use core::hash::Hasher; + let mut state = hash_builder.build_hasher(); + val.hash(&mut state); + state.finish() +} + +#[cfg(feature = "nightly")] +#[cfg_attr(feature = "inline-more", inline)] +pub(crate) fn make_hash<K, Q, S>(hash_builder: &S, val: &Q) -> u64 +where + K: Borrow<Q>, + Q: Hash + ?Sized, + S: BuildHasher, +{ + hash_builder.hash_one(val) +} + +#[cfg(not(feature = "nightly"))] +#[cfg_attr(feature = "inline-more", inline)] +pub(crate) fn make_insert_hash<K, S>(hash_builder: &S, val: &K) -> u64 +where + K: Hash, + S: BuildHasher, +{ + use core::hash::Hasher; + let mut state = hash_builder.build_hasher(); + val.hash(&mut state); + state.finish() +} + +#[cfg(feature = "nightly")] +#[cfg_attr(feature = "inline-more", inline)] +pub(crate) fn make_insert_hash<K, S>(hash_builder: &S, val: &K) -> u64 +where + K: Hash, + S: BuildHasher, +{ + hash_builder.hash_one(val) +} + +#[cfg(feature = "ahash")] +impl<K, V> HashMap<K, V, DefaultHashBuilder> { + /// Creates an empty `HashMap`. + /// + /// The hash map is initially created with a capacity of 0, so it will not allocate until it + /// is first inserted into. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// let mut map: HashMap<&str, i32> = HashMap::new(); + /// assert_eq!(map.len(), 0); + /// assert_eq!(map.capacity(), 0); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn new() -> Self { + Self::default() + } + + /// Creates an empty `HashMap` with the specified capacity. + /// + /// The hash map will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash map will not allocate. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// let mut map: HashMap<&str, i32> = HashMap::with_capacity(10); + /// assert_eq!(map.len(), 0); + /// assert!(map.capacity() >= 10); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_capacity(capacity: usize) -> Self { + Self::with_capacity_and_hasher(capacity, DefaultHashBuilder::default()) + } +} + +#[cfg(feature = "ahash")] +impl<K, V, A: Allocator + Clone> HashMap<K, V, DefaultHashBuilder, A> { + /// Creates an empty `HashMap` using the given allocator. + /// + /// The hash map is initially created with a capacity of 0, so it will not allocate until it + /// is first inserted into. + #[cfg_attr(feature = "inline-more", inline)] + pub fn new_in(alloc: A) -> Self { + Self::with_hasher_in(DefaultHashBuilder::default(), alloc) + } + + /// Creates an empty `HashMap` with the specified capacity using the given allocator. + /// + /// The hash map will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash map will not allocate. + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_capacity_in(capacity: usize, alloc: A) -> Self { + Self::with_capacity_and_hasher_in(capacity, DefaultHashBuilder::default(), alloc) + } +} + +impl<K, V, S> HashMap<K, V, S> { + /// Creates an empty `HashMap` which will use the given hash builder to hash + /// keys. + /// + /// The hash map is initially created with a capacity of 0, so it will not + /// allocate until it is first inserted into. + /// + /// Warning: `hash_builder` is normally randomly generated, and + /// is designed to allow HashMaps to be resistant to attacks that + /// cause many collisions and very poor performance. Setting it + /// manually using this function can expose a DoS attack vector. + /// + /// The `hash_builder` passed should implement the [`BuildHasher`] trait for + /// the HashMap to be useful, see its documentation for details. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let s = DefaultHashBuilder::default(); + /// let mut map = HashMap::with_hasher(s); + /// assert_eq!(map.len(), 0); + /// assert_eq!(map.capacity(), 0); + /// + /// map.insert(1, 2); + /// ``` + /// + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html + #[cfg_attr(feature = "inline-more", inline)] + pub const fn with_hasher(hash_builder: S) -> Self { + Self { + hash_builder, + table: RawTable::new(), + } + } + + /// Creates an empty `HashMap` with the specified capacity, using `hash_builder` + /// to hash the keys. + /// + /// The hash map will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash map will not allocate. + /// + /// Warning: `hash_builder` is normally randomly generated, and + /// is designed to allow HashMaps to be resistant to attacks that + /// cause many collisions and very poor performance. Setting it + /// manually using this function can expose a DoS attack vector. + /// + /// The `hash_builder` passed should implement the [`BuildHasher`] trait for + /// the HashMap to be useful, see its documentation for details. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let s = DefaultHashBuilder::default(); + /// let mut map = HashMap::with_capacity_and_hasher(10, s); + /// assert_eq!(map.len(), 0); + /// assert!(map.capacity() >= 10); + /// + /// map.insert(1, 2); + /// ``` + /// + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_capacity_and_hasher(capacity: usize, hash_builder: S) -> Self { + Self { + hash_builder, + table: RawTable::with_capacity(capacity), + } + } +} + +impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { + /// Returns a reference to the underlying allocator. + #[inline] + pub fn allocator(&self) -> &A { + self.table.allocator() + } + + /// Creates an empty `HashMap` which will use the given hash builder to hash + /// keys. It will be allocated with the given allocator. + /// + /// The created map has the default initial capacity. + /// + /// Warning: `hash_builder` is normally randomly generated, and + /// is designed to allow HashMaps to be resistant to attacks that + /// cause many collisions and very poor performance. Setting it + /// manually using this function can expose a DoS attack vector. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let s = DefaultHashBuilder::default(); + /// let mut map = HashMap::with_hasher(s); + /// map.insert(1, 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_hasher_in(hash_builder: S, alloc: A) -> Self { + Self { + hash_builder, + table: RawTable::new_in(alloc), + } + } + + /// Creates an empty `HashMap` with the specified capacity, using `hash_builder` + /// to hash the keys. It will be allocated with the given allocator. + /// + /// The hash map will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash map will not allocate. + /// + /// Warning: `hash_builder` is normally randomly generated, and + /// is designed to allow HashMaps to be resistant to attacks that + /// cause many collisions and very poor performance. Setting it + /// manually using this function can expose a DoS attack vector. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let s = DefaultHashBuilder::default(); + /// let mut map = HashMap::with_capacity_and_hasher(10, s); + /// map.insert(1, 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_capacity_and_hasher_in(capacity: usize, hash_builder: S, alloc: A) -> Self { + Self { + hash_builder, + table: RawTable::with_capacity_in(capacity, alloc), + } + } + + /// Returns a reference to the map's [`BuildHasher`]. + /// + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let hasher = DefaultHashBuilder::default(); + /// let map: HashMap<i32, i32> = HashMap::with_hasher(hasher); + /// let hasher: &DefaultHashBuilder = map.hasher(); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn hasher(&self) -> &S { + &self.hash_builder + } + + /// Returns the number of elements the map can hold without reallocating. + /// + /// This number is a lower bound; the `HashMap<K, V>` might be able to hold + /// more, but is guaranteed to be able to hold at least this many. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// let map: HashMap<i32, i32> = HashMap::with_capacity(100); + /// assert_eq!(map.len(), 0); + /// assert!(map.capacity() >= 100); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn capacity(&self) -> usize { + self.table.capacity() + } + + /// An iterator visiting all keys in arbitrary order. + /// The iterator element type is `&'a K`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert("a", 1); + /// map.insert("b", 2); + /// map.insert("c", 3); + /// assert_eq!(map.len(), 3); + /// let mut vec: Vec<&str> = Vec::new(); + /// + /// for key in map.keys() { + /// println!("{}", key); + /// vec.push(*key); + /// } + /// + /// // The `Keys` iterator produces keys in arbitrary order, so the + /// // keys must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, ["a", "b", "c"]); + /// + /// assert_eq!(map.len(), 3); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn keys(&self) -> Keys<'_, K, V> { + Keys { inner: self.iter() } + } + + /// An iterator visiting all values in arbitrary order. + /// The iterator element type is `&'a V`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert("a", 1); + /// map.insert("b", 2); + /// map.insert("c", 3); + /// assert_eq!(map.len(), 3); + /// let mut vec: Vec<i32> = Vec::new(); + /// + /// for val in map.values() { + /// println!("{}", val); + /// vec.push(*val); + /// } + /// + /// // The `Values` iterator produces values in arbitrary order, so the + /// // values must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [1, 2, 3]); + /// + /// assert_eq!(map.len(), 3); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn values(&self) -> Values<'_, K, V> { + Values { inner: self.iter() } + } + + /// An iterator visiting all values mutably in arbitrary order. + /// The iterator element type is `&'a mut V`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// + /// map.insert("a", 1); + /// map.insert("b", 2); + /// map.insert("c", 3); + /// + /// for val in map.values_mut() { + /// *val = *val + 10; + /// } + /// + /// assert_eq!(map.len(), 3); + /// let mut vec: Vec<i32> = Vec::new(); + /// + /// for val in map.values() { + /// println!("{}", val); + /// vec.push(*val); + /// } + /// + /// // The `Values` iterator produces values in arbitrary order, so the + /// // values must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [11, 12, 13]); + /// + /// assert_eq!(map.len(), 3); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> { + ValuesMut { + inner: self.iter_mut(), + } + } + + /// An iterator visiting all key-value pairs in arbitrary order. + /// The iterator element type is `(&'a K, &'a V)`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert("a", 1); + /// map.insert("b", 2); + /// map.insert("c", 3); + /// assert_eq!(map.len(), 3); + /// let mut vec: Vec<(&str, i32)> = Vec::new(); + /// + /// for (key, val) in map.iter() { + /// println!("key: {} val: {}", key, val); + /// vec.push((*key, *val)); + /// } + /// + /// // The `Iter` iterator produces items in arbitrary order, so the + /// // items must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [("a", 1), ("b", 2), ("c", 3)]); + /// + /// assert_eq!(map.len(), 3); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn iter(&self) -> Iter<'_, K, V> { + // Here we tie the lifetime of self to the iter. + unsafe { + Iter { + inner: self.table.iter(), + marker: PhantomData, + } + } + } + + /// An iterator visiting all key-value pairs in arbitrary order, + /// with mutable references to the values. + /// The iterator element type is `(&'a K, &'a mut V)`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert("a", 1); + /// map.insert("b", 2); + /// map.insert("c", 3); + /// + /// // Update all values + /// for (_, val) in map.iter_mut() { + /// *val *= 2; + /// } + /// + /// assert_eq!(map.len(), 3); + /// let mut vec: Vec<(&str, i32)> = Vec::new(); + /// + /// for (key, val) in &map { + /// println!("key: {} val: {}", key, val); + /// vec.push((*key, *val)); + /// } + /// + /// // The `Iter` iterator produces items in arbitrary order, so the + /// // items must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [("a", 2), ("b", 4), ("c", 6)]); + /// + /// assert_eq!(map.len(), 3); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn iter_mut(&mut self) -> IterMut<'_, K, V> { + // Here we tie the lifetime of self to the iter. + unsafe { + IterMut { + inner: self.table.iter(), + marker: PhantomData, + } + } + } + + #[cfg(test)] + #[cfg_attr(feature = "inline-more", inline)] + fn raw_capacity(&self) -> usize { + self.table.buckets() + } + + /// Returns the number of elements in the map. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut a = HashMap::new(); + /// assert_eq!(a.len(), 0); + /// a.insert(1, "a"); + /// assert_eq!(a.len(), 1); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn len(&self) -> usize { + self.table.len() + } + + /// Returns `true` if the map contains no elements. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut a = HashMap::new(); + /// assert!(a.is_empty()); + /// a.insert(1, "a"); + /// assert!(!a.is_empty()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn is_empty(&self) -> bool { + self.len() == 0 + } + + /// Clears the map, returning all key-value pairs as an iterator. Keeps the + /// allocated memory for reuse. + /// + /// If the returned iterator is dropped before being fully consumed, it + /// drops the remaining key-value pairs. The returned iterator keeps a + /// mutable borrow on the vector to optimize its implementation. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut a = HashMap::new(); + /// a.insert(1, "a"); + /// a.insert(2, "b"); + /// let capacity_before_drain = a.capacity(); + /// + /// for (k, v) in a.drain().take(1) { + /// assert!(k == 1 || k == 2); + /// assert!(v == "a" || v == "b"); + /// } + /// + /// // As we can see, the map is empty and contains no element. + /// assert!(a.is_empty() && a.len() == 0); + /// // But map capacity is equal to old one. + /// assert_eq!(a.capacity(), capacity_before_drain); + /// + /// let mut a = HashMap::new(); + /// a.insert(1, "a"); + /// a.insert(2, "b"); + /// + /// { // Iterator is dropped without being consumed. + /// let d = a.drain(); + /// } + /// + /// // But the map is empty even if we do not use Drain iterator. + /// assert!(a.is_empty()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn drain(&mut self) -> Drain<'_, K, V, A> { + Drain { + inner: self.table.drain(), + } + } + + /// Retains only the elements specified by the predicate. Keeps the + /// allocated memory for reuse. + /// + /// In other words, remove all pairs `(k, v)` such that `f(&k, &mut v)` returns `false`. + /// The elements are visited in unsorted (and unspecified) order. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<i32, i32> = (0..8).map(|x|(x, x*10)).collect(); + /// assert_eq!(map.len(), 8); + /// let capacity_before_retain = map.capacity(); + /// + /// map.retain(|&k, _| k % 2 == 0); + /// + /// // We can see, that the number of elements inside map is changed. + /// assert_eq!(map.len(), 4); + /// // But map capacity is equal to old one. + /// assert_eq!(map.capacity(), capacity_before_retain); + /// + /// let mut vec: Vec<(i32, i32)> = map.iter().map(|(&k, &v)| (k, v)).collect(); + /// vec.sort_unstable(); + /// assert_eq!(vec, [(0, 0), (2, 20), (4, 40), (6, 60)]); + /// ``` + pub fn retain<F>(&mut self, mut f: F) + where + F: FnMut(&K, &mut V) -> bool, + { + // Here we only use `iter` as a temporary, preventing use-after-free + unsafe { + for item in self.table.iter() { + let &mut (ref key, ref mut value) = item.as_mut(); + if !f(key, value) { + self.table.erase(item); + } + } + } + } + + /// Drains elements which are true under the given predicate, + /// and returns an iterator over the removed items. + /// + /// In other words, move all pairs `(k, v)` such that `f(&k, &mut v)` returns `true` out + /// into another iterator. + /// + /// Note that `drain_filter` lets you mutate every value in the filter closure, regardless of + /// whether you choose to keep or remove it. + /// + /// When the returned DrainedFilter is dropped, any remaining elements that satisfy + /// the predicate are dropped from the table. + /// + /// It is unspecified how many more elements will be subjected to the closure + /// if a panic occurs in the closure, or a panic occurs while dropping an element, + /// or if the `DrainFilter` value is leaked. + /// + /// Keeps the allocated memory for reuse. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x)).collect(); + /// let capacity_before_drain_filter = map.capacity(); + /// let drained: HashMap<i32, i32> = map.drain_filter(|k, _v| k % 2 == 0).collect(); + /// + /// let mut evens = drained.keys().cloned().collect::<Vec<_>>(); + /// let mut odds = map.keys().cloned().collect::<Vec<_>>(); + /// evens.sort(); + /// odds.sort(); + /// + /// assert_eq!(evens, vec![0, 2, 4, 6]); + /// assert_eq!(odds, vec![1, 3, 5, 7]); + /// // Map capacity is equal to old one. + /// assert_eq!(map.capacity(), capacity_before_drain_filter); + /// + /// let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x)).collect(); + /// + /// { // Iterator is dropped without being consumed. + /// let d = map.drain_filter(|k, _v| k % 2 != 0); + /// } + /// + /// // But the map lens have been reduced by half + /// // even if we do not use DrainFilter iterator. + /// assert_eq!(map.len(), 4); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn drain_filter<F>(&mut self, f: F) -> DrainFilter<'_, K, V, F, A> + where + F: FnMut(&K, &mut V) -> bool, + { + DrainFilter { + f, + inner: DrainFilterInner { + iter: unsafe { self.table.iter() }, + table: &mut self.table, + }, + } + } + + /// Clears the map, removing all key-value pairs. Keeps the allocated memory + /// for reuse. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut a = HashMap::new(); + /// a.insert(1, "a"); + /// let capacity_before_clear = a.capacity(); + /// + /// a.clear(); + /// + /// // Map is empty. + /// assert!(a.is_empty()); + /// // But map capacity is equal to old one. + /// assert_eq!(a.capacity(), capacity_before_clear); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn clear(&mut self) { + self.table.clear(); + } + + /// Creates a consuming iterator visiting all the keys in arbitrary order. + /// The map cannot be used after calling this. + /// The iterator element type is `K`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert("a", 1); + /// map.insert("b", 2); + /// map.insert("c", 3); + /// + /// let mut vec: Vec<&str> = map.into_keys().collect(); + /// + /// // The `IntoKeys` iterator produces keys in arbitrary order, so the + /// // keys must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, ["a", "b", "c"]); + /// ``` + #[inline] + pub fn into_keys(self) -> IntoKeys<K, V, A> { + IntoKeys { + inner: self.into_iter(), + } + } + + /// Creates a consuming iterator visiting all the values in arbitrary order. + /// The map cannot be used after calling this. + /// The iterator element type is `V`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert("a", 1); + /// map.insert("b", 2); + /// map.insert("c", 3); + /// + /// let mut vec: Vec<i32> = map.into_values().collect(); + /// + /// // The `IntoValues` iterator produces values in arbitrary order, so + /// // the values must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [1, 2, 3]); + /// ``` + #[inline] + pub fn into_values(self) -> IntoValues<K, V, A> { + IntoValues { + inner: self.into_iter(), + } + } +} + +impl<K, V, S, A> HashMap<K, V, S, A> +where + K: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + /// Reserves capacity for at least `additional` more elements to be inserted + /// in the `HashMap`. The collection may reserve more space to avoid + /// frequent reallocations. + /// + /// # Panics + /// + /// Panics if the new allocation size overflows [`usize`]. + /// + /// [`usize`]: https://doc.rust-lang.org/std/primitive.usize.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// let mut map: HashMap<&str, i32> = HashMap::new(); + /// // Map is empty and doesn't allocate memory + /// assert_eq!(map.capacity(), 0); + /// + /// map.reserve(10); + /// + /// // And now map can hold at least 10 elements + /// assert!(map.capacity() >= 10); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn reserve(&mut self, additional: usize) { + self.table + .reserve(additional, make_hasher::<K, _, V, S>(&self.hash_builder)); + } + + /// Tries to reserve capacity for at least `additional` more elements to be inserted + /// in the given `HashMap<K,V>`. The collection may reserve more space to avoid + /// frequent reallocations. + /// + /// # Errors + /// + /// If the capacity overflows, or the allocator reports a failure, then an error + /// is returned. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, isize> = HashMap::new(); + /// // Map is empty and doesn't allocate memory + /// assert_eq!(map.capacity(), 0); + /// + /// map.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?"); + /// + /// // And now map can hold at least 10 elements + /// assert!(map.capacity() >= 10); + /// ``` + /// If the capacity overflows, or the allocator reports a failure, then an error + /// is returned: + /// ``` + /// # fn test() { + /// use hashbrown::HashMap; + /// use hashbrown::TryReserveError; + /// let mut map: HashMap<i32, i32> = HashMap::new(); + /// + /// match map.try_reserve(usize::MAX) { + /// Err(error) => match error { + /// TryReserveError::CapacityOverflow => {} + /// _ => panic!("TryReserveError::AllocError ?"), + /// }, + /// _ => panic!(), + /// } + /// # } + /// # fn main() { + /// # #[cfg(not(miri))] + /// # test() + /// # } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> { + self.table + .try_reserve(additional, make_hasher::<K, _, V, S>(&self.hash_builder)) + } + + /// Shrinks the capacity of the map as much as possible. It will drop + /// down as much as possible while maintaining the internal rules + /// and possibly leaving some space in accordance with the resize policy. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<i32, i32> = HashMap::with_capacity(100); + /// map.insert(1, 2); + /// map.insert(3, 4); + /// assert!(map.capacity() >= 100); + /// map.shrink_to_fit(); + /// assert!(map.capacity() >= 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn shrink_to_fit(&mut self) { + self.table + .shrink_to(0, make_hasher::<K, _, V, S>(&self.hash_builder)); + } + + /// Shrinks the capacity of the map with a lower limit. It will drop + /// down no lower than the supplied limit while maintaining the internal rules + /// and possibly leaving some space in accordance with the resize policy. + /// + /// This function does nothing if the current capacity is smaller than the + /// supplied minimum capacity. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<i32, i32> = HashMap::with_capacity(100); + /// map.insert(1, 2); + /// map.insert(3, 4); + /// assert!(map.capacity() >= 100); + /// map.shrink_to(10); + /// assert!(map.capacity() >= 10); + /// map.shrink_to(0); + /// assert!(map.capacity() >= 2); + /// map.shrink_to(10); + /// assert!(map.capacity() >= 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn shrink_to(&mut self, min_capacity: usize) { + self.table + .shrink_to(min_capacity, make_hasher::<K, _, V, S>(&self.hash_builder)); + } + + /// Gets the given key's corresponding entry in the map for in-place manipulation. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut letters = HashMap::new(); + /// + /// for ch in "a short treatise on fungi".chars() { + /// let counter = letters.entry(ch).or_insert(0); + /// *counter += 1; + /// } + /// + /// assert_eq!(letters[&'s'], 2); + /// assert_eq!(letters[&'t'], 3); + /// assert_eq!(letters[&'u'], 1); + /// assert_eq!(letters.get(&'y'), None); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn entry(&mut self, key: K) -> Entry<'_, K, V, S, A> { + let hash = make_insert_hash::<K, S>(&self.hash_builder, &key); + if let Some(elem) = self.table.find(hash, equivalent_key(&key)) { + Entry::Occupied(OccupiedEntry { + hash, + key: Some(key), + elem, + table: self, + }) + } else { + Entry::Vacant(VacantEntry { + hash, + key, + table: self, + }) + } + } + + /// Gets the given key's corresponding entry by reference in the map for in-place manipulation. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut words: HashMap<String, usize> = HashMap::new(); + /// let source = ["poneyland", "horseyland", "poneyland", "poneyland"]; + /// for (i, &s) in source.iter().enumerate() { + /// let counter = words.entry_ref(s).or_insert(0); + /// *counter += 1; + /// } + /// + /// assert_eq!(words["poneyland"], 3); + /// assert_eq!(words["horseyland"], 1); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn entry_ref<'a, 'b, Q: ?Sized>(&'a mut self, key: &'b Q) -> EntryRef<'a, 'b, K, Q, V, S, A> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + let hash = make_hash::<K, Q, S>(&self.hash_builder, key); + if let Some(elem) = self.table.find(hash, equivalent_key(key)) { + EntryRef::Occupied(OccupiedEntryRef { + hash, + key: Some(KeyOrRef::Borrowed(key)), + elem, + table: self, + }) + } else { + EntryRef::Vacant(VacantEntryRef { + hash, + key: KeyOrRef::Borrowed(key), + table: self, + }) + } + } + + /// Returns a reference to the value corresponding to the key. + /// + /// The key may be any borrowed form of the map's key type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the key type. + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert(1, "a"); + /// assert_eq!(map.get(&1), Some(&"a")); + /// assert_eq!(map.get(&2), None); + /// ``` + #[inline] + pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + // Avoid `Option::map` because it bloats LLVM IR. + match self.get_inner(k) { + Some(&(_, ref v)) => Some(v), + None => None, + } + } + + /// Returns the key-value pair corresponding to the supplied key. + /// + /// The supplied key may be any borrowed form of the map's key type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the key type. + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert(1, "a"); + /// assert_eq!(map.get_key_value(&1), Some((&1, &"a"))); + /// assert_eq!(map.get_key_value(&2), None); + /// ``` + #[inline] + pub fn get_key_value<Q: ?Sized>(&self, k: &Q) -> Option<(&K, &V)> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + // Avoid `Option::map` because it bloats LLVM IR. + match self.get_inner(k) { + Some(&(ref key, ref value)) => Some((key, value)), + None => None, + } + } + + #[inline] + fn get_inner<Q: ?Sized>(&self, k: &Q) -> Option<&(K, V)> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + if self.table.is_empty() { + None + } else { + let hash = make_hash::<K, Q, S>(&self.hash_builder, k); + self.table.get(hash, equivalent_key(k)) + } + } + + /// Returns the key-value pair corresponding to the supplied key, with a mutable reference to value. + /// + /// The supplied key may be any borrowed form of the map's key type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the key type. + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert(1, "a"); + /// let (k, v) = map.get_key_value_mut(&1).unwrap(); + /// assert_eq!(k, &1); + /// assert_eq!(v, &mut "a"); + /// *v = "b"; + /// assert_eq!(map.get_key_value_mut(&1), Some((&1, &mut "b"))); + /// assert_eq!(map.get_key_value_mut(&2), None); + /// ``` + #[inline] + pub fn get_key_value_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<(&K, &mut V)> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + // Avoid `Option::map` because it bloats LLVM IR. + match self.get_inner_mut(k) { + Some(&mut (ref key, ref mut value)) => Some((key, value)), + None => None, + } + } + + /// Returns `true` if the map contains a value for the specified key. + /// + /// The key may be any borrowed form of the map's key type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the key type. + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert(1, "a"); + /// assert_eq!(map.contains_key(&1), true); + /// assert_eq!(map.contains_key(&2), false); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool + where + K: Borrow<Q>, + Q: Hash + Eq, + { + self.get_inner(k).is_some() + } + + /// Returns a mutable reference to the value corresponding to the key. + /// + /// The key may be any borrowed form of the map's key type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the key type. + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert(1, "a"); + /// if let Some(x) = map.get_mut(&1) { + /// *x = "b"; + /// } + /// assert_eq!(map[&1], "b"); + /// + /// assert_eq!(map.get_mut(&2), None); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + // Avoid `Option::map` because it bloats LLVM IR. + match self.get_inner_mut(k) { + Some(&mut (_, ref mut v)) => Some(v), + None => None, + } + } + + #[inline] + fn get_inner_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut (K, V)> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + if self.table.is_empty() { + None + } else { + let hash = make_hash::<K, Q, S>(&self.hash_builder, k); + self.table.get_mut(hash, equivalent_key(k)) + } + } + + /// Attempts to get mutable references to `N` values in the map at once. + /// + /// Returns an array of length `N` with the results of each query. For soundness, at most one + /// mutable reference will be returned to any value. `None` will be returned if any of the + /// keys are duplicates or missing. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut libraries = HashMap::new(); + /// libraries.insert("Bodleian Library".to_string(), 1602); + /// libraries.insert("Athenæum".to_string(), 1807); + /// libraries.insert("Herzogin-Anna-Amalia-Bibliothek".to_string(), 1691); + /// libraries.insert("Library of Congress".to_string(), 1800); + /// + /// let got = libraries.get_many_mut([ + /// "Athenæum", + /// "Library of Congress", + /// ]); + /// assert_eq!( + /// got, + /// Some([ + /// &mut 1807, + /// &mut 1800, + /// ]), + /// ); + /// + /// // Missing keys result in None + /// let got = libraries.get_many_mut([ + /// "Athenæum", + /// "New York Public Library", + /// ]); + /// assert_eq!(got, None); + /// + /// // Duplicate keys result in None + /// let got = libraries.get_many_mut([ + /// "Athenæum", + /// "Athenæum", + /// ]); + /// assert_eq!(got, None); + /// ``` + pub fn get_many_mut<Q: ?Sized, const N: usize>(&mut self, ks: [&Q; N]) -> Option<[&'_ mut V; N]> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + self.get_many_mut_inner(ks).map(|res| res.map(|(_, v)| v)) + } + + /// Attempts to get mutable references to `N` values in the map at once, without validating that + /// the values are unique. + /// + /// Returns an array of length `N` with the results of each query. `None` will be returned if + /// any of the keys are missing. + /// + /// For a safe alternative see [`get_many_mut`](`HashMap::get_many_mut`). + /// + /// # Safety + /// + /// Calling this method with overlapping keys is *[undefined behavior]* even if the resulting + /// references are not used. + /// + /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut libraries = HashMap::new(); + /// libraries.insert("Bodleian Library".to_string(), 1602); + /// libraries.insert("Athenæum".to_string(), 1807); + /// libraries.insert("Herzogin-Anna-Amalia-Bibliothek".to_string(), 1691); + /// libraries.insert("Library of Congress".to_string(), 1800); + /// + /// let got = libraries.get_many_mut([ + /// "Athenæum", + /// "Library of Congress", + /// ]); + /// assert_eq!( + /// got, + /// Some([ + /// &mut 1807, + /// &mut 1800, + /// ]), + /// ); + /// + /// // Missing keys result in None + /// let got = libraries.get_many_mut([ + /// "Athenæum", + /// "New York Public Library", + /// ]); + /// assert_eq!(got, None); + /// ``` + pub unsafe fn get_many_unchecked_mut<Q: ?Sized, const N: usize>( + &mut self, + ks: [&Q; N], + ) -> Option<[&'_ mut V; N]> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + self.get_many_unchecked_mut_inner(ks) + .map(|res| res.map(|(_, v)| v)) + } + + /// Attempts to get mutable references to `N` values in the map at once, with immutable + /// references to the corresponding keys. + /// + /// Returns an array of length `N` with the results of each query. For soundness, at most one + /// mutable reference will be returned to any value. `None` will be returned if any of the keys + /// are duplicates or missing. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut libraries = HashMap::new(); + /// libraries.insert("Bodleian Library".to_string(), 1602); + /// libraries.insert("Athenæum".to_string(), 1807); + /// libraries.insert("Herzogin-Anna-Amalia-Bibliothek".to_string(), 1691); + /// libraries.insert("Library of Congress".to_string(), 1800); + /// + /// let got = libraries.get_many_key_value_mut([ + /// "Bodleian Library", + /// "Herzogin-Anna-Amalia-Bibliothek", + /// ]); + /// assert_eq!( + /// got, + /// Some([ + /// (&"Bodleian Library".to_string(), &mut 1602), + /// (&"Herzogin-Anna-Amalia-Bibliothek".to_string(), &mut 1691), + /// ]), + /// ); + /// // Missing keys result in None + /// let got = libraries.get_many_key_value_mut([ + /// "Bodleian Library", + /// "Gewandhaus", + /// ]); + /// assert_eq!(got, None); + /// + /// // Duplicate keys result in None + /// let got = libraries.get_many_key_value_mut([ + /// "Bodleian Library", + /// "Herzogin-Anna-Amalia-Bibliothek", + /// "Herzogin-Anna-Amalia-Bibliothek", + /// ]); + /// assert_eq!(got, None); + /// ``` + pub fn get_many_key_value_mut<Q: ?Sized, const N: usize>( + &mut self, + ks: [&Q; N], + ) -> Option<[(&'_ K, &'_ mut V); N]> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + self.get_many_mut_inner(ks) + .map(|res| res.map(|(k, v)| (&*k, v))) + } + + /// Attempts to get mutable references to `N` values in the map at once, with immutable + /// references to the corresponding keys, without validating that the values are unique. + /// + /// Returns an array of length `N` with the results of each query. `None` will be returned if + /// any of the keys are missing. + /// + /// For a safe alternative see [`get_many_key_value_mut`](`HashMap::get_many_key_value_mut`). + /// + /// # Safety + /// + /// Calling this method with overlapping keys is *[undefined behavior]* even if the resulting + /// references are not used. + /// + /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut libraries = HashMap::new(); + /// libraries.insert("Bodleian Library".to_string(), 1602); + /// libraries.insert("Athenæum".to_string(), 1807); + /// libraries.insert("Herzogin-Anna-Amalia-Bibliothek".to_string(), 1691); + /// libraries.insert("Library of Congress".to_string(), 1800); + /// + /// let got = libraries.get_many_key_value_mut([ + /// "Bodleian Library", + /// "Herzogin-Anna-Amalia-Bibliothek", + /// ]); + /// assert_eq!( + /// got, + /// Some([ + /// (&"Bodleian Library".to_string(), &mut 1602), + /// (&"Herzogin-Anna-Amalia-Bibliothek".to_string(), &mut 1691), + /// ]), + /// ); + /// // Missing keys result in None + /// let got = libraries.get_many_key_value_mut([ + /// "Bodleian Library", + /// "Gewandhaus", + /// ]); + /// assert_eq!(got, None); + /// ``` + pub unsafe fn get_many_key_value_unchecked_mut<Q: ?Sized, const N: usize>( + &mut self, + ks: [&Q; N], + ) -> Option<[(&'_ K, &'_ mut V); N]> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + self.get_many_unchecked_mut_inner(ks) + .map(|res| res.map(|(k, v)| (&*k, v))) + } + + fn get_many_mut_inner<Q: ?Sized, const N: usize>( + &mut self, + ks: [&Q; N], + ) -> Option<[&'_ mut (K, V); N]> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + let hashes = self.build_hashes_inner(ks); + self.table + .get_many_mut(hashes, |i, (k, _)| ks[i].eq(k.borrow())) + } + + unsafe fn get_many_unchecked_mut_inner<Q: ?Sized, const N: usize>( + &mut self, + ks: [&Q; N], + ) -> Option<[&'_ mut (K, V); N]> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + let hashes = self.build_hashes_inner(ks); + self.table + .get_many_unchecked_mut(hashes, |i, (k, _)| ks[i].eq(k.borrow())) + } + + fn build_hashes_inner<Q: ?Sized, const N: usize>(&self, ks: [&Q; N]) -> [u64; N] + where + K: Borrow<Q>, + Q: Hash + Eq, + { + let mut hashes = [0_u64; N]; + for i in 0..N { + hashes[i] = make_hash::<K, Q, S>(&self.hash_builder, ks[i]); + } + hashes + } + + /// Inserts a key-value pair into the map. + /// + /// If the map did not have this key present, [`None`] is returned. + /// + /// If the map did have this key present, the value is updated, and the old + /// value is returned. The key is not updated, though; this matters for + /// types that can be `==` without being identical. See the [`std::collections`] + /// [module-level documentation] for more. + /// + /// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None + /// [`std::collections`]: https://doc.rust-lang.org/std/collections/index.html + /// [module-level documentation]: https://doc.rust-lang.org/std/collections/index.html#insert-and-complex-keys + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// assert_eq!(map.insert(37, "a"), None); + /// assert_eq!(map.is_empty(), false); + /// + /// map.insert(37, "b"); + /// assert_eq!(map.insert(37, "c"), Some("b")); + /// assert_eq!(map[&37], "c"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(&mut self, k: K, v: V) -> Option<V> { + let hash = make_insert_hash::<K, S>(&self.hash_builder, &k); + if let Some((_, item)) = self.table.get_mut(hash, equivalent_key(&k)) { + Some(mem::replace(item, v)) + } else { + self.table + .insert(hash, (k, v), make_hasher::<K, _, V, S>(&self.hash_builder)); + None + } + } + + /// Insert a key-value pair into the map without checking + /// if the key already exists in the map. + /// + /// Returns a reference to the key and value just inserted. + /// + /// This operation is safe if a key does not exist in the map. + /// + /// However, if a key exists in the map already, the behavior is unspecified: + /// this operation may panic, loop forever, or any following operation with the map + /// may panic, loop forever or return arbitrary result. + /// + /// That said, this operation (and following operations) are guaranteed to + /// not violate memory safety. + /// + /// This operation is faster than regular insert, because it does not perform + /// lookup before insertion. + /// + /// This operation is useful during initial population of the map. + /// For example, when constructing a map from another map, we know + /// that keys are unique. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map1 = HashMap::new(); + /// assert_eq!(map1.insert(1, "a"), None); + /// assert_eq!(map1.insert(2, "b"), None); + /// assert_eq!(map1.insert(3, "c"), None); + /// assert_eq!(map1.len(), 3); + /// + /// let mut map2 = HashMap::new(); + /// + /// for (key, value) in map1.into_iter() { + /// map2.insert_unique_unchecked(key, value); + /// } + /// + /// let (key, value) = map2.insert_unique_unchecked(4, "d"); + /// assert_eq!(key, &4); + /// assert_eq!(value, &mut "d"); + /// *value = "e"; + /// + /// assert_eq!(map2[&1], "a"); + /// assert_eq!(map2[&2], "b"); + /// assert_eq!(map2[&3], "c"); + /// assert_eq!(map2[&4], "e"); + /// assert_eq!(map2.len(), 4); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert_unique_unchecked(&mut self, k: K, v: V) -> (&K, &mut V) { + let hash = make_insert_hash::<K, S>(&self.hash_builder, &k); + let bucket = self + .table + .insert(hash, (k, v), make_hasher::<K, _, V, S>(&self.hash_builder)); + let (k_ref, v_ref) = unsafe { bucket.as_mut() }; + (k_ref, v_ref) + } + + /// Tries to insert a key-value pair into the map, and returns + /// a mutable reference to the value in the entry. + /// + /// # Errors + /// + /// If the map already had this key present, nothing is updated, and + /// an error containing the occupied entry and the value is returned. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::OccupiedError; + /// + /// let mut map = HashMap::new(); + /// assert_eq!(map.try_insert(37, "a").unwrap(), &"a"); + /// + /// match map.try_insert(37, "b") { + /// Err(OccupiedError { entry, value }) => { + /// assert_eq!(entry.key(), &37); + /// assert_eq!(entry.get(), &"a"); + /// assert_eq!(value, "b"); + /// } + /// _ => panic!() + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn try_insert( + &mut self, + key: K, + value: V, + ) -> Result<&mut V, OccupiedError<'_, K, V, S, A>> { + match self.entry(key) { + Entry::Occupied(entry) => Err(OccupiedError { entry, value }), + Entry::Vacant(entry) => Ok(entry.insert(value)), + } + } + + /// Removes a key from the map, returning the value at the key if the key + /// was previously in the map. Keeps the allocated memory for reuse. + /// + /// The key may be any borrowed form of the map's key type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the key type. + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// // The map is empty + /// assert!(map.is_empty() && map.capacity() == 0); + /// + /// map.insert(1, "a"); + /// let capacity_before_remove = map.capacity(); + /// + /// assert_eq!(map.remove(&1), Some("a")); + /// assert_eq!(map.remove(&1), None); + /// + /// // Now map holds none elements but capacity is equal to the old one + /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<V> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + // Avoid `Option::map` because it bloats LLVM IR. + match self.remove_entry(k) { + Some((_, v)) => Some(v), + None => None, + } + } + + /// Removes a key from the map, returning the stored key and value if the + /// key was previously in the map. Keeps the allocated memory for reuse. + /// + /// The key may be any borrowed form of the map's key type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the key type. + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// // The map is empty + /// assert!(map.is_empty() && map.capacity() == 0); + /// + /// map.insert(1, "a"); + /// let capacity_before_remove = map.capacity(); + /// + /// assert_eq!(map.remove_entry(&1), Some((1, "a"))); + /// assert_eq!(map.remove(&1), None); + /// + /// // Now map hold none elements but capacity is equal to the old one + /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove_entry<Q: ?Sized>(&mut self, k: &Q) -> Option<(K, V)> + where + K: Borrow<Q>, + Q: Hash + Eq, + { + let hash = make_hash::<K, Q, S>(&self.hash_builder, k); + self.table.remove_entry(hash, equivalent_key(k)) + } +} + +impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { + /// Creates a raw entry builder for the HashMap. + /// + /// Raw entries provide the lowest level of control for searching and + /// manipulating a map. They must be manually initialized with a hash and + /// then manually searched. After this, insertions into a vacant entry + /// still require an owned key to be provided. + /// + /// Raw entries are useful for such exotic situations as: + /// + /// * Hash memoization + /// * Deferring the creation of an owned key until it is known to be required + /// * Using a search key that doesn't work with the Borrow trait + /// * Using custom comparison logic without newtype wrappers + /// + /// Because raw entries provide much more low-level control, it's much easier + /// to put the HashMap into an inconsistent state which, while memory-safe, + /// will cause the map to produce seemingly random results. Higher-level and + /// more foolproof APIs like `entry` should be preferred when possible. + /// + /// In particular, the hash used to initialized the raw entry must still be + /// consistent with the hash of the key that is ultimately stored in the entry. + /// This is because implementations of HashMap may need to recompute hashes + /// when resizing, at which point only the keys are available. + /// + /// Raw entries give mutable access to the keys. This must not be used + /// to modify how the key would compare or hash, as the map will not re-evaluate + /// where the key should go, meaning the keys may become "lost" if their + /// location does not reflect their state. For instance, if you change a key + /// so that the map now contains keys which compare equal, search may start + /// acting erratically, with two keys randomly masking each other. Implementations + /// are free to assume this doesn't happen (within the limits of memory-safety). + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map = HashMap::new(); + /// map.extend([("a", 100), ("b", 200), ("c", 300)]); + /// + /// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// // Existing key (insert and update) + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => unreachable!(), + /// RawEntryMut::Occupied(mut view) => { + /// assert_eq!(view.get(), &100); + /// let v = view.get_mut(); + /// let new_v = (*v) * 10; + /// *v = new_v; + /// assert_eq!(view.insert(1111), 1000); + /// } + /// } + /// + /// assert_eq!(map[&"a"], 1111); + /// assert_eq!(map.len(), 3); + /// + /// // Existing key (take) + /// let hash = compute_hash(map.hasher(), &"c"); + /// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &"c") { + /// RawEntryMut::Vacant(_) => unreachable!(), + /// RawEntryMut::Occupied(view) => { + /// assert_eq!(view.remove_entry(), ("c", 300)); + /// } + /// } + /// assert_eq!(map.raw_entry().from_key(&"c"), None); + /// assert_eq!(map.len(), 2); + /// + /// // Nonexistent key (insert and update) + /// let key = "d"; + /// let hash = compute_hash(map.hasher(), &key); + /// match map.raw_entry_mut().from_hash(hash, |q| *q == key) { + /// RawEntryMut::Occupied(_) => unreachable!(), + /// RawEntryMut::Vacant(view) => { + /// let (k, value) = view.insert("d", 4000); + /// assert_eq!((*k, *value), ("d", 4000)); + /// *value = 40000; + /// } + /// } + /// assert_eq!(map[&"d"], 40000); + /// assert_eq!(map.len(), 3); + /// + /// match map.raw_entry_mut().from_hash(hash, |q| *q == key) { + /// RawEntryMut::Vacant(_) => unreachable!(), + /// RawEntryMut::Occupied(view) => { + /// assert_eq!(view.remove_entry(), ("d", 40000)); + /// } + /// } + /// assert_eq!(map.get(&"d"), None); + /// assert_eq!(map.len(), 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn raw_entry_mut(&mut self) -> RawEntryBuilderMut<'_, K, V, S, A> { + RawEntryBuilderMut { map: self } + } + + /// Creates a raw immutable entry builder for the HashMap. + /// + /// Raw entries provide the lowest level of control for searching and + /// manipulating a map. They must be manually initialized with a hash and + /// then manually searched. + /// + /// This is useful for + /// * Hash memoization + /// * Using a search key that doesn't work with the Borrow trait + /// * Using custom comparison logic without newtype wrappers + /// + /// Unless you are in such a situation, higher-level and more foolproof APIs like + /// `get` should be preferred. + /// + /// Immutable raw entries have very limited use; you might instead want `raw_entry_mut`. + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.extend([("a", 100), ("b", 200), ("c", 300)]); + /// + /// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// for k in ["a", "b", "c", "d", "e", "f"] { + /// let hash = compute_hash(map.hasher(), k); + /// let v = map.get(&k).cloned(); + /// let kv = v.as_ref().map(|v| (&k, v)); + /// + /// println!("Key: {} and value: {:?}", k, v); + /// + /// assert_eq!(map.raw_entry().from_key(&k), kv); + /// assert_eq!(map.raw_entry().from_hash(hash, |q| *q == k), kv); + /// assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv); + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn raw_entry(&self) -> RawEntryBuilder<'_, K, V, S, A> { + RawEntryBuilder { map: self } + } + + /// Returns a mutable reference to the [`RawTable`] used underneath [`HashMap`]. + /// This function is only available if the `raw` feature of the crate is enabled. + /// + /// # Note + /// + /// Calling the function safe, but using raw hash table API's may require + /// unsafe functions or blocks. + /// + /// `RawTable` API gives the lowest level of control under the map that can be useful + /// for extending the HashMap's API, but may lead to *[undefined behavior]*. + /// + /// [`HashMap`]: struct.HashMap.html + /// [`RawTable`]: raw/struct.RawTable.html + /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.extend([("a", 10), ("b", 20), ("c", 30)]); + /// assert_eq!(map.len(), 3); + /// + /// // Let's imagine that we have a value and a hash of the key, but not the key itself. + /// // However, if you want to remove the value from the map by hash and value, and you + /// // know exactly that the value is unique, then you can create a function like this: + /// fn remove_by_hash<K, V, S, F>( + /// map: &mut HashMap<K, V, S>, + /// hash: u64, + /// is_match: F, + /// ) -> Option<(K, V)> + /// where + /// F: Fn(&(K, V)) -> bool, + /// { + /// let raw_table = map.raw_table(); + /// match raw_table.find(hash, is_match) { + /// Some(bucket) => Some(unsafe { raw_table.remove(bucket) }), + /// None => None, + /// } + /// } + /// + /// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let hash = compute_hash(map.hasher(), "a"); + /// assert_eq!(remove_by_hash(&mut map, hash, |(_, v)| *v == 10), Some(("a", 10))); + /// assert_eq!(map.get(&"a"), None); + /// assert_eq!(map.len(), 2); + /// ``` + #[cfg(feature = "raw")] + #[cfg_attr(feature = "inline-more", inline)] + pub fn raw_table(&mut self) -> &mut RawTable<(K, V), A> { + &mut self.table + } +} + +impl<K, V, S, A> PartialEq for HashMap<K, V, S, A> +where + K: Eq + Hash, + V: PartialEq, + S: BuildHasher, + A: Allocator + Clone, +{ + fn eq(&self, other: &Self) -> bool { + if self.len() != other.len() { + return false; + } + + self.iter() + .all(|(key, value)| other.get(key).map_or(false, |v| *value == *v)) + } +} + +impl<K, V, S, A> Eq for HashMap<K, V, S, A> +where + K: Eq + Hash, + V: Eq, + S: BuildHasher, + A: Allocator + Clone, +{ +} + +impl<K, V, S, A> Debug for HashMap<K, V, S, A> +where + K: Debug, + V: Debug, + A: Allocator + Clone, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_map().entries(self.iter()).finish() + } +} + +impl<K, V, S, A> Default for HashMap<K, V, S, A> +where + S: Default, + A: Default + Allocator + Clone, +{ + /// Creates an empty `HashMap<K, V, S, A>`, with the `Default` value for the hasher and allocator. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use std::collections::hash_map::RandomState; + /// + /// // You can specify all types of HashMap, including hasher and allocator. + /// // Created map is empty and don't allocate memory + /// let map: HashMap<u32, String> = Default::default(); + /// assert_eq!(map.capacity(), 0); + /// let map: HashMap<u32, String, RandomState> = HashMap::default(); + /// assert_eq!(map.capacity(), 0); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn default() -> Self { + Self::with_hasher_in(Default::default(), Default::default()) + } +} + +impl<K, Q: ?Sized, V, S, A> Index<&Q> for HashMap<K, V, S, A> +where + K: Eq + Hash + Borrow<Q>, + Q: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + type Output = V; + + /// Returns a reference to the value corresponding to the supplied key. + /// + /// # Panics + /// + /// Panics if the key is not present in the `HashMap`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let map: HashMap<_, _> = [("a", "One"), ("b", "Two")].into(); + /// + /// assert_eq!(map[&"a"], "One"); + /// assert_eq!(map[&"b"], "Two"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn index(&self, key: &Q) -> &V { + self.get(key).expect("no entry found for key") + } +} + +// The default hasher is used to match the std implementation signature +#[cfg(feature = "ahash")] +impl<K, V, A, const N: usize> From<[(K, V); N]> for HashMap<K, V, DefaultHashBuilder, A> +where + K: Eq + Hash, + A: Default + Allocator + Clone, +{ + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let map1 = HashMap::from([(1, 2), (3, 4)]); + /// let map2: HashMap<_, _> = [(1, 2), (3, 4)].into(); + /// assert_eq!(map1, map2); + /// ``` + fn from(arr: [(K, V); N]) -> Self { + arr.into_iter().collect() + } +} + +/// An iterator over the entries of a `HashMap` in arbitrary order. +/// The iterator element type is `(&'a K, &'a V)`. +/// +/// This `struct` is created by the [`iter`] method on [`HashMap`]. See its +/// documentation for more. +/// +/// [`iter`]: struct.HashMap.html#method.iter +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into(); +/// +/// let mut iter = map.iter(); +/// let mut vec = vec![iter.next(), iter.next(), iter.next()]; +/// +/// // The `Iter` iterator produces items in arbitrary order, so the +/// // items must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [Some((&1, &"a")), Some((&2, &"b")), Some((&3, &"c"))]); +/// +/// // It is fused iterator +/// assert_eq!(iter.next(), None); +/// assert_eq!(iter.next(), None); +/// ``` +pub struct Iter<'a, K, V> { + inner: RawIter<(K, V)>, + marker: PhantomData<(&'a K, &'a V)>, +} + +// FIXME(#26925) Remove in favor of `#[derive(Clone)]` +impl<K, V> Clone for Iter<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Iter { + inner: self.inner.clone(), + marker: PhantomData, + } + } +} + +impl<K: Debug, V: Debug> fmt::Debug for Iter<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.clone()).finish() + } +} + +/// A mutable iterator over the entries of a `HashMap` in arbitrary order. +/// The iterator element type is `(&'a K, &'a mut V)`. +/// +/// This `struct` is created by the [`iter_mut`] method on [`HashMap`]. See its +/// documentation for more. +/// +/// [`iter_mut`]: struct.HashMap.html#method.iter_mut +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let mut map: HashMap<_, _> = [(1, "One".to_owned()), (2, "Two".into())].into(); +/// +/// let mut iter = map.iter_mut(); +/// iter.next().map(|(_, v)| v.push_str(" Mississippi")); +/// iter.next().map(|(_, v)| v.push_str(" Mississippi")); +/// +/// // It is fused iterator +/// assert_eq!(iter.next(), None); +/// assert_eq!(iter.next(), None); +/// +/// assert_eq!(map.get(&1).unwrap(), &"One Mississippi".to_owned()); +/// assert_eq!(map.get(&2).unwrap(), &"Two Mississippi".to_owned()); +/// ``` +pub struct IterMut<'a, K, V> { + inner: RawIter<(K, V)>, + // To ensure invariance with respect to V + marker: PhantomData<(&'a K, &'a mut V)>, +} + +// We override the default Send impl which has K: Sync instead of K: Send. Both +// are correct, but this one is more general since it allows keys which +// implement Send but not Sync. +unsafe impl<K: Send, V: Send> Send for IterMut<'_, K, V> {} + +impl<K, V> IterMut<'_, K, V> { + /// Returns a iterator of references over the remaining items. + #[cfg_attr(feature = "inline-more", inline)] + pub(super) fn iter(&self) -> Iter<'_, K, V> { + Iter { + inner: self.inner.clone(), + marker: PhantomData, + } + } +} + +/// An owning iterator over the entries of a `HashMap` in arbitrary order. +/// The iterator element type is `(K, V)`. +/// +/// This `struct` is created by the [`into_iter`] method on [`HashMap`] +/// (provided by the [`IntoIterator`] trait). See its documentation for more. +/// The map cannot be used after calling that method. +/// +/// [`into_iter`]: struct.HashMap.html#method.into_iter +/// [`HashMap`]: struct.HashMap.html +/// [`IntoIterator`]: https://doc.rust-lang.org/core/iter/trait.IntoIterator.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into(); +/// +/// let mut iter = map.into_iter(); +/// let mut vec = vec![iter.next(), iter.next(), iter.next()]; +/// +/// // The `IntoIter` iterator produces items in arbitrary order, so the +/// // items must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [Some((1, "a")), Some((2, "b")), Some((3, "c"))]); +/// +/// // It is fused iterator +/// assert_eq!(iter.next(), None); +/// assert_eq!(iter.next(), None); +/// ``` +pub struct IntoIter<K, V, A: Allocator + Clone = Global> { + inner: RawIntoIter<(K, V), A>, +} + +impl<K, V, A: Allocator + Clone> IntoIter<K, V, A> { + /// Returns a iterator of references over the remaining items. + #[cfg_attr(feature = "inline-more", inline)] + pub(super) fn iter(&self) -> Iter<'_, K, V> { + Iter { + inner: self.inner.iter(), + marker: PhantomData, + } + } +} + +/// An owning iterator over the keys of a `HashMap` in arbitrary order. +/// The iterator element type is `K`. +/// +/// This `struct` is created by the [`into_keys`] method on [`HashMap`]. +/// See its documentation for more. +/// The map cannot be used after calling that method. +/// +/// [`into_keys`]: struct.HashMap.html#method.into_keys +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into(); +/// +/// let mut keys = map.into_keys(); +/// let mut vec = vec![keys.next(), keys.next(), keys.next()]; +/// +/// // The `IntoKeys` iterator produces keys in arbitrary order, so the +/// // keys must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [Some(1), Some(2), Some(3)]); +/// +/// // It is fused iterator +/// assert_eq!(keys.next(), None); +/// assert_eq!(keys.next(), None); +/// ``` +pub struct IntoKeys<K, V, A: Allocator + Clone = Global> { + inner: IntoIter<K, V, A>, +} + +impl<K, V, A: Allocator + Clone> Iterator for IntoKeys<K, V, A> { + type Item = K; + + #[inline] + fn next(&mut self) -> Option<K> { + self.inner.next().map(|(k, _)| k) + } + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} + +impl<K, V, A: Allocator + Clone> ExactSizeIterator for IntoKeys<K, V, A> { + #[inline] + fn len(&self) -> usize { + self.inner.len() + } +} + +impl<K, V, A: Allocator + Clone> FusedIterator for IntoKeys<K, V, A> {} + +impl<K: Debug, V: Debug, A: Allocator + Clone> fmt::Debug for IntoKeys<K, V, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list() + .entries(self.inner.iter().map(|(k, _)| k)) + .finish() + } +} + +/// An owning iterator over the values of a `HashMap` in arbitrary order. +/// The iterator element type is `V`. +/// +/// This `struct` is created by the [`into_values`] method on [`HashMap`]. +/// See its documentation for more. The map cannot be used after calling that method. +/// +/// [`into_values`]: struct.HashMap.html#method.into_values +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into(); +/// +/// let mut values = map.into_values(); +/// let mut vec = vec![values.next(), values.next(), values.next()]; +/// +/// // The `IntoValues` iterator produces values in arbitrary order, so +/// // the values must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [Some("a"), Some("b"), Some("c")]); +/// +/// // It is fused iterator +/// assert_eq!(values.next(), None); +/// assert_eq!(values.next(), None); +/// ``` +pub struct IntoValues<K, V, A: Allocator + Clone = Global> { + inner: IntoIter<K, V, A>, +} + +impl<K, V, A: Allocator + Clone> Iterator for IntoValues<K, V, A> { + type Item = V; + + #[inline] + fn next(&mut self) -> Option<V> { + self.inner.next().map(|(_, v)| v) + } + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} + +impl<K, V, A: Allocator + Clone> ExactSizeIterator for IntoValues<K, V, A> { + #[inline] + fn len(&self) -> usize { + self.inner.len() + } +} + +impl<K, V, A: Allocator + Clone> FusedIterator for IntoValues<K, V, A> {} + +impl<K, V: Debug, A: Allocator + Clone> fmt::Debug for IntoValues<K, V, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list() + .entries(self.inner.iter().map(|(_, v)| v)) + .finish() + } +} + +/// An iterator over the keys of a `HashMap` in arbitrary order. +/// The iterator element type is `&'a K`. +/// +/// This `struct` is created by the [`keys`] method on [`HashMap`]. See its +/// documentation for more. +/// +/// [`keys`]: struct.HashMap.html#method.keys +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into(); +/// +/// let mut keys = map.keys(); +/// let mut vec = vec![keys.next(), keys.next(), keys.next()]; +/// +/// // The `Keys` iterator produces keys in arbitrary order, so the +/// // keys must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [Some(&1), Some(&2), Some(&3)]); +/// +/// // It is fused iterator +/// assert_eq!(keys.next(), None); +/// assert_eq!(keys.next(), None); +/// ``` +pub struct Keys<'a, K, V> { + inner: Iter<'a, K, V>, +} + +// FIXME(#26925) Remove in favor of `#[derive(Clone)]` +impl<K, V> Clone for Keys<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Keys { + inner: self.inner.clone(), + } + } +} + +impl<K: Debug, V> fmt::Debug for Keys<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.clone()).finish() + } +} + +/// An iterator over the values of a `HashMap` in arbitrary order. +/// The iterator element type is `&'a V`. +/// +/// This `struct` is created by the [`values`] method on [`HashMap`]. See its +/// documentation for more. +/// +/// [`values`]: struct.HashMap.html#method.values +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into(); +/// +/// let mut values = map.values(); +/// let mut vec = vec![values.next(), values.next(), values.next()]; +/// +/// // The `Values` iterator produces values in arbitrary order, so the +/// // values must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [Some(&"a"), Some(&"b"), Some(&"c")]); +/// +/// // It is fused iterator +/// assert_eq!(values.next(), None); +/// assert_eq!(values.next(), None); +/// ``` +pub struct Values<'a, K, V> { + inner: Iter<'a, K, V>, +} + +// FIXME(#26925) Remove in favor of `#[derive(Clone)]` +impl<K, V> Clone for Values<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Values { + inner: self.inner.clone(), + } + } +} + +impl<K, V: Debug> fmt::Debug for Values<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.clone()).finish() + } +} + +/// A draining iterator over the entries of a `HashMap` in arbitrary +/// order. The iterator element type is `(K, V)`. +/// +/// This `struct` is created by the [`drain`] method on [`HashMap`]. See its +/// documentation for more. +/// +/// [`drain`]: struct.HashMap.html#method.drain +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let mut map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into(); +/// +/// let mut drain_iter = map.drain(); +/// let mut vec = vec![drain_iter.next(), drain_iter.next(), drain_iter.next()]; +/// +/// // The `Drain` iterator produces items in arbitrary order, so the +/// // items must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [Some((1, "a")), Some((2, "b")), Some((3, "c"))]); +/// +/// // It is fused iterator +/// assert_eq!(drain_iter.next(), None); +/// assert_eq!(drain_iter.next(), None); +/// ``` +pub struct Drain<'a, K, V, A: Allocator + Clone = Global> { + inner: RawDrain<'a, (K, V), A>, +} + +impl<K, V, A: Allocator + Clone> Drain<'_, K, V, A> { + /// Returns a iterator of references over the remaining items. + #[cfg_attr(feature = "inline-more", inline)] + pub(super) fn iter(&self) -> Iter<'_, K, V> { + Iter { + inner: self.inner.iter(), + marker: PhantomData, + } + } +} + +/// A draining iterator over entries of a `HashMap` which don't satisfy the predicate +/// `f(&k, &mut v)` in arbitrary order. The iterator element type is `(K, V)`. +/// +/// This `struct` is created by the [`drain_filter`] method on [`HashMap`]. See its +/// documentation for more. +/// +/// [`drain_filter`]: struct.HashMap.html#method.drain_filter +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let mut map: HashMap<i32, &str> = [(1, "a"), (2, "b"), (3, "c")].into(); +/// +/// let mut drain_filter = map.drain_filter(|k, _v| k % 2 != 0); +/// let mut vec = vec![drain_filter.next(), drain_filter.next()]; +/// +/// // The `DrainFilter` iterator produces items in arbitrary order, so the +/// // items must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [Some((1, "a")),Some((3, "c"))]); +/// +/// // It is fused iterator +/// assert_eq!(drain_filter.next(), None); +/// assert_eq!(drain_filter.next(), None); +/// drop(drain_filter); +/// +/// assert_eq!(map.len(), 1); +/// ``` +pub struct DrainFilter<'a, K, V, F, A: Allocator + Clone = Global> +where + F: FnMut(&K, &mut V) -> bool, +{ + f: F, + inner: DrainFilterInner<'a, K, V, A>, +} + +impl<'a, K, V, F, A> Drop for DrainFilter<'a, K, V, F, A> +where + F: FnMut(&K, &mut V) -> bool, + A: Allocator + Clone, +{ + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + while let Some(item) = self.next() { + let guard = ConsumeAllOnDrop(self); + drop(item); + mem::forget(guard); + } + } +} + +pub(super) struct ConsumeAllOnDrop<'a, T: Iterator>(pub &'a mut T); + +impl<T: Iterator> Drop for ConsumeAllOnDrop<'_, T> { + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + self.0.for_each(drop); + } +} + +impl<K, V, F, A> Iterator for DrainFilter<'_, K, V, F, A> +where + F: FnMut(&K, &mut V) -> bool, + A: Allocator + Clone, +{ + type Item = (K, V); + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<Self::Item> { + self.inner.next(&mut self.f) + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + (0, self.inner.iter.size_hint().1) + } +} + +impl<K, V, F> FusedIterator for DrainFilter<'_, K, V, F> where F: FnMut(&K, &mut V) -> bool {} + +/// Portions of `DrainFilter` shared with `set::DrainFilter` +pub(super) struct DrainFilterInner<'a, K, V, A: Allocator + Clone> { + pub iter: RawIter<(K, V)>, + pub table: &'a mut RawTable<(K, V), A>, +} + +impl<K, V, A: Allocator + Clone> DrainFilterInner<'_, K, V, A> { + #[cfg_attr(feature = "inline-more", inline)] + pub(super) fn next<F>(&mut self, f: &mut F) -> Option<(K, V)> + where + F: FnMut(&K, &mut V) -> bool, + { + unsafe { + for item in &mut self.iter { + let &mut (ref key, ref mut value) = item.as_mut(); + if f(key, value) { + return Some(self.table.remove(item)); + } + } + } + None + } +} + +/// A mutable iterator over the values of a `HashMap` in arbitrary order. +/// The iterator element type is `&'a mut V`. +/// +/// This `struct` is created by the [`values_mut`] method on [`HashMap`]. See its +/// documentation for more. +/// +/// [`values_mut`]: struct.HashMap.html#method.values_mut +/// [`HashMap`]: struct.HashMap.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashMap; +/// +/// let mut map: HashMap<_, _> = [(1, "One".to_owned()), (2, "Two".into())].into(); +/// +/// let mut values = map.values_mut(); +/// values.next().map(|v| v.push_str(" Mississippi")); +/// values.next().map(|v| v.push_str(" Mississippi")); +/// +/// // It is fused iterator +/// assert_eq!(values.next(), None); +/// assert_eq!(values.next(), None); +/// +/// assert_eq!(map.get(&1).unwrap(), &"One Mississippi".to_owned()); +/// assert_eq!(map.get(&2).unwrap(), &"Two Mississippi".to_owned()); +/// ``` +pub struct ValuesMut<'a, K, V> { + inner: IterMut<'a, K, V>, +} + +/// A builder for computing where in a [`HashMap`] a key-value pair would be stored. +/// +/// See the [`HashMap::raw_entry_mut`] docs for usage examples. +/// +/// [`HashMap::raw_entry_mut`]: struct.HashMap.html#method.raw_entry_mut +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{RawEntryBuilderMut, RawEntryMut::Vacant, RawEntryMut::Occupied}; +/// use hashbrown::HashMap; +/// use core::hash::{BuildHasher, Hash}; +/// +/// let mut map = HashMap::new(); +/// map.extend([(1, 11), (2, 12), (3, 13), (4, 14), (5, 15), (6, 16)]); +/// assert_eq!(map.len(), 6); +/// +/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { +/// use core::hash::Hasher; +/// let mut state = hash_builder.build_hasher(); +/// key.hash(&mut state); +/// state.finish() +/// } +/// +/// let builder: RawEntryBuilderMut<_, _, _> = map.raw_entry_mut(); +/// +/// // Existing key +/// match builder.from_key(&6) { +/// Vacant(_) => unreachable!(), +/// Occupied(view) => assert_eq!(view.get(), &16), +/// } +/// +/// for key in 0..12 { +/// let hash = compute_hash(map.hasher(), &key); +/// let value = map.get(&key).cloned(); +/// let key_value = value.as_ref().map(|v| (&key, v)); +/// +/// println!("Key: {} and value: {:?}", key, value); +/// +/// match map.raw_entry_mut().from_key(&key) { +/// Occupied(mut o) => assert_eq!(Some(o.get_key_value()), key_value), +/// Vacant(_) => assert_eq!(value, None), +/// } +/// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &key) { +/// Occupied(mut o) => assert_eq!(Some(o.get_key_value()), key_value), +/// Vacant(_) => assert_eq!(value, None), +/// } +/// match map.raw_entry_mut().from_hash(hash, |q| *q == key) { +/// Occupied(mut o) => assert_eq!(Some(o.get_key_value()), key_value), +/// Vacant(_) => assert_eq!(value, None), +/// } +/// } +/// +/// assert_eq!(map.len(), 6); +/// ``` +pub struct RawEntryBuilderMut<'a, K, V, S, A: Allocator + Clone = Global> { + map: &'a mut HashMap<K, V, S, A>, +} + +/// A view into a single entry in a map, which may either be vacant or occupied. +/// +/// This is a lower-level version of [`Entry`]. +/// +/// This `enum` is constructed through the [`raw_entry_mut`] method on [`HashMap`], +/// then calling one of the methods of that [`RawEntryBuilderMut`]. +/// +/// [`HashMap`]: struct.HashMap.html +/// [`Entry`]: enum.Entry.html +/// [`raw_entry_mut`]: struct.HashMap.html#method.raw_entry_mut +/// [`RawEntryBuilderMut`]: struct.RawEntryBuilderMut.html +/// +/// # Examples +/// +/// ``` +/// use core::hash::{BuildHasher, Hash}; +/// use hashbrown::hash_map::{HashMap, RawEntryMut, RawOccupiedEntryMut}; +/// +/// let mut map = HashMap::new(); +/// map.extend([('a', 1), ('b', 2), ('c', 3)]); +/// assert_eq!(map.len(), 3); +/// +/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { +/// use core::hash::Hasher; +/// let mut state = hash_builder.build_hasher(); +/// key.hash(&mut state); +/// state.finish() +/// } +/// +/// // Existing key (insert) +/// let raw: RawEntryMut<_, _, _> = map.raw_entry_mut().from_key(&'a'); +/// let _raw_o: RawOccupiedEntryMut<_, _, _> = raw.insert('a', 10); +/// assert_eq!(map.len(), 3); +/// +/// // Nonexistent key (insert) +/// map.raw_entry_mut().from_key(&'d').insert('d', 40); +/// assert_eq!(map.len(), 4); +/// +/// // Existing key (or_insert) +/// let hash = compute_hash(map.hasher(), &'b'); +/// let kv = map +/// .raw_entry_mut() +/// .from_key_hashed_nocheck(hash, &'b') +/// .or_insert('b', 20); +/// assert_eq!(kv, (&mut 'b', &mut 2)); +/// *kv.1 = 20; +/// assert_eq!(map.len(), 4); +/// +/// // Nonexistent key (or_insert) +/// let hash = compute_hash(map.hasher(), &'e'); +/// let kv = map +/// .raw_entry_mut() +/// .from_key_hashed_nocheck(hash, &'e') +/// .or_insert('e', 50); +/// assert_eq!(kv, (&mut 'e', &mut 50)); +/// assert_eq!(map.len(), 5); +/// +/// // Existing key (or_insert_with) +/// let hash = compute_hash(map.hasher(), &'c'); +/// let kv = map +/// .raw_entry_mut() +/// .from_hash(hash, |q| q == &'c') +/// .or_insert_with(|| ('c', 30)); +/// assert_eq!(kv, (&mut 'c', &mut 3)); +/// *kv.1 = 30; +/// assert_eq!(map.len(), 5); +/// +/// // Nonexistent key (or_insert_with) +/// let hash = compute_hash(map.hasher(), &'f'); +/// let kv = map +/// .raw_entry_mut() +/// .from_hash(hash, |q| q == &'f') +/// .or_insert_with(|| ('f', 60)); +/// assert_eq!(kv, (&mut 'f', &mut 60)); +/// assert_eq!(map.len(), 6); +/// +/// println!("Our HashMap: {:?}", map); +/// +/// let mut vec: Vec<_> = map.iter().map(|(&k, &v)| (k, v)).collect(); +/// // The `Iter` iterator produces items in arbitrary order, so the +/// // items must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [('a', 10), ('b', 20), ('c', 30), ('d', 40), ('e', 50), ('f', 60)]); +/// ``` +pub enum RawEntryMut<'a, K, V, S, A: Allocator + Clone = Global> { + /// An occupied entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::{hash_map::RawEntryMut, HashMap}; + /// let mut map: HashMap<_, _> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => unreachable!(), + /// RawEntryMut::Occupied(_) => { } + /// } + /// ``` + Occupied(RawOccupiedEntryMut<'a, K, V, S, A>), + /// A vacant entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::{hash_map::RawEntryMut, HashMap}; + /// let mut map: HashMap<&str, i32> = HashMap::new(); + /// + /// match map.raw_entry_mut().from_key("a") { + /// RawEntryMut::Occupied(_) => unreachable!(), + /// RawEntryMut::Vacant(_) => { } + /// } + /// ``` + Vacant(RawVacantEntryMut<'a, K, V, S, A>), +} + +/// A view into an occupied entry in a `HashMap`. +/// It is part of the [`RawEntryMut`] enum. +/// +/// [`RawEntryMut`]: enum.RawEntryMut.html +/// +/// # Examples +/// +/// ``` +/// use core::hash::{BuildHasher, Hash}; +/// use hashbrown::hash_map::{HashMap, RawEntryMut, RawOccupiedEntryMut}; +/// +/// let mut map = HashMap::new(); +/// map.extend([("a", 10), ("b", 20), ("c", 30)]); +/// +/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { +/// use core::hash::Hasher; +/// let mut state = hash_builder.build_hasher(); +/// key.hash(&mut state); +/// state.finish() +/// } +/// +/// let _raw_o: RawOccupiedEntryMut<_, _, _> = map.raw_entry_mut().from_key(&"a").insert("a", 100); +/// assert_eq!(map.len(), 3); +/// +/// // Existing key (insert and update) +/// match map.raw_entry_mut().from_key(&"a") { +/// RawEntryMut::Vacant(_) => unreachable!(), +/// RawEntryMut::Occupied(mut view) => { +/// assert_eq!(view.get(), &100); +/// let v = view.get_mut(); +/// let new_v = (*v) * 10; +/// *v = new_v; +/// assert_eq!(view.insert(1111), 1000); +/// } +/// } +/// +/// assert_eq!(map[&"a"], 1111); +/// assert_eq!(map.len(), 3); +/// +/// // Existing key (take) +/// let hash = compute_hash(map.hasher(), &"c"); +/// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &"c") { +/// RawEntryMut::Vacant(_) => unreachable!(), +/// RawEntryMut::Occupied(view) => { +/// assert_eq!(view.remove_entry(), ("c", 30)); +/// } +/// } +/// assert_eq!(map.raw_entry().from_key(&"c"), None); +/// assert_eq!(map.len(), 2); +/// +/// let hash = compute_hash(map.hasher(), &"b"); +/// match map.raw_entry_mut().from_hash(hash, |q| *q == "b") { +/// RawEntryMut::Vacant(_) => unreachable!(), +/// RawEntryMut::Occupied(view) => { +/// assert_eq!(view.remove_entry(), ("b", 20)); +/// } +/// } +/// assert_eq!(map.get(&"b"), None); +/// assert_eq!(map.len(), 1); +/// ``` +pub struct RawOccupiedEntryMut<'a, K, V, S, A: Allocator + Clone = Global> { + elem: Bucket<(K, V)>, + table: &'a mut RawTable<(K, V), A>, + hash_builder: &'a S, +} + +unsafe impl<K, V, S, A> Send for RawOccupiedEntryMut<'_, K, V, S, A> +where + K: Send, + V: Send, + S: Send, + A: Send + Allocator + Clone, +{ +} +unsafe impl<K, V, S, A> Sync for RawOccupiedEntryMut<'_, K, V, S, A> +where + K: Sync, + V: Sync, + S: Sync, + A: Sync + Allocator + Clone, +{ +} + +/// A view into a vacant entry in a `HashMap`. +/// It is part of the [`RawEntryMut`] enum. +/// +/// [`RawEntryMut`]: enum.RawEntryMut.html +/// +/// # Examples +/// +/// ``` +/// use core::hash::{BuildHasher, Hash}; +/// use hashbrown::hash_map::{HashMap, RawEntryMut, RawVacantEntryMut}; +/// +/// let mut map = HashMap::<&str, i32>::new(); +/// +/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { +/// use core::hash::Hasher; +/// let mut state = hash_builder.build_hasher(); +/// key.hash(&mut state); +/// state.finish() +/// } +/// +/// let raw_v: RawVacantEntryMut<_, _, _> = match map.raw_entry_mut().from_key(&"a") { +/// RawEntryMut::Vacant(view) => view, +/// RawEntryMut::Occupied(_) => unreachable!(), +/// }; +/// raw_v.insert("a", 10); +/// assert!(map[&"a"] == 10 && map.len() == 1); +/// +/// // Nonexistent key (insert and update) +/// let hash = compute_hash(map.hasher(), &"b"); +/// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &"b") { +/// RawEntryMut::Occupied(_) => unreachable!(), +/// RawEntryMut::Vacant(view) => { +/// let (k, value) = view.insert("b", 2); +/// assert_eq!((*k, *value), ("b", 2)); +/// *value = 20; +/// } +/// } +/// assert!(map[&"b"] == 20 && map.len() == 2); +/// +/// let hash = compute_hash(map.hasher(), &"c"); +/// match map.raw_entry_mut().from_hash(hash, |q| *q == "c") { +/// RawEntryMut::Occupied(_) => unreachable!(), +/// RawEntryMut::Vacant(view) => { +/// assert_eq!(view.insert("c", 30), (&mut "c", &mut 30)); +/// } +/// } +/// assert!(map[&"c"] == 30 && map.len() == 3); +/// ``` +pub struct RawVacantEntryMut<'a, K, V, S, A: Allocator + Clone = Global> { + table: &'a mut RawTable<(K, V), A>, + hash_builder: &'a S, +} + +/// A builder for computing where in a [`HashMap`] a key-value pair would be stored. +/// +/// See the [`HashMap::raw_entry`] docs for usage examples. +/// +/// [`HashMap::raw_entry`]: struct.HashMap.html#method.raw_entry +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{HashMap, RawEntryBuilder}; +/// use core::hash::{BuildHasher, Hash}; +/// +/// let mut map = HashMap::new(); +/// map.extend([(1, 10), (2, 20), (3, 30)]); +/// +/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { +/// use core::hash::Hasher; +/// let mut state = hash_builder.build_hasher(); +/// key.hash(&mut state); +/// state.finish() +/// } +/// +/// for k in 0..6 { +/// let hash = compute_hash(map.hasher(), &k); +/// let v = map.get(&k).cloned(); +/// let kv = v.as_ref().map(|v| (&k, v)); +/// +/// println!("Key: {} and value: {:?}", k, v); +/// let builder: RawEntryBuilder<_, _, _> = map.raw_entry(); +/// assert_eq!(builder.from_key(&k), kv); +/// assert_eq!(map.raw_entry().from_hash(hash, |q| *q == k), kv); +/// assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv); +/// } +/// ``` +pub struct RawEntryBuilder<'a, K, V, S, A: Allocator + Clone = Global> { + map: &'a HashMap<K, V, S, A>, +} + +impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilderMut<'a, K, V, S, A> { + /// Creates a `RawEntryMut` from the given key. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// let key = "a"; + /// let entry: RawEntryMut<&str, u32, _> = map.raw_entry_mut().from_key(&key); + /// entry.insert(key, 100); + /// assert_eq!(map[&"a"], 100); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + #[allow(clippy::wrong_self_convention)] + pub fn from_key<Q: ?Sized>(self, k: &Q) -> RawEntryMut<'a, K, V, S, A> + where + S: BuildHasher, + K: Borrow<Q>, + Q: Hash + Eq, + { + let hash = make_hash::<K, Q, S>(&self.map.hash_builder, k); + self.from_key_hashed_nocheck(hash, k) + } + + /// Creates a `RawEntryMut` from the given key and its hash. + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// let key = "a"; + /// let hash = compute_hash(map.hasher(), &key); + /// let entry: RawEntryMut<&str, u32, _> = map.raw_entry_mut().from_key_hashed_nocheck(hash, &key); + /// entry.insert(key, 100); + /// assert_eq!(map[&"a"], 100); + /// ``` + #[inline] + #[allow(clippy::wrong_self_convention)] + pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> RawEntryMut<'a, K, V, S, A> + where + K: Borrow<Q>, + Q: Eq, + { + self.from_hash(hash, equivalent(k)) + } +} + +impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilderMut<'a, K, V, S, A> { + /// Creates a `RawEntryMut` from the given hash and matching function. + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// let key = "a"; + /// let hash = compute_hash(map.hasher(), &key); + /// let entry: RawEntryMut<&str, u32, _> = map.raw_entry_mut().from_hash(hash, |k| k == &key); + /// entry.insert(key, 100); + /// assert_eq!(map[&"a"], 100); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + #[allow(clippy::wrong_self_convention)] + pub fn from_hash<F>(self, hash: u64, is_match: F) -> RawEntryMut<'a, K, V, S, A> + where + for<'b> F: FnMut(&'b K) -> bool, + { + self.search(hash, is_match) + } + + #[cfg_attr(feature = "inline-more", inline)] + fn search<F>(self, hash: u64, mut is_match: F) -> RawEntryMut<'a, K, V, S, A> + where + for<'b> F: FnMut(&'b K) -> bool, + { + match self.map.table.find(hash, |(k, _)| is_match(k)) { + Some(elem) => RawEntryMut::Occupied(RawOccupiedEntryMut { + elem, + table: &mut self.map.table, + hash_builder: &self.map.hash_builder, + }), + None => RawEntryMut::Vacant(RawVacantEntryMut { + table: &mut self.map.table, + hash_builder: &self.map.hash_builder, + }), + } + } +} + +impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilder<'a, K, V, S, A> { + /// Access an immutable entry by key. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// let key = "a"; + /// assert_eq!(map.raw_entry().from_key(&key), Some((&"a", &100))); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + #[allow(clippy::wrong_self_convention)] + pub fn from_key<Q: ?Sized>(self, k: &Q) -> Option<(&'a K, &'a V)> + where + S: BuildHasher, + K: Borrow<Q>, + Q: Hash + Eq, + { + let hash = make_hash::<K, Q, S>(&self.map.hash_builder, k); + self.from_key_hashed_nocheck(hash, k) + } + + /// Access an immutable entry by a key and its hash. + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::HashMap; + /// + /// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// let key = "a"; + /// let hash = compute_hash(map.hasher(), &key); + /// assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &key), Some((&"a", &100))); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + #[allow(clippy::wrong_self_convention)] + pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> Option<(&'a K, &'a V)> + where + K: Borrow<Q>, + Q: Eq, + { + self.from_hash(hash, equivalent(k)) + } + + #[cfg_attr(feature = "inline-more", inline)] + fn search<F>(self, hash: u64, mut is_match: F) -> Option<(&'a K, &'a V)> + where + F: FnMut(&K) -> bool, + { + match self.map.table.get(hash, |(k, _)| is_match(k)) { + Some(&(ref key, ref value)) => Some((key, value)), + None => None, + } + } + + /// Access an immutable entry by hash and matching function. + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::HashMap; + /// + /// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// let key = "a"; + /// let hash = compute_hash(map.hasher(), &key); + /// assert_eq!(map.raw_entry().from_hash(hash, |k| k == &key), Some((&"a", &100))); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + #[allow(clippy::wrong_self_convention)] + pub fn from_hash<F>(self, hash: u64, is_match: F) -> Option<(&'a K, &'a V)> + where + F: FnMut(&K) -> bool, + { + self.search(hash, is_match) + } +} + +impl<'a, K, V, S, A: Allocator + Clone> RawEntryMut<'a, K, V, S, A> { + /// Sets the value of the entry, and returns a RawOccupiedEntryMut. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// let entry = map.raw_entry_mut().from_key("horseyland").insert("horseyland", 37); + /// + /// assert_eq!(entry.remove_entry(), ("horseyland", 37)); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self, key: K, value: V) -> RawOccupiedEntryMut<'a, K, V, S, A> + where + K: Hash, + S: BuildHasher, + { + match self { + RawEntryMut::Occupied(mut entry) => { + entry.insert(value); + entry + } + RawEntryMut::Vacant(entry) => entry.insert_entry(key, value), + } + } + + /// Ensures a value is in the entry by inserting the default if empty, and returns + /// mutable references to the key and value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 3); + /// assert_eq!(map["poneyland"], 3); + /// + /// *map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 10).1 *= 2; + /// assert_eq!(map["poneyland"], 6); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert(self, default_key: K, default_val: V) -> (&'a mut K, &'a mut V) + where + K: Hash, + S: BuildHasher, + { + match self { + RawEntryMut::Occupied(entry) => entry.into_key_value(), + RawEntryMut::Vacant(entry) => entry.insert(default_key, default_val), + } + } + + /// Ensures a value is in the entry by inserting the result of the default function if empty, + /// and returns mutable references to the key and value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, String> = HashMap::new(); + /// + /// map.raw_entry_mut().from_key("poneyland").or_insert_with(|| { + /// ("poneyland", "hoho".to_string()) + /// }); + /// + /// assert_eq!(map["poneyland"], "hoho".to_string()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V) + where + F: FnOnce() -> (K, V), + K: Hash, + S: BuildHasher, + { + match self { + RawEntryMut::Occupied(entry) => entry.into_key_value(), + RawEntryMut::Vacant(entry) => { + let (k, v) = default(); + entry.insert(k, v) + } + } + } + + /// Provides in-place mutable access to an occupied entry before any + /// potential inserts into the map. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// map.raw_entry_mut() + /// .from_key("poneyland") + /// .and_modify(|_k, v| { *v += 1 }) + /// .or_insert("poneyland", 42); + /// assert_eq!(map["poneyland"], 42); + /// + /// map.raw_entry_mut() + /// .from_key("poneyland") + /// .and_modify(|_k, v| { *v += 1 }) + /// .or_insert("poneyland", 0); + /// assert_eq!(map["poneyland"], 43); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn and_modify<F>(self, f: F) -> Self + where + F: FnOnce(&mut K, &mut V), + { + match self { + RawEntryMut::Occupied(mut entry) => { + { + let (k, v) = entry.get_key_value_mut(); + f(k, v); + } + RawEntryMut::Occupied(entry) + } + RawEntryMut::Vacant(entry) => RawEntryMut::Vacant(entry), + } + } + + /// Provides shared access to the key and owned access to the value of + /// an occupied entry and allows to replace or remove it based on the + /// value of the returned option. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RawEntryMut; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// let entry = map + /// .raw_entry_mut() + /// .from_key("poneyland") + /// .and_replace_entry_with(|_k, _v| panic!()); + /// + /// match entry { + /// RawEntryMut::Vacant(_) => {}, + /// RawEntryMut::Occupied(_) => panic!(), + /// } + /// + /// map.insert("poneyland", 42); + /// + /// let entry = map + /// .raw_entry_mut() + /// .from_key("poneyland") + /// .and_replace_entry_with(|k, v| { + /// assert_eq!(k, &"poneyland"); + /// assert_eq!(v, 42); + /// Some(v + 1) + /// }); + /// + /// match entry { + /// RawEntryMut::Occupied(e) => { + /// assert_eq!(e.key(), &"poneyland"); + /// assert_eq!(e.get(), &43); + /// }, + /// RawEntryMut::Vacant(_) => panic!(), + /// } + /// + /// assert_eq!(map["poneyland"], 43); + /// + /// let entry = map + /// .raw_entry_mut() + /// .from_key("poneyland") + /// .and_replace_entry_with(|_k, _v| None); + /// + /// match entry { + /// RawEntryMut::Vacant(_) => {}, + /// RawEntryMut::Occupied(_) => panic!(), + /// } + /// + /// assert!(!map.contains_key("poneyland")); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn and_replace_entry_with<F>(self, f: F) -> Self + where + F: FnOnce(&K, V) -> Option<V>, + { + match self { + RawEntryMut::Occupied(entry) => entry.replace_entry_with(f), + RawEntryMut::Vacant(_) => self, + } + } +} + +impl<'a, K, V, S, A: Allocator + Clone> RawOccupiedEntryMut<'a, K, V, S, A> { + /// Gets a reference to the key in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => assert_eq!(o.key(), &"a") + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &K { + unsafe { &self.elem.as_ref().0 } + } + + /// Gets a mutable reference to the key in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// use std::rc::Rc; + /// + /// let key_one = Rc::new("a"); + /// let key_two = Rc::new("a"); + /// + /// let mut map: HashMap<Rc<&str>, u32> = HashMap::new(); + /// map.insert(key_one.clone(), 10); + /// + /// assert_eq!(map[&key_one], 10); + /// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1); + /// + /// match map.raw_entry_mut().from_key(&key_one) { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(mut o) => { + /// *o.key_mut() = key_two.clone(); + /// } + /// } + /// assert_eq!(map[&key_two], 10); + /// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key_mut(&mut self) -> &mut K { + unsafe { &mut self.elem.as_mut().0 } + } + + /// Converts the entry into a mutable reference to the key in the entry + /// with a lifetime bound to the map itself. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// use std::rc::Rc; + /// + /// let key_one = Rc::new("a"); + /// let key_two = Rc::new("a"); + /// + /// let mut map: HashMap<Rc<&str>, u32> = HashMap::new(); + /// map.insert(key_one.clone(), 10); + /// + /// assert_eq!(map[&key_one], 10); + /// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1); + /// + /// let inside_key: &mut Rc<&str>; + /// + /// match map.raw_entry_mut().from_key(&key_one) { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => inside_key = o.into_key(), + /// } + /// *inside_key = key_two.clone(); + /// + /// assert_eq!(map[&key_two], 10); + /// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_key(self) -> &'a mut K { + unsafe { &mut self.elem.as_mut().0 } + } + + /// Gets a reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => assert_eq!(o.get(), &100), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get(&self) -> &V { + unsafe { &self.elem.as_ref().1 } + } + + /// Converts the OccupiedEntry into a mutable reference to the value in the entry + /// with a lifetime bound to the map itself. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// let value: &mut u32; + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => value = o.into_mut(), + /// } + /// *value += 900; + /// + /// assert_eq!(map[&"a"], 1000); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_mut(self) -> &'a mut V { + unsafe { &mut self.elem.as_mut().1 } + } + + /// Gets a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(mut o) => *o.get_mut() += 900, + /// } + /// + /// assert_eq!(map[&"a"], 1000); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_mut(&mut self) -> &mut V { + unsafe { &mut self.elem.as_mut().1 } + } + + /// Gets a reference to the key and value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => assert_eq!(o.get_key_value(), (&"a", &100)), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_key_value(&self) -> (&K, &V) { + unsafe { + let &(ref key, ref value) = self.elem.as_ref(); + (key, value) + } + } + + /// Gets a mutable reference to the key and value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// use std::rc::Rc; + /// + /// let key_one = Rc::new("a"); + /// let key_two = Rc::new("a"); + /// + /// let mut map: HashMap<Rc<&str>, u32> = HashMap::new(); + /// map.insert(key_one.clone(), 10); + /// + /// assert_eq!(map[&key_one], 10); + /// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1); + /// + /// match map.raw_entry_mut().from_key(&key_one) { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(mut o) => { + /// let (inside_key, inside_value) = o.get_key_value_mut(); + /// *inside_key = key_two.clone(); + /// *inside_value = 100; + /// } + /// } + /// assert_eq!(map[&key_two], 100); + /// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_key_value_mut(&mut self) -> (&mut K, &mut V) { + unsafe { + let &mut (ref mut key, ref mut value) = self.elem.as_mut(); + (key, value) + } + } + + /// Converts the OccupiedEntry into a mutable reference to the key and value in the entry + /// with a lifetime bound to the map itself. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// use std::rc::Rc; + /// + /// let key_one = Rc::new("a"); + /// let key_two = Rc::new("a"); + /// + /// let mut map: HashMap<Rc<&str>, u32> = HashMap::new(); + /// map.insert(key_one.clone(), 10); + /// + /// assert_eq!(map[&key_one], 10); + /// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1); + /// + /// let inside_key: &mut Rc<&str>; + /// let inside_value: &mut u32; + /// match map.raw_entry_mut().from_key(&key_one) { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => { + /// let tuple = o.into_key_value(); + /// inside_key = tuple.0; + /// inside_value = tuple.1; + /// } + /// } + /// *inside_key = key_two.clone(); + /// *inside_value = 100; + /// assert_eq!(map[&key_two], 100); + /// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_key_value(self) -> (&'a mut K, &'a mut V) { + unsafe { + let &mut (ref mut key, ref mut value) = self.elem.as_mut(); + (key, value) + } + } + + /// Sets the value of the entry, and returns the entry's old value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(mut o) => assert_eq!(o.insert(1000), 100), + /// } + /// + /// assert_eq!(map[&"a"], 1000); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(&mut self, value: V) -> V { + mem::replace(self.get_mut(), value) + } + + /// Sets the value of the entry, and returns the entry's old value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// use std::rc::Rc; + /// + /// let key_one = Rc::new("a"); + /// let key_two = Rc::new("a"); + /// + /// let mut map: HashMap<Rc<&str>, u32> = HashMap::new(); + /// map.insert(key_one.clone(), 10); + /// + /// assert_eq!(map[&key_one], 10); + /// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1); + /// + /// match map.raw_entry_mut().from_key(&key_one) { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(mut o) => { + /// let old_key = o.insert_key(key_two.clone()); + /// assert!(Rc::ptr_eq(&old_key, &key_one)); + /// } + /// } + /// assert_eq!(map[&key_two], 10); + /// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert_key(&mut self, key: K) -> K { + mem::replace(self.key_mut(), key) + } + + /// Takes the value out of the entry, and returns it. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => assert_eq!(o.remove(), 100), + /// } + /// assert_eq!(map.get(&"a"), None); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove(self) -> V { + self.remove_entry().1 + } + + /// Take the ownership of the key and value from the map. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => assert_eq!(o.remove_entry(), ("a", 100)), + /// } + /// assert_eq!(map.get(&"a"), None); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove_entry(self) -> (K, V) { + unsafe { self.table.remove(self.elem) } + } + + /// Provides shared access to the key and owned access to the value of + /// the entry and allows to replace or remove it based on the + /// value of the returned option. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// let raw_entry = match map.raw_entry_mut().from_key(&"a") { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => o.replace_entry_with(|k, v| { + /// assert_eq!(k, &"a"); + /// assert_eq!(v, 100); + /// Some(v + 900) + /// }), + /// }; + /// let raw_entry = match raw_entry { + /// RawEntryMut::Vacant(_) => panic!(), + /// RawEntryMut::Occupied(o) => o.replace_entry_with(|k, v| { + /// assert_eq!(k, &"a"); + /// assert_eq!(v, 1000); + /// None + /// }), + /// }; + /// match raw_entry { + /// RawEntryMut::Vacant(_) => { }, + /// RawEntryMut::Occupied(_) => panic!(), + /// }; + /// assert_eq!(map.get(&"a"), None); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_entry_with<F>(self, f: F) -> RawEntryMut<'a, K, V, S, A> + where + F: FnOnce(&K, V) -> Option<V>, + { + unsafe { + let still_occupied = self + .table + .replace_bucket_with(self.elem.clone(), |(key, value)| { + f(&key, value).map(|new_value| (key, new_value)) + }); + + if still_occupied { + RawEntryMut::Occupied(self) + } else { + RawEntryMut::Vacant(RawVacantEntryMut { + table: self.table, + hash_builder: self.hash_builder, + }) + } + } + } +} + +impl<'a, K, V, S, A: Allocator + Clone> RawVacantEntryMut<'a, K, V, S, A> { + /// Sets the value of the entry with the VacantEntry's key, + /// and returns a mutable reference to it. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// + /// match map.raw_entry_mut().from_key(&"c") { + /// RawEntryMut::Occupied(_) => panic!(), + /// RawEntryMut::Vacant(v) => assert_eq!(v.insert("c", 300), (&mut "c", &mut 300)), + /// } + /// + /// assert_eq!(map[&"c"], 300); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self, key: K, value: V) -> (&'a mut K, &'a mut V) + where + K: Hash, + S: BuildHasher, + { + let hash = make_insert_hash::<K, S>(self.hash_builder, &key); + self.insert_hashed_nocheck(hash, key, value) + } + + /// Sets the value of the entry with the VacantEntry's key, + /// and returns a mutable reference to it. + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into(); + /// let key = "c"; + /// let hash = compute_hash(map.hasher(), &key); + /// + /// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &key) { + /// RawEntryMut::Occupied(_) => panic!(), + /// RawEntryMut::Vacant(v) => assert_eq!( + /// v.insert_hashed_nocheck(hash, key, 300), + /// (&mut "c", &mut 300) + /// ), + /// } + /// + /// assert_eq!(map[&"c"], 300); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + #[allow(clippy::shadow_unrelated)] + pub fn insert_hashed_nocheck(self, hash: u64, key: K, value: V) -> (&'a mut K, &'a mut V) + where + K: Hash, + S: BuildHasher, + { + let &mut (ref mut k, ref mut v) = self.table.insert_entry( + hash, + (key, value), + make_hasher::<K, _, V, S>(self.hash_builder), + ); + (k, v) + } + + /// Set the value of an entry with a custom hasher function. + /// + /// # Examples + /// + /// ``` + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::hash_map::{HashMap, RawEntryMut}; + /// + /// fn make_hasher<K, S>(hash_builder: &S) -> impl Fn(&K) -> u64 + '_ + /// where + /// K: Hash + ?Sized, + /// S: BuildHasher, + /// { + /// move |key: &K| { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// } + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// let key = "a"; + /// let hash_builder = map.hasher().clone(); + /// let hash = make_hasher(&hash_builder)(&key); + /// + /// match map.raw_entry_mut().from_hash(hash, |q| q == &key) { + /// RawEntryMut::Occupied(_) => panic!(), + /// RawEntryMut::Vacant(v) => assert_eq!( + /// v.insert_with_hasher(hash, key, 100, make_hasher(&hash_builder)), + /// (&mut "a", &mut 100) + /// ), + /// } + /// map.extend([("b", 200), ("c", 300), ("d", 400), ("e", 500), ("f", 600)]); + /// assert_eq!(map[&"a"], 100); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert_with_hasher<H>( + self, + hash: u64, + key: K, + value: V, + hasher: H, + ) -> (&'a mut K, &'a mut V) + where + H: Fn(&K) -> u64, + { + let &mut (ref mut k, ref mut v) = self + .table + .insert_entry(hash, (key, value), |x| hasher(&x.0)); + (k, v) + } + + #[cfg_attr(feature = "inline-more", inline)] + fn insert_entry(self, key: K, value: V) -> RawOccupiedEntryMut<'a, K, V, S, A> + where + K: Hash, + S: BuildHasher, + { + let hash = make_insert_hash::<K, S>(self.hash_builder, &key); + let elem = self.table.insert( + hash, + (key, value), + make_hasher::<K, _, V, S>(self.hash_builder), + ); + RawOccupiedEntryMut { + elem, + table: self.table, + hash_builder: self.hash_builder, + } + } +} + +impl<K, V, S, A: Allocator + Clone> Debug for RawEntryBuilderMut<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("RawEntryBuilder").finish() + } +} + +impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for RawEntryMut<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + RawEntryMut::Vacant(ref v) => f.debug_tuple("RawEntry").field(v).finish(), + RawEntryMut::Occupied(ref o) => f.debug_tuple("RawEntry").field(o).finish(), + } + } +} + +impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for RawOccupiedEntryMut<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("RawOccupiedEntryMut") + .field("key", self.key()) + .field("value", self.get()) + .finish() + } +} + +impl<K, V, S, A: Allocator + Clone> Debug for RawVacantEntryMut<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("RawVacantEntryMut").finish() + } +} + +impl<K, V, S, A: Allocator + Clone> Debug for RawEntryBuilder<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("RawEntryBuilder").finish() + } +} + +/// A view into a single entry in a map, which may either be vacant or occupied. +/// +/// This `enum` is constructed from the [`entry`] method on [`HashMap`]. +/// +/// [`HashMap`]: struct.HashMap.html +/// [`entry`]: struct.HashMap.html#method.entry +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{Entry, HashMap, OccupiedEntry}; +/// +/// let mut map = HashMap::new(); +/// map.extend([("a", 10), ("b", 20), ("c", 30)]); +/// assert_eq!(map.len(), 3); +/// +/// // Existing key (insert) +/// let entry: Entry<_, _, _> = map.entry("a"); +/// let _raw_o: OccupiedEntry<_, _, _> = entry.insert(1); +/// assert_eq!(map.len(), 3); +/// // Nonexistent key (insert) +/// map.entry("d").insert(4); +/// +/// // Existing key (or_insert) +/// let v = map.entry("b").or_insert(2); +/// assert_eq!(std::mem::replace(v, 2), 20); +/// // Nonexistent key (or_insert) +/// map.entry("e").or_insert(5); +/// +/// // Existing key (or_insert_with) +/// let v = map.entry("c").or_insert_with(|| 3); +/// assert_eq!(std::mem::replace(v, 3), 30); +/// // Nonexistent key (or_insert_with) +/// map.entry("f").or_insert_with(|| 6); +/// +/// println!("Our HashMap: {:?}", map); +/// +/// let mut vec: Vec<_> = map.iter().map(|(&k, &v)| (k, v)).collect(); +/// // The `Iter` iterator produces items in arbitrary order, so the +/// // items must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, [("a", 1), ("b", 2), ("c", 3), ("d", 4), ("e", 5), ("f", 6)]); +/// ``` +pub enum Entry<'a, K, V, S, A = Global> +where + A: Allocator + Clone, +{ + /// An occupied entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{Entry, HashMap}; + /// let mut map: HashMap<_, _> = [("a", 100), ("b", 200)].into(); + /// + /// match map.entry("a") { + /// Entry::Vacant(_) => unreachable!(), + /// Entry::Occupied(_) => { } + /// } + /// ``` + Occupied(OccupiedEntry<'a, K, V, S, A>), + + /// A vacant entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{Entry, HashMap}; + /// let mut map: HashMap<&str, i32> = HashMap::new(); + /// + /// match map.entry("a") { + /// Entry::Occupied(_) => unreachable!(), + /// Entry::Vacant(_) => { } + /// } + /// ``` + Vacant(VacantEntry<'a, K, V, S, A>), +} + +impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for Entry<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + Entry::Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(), + Entry::Occupied(ref o) => f.debug_tuple("Entry").field(o).finish(), + } + } +} + +/// A view into an occupied entry in a `HashMap`. +/// It is part of the [`Entry`] enum. +/// +/// [`Entry`]: enum.Entry.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{Entry, HashMap, OccupiedEntry}; +/// +/// let mut map = HashMap::new(); +/// map.extend([("a", 10), ("b", 20), ("c", 30)]); +/// +/// let _entry_o: OccupiedEntry<_, _, _> = map.entry("a").insert(100); +/// assert_eq!(map.len(), 3); +/// +/// // Existing key (insert and update) +/// match map.entry("a") { +/// Entry::Vacant(_) => unreachable!(), +/// Entry::Occupied(mut view) => { +/// assert_eq!(view.get(), &100); +/// let v = view.get_mut(); +/// *v *= 10; +/// assert_eq!(view.insert(1111), 1000); +/// } +/// } +/// +/// assert_eq!(map[&"a"], 1111); +/// assert_eq!(map.len(), 3); +/// +/// // Existing key (take) +/// match map.entry("c") { +/// Entry::Vacant(_) => unreachable!(), +/// Entry::Occupied(view) => { +/// assert_eq!(view.remove_entry(), ("c", 30)); +/// } +/// } +/// assert_eq!(map.get(&"c"), None); +/// assert_eq!(map.len(), 2); +/// ``` +pub struct OccupiedEntry<'a, K, V, S, A: Allocator + Clone = Global> { + hash: u64, + key: Option<K>, + elem: Bucket<(K, V)>, + table: &'a mut HashMap<K, V, S, A>, +} + +unsafe impl<K, V, S, A> Send for OccupiedEntry<'_, K, V, S, A> +where + K: Send, + V: Send, + S: Send, + A: Send + Allocator + Clone, +{ +} +unsafe impl<K, V, S, A> Sync for OccupiedEntry<'_, K, V, S, A> +where + K: Sync, + V: Sync, + S: Sync, + A: Sync + Allocator + Clone, +{ +} + +impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for OccupiedEntry<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("OccupiedEntry") + .field("key", self.key()) + .field("value", self.get()) + .finish() + } +} + +/// A view into a vacant entry in a `HashMap`. +/// It is part of the [`Entry`] enum. +/// +/// [`Entry`]: enum.Entry.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{Entry, HashMap, VacantEntry}; +/// +/// let mut map = HashMap::<&str, i32>::new(); +/// +/// let entry_v: VacantEntry<_, _, _> = match map.entry("a") { +/// Entry::Vacant(view) => view, +/// Entry::Occupied(_) => unreachable!(), +/// }; +/// entry_v.insert(10); +/// assert!(map[&"a"] == 10 && map.len() == 1); +/// +/// // Nonexistent key (insert and update) +/// match map.entry("b") { +/// Entry::Occupied(_) => unreachable!(), +/// Entry::Vacant(view) => { +/// let value = view.insert(2); +/// assert_eq!(*value, 2); +/// *value = 20; +/// } +/// } +/// assert!(map[&"b"] == 20 && map.len() == 2); +/// ``` +pub struct VacantEntry<'a, K, V, S, A: Allocator + Clone = Global> { + hash: u64, + key: K, + table: &'a mut HashMap<K, V, S, A>, +} + +impl<K: Debug, V, S, A: Allocator + Clone> Debug for VacantEntry<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("VacantEntry").field(self.key()).finish() + } +} + +/// A view into a single entry in a map, which may either be vacant or occupied, +/// with any borrowed form of the map's key type. +/// +/// +/// This `enum` is constructed from the [`entry_ref`] method on [`HashMap`]. +/// +/// [`Hash`] and [`Eq`] on the borrowed form of the map's key type *must* match those +/// for the key type. It also require that key may be constructed from the borrowed +/// form through the [`From`] trait. +/// +/// [`HashMap`]: struct.HashMap.html +/// [`entry_ref`]: struct.HashMap.html#method.entry_ref +/// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html +/// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html +/// [`From`]: https://doc.rust-lang.org/std/convert/trait.From.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{EntryRef, HashMap, OccupiedEntryRef}; +/// +/// let mut map = HashMap::new(); +/// map.extend([("a".to_owned(), 10), ("b".into(), 20), ("c".into(), 30)]); +/// assert_eq!(map.len(), 3); +/// +/// // Existing key (insert) +/// let key = String::from("a"); +/// let entry: EntryRef<_, _, _, _> = map.entry_ref(&key); +/// let _raw_o: OccupiedEntryRef<_, _, _, _> = entry.insert(1); +/// assert_eq!(map.len(), 3); +/// // Nonexistent key (insert) +/// map.entry_ref("d").insert(4); +/// +/// // Existing key (or_insert) +/// let v = map.entry_ref("b").or_insert(2); +/// assert_eq!(std::mem::replace(v, 2), 20); +/// // Nonexistent key (or_insert) +/// map.entry_ref("e").or_insert(5); +/// +/// // Existing key (or_insert_with) +/// let v = map.entry_ref("c").or_insert_with(|| 3); +/// assert_eq!(std::mem::replace(v, 3), 30); +/// // Nonexistent key (or_insert_with) +/// map.entry_ref("f").or_insert_with(|| 6); +/// +/// println!("Our HashMap: {:?}", map); +/// +/// for (key, value) in ["a", "b", "c", "d", "e", "f"].into_iter().zip(1..=6) { +/// assert_eq!(map[key], value) +/// } +/// assert_eq!(map.len(), 6); +/// ``` +pub enum EntryRef<'a, 'b, K, Q: ?Sized, V, S, A = Global> +where + A: Allocator + Clone, +{ + /// An occupied entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{EntryRef, HashMap}; + /// let mut map: HashMap<_, _> = [("a".to_owned(), 100), ("b".into(), 200)].into(); + /// + /// match map.entry_ref("a") { + /// EntryRef::Vacant(_) => unreachable!(), + /// EntryRef::Occupied(_) => { } + /// } + /// ``` + Occupied(OccupiedEntryRef<'a, 'b, K, Q, V, S, A>), + + /// A vacant entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{EntryRef, HashMap}; + /// let mut map: HashMap<String, i32> = HashMap::new(); + /// + /// match map.entry_ref("a") { + /// EntryRef::Occupied(_) => unreachable!(), + /// EntryRef::Vacant(_) => { } + /// } + /// ``` + Vacant(VacantEntryRef<'a, 'b, K, Q, V, S, A>), +} + +impl<K: Borrow<Q>, Q: ?Sized + Debug, V: Debug, S, A: Allocator + Clone> Debug + for EntryRef<'_, '_, K, Q, V, S, A> +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + EntryRef::Vacant(ref v) => f.debug_tuple("EntryRef").field(v).finish(), + EntryRef::Occupied(ref o) => f.debug_tuple("EntryRef").field(o).finish(), + } + } +} + +enum KeyOrRef<'a, K, Q: ?Sized> { + Borrowed(&'a Q), + Owned(K), +} + +impl<'a, K, Q: ?Sized> KeyOrRef<'a, K, Q> { + fn into_owned(self) -> K + where + K: From<&'a Q>, + { + match self { + Self::Borrowed(borrowed) => borrowed.into(), + Self::Owned(owned) => owned, + } + } +} + +impl<'a, K: Borrow<Q>, Q: ?Sized> AsRef<Q> for KeyOrRef<'a, K, Q> { + fn as_ref(&self) -> &Q { + match self { + Self::Borrowed(borrowed) => borrowed, + Self::Owned(owned) => owned.borrow(), + } + } +} + +/// A view into an occupied entry in a `HashMap`. +/// It is part of the [`EntryRef`] enum. +/// +/// [`EntryRef`]: enum.EntryRef.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{EntryRef, HashMap, OccupiedEntryRef}; +/// +/// let mut map = HashMap::new(); +/// map.extend([("a".to_owned(), 10), ("b".into(), 20), ("c".into(), 30)]); +/// +/// let key = String::from("a"); +/// let _entry_o: OccupiedEntryRef<_, _, _, _> = map.entry_ref(&key).insert(100); +/// assert_eq!(map.len(), 3); +/// +/// // Existing key (insert and update) +/// match map.entry_ref("a") { +/// EntryRef::Vacant(_) => unreachable!(), +/// EntryRef::Occupied(mut view) => { +/// assert_eq!(view.get(), &100); +/// let v = view.get_mut(); +/// *v *= 10; +/// assert_eq!(view.insert(1111), 1000); +/// } +/// } +/// +/// assert_eq!(map["a"], 1111); +/// assert_eq!(map.len(), 3); +/// +/// // Existing key (take) +/// match map.entry_ref("c") { +/// EntryRef::Vacant(_) => unreachable!(), +/// EntryRef::Occupied(view) => { +/// assert_eq!(view.remove_entry(), ("c".to_owned(), 30)); +/// } +/// } +/// assert_eq!(map.get("c"), None); +/// assert_eq!(map.len(), 2); +/// ``` +pub struct OccupiedEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone = Global> { + hash: u64, + key: Option<KeyOrRef<'b, K, Q>>, + elem: Bucket<(K, V)>, + table: &'a mut HashMap<K, V, S, A>, +} + +unsafe impl<'a, 'b, K, Q, V, S, A> Send for OccupiedEntryRef<'a, 'b, K, Q, V, S, A> +where + K: Send, + Q: Sync + ?Sized, + V: Send, + S: Send, + A: Send + Allocator + Clone, +{ +} +unsafe impl<'a, 'b, K, Q, V, S, A> Sync for OccupiedEntryRef<'a, 'b, K, Q, V, S, A> +where + K: Sync, + Q: Sync + ?Sized, + V: Sync, + S: Sync, + A: Sync + Allocator + Clone, +{ +} + +impl<K: Borrow<Q>, Q: ?Sized + Debug, V: Debug, S, A: Allocator + Clone> Debug + for OccupiedEntryRef<'_, '_, K, Q, V, S, A> +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("OccupiedEntryRef") + .field("key", &self.key()) + .field("value", &self.get()) + .finish() + } +} + +/// A view into a vacant entry in a `HashMap`. +/// It is part of the [`EntryRef`] enum. +/// +/// [`EntryRef`]: enum.EntryRef.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{EntryRef, HashMap, VacantEntryRef}; +/// +/// let mut map = HashMap::<String, i32>::new(); +/// +/// let entry_v: VacantEntryRef<_, _, _, _> = match map.entry_ref("a") { +/// EntryRef::Vacant(view) => view, +/// EntryRef::Occupied(_) => unreachable!(), +/// }; +/// entry_v.insert(10); +/// assert!(map["a"] == 10 && map.len() == 1); +/// +/// // Nonexistent key (insert and update) +/// match map.entry_ref("b") { +/// EntryRef::Occupied(_) => unreachable!(), +/// EntryRef::Vacant(view) => { +/// let value = view.insert(2); +/// assert_eq!(*value, 2); +/// *value = 20; +/// } +/// } +/// assert!(map["b"] == 20 && map.len() == 2); +/// ``` +pub struct VacantEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone = Global> { + hash: u64, + key: KeyOrRef<'b, K, Q>, + table: &'a mut HashMap<K, V, S, A>, +} + +impl<K: Borrow<Q>, Q: ?Sized + Debug, V, S, A: Allocator + Clone> Debug + for VacantEntryRef<'_, '_, K, Q, V, S, A> +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("VacantEntryRef").field(&self.key()).finish() + } +} + +/// The error returned by [`try_insert`](HashMap::try_insert) when the key already exists. +/// +/// Contains the occupied entry, and the value that was not inserted. +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_map::{HashMap, OccupiedError}; +/// +/// let mut map: HashMap<_, _> = [("a", 10), ("b", 20)].into(); +/// +/// // try_insert method returns mutable reference to the value if keys are vacant, +/// // but if the map did have key present, nothing is updated, and the provided +/// // value is returned inside `Err(_)` variant +/// match map.try_insert("a", 100) { +/// Err(OccupiedError { mut entry, value }) => { +/// assert_eq!(entry.key(), &"a"); +/// assert_eq!(value, 100); +/// assert_eq!(entry.insert(100), 10) +/// } +/// _ => unreachable!(), +/// } +/// assert_eq!(map[&"a"], 100); +/// ``` +pub struct OccupiedError<'a, K, V, S, A: Allocator + Clone = Global> { + /// The entry in the map that was already occupied. + pub entry: OccupiedEntry<'a, K, V, S, A>, + /// The value which was not inserted, because the entry was already occupied. + pub value: V, +} + +impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for OccupiedError<'_, K, V, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("OccupiedError") + .field("key", self.entry.key()) + .field("old_value", self.entry.get()) + .field("new_value", &self.value) + .finish() + } +} + +impl<'a, K: Debug, V: Debug, S, A: Allocator + Clone> fmt::Display + for OccupiedError<'a, K, V, S, A> +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!( + f, + "failed to insert {:?}, key {:?} already exists with value {:?}", + self.value, + self.entry.key(), + self.entry.get(), + ) + } +} + +impl<'a, K, V, S, A: Allocator + Clone> IntoIterator for &'a HashMap<K, V, S, A> { + type Item = (&'a K, &'a V); + type IntoIter = Iter<'a, K, V>; + + /// Creates an iterator over the entries of a `HashMap` in arbitrary order. + /// The iterator element type is `(&'a K, &'a V)`. + /// + /// Return the same `Iter` struct as by the [`iter`] method on [`HashMap`]. + /// + /// [`iter`]: struct.HashMap.html#method.iter + /// [`HashMap`]: struct.HashMap.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// let map_one: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into(); + /// let mut map_two = HashMap::new(); + /// + /// for (key, value) in &map_one { + /// println!("Key: {}, Value: {}", key, value); + /// map_two.insert_unique_unchecked(*key, *value); + /// } + /// + /// assert_eq!(map_one, map_two); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn into_iter(self) -> Iter<'a, K, V> { + self.iter() + } +} + +impl<'a, K, V, S, A: Allocator + Clone> IntoIterator for &'a mut HashMap<K, V, S, A> { + type Item = (&'a K, &'a mut V); + type IntoIter = IterMut<'a, K, V>; + + /// Creates an iterator over the entries of a `HashMap` in arbitrary order + /// with mutable references to the values. The iterator element type is + /// `(&'a K, &'a mut V)`. + /// + /// Return the same `IterMut` struct as by the [`iter_mut`] method on + /// [`HashMap`]. + /// + /// [`iter_mut`]: struct.HashMap.html#method.iter_mut + /// [`HashMap`]: struct.HashMap.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// let mut map: HashMap<_, _> = [("a", 1), ("b", 2), ("c", 3)].into(); + /// + /// for (key, value) in &mut map { + /// println!("Key: {}, Value: {}", key, value); + /// *value *= 2; + /// } + /// + /// let mut vec = map.iter().collect::<Vec<_>>(); + /// // The `Iter` iterator produces items in arbitrary order, so the + /// // items must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [(&"a", &2), (&"b", &4), (&"c", &6)]); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn into_iter(self) -> IterMut<'a, K, V> { + self.iter_mut() + } +} + +impl<K, V, S, A: Allocator + Clone> IntoIterator for HashMap<K, V, S, A> { + type Item = (K, V); + type IntoIter = IntoIter<K, V, A>; + + /// Creates a consuming iterator, that is, one that moves each key-value + /// pair out of the map in arbitrary order. The map cannot be used after + /// calling this. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let map: HashMap<_, _> = [("a", 1), ("b", 2), ("c", 3)].into(); + /// + /// // Not possible with .iter() + /// let mut vec: Vec<(&str, i32)> = map.into_iter().collect(); + /// // The `IntoIter` iterator produces items in arbitrary order, so + /// // the items must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [("a", 1), ("b", 2), ("c", 3)]); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn into_iter(self) -> IntoIter<K, V, A> { + IntoIter { + inner: self.table.into_iter(), + } + } +} + +impl<'a, K, V> Iterator for Iter<'a, K, V> { + type Item = (&'a K, &'a V); + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<(&'a K, &'a V)> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.inner.next() { + Some(x) => unsafe { + let r = x.as_ref(); + Some((&r.0, &r.1)) + }, + None => None, + } + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} +impl<K, V> ExactSizeIterator for Iter<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.inner.len() + } +} + +impl<K, V> FusedIterator for Iter<'_, K, V> {} + +impl<'a, K, V> Iterator for IterMut<'a, K, V> { + type Item = (&'a K, &'a mut V); + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<(&'a K, &'a mut V)> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.inner.next() { + Some(x) => unsafe { + let r = x.as_mut(); + Some((&r.0, &mut r.1)) + }, + None => None, + } + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} +impl<K, V> ExactSizeIterator for IterMut<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.inner.len() + } +} +impl<K, V> FusedIterator for IterMut<'_, K, V> {} + +impl<K, V> fmt::Debug for IterMut<'_, K, V> +where + K: fmt::Debug, + V: fmt::Debug, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.iter()).finish() + } +} + +impl<K, V, A: Allocator + Clone> Iterator for IntoIter<K, V, A> { + type Item = (K, V); + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<(K, V)> { + self.inner.next() + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} +impl<K, V, A: Allocator + Clone> ExactSizeIterator for IntoIter<K, V, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.inner.len() + } +} +impl<K, V, A: Allocator + Clone> FusedIterator for IntoIter<K, V, A> {} + +impl<K: Debug, V: Debug, A: Allocator + Clone> fmt::Debug for IntoIter<K, V, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.iter()).finish() + } +} + +impl<'a, K, V> Iterator for Keys<'a, K, V> { + type Item = &'a K; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<&'a K> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.inner.next() { + Some((k, _)) => Some(k), + None => None, + } + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} +impl<K, V> ExactSizeIterator for Keys<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.inner.len() + } +} +impl<K, V> FusedIterator for Keys<'_, K, V> {} + +impl<'a, K, V> Iterator for Values<'a, K, V> { + type Item = &'a V; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<&'a V> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.inner.next() { + Some((_, v)) => Some(v), + None => None, + } + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} +impl<K, V> ExactSizeIterator for Values<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.inner.len() + } +} +impl<K, V> FusedIterator for Values<'_, K, V> {} + +impl<'a, K, V> Iterator for ValuesMut<'a, K, V> { + type Item = &'a mut V; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<&'a mut V> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.inner.next() { + Some((_, v)) => Some(v), + None => None, + } + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} +impl<K, V> ExactSizeIterator for ValuesMut<'_, K, V> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.inner.len() + } +} +impl<K, V> FusedIterator for ValuesMut<'_, K, V> {} + +impl<K, V: Debug> fmt::Debug for ValuesMut<'_, K, V> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list() + .entries(self.inner.iter().map(|(_, val)| val)) + .finish() + } +} + +impl<'a, K, V, A: Allocator + Clone> Iterator for Drain<'a, K, V, A> { + type Item = (K, V); + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<(K, V)> { + self.inner.next() + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} +impl<K, V, A: Allocator + Clone> ExactSizeIterator for Drain<'_, K, V, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.inner.len() + } +} +impl<K, V, A: Allocator + Clone> FusedIterator for Drain<'_, K, V, A> {} + +impl<K, V, A> fmt::Debug for Drain<'_, K, V, A> +where + K: fmt::Debug, + V: fmt::Debug, + A: Allocator + Clone, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.iter()).finish() + } +} + +impl<'a, K, V, S, A: Allocator + Clone> Entry<'a, K, V, S, A> { + /// Sets the value of the entry, and returns an OccupiedEntry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// let entry = map.entry("horseyland").insert(37); + /// + /// assert_eq!(entry.key(), &"horseyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self, value: V) -> OccupiedEntry<'a, K, V, S, A> + where + K: Hash, + S: BuildHasher, + { + match self { + Entry::Occupied(mut entry) => { + entry.insert(value); + entry + } + Entry::Vacant(entry) => entry.insert_entry(value), + } + } + + /// Ensures a value is in the entry by inserting the default if empty, and returns + /// a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// // nonexistent key + /// map.entry("poneyland").or_insert(3); + /// assert_eq!(map["poneyland"], 3); + /// + /// // existing key + /// *map.entry("poneyland").or_insert(10) *= 2; + /// assert_eq!(map["poneyland"], 6); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert(self, default: V) -> &'a mut V + where + K: Hash, + S: BuildHasher, + { + match self { + Entry::Occupied(entry) => entry.into_mut(), + Entry::Vacant(entry) => entry.insert(default), + } + } + + /// Ensures a value is in the entry by inserting the result of the default function if empty, + /// and returns a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// // nonexistent key + /// map.entry("poneyland").or_insert_with(|| 3); + /// assert_eq!(map["poneyland"], 3); + /// + /// // existing key + /// *map.entry("poneyland").or_insert_with(|| 10) *= 2; + /// assert_eq!(map["poneyland"], 6); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V + where + K: Hash, + S: BuildHasher, + { + match self { + Entry::Occupied(entry) => entry.into_mut(), + Entry::Vacant(entry) => entry.insert(default()), + } + } + + /// Ensures a value is in the entry by inserting, if empty, the result of the default function. + /// This method allows for generating key-derived values for insertion by providing the default + /// function a reference to the key that was moved during the `.entry(key)` method call. + /// + /// The reference to the moved key is provided so that cloning or copying the key is + /// unnecessary, unlike with `.or_insert_with(|| ... )`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, usize> = HashMap::new(); + /// + /// // nonexistent key + /// map.entry("poneyland").or_insert_with_key(|key| key.chars().count()); + /// assert_eq!(map["poneyland"], 9); + /// + /// // existing key + /// *map.entry("poneyland").or_insert_with_key(|key| key.chars().count() * 10) *= 2; + /// assert_eq!(map["poneyland"], 18); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut V + where + K: Hash, + S: BuildHasher, + { + match self { + Entry::Occupied(entry) => entry.into_mut(), + Entry::Vacant(entry) => { + let value = default(entry.key()); + entry.insert(value) + } + } + } + + /// Returns a reference to this entry's key. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.entry("poneyland").or_insert(3); + /// // existing key + /// assert_eq!(map.entry("poneyland").key(), &"poneyland"); + /// // nonexistent key + /// assert_eq!(map.entry("horseland").key(), &"horseland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &K { + match *self { + Entry::Occupied(ref entry) => entry.key(), + Entry::Vacant(ref entry) => entry.key(), + } + } + + /// Provides in-place mutable access to an occupied entry before any + /// potential inserts into the map. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// map.entry("poneyland") + /// .and_modify(|e| { *e += 1 }) + /// .or_insert(42); + /// assert_eq!(map["poneyland"], 42); + /// + /// map.entry("poneyland") + /// .and_modify(|e| { *e += 1 }) + /// .or_insert(42); + /// assert_eq!(map["poneyland"], 43); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn and_modify<F>(self, f: F) -> Self + where + F: FnOnce(&mut V), + { + match self { + Entry::Occupied(mut entry) => { + f(entry.get_mut()); + Entry::Occupied(entry) + } + Entry::Vacant(entry) => Entry::Vacant(entry), + } + } + + /// Provides shared access to the key and owned access to the value of + /// an occupied entry and allows to replace or remove it based on the + /// value of the returned option. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::Entry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// let entry = map + /// .entry("poneyland") + /// .and_replace_entry_with(|_k, _v| panic!()); + /// + /// match entry { + /// Entry::Vacant(e) => { + /// assert_eq!(e.key(), &"poneyland"); + /// } + /// Entry::Occupied(_) => panic!(), + /// } + /// + /// map.insert("poneyland", 42); + /// + /// let entry = map + /// .entry("poneyland") + /// .and_replace_entry_with(|k, v| { + /// assert_eq!(k, &"poneyland"); + /// assert_eq!(v, 42); + /// Some(v + 1) + /// }); + /// + /// match entry { + /// Entry::Occupied(e) => { + /// assert_eq!(e.key(), &"poneyland"); + /// assert_eq!(e.get(), &43); + /// } + /// Entry::Vacant(_) => panic!(), + /// } + /// + /// assert_eq!(map["poneyland"], 43); + /// + /// let entry = map + /// .entry("poneyland") + /// .and_replace_entry_with(|_k, _v| None); + /// + /// match entry { + /// Entry::Vacant(e) => assert_eq!(e.key(), &"poneyland"), + /// Entry::Occupied(_) => panic!(), + /// } + /// + /// assert!(!map.contains_key("poneyland")); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn and_replace_entry_with<F>(self, f: F) -> Self + where + F: FnOnce(&K, V) -> Option<V>, + { + match self { + Entry::Occupied(entry) => entry.replace_entry_with(f), + Entry::Vacant(_) => self, + } + } +} + +impl<'a, K, V: Default, S, A: Allocator + Clone> Entry<'a, K, V, S, A> { + /// Ensures a value is in the entry by inserting the default value if empty, + /// and returns a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, Option<u32>> = HashMap::new(); + /// + /// // nonexistent key + /// map.entry("poneyland").or_default(); + /// assert_eq!(map["poneyland"], None); + /// + /// map.insert("horseland", Some(3)); + /// + /// // existing key + /// assert_eq!(map.entry("horseland").or_default(), &mut Some(3)); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_default(self) -> &'a mut V + where + K: Hash, + S: BuildHasher, + { + match self { + Entry::Occupied(entry) => entry.into_mut(), + Entry::Vacant(entry) => entry.insert(Default::default()), + } + } +} + +impl<'a, K, V, S, A: Allocator + Clone> OccupiedEntry<'a, K, V, S, A> { + /// Gets a reference to the key in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{Entry, HashMap}; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.entry("poneyland").or_insert(12); + /// + /// match map.entry("poneyland") { + /// Entry::Vacant(_) => panic!(), + /// Entry::Occupied(entry) => assert_eq!(entry.key(), &"poneyland"), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &K { + unsafe { &self.elem.as_ref().0 } + } + + /// Take the ownership of the key and value from the map. + /// Keeps the allocated memory for reuse. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::Entry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// // The map is empty + /// assert!(map.is_empty() && map.capacity() == 0); + /// + /// map.entry("poneyland").or_insert(12); + /// let capacity_before_remove = map.capacity(); + /// + /// if let Entry::Occupied(o) = map.entry("poneyland") { + /// // We delete the entry from the map. + /// assert_eq!(o.remove_entry(), ("poneyland", 12)); + /// } + /// + /// assert_eq!(map.contains_key("poneyland"), false); + /// // Now map hold none elements but capacity is equal to the old one + /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove_entry(self) -> (K, V) { + unsafe { self.table.table.remove(self.elem) } + } + + /// Gets a reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::Entry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.entry("poneyland").or_insert(12); + /// + /// match map.entry("poneyland") { + /// Entry::Vacant(_) => panic!(), + /// Entry::Occupied(entry) => assert_eq!(entry.get(), &12), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get(&self) -> &V { + unsafe { &self.elem.as_ref().1 } + } + + /// Gets a mutable reference to the value in the entry. + /// + /// If you need a reference to the `OccupiedEntry` which may outlive the + /// destruction of the `Entry` value, see [`into_mut`]. + /// + /// [`into_mut`]: #method.into_mut + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::Entry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.entry("poneyland").or_insert(12); + /// + /// assert_eq!(map["poneyland"], 12); + /// if let Entry::Occupied(mut o) = map.entry("poneyland") { + /// *o.get_mut() += 10; + /// assert_eq!(*o.get(), 22); + /// + /// // We can use the same Entry multiple times. + /// *o.get_mut() += 2; + /// } + /// + /// assert_eq!(map["poneyland"], 24); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_mut(&mut self) -> &mut V { + unsafe { &mut self.elem.as_mut().1 } + } + + /// Converts the OccupiedEntry into a mutable reference to the value in the entry + /// with a lifetime bound to the map itself. + /// + /// If you need multiple references to the `OccupiedEntry`, see [`get_mut`]. + /// + /// [`get_mut`]: #method.get_mut + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{Entry, HashMap}; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.entry("poneyland").or_insert(12); + /// + /// assert_eq!(map["poneyland"], 12); + /// + /// let value: &mut u32; + /// match map.entry("poneyland") { + /// Entry::Occupied(entry) => value = entry.into_mut(), + /// Entry::Vacant(_) => panic!(), + /// } + /// *value += 10; + /// + /// assert_eq!(map["poneyland"], 22); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_mut(self) -> &'a mut V { + unsafe { &mut self.elem.as_mut().1 } + } + + /// Sets the value of the entry, and returns the entry's old value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::Entry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.entry("poneyland").or_insert(12); + /// + /// if let Entry::Occupied(mut o) = map.entry("poneyland") { + /// assert_eq!(o.insert(15), 12); + /// } + /// + /// assert_eq!(map["poneyland"], 15); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(&mut self, value: V) -> V { + mem::replace(self.get_mut(), value) + } + + /// Takes the value out of the entry, and returns it. + /// Keeps the allocated memory for reuse. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::Entry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// // The map is empty + /// assert!(map.is_empty() && map.capacity() == 0); + /// + /// map.entry("poneyland").or_insert(12); + /// let capacity_before_remove = map.capacity(); + /// + /// if let Entry::Occupied(o) = map.entry("poneyland") { + /// assert_eq!(o.remove(), 12); + /// } + /// + /// assert_eq!(map.contains_key("poneyland"), false); + /// // Now map hold none elements but capacity is equal to the old one + /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove(self) -> V { + self.remove_entry().1 + } + + /// Replaces the entry, returning the old key and value. The new key in the hash map will be + /// the key used to create this entry. + /// + /// # Panics + /// + /// Will panic if this OccupiedEntry was created through [`Entry::insert`]. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{Entry, HashMap}; + /// use std::rc::Rc; + /// + /// let mut map: HashMap<Rc<String>, u32> = HashMap::new(); + /// let key_one = Rc::new("Stringthing".to_string()); + /// let key_two = Rc::new("Stringthing".to_string()); + /// + /// map.insert(key_one.clone(), 15); + /// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1); + /// + /// match map.entry(key_two.clone()) { + /// Entry::Occupied(entry) => { + /// let (old_key, old_value): (Rc<String>, u32) = entry.replace_entry(16); + /// assert!(Rc::ptr_eq(&key_one, &old_key) && old_value == 15); + /// } + /// Entry::Vacant(_) => panic!(), + /// } + /// + /// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2); + /// assert_eq!(map[&"Stringthing".to_owned()], 16); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_entry(self, value: V) -> (K, V) { + let entry = unsafe { self.elem.as_mut() }; + + let old_key = mem::replace(&mut entry.0, self.key.unwrap()); + let old_value = mem::replace(&mut entry.1, value); + + (old_key, old_value) + } + + /// Replaces the key in the hash map with the key used to create this entry. + /// + /// # Panics + /// + /// Will panic if this OccupiedEntry was created through [`Entry::insert`]. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{Entry, HashMap}; + /// use std::rc::Rc; + /// + /// let mut map: HashMap<Rc<String>, usize> = HashMap::with_capacity(6); + /// let mut keys_one: Vec<Rc<String>> = Vec::with_capacity(6); + /// let mut keys_two: Vec<Rc<String>> = Vec::with_capacity(6); + /// + /// for (value, key) in ["a", "b", "c", "d", "e", "f"].into_iter().enumerate() { + /// let rc_key = Rc::new(key.to_owned()); + /// keys_one.push(rc_key.clone()); + /// map.insert(rc_key.clone(), value); + /// keys_two.push(Rc::new(key.to_owned())); + /// } + /// + /// assert!( + /// keys_one.iter().all(|key| Rc::strong_count(key) == 2) + /// && keys_two.iter().all(|key| Rc::strong_count(key) == 1) + /// ); + /// + /// reclaim_memory(&mut map, &keys_two); + /// + /// assert!( + /// keys_one.iter().all(|key| Rc::strong_count(key) == 1) + /// && keys_two.iter().all(|key| Rc::strong_count(key) == 2) + /// ); + /// + /// fn reclaim_memory(map: &mut HashMap<Rc<String>, usize>, keys: &[Rc<String>]) { + /// for key in keys { + /// if let Entry::Occupied(entry) = map.entry(key.clone()) { + /// // Replaces the entry's key with our version of it in `keys`. + /// entry.replace_key(); + /// } + /// } + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_key(self) -> K { + let entry = unsafe { self.elem.as_mut() }; + mem::replace(&mut entry.0, self.key.unwrap()) + } + + /// Provides shared access to the key and owned access to the value of + /// the entry and allows to replace or remove it based on the + /// value of the returned option. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::Entry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.insert("poneyland", 42); + /// + /// let entry = match map.entry("poneyland") { + /// Entry::Occupied(e) => { + /// e.replace_entry_with(|k, v| { + /// assert_eq!(k, &"poneyland"); + /// assert_eq!(v, 42); + /// Some(v + 1) + /// }) + /// } + /// Entry::Vacant(_) => panic!(), + /// }; + /// + /// match entry { + /// Entry::Occupied(e) => { + /// assert_eq!(e.key(), &"poneyland"); + /// assert_eq!(e.get(), &43); + /// } + /// Entry::Vacant(_) => panic!(), + /// } + /// + /// assert_eq!(map["poneyland"], 43); + /// + /// let entry = match map.entry("poneyland") { + /// Entry::Occupied(e) => e.replace_entry_with(|_k, _v| None), + /// Entry::Vacant(_) => panic!(), + /// }; + /// + /// match entry { + /// Entry::Vacant(e) => { + /// assert_eq!(e.key(), &"poneyland"); + /// } + /// Entry::Occupied(_) => panic!(), + /// } + /// + /// assert!(!map.contains_key("poneyland")); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_entry_with<F>(self, f: F) -> Entry<'a, K, V, S, A> + where + F: FnOnce(&K, V) -> Option<V>, + { + unsafe { + let mut spare_key = None; + + self.table + .table + .replace_bucket_with(self.elem.clone(), |(key, value)| { + if let Some(new_value) = f(&key, value) { + Some((key, new_value)) + } else { + spare_key = Some(key); + None + } + }); + + if let Some(key) = spare_key { + Entry::Vacant(VacantEntry { + hash: self.hash, + key, + table: self.table, + }) + } else { + Entry::Occupied(self) + } + } + } +} + +impl<'a, K, V, S, A: Allocator + Clone> VacantEntry<'a, K, V, S, A> { + /// Gets a reference to the key that would be used when inserting a value + /// through the `VacantEntry`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// assert_eq!(map.entry("poneyland").key(), &"poneyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &K { + &self.key + } + + /// Take ownership of the key. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{Entry, HashMap}; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// match map.entry("poneyland") { + /// Entry::Occupied(_) => panic!(), + /// Entry::Vacant(v) => assert_eq!(v.into_key(), "poneyland"), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_key(self) -> K { + self.key + } + + /// Sets the value of the entry with the VacantEntry's key, + /// and returns a mutable reference to it. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::Entry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// if let Entry::Vacant(o) = map.entry("poneyland") { + /// o.insert(37); + /// } + /// assert_eq!(map["poneyland"], 37); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self, value: V) -> &'a mut V + where + K: Hash, + S: BuildHasher, + { + let table = &mut self.table.table; + let entry = table.insert_entry( + self.hash, + (self.key, value), + make_hasher::<K, _, V, S>(&self.table.hash_builder), + ); + &mut entry.1 + } + + #[cfg_attr(feature = "inline-more", inline)] + pub(crate) fn insert_entry(self, value: V) -> OccupiedEntry<'a, K, V, S, A> + where + K: Hash, + S: BuildHasher, + { + let elem = self.table.table.insert( + self.hash, + (self.key, value), + make_hasher::<K, _, V, S>(&self.table.hash_builder), + ); + OccupiedEntry { + hash: self.hash, + key: None, + elem, + table: self.table, + } + } +} + +impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> EntryRef<'a, 'b, K, Q, V, S, A> { + /// Sets the value of the entry, and returns an OccupiedEntryRef. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// let entry = map.entry_ref("horseyland").insert(37); + /// + /// assert_eq!(entry.key(), "horseyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self, value: V) -> OccupiedEntryRef<'a, 'b, K, Q, V, S, A> + where + K: Hash + From<&'b Q>, + S: BuildHasher, + { + match self { + EntryRef::Occupied(mut entry) => { + entry.insert(value); + entry + } + EntryRef::Vacant(entry) => entry.insert_entry(value), + } + } + + /// Ensures a value is in the entry by inserting the default if empty, and returns + /// a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// + /// // nonexistent key + /// map.entry_ref("poneyland").or_insert(3); + /// assert_eq!(map["poneyland"], 3); + /// + /// // existing key + /// *map.entry_ref("poneyland").or_insert(10) *= 2; + /// assert_eq!(map["poneyland"], 6); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert(self, default: V) -> &'a mut V + where + K: Hash + From<&'b Q>, + S: BuildHasher, + { + match self { + EntryRef::Occupied(entry) => entry.into_mut(), + EntryRef::Vacant(entry) => entry.insert(default), + } + } + + /// Ensures a value is in the entry by inserting the result of the default function if empty, + /// and returns a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// + /// // nonexistent key + /// map.entry_ref("poneyland").or_insert_with(|| 3); + /// assert_eq!(map["poneyland"], 3); + /// + /// // existing key + /// *map.entry_ref("poneyland").or_insert_with(|| 10) *= 2; + /// assert_eq!(map["poneyland"], 6); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V + where + K: Hash + From<&'b Q>, + S: BuildHasher, + { + match self { + EntryRef::Occupied(entry) => entry.into_mut(), + EntryRef::Vacant(entry) => entry.insert(default()), + } + } + + /// Ensures a value is in the entry by inserting, if empty, the result of the default function. + /// This method allows for generating key-derived values for insertion by providing the default + /// function a reference to the key that was moved during the `.entry_ref(key)` method call. + /// + /// The reference to the moved key is provided so that cloning or copying the key is + /// unnecessary, unlike with `.or_insert_with(|| ... )`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<String, usize> = HashMap::new(); + /// + /// // nonexistent key + /// map.entry_ref("poneyland").or_insert_with_key(|key| key.chars().count()); + /// assert_eq!(map["poneyland"], 9); + /// + /// // existing key + /// *map.entry_ref("poneyland").or_insert_with_key(|key| key.chars().count() * 10) *= 2; + /// assert_eq!(map["poneyland"], 18); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert_with_key<F: FnOnce(&Q) -> V>(self, default: F) -> &'a mut V + where + K: Hash + Borrow<Q> + From<&'b Q>, + S: BuildHasher, + { + match self { + EntryRef::Occupied(entry) => entry.into_mut(), + EntryRef::Vacant(entry) => { + let value = default(entry.key.as_ref()); + entry.insert(value) + } + } + } + + /// Returns a reference to this entry's key. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// map.entry_ref("poneyland").or_insert(3); + /// // existing key + /// assert_eq!(map.entry_ref("poneyland").key(), "poneyland"); + /// // nonexistent key + /// assert_eq!(map.entry_ref("horseland").key(), "horseland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &Q + where + K: Borrow<Q>, + { + match *self { + EntryRef::Occupied(ref entry) => entry.key(), + EntryRef::Vacant(ref entry) => entry.key(), + } + } + + /// Provides in-place mutable access to an occupied entry before any + /// potential inserts into the map. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// + /// map.entry_ref("poneyland") + /// .and_modify(|e| { *e += 1 }) + /// .or_insert(42); + /// assert_eq!(map["poneyland"], 42); + /// + /// map.entry_ref("poneyland") + /// .and_modify(|e| { *e += 1 }) + /// .or_insert(42); + /// assert_eq!(map["poneyland"], 43); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn and_modify<F>(self, f: F) -> Self + where + F: FnOnce(&mut V), + { + match self { + EntryRef::Occupied(mut entry) => { + f(entry.get_mut()); + EntryRef::Occupied(entry) + } + EntryRef::Vacant(entry) => EntryRef::Vacant(entry), + } + } + + /// Provides shared access to the key and owned access to the value of + /// an occupied entry and allows to replace or remove it based on the + /// value of the returned option. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::EntryRef; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// + /// let entry = map + /// .entry_ref("poneyland") + /// .and_replace_entry_with(|_k, _v| panic!()); + /// + /// match entry { + /// EntryRef::Vacant(e) => { + /// assert_eq!(e.key(), "poneyland"); + /// } + /// EntryRef::Occupied(_) => panic!(), + /// } + /// + /// map.insert("poneyland".to_string(), 42); + /// + /// let entry = map + /// .entry_ref("poneyland") + /// .and_replace_entry_with(|k, v| { + /// assert_eq!(k, "poneyland"); + /// assert_eq!(v, 42); + /// Some(v + 1) + /// }); + /// + /// match entry { + /// EntryRef::Occupied(e) => { + /// assert_eq!(e.key(), "poneyland"); + /// assert_eq!(e.get(), &43); + /// } + /// EntryRef::Vacant(_) => panic!(), + /// } + /// + /// assert_eq!(map["poneyland"], 43); + /// + /// let entry = map + /// .entry_ref("poneyland") + /// .and_replace_entry_with(|_k, _v| None); + /// + /// match entry { + /// EntryRef::Vacant(e) => assert_eq!(e.key(), "poneyland"), + /// EntryRef::Occupied(_) => panic!(), + /// } + /// + /// assert!(!map.contains_key("poneyland")); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn and_replace_entry_with<F>(self, f: F) -> Self + where + F: FnOnce(&Q, V) -> Option<V>, + K: Borrow<Q>, + { + match self { + EntryRef::Occupied(entry) => entry.replace_entry_with(f), + EntryRef::Vacant(_) => self, + } + } +} + +impl<'a, 'b, K, Q: ?Sized, V: Default, S, A: Allocator + Clone> EntryRef<'a, 'b, K, Q, V, S, A> { + /// Ensures a value is in the entry by inserting the default value if empty, + /// and returns a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<String, Option<u32>> = HashMap::new(); + /// + /// // nonexistent key + /// map.entry_ref("poneyland").or_default(); + /// assert_eq!(map["poneyland"], None); + /// + /// map.insert("horseland".to_string(), Some(3)); + /// + /// // existing key + /// assert_eq!(map.entry_ref("horseland").or_default(), &mut Some(3)); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_default(self) -> &'a mut V + where + K: Hash + From<&'b Q>, + S: BuildHasher, + { + match self { + EntryRef::Occupied(entry) => entry.into_mut(), + EntryRef::Vacant(entry) => entry.insert(Default::default()), + } + } +} + +impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, K, Q, V, S, A> { + /// Gets a reference to the key in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{EntryRef, HashMap}; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// map.entry_ref("poneyland").or_insert(12); + /// + /// match map.entry_ref("poneyland") { + /// EntryRef::Vacant(_) => panic!(), + /// EntryRef::Occupied(entry) => assert_eq!(entry.key(), "poneyland"), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &Q + where + K: Borrow<Q>, + { + unsafe { &self.elem.as_ref().0 }.borrow() + } + + /// Take the ownership of the key and value from the map. + /// Keeps the allocated memory for reuse. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::EntryRef; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// // The map is empty + /// assert!(map.is_empty() && map.capacity() == 0); + /// + /// map.entry_ref("poneyland").or_insert(12); + /// let capacity_before_remove = map.capacity(); + /// + /// if let EntryRef::Occupied(o) = map.entry_ref("poneyland") { + /// // We delete the entry from the map. + /// assert_eq!(o.remove_entry(), ("poneyland".to_owned(), 12)); + /// } + /// + /// assert_eq!(map.contains_key("poneyland"), false); + /// // Now map hold none elements but capacity is equal to the old one + /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove_entry(self) -> (K, V) { + unsafe { self.table.table.remove(self.elem) } + } + + /// Gets a reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::EntryRef; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// map.entry_ref("poneyland").or_insert(12); + /// + /// match map.entry_ref("poneyland") { + /// EntryRef::Vacant(_) => panic!(), + /// EntryRef::Occupied(entry) => assert_eq!(entry.get(), &12), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get(&self) -> &V { + unsafe { &self.elem.as_ref().1 } + } + + /// Gets a mutable reference to the value in the entry. + /// + /// If you need a reference to the `OccupiedEntryRef` which may outlive the + /// destruction of the `EntryRef` value, see [`into_mut`]. + /// + /// [`into_mut`]: #method.into_mut + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::EntryRef; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// map.entry_ref("poneyland").or_insert(12); + /// + /// assert_eq!(map["poneyland"], 12); + /// if let EntryRef::Occupied(mut o) = map.entry_ref("poneyland") { + /// *o.get_mut() += 10; + /// assert_eq!(*o.get(), 22); + /// + /// // We can use the same Entry multiple times. + /// *o.get_mut() += 2; + /// } + /// + /// assert_eq!(map["poneyland"], 24); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_mut(&mut self) -> &mut V { + unsafe { &mut self.elem.as_mut().1 } + } + + /// Converts the OccupiedEntryRef into a mutable reference to the value in the entry + /// with a lifetime bound to the map itself. + /// + /// If you need multiple references to the `OccupiedEntryRef`, see [`get_mut`]. + /// + /// [`get_mut`]: #method.get_mut + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{EntryRef, HashMap}; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// map.entry_ref("poneyland").or_insert(12); + /// + /// let value: &mut u32; + /// match map.entry_ref("poneyland") { + /// EntryRef::Occupied(entry) => value = entry.into_mut(), + /// EntryRef::Vacant(_) => panic!(), + /// } + /// *value += 10; + /// + /// assert_eq!(map["poneyland"], 22); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_mut(self) -> &'a mut V { + unsafe { &mut self.elem.as_mut().1 } + } + + /// Sets the value of the entry, and returns the entry's old value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::EntryRef; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// map.entry_ref("poneyland").or_insert(12); + /// + /// if let EntryRef::Occupied(mut o) = map.entry_ref("poneyland") { + /// assert_eq!(o.insert(15), 12); + /// } + /// + /// assert_eq!(map["poneyland"], 15); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(&mut self, value: V) -> V { + mem::replace(self.get_mut(), value) + } + + /// Takes the value out of the entry, and returns it. + /// Keeps the allocated memory for reuse. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::EntryRef; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// // The map is empty + /// assert!(map.is_empty() && map.capacity() == 0); + /// + /// map.entry_ref("poneyland").or_insert(12); + /// let capacity_before_remove = map.capacity(); + /// + /// if let EntryRef::Occupied(o) = map.entry_ref("poneyland") { + /// assert_eq!(o.remove(), 12); + /// } + /// + /// assert_eq!(map.contains_key("poneyland"), false); + /// // Now map hold none elements but capacity is equal to the old one + /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove(self) -> V { + self.remove_entry().1 + } + + /// Replaces the entry, returning the old key and value. The new key in the hash map will be + /// the key used to create this entry. + /// + /// # Panics + /// + /// Will panic if this OccupiedEntry was created through [`EntryRef::insert`]. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{EntryRef, HashMap}; + /// use std::rc::Rc; + /// + /// let mut map: HashMap<Rc<str>, u32> = HashMap::new(); + /// let key: Rc<str> = Rc::from("Stringthing"); + /// + /// map.insert(key.clone(), 15); + /// assert_eq!(Rc::strong_count(&key), 2); + /// + /// match map.entry_ref("Stringthing") { + /// EntryRef::Occupied(entry) => { + /// let (old_key, old_value): (Rc<str>, u32) = entry.replace_entry(16); + /// assert!(Rc::ptr_eq(&key, &old_key) && old_value == 15); + /// } + /// EntryRef::Vacant(_) => panic!(), + /// } + /// + /// assert_eq!(Rc::strong_count(&key), 1); + /// assert_eq!(map["Stringthing"], 16); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_entry(self, value: V) -> (K, V) + where + K: From<&'b Q>, + { + let entry = unsafe { self.elem.as_mut() }; + + let old_key = mem::replace(&mut entry.0, self.key.unwrap().into_owned()); + let old_value = mem::replace(&mut entry.1, value); + + (old_key, old_value) + } + + /// Replaces the key in the hash map with the key used to create this entry. + /// + /// # Panics + /// + /// Will panic if this OccupiedEntry was created through [`Entry::insert`]. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{EntryRef, HashMap}; + /// use std::rc::Rc; + /// + /// let mut map: HashMap<Rc<str>, usize> = HashMap::with_capacity(6); + /// let mut keys: Vec<Rc<str>> = Vec::with_capacity(6); + /// + /// for (value, key) in ["a", "b", "c", "d", "e", "f"].into_iter().enumerate() { + /// let rc_key: Rc<str> = Rc::from(key); + /// keys.push(rc_key.clone()); + /// map.insert(rc_key.clone(), value); + /// } + /// + /// assert!(keys.iter().all(|key| Rc::strong_count(key) == 2)); + /// + /// // It doesn't matter that we kind of use a vector with the same keys, + /// // because all keys will be newly created from the references + /// reclaim_memory(&mut map, &keys); + /// + /// assert!(keys.iter().all(|key| Rc::strong_count(key) == 1)); + /// + /// fn reclaim_memory(map: &mut HashMap<Rc<str>, usize>, keys: &[Rc<str>]) { + /// for key in keys { + /// if let EntryRef::Occupied(entry) = map.entry_ref(key.as_ref()) { + /// /// Replaces the entry's key with our version of it in `keys`. + /// entry.replace_key(); + /// } + /// } + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_key(self) -> K + where + K: From<&'b Q>, + { + let entry = unsafe { self.elem.as_mut() }; + mem::replace(&mut entry.0, self.key.unwrap().into_owned()) + } + + /// Provides shared access to the key and owned access to the value of + /// the entry and allows to replace or remove it based on the + /// value of the returned option. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::EntryRef; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// map.insert("poneyland".to_string(), 42); + /// + /// let entry = match map.entry_ref("poneyland") { + /// EntryRef::Occupied(e) => { + /// e.replace_entry_with(|k, v| { + /// assert_eq!(k, "poneyland"); + /// assert_eq!(v, 42); + /// Some(v + 1) + /// }) + /// } + /// EntryRef::Vacant(_) => panic!(), + /// }; + /// + /// match entry { + /// EntryRef::Occupied(e) => { + /// assert_eq!(e.key(), "poneyland"); + /// assert_eq!(e.get(), &43); + /// } + /// EntryRef::Vacant(_) => panic!(), + /// } + /// + /// assert_eq!(map["poneyland"], 43); + /// + /// let entry = match map.entry_ref("poneyland") { + /// EntryRef::Occupied(e) => e.replace_entry_with(|_k, _v| None), + /// EntryRef::Vacant(_) => panic!(), + /// }; + /// + /// match entry { + /// EntryRef::Vacant(e) => { + /// assert_eq!(e.key(), "poneyland"); + /// } + /// EntryRef::Occupied(_) => panic!(), + /// } + /// + /// assert!(!map.contains_key("poneyland")); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_entry_with<F>(self, f: F) -> EntryRef<'a, 'b, K, Q, V, S, A> + where + F: FnOnce(&Q, V) -> Option<V>, + K: Borrow<Q>, + { + unsafe { + let mut spare_key = None; + + self.table + .table + .replace_bucket_with(self.elem.clone(), |(key, value)| { + if let Some(new_value) = f(key.borrow(), value) { + Some((key, new_value)) + } else { + spare_key = Some(KeyOrRef::Owned(key)); + None + } + }); + + if let Some(key) = spare_key { + EntryRef::Vacant(VacantEntryRef { + hash: self.hash, + key, + table: self.table, + }) + } else { + EntryRef::Occupied(self) + } + } + } +} + +impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> VacantEntryRef<'a, 'b, K, Q, V, S, A> { + /// Gets a reference to the key that would be used when inserting a value + /// through the `VacantEntryRef`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// let key: &str = "poneyland"; + /// assert_eq!(map.entry_ref(key).key(), "poneyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &Q + where + K: Borrow<Q>, + { + self.key.as_ref() + } + + /// Take ownership of the key. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{EntryRef, HashMap}; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// let key: &str = "poneyland"; + /// + /// match map.entry_ref(key) { + /// EntryRef::Occupied(_) => panic!(), + /// EntryRef::Vacant(v) => assert_eq!(v.into_key(), "poneyland".to_owned()), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_key(self) -> K + where + K: From<&'b Q>, + { + self.key.into_owned() + } + + /// Sets the value of the entry with the VacantEntryRef's key, + /// and returns a mutable reference to it. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::EntryRef; + /// + /// let mut map: HashMap<String, u32> = HashMap::new(); + /// let key: &str = "poneyland"; + /// + /// if let EntryRef::Vacant(o) = map.entry_ref(key) { + /// o.insert(37); + /// } + /// assert_eq!(map["poneyland"], 37); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self, value: V) -> &'a mut V + where + K: Hash + From<&'b Q>, + S: BuildHasher, + { + let table = &mut self.table.table; + let entry = table.insert_entry( + self.hash, + (self.key.into_owned(), value), + make_hasher::<K, _, V, S>(&self.table.hash_builder), + ); + &mut entry.1 + } + + #[cfg_attr(feature = "inline-more", inline)] + fn insert_entry(self, value: V) -> OccupiedEntryRef<'a, 'b, K, Q, V, S, A> + where + K: Hash + From<&'b Q>, + S: BuildHasher, + { + let elem = self.table.table.insert( + self.hash, + (self.key.into_owned(), value), + make_hasher::<K, _, V, S>(&self.table.hash_builder), + ); + OccupiedEntryRef { + hash: self.hash, + key: None, + elem, + table: self.table, + } + } +} + +impl<K, V, S, A> FromIterator<(K, V)> for HashMap<K, V, S, A> +where + K: Eq + Hash, + S: BuildHasher + Default, + A: Default + Allocator + Clone, +{ + #[cfg_attr(feature = "inline-more", inline)] + fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> Self { + let iter = iter.into_iter(); + let mut map = + Self::with_capacity_and_hasher_in(iter.size_hint().0, S::default(), A::default()); + iter.for_each(|(k, v)| { + map.insert(k, v); + }); + map + } +} + +/// Inserts all new key-values from the iterator and replaces values with existing +/// keys with new values returned from the iterator. +impl<K, V, S, A> Extend<(K, V)> for HashMap<K, V, S, A> +where + K: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + /// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`. + /// Replace values with existing keys with new values returned from the iterator. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert(1, 100); + /// + /// let some_iter = [(1, 1), (2, 2)].into_iter(); + /// map.extend(some_iter); + /// // Replace values with existing keys with new values returned from the iterator. + /// // So that the map.get(&1) doesn't return Some(&100). + /// assert_eq!(map.get(&1), Some(&1)); + /// + /// let some_vec: Vec<_> = vec![(3, 3), (4, 4)]; + /// map.extend(some_vec); + /// + /// let some_arr = [(5, 5), (6, 6)]; + /// map.extend(some_arr); + /// let old_map_len = map.len(); + /// + /// // You can also extend from another HashMap + /// let mut new_map = HashMap::new(); + /// new_map.extend(map); + /// assert_eq!(new_map.len(), old_map_len); + /// + /// let mut vec: Vec<_> = new_map.into_iter().collect(); + /// // The `IntoIter` iterator produces items in arbitrary order, so the + /// // items must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn extend<T: IntoIterator<Item = (K, V)>>(&mut self, iter: T) { + // Keys may be already present or show multiple times in the iterator. + // Reserve the entire hint lower bound if the map is empty. + // Otherwise reserve half the hint (rounded up), so the map + // will only resize twice in the worst case. + let iter = iter.into_iter(); + let reserve = if self.is_empty() { + iter.size_hint().0 + } else { + (iter.size_hint().0 + 1) / 2 + }; + self.reserve(reserve); + iter.for_each(move |(k, v)| { + self.insert(k, v); + }); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_one(&mut self, (k, v): (K, V)) { + self.insert(k, v); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_reserve(&mut self, additional: usize) { + // Keys may be already present or show multiple times in the iterator. + // Reserve the entire hint lower bound if the map is empty. + // Otherwise reserve half the hint (rounded up), so the map + // will only resize twice in the worst case. + let reserve = if self.is_empty() { + additional + } else { + (additional + 1) / 2 + }; + self.reserve(reserve); + } +} + +/// Inserts all new key-values from the iterator and replaces values with existing +/// keys with new values returned from the iterator. +impl<'a, K, V, S, A> Extend<(&'a K, &'a V)> for HashMap<K, V, S, A> +where + K: Eq + Hash + Copy, + V: Copy, + S: BuildHasher, + A: Allocator + Clone, +{ + /// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`. + /// Replace values with existing keys with new values returned from the iterator. + /// The keys and values must implement [`Copy`] trait. + /// + /// [`Copy`]: https://doc.rust-lang.org/core/marker/trait.Copy.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert(1, 100); + /// + /// let arr = [(1, 1), (2, 2)]; + /// let some_iter = arr.iter().map(|&(k, v)| (k, v)); + /// map.extend(some_iter); + /// // Replace values with existing keys with new values returned from the iterator. + /// // So that the map.get(&1) doesn't return Some(&100). + /// assert_eq!(map.get(&1), Some(&1)); + /// + /// let some_vec: Vec<_> = vec![(3, 3), (4, 4)]; + /// map.extend(some_vec.iter().map(|&(k, v)| (k, v))); + /// + /// let some_arr = [(5, 5), (6, 6)]; + /// map.extend(some_arr.iter().map(|&(k, v)| (k, v))); + /// + /// // You can also extend from another HashMap + /// let mut new_map = HashMap::new(); + /// new_map.extend(&map); + /// assert_eq!(new_map, map); + /// + /// let mut vec: Vec<_> = new_map.into_iter().collect(); + /// // The `IntoIter` iterator produces items in arbitrary order, so the + /// // items must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn extend<T: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: T) { + self.extend(iter.into_iter().map(|(&key, &value)| (key, value))); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_one(&mut self, (k, v): (&'a K, &'a V)) { + self.insert(*k, *v); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_reserve(&mut self, additional: usize) { + Extend::<(K, V)>::extend_reserve(self, additional); + } +} + +/// Inserts all new key-values from the iterator and replaces values with existing +/// keys with new values returned from the iterator. +impl<'a, K, V, S, A> Extend<&'a (K, V)> for HashMap<K, V, S, A> +where + K: Eq + Hash + Copy, + V: Copy, + S: BuildHasher, + A: Allocator + Clone, +{ + /// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`. + /// Replace values with existing keys with new values returned from the iterator. + /// The keys and values must implement [`Copy`] trait. + /// + /// [`Copy`]: https://doc.rust-lang.org/core/marker/trait.Copy.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::HashMap; + /// + /// let mut map = HashMap::new(); + /// map.insert(1, 100); + /// + /// let arr = [(1, 1), (2, 2)]; + /// let some_iter = arr.iter(); + /// map.extend(some_iter); + /// // Replace values with existing keys with new values returned from the iterator. + /// // So that the map.get(&1) doesn't return Some(&100). + /// assert_eq!(map.get(&1), Some(&1)); + /// + /// let some_vec: Vec<_> = vec![(3, 3), (4, 4)]; + /// map.extend(&some_vec); + /// + /// let some_arr = [(5, 5), (6, 6)]; + /// map.extend(&some_arr); + /// + /// let mut vec: Vec<_> = map.into_iter().collect(); + /// // The `IntoIter` iterator produces items in arbitrary order, so the + /// // items must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn extend<T: IntoIterator<Item = &'a (K, V)>>(&mut self, iter: T) { + self.extend(iter.into_iter().map(|&(key, value)| (key, value))); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_one(&mut self, &(k, v): &'a (K, V)) { + self.insert(k, v); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_reserve(&mut self, additional: usize) { + Extend::<(K, V)>::extend_reserve(self, additional); + } +} + +#[allow(dead_code)] +fn assert_covariance() { + fn map_key<'new>(v: HashMap<&'static str, u8>) -> HashMap<&'new str, u8> { + v + } + fn map_val<'new>(v: HashMap<u8, &'static str>) -> HashMap<u8, &'new str> { + v + } + fn iter_key<'a, 'new>(v: Iter<'a, &'static str, u8>) -> Iter<'a, &'new str, u8> { + v + } + fn iter_val<'a, 'new>(v: Iter<'a, u8, &'static str>) -> Iter<'a, u8, &'new str> { + v + } + fn into_iter_key<'new, A: Allocator + Clone>( + v: IntoIter<&'static str, u8, A>, + ) -> IntoIter<&'new str, u8, A> { + v + } + fn into_iter_val<'new, A: Allocator + Clone>( + v: IntoIter<u8, &'static str, A>, + ) -> IntoIter<u8, &'new str, A> { + v + } + fn keys_key<'a, 'new>(v: Keys<'a, &'static str, u8>) -> Keys<'a, &'new str, u8> { + v + } + fn keys_val<'a, 'new>(v: Keys<'a, u8, &'static str>) -> Keys<'a, u8, &'new str> { + v + } + fn values_key<'a, 'new>(v: Values<'a, &'static str, u8>) -> Values<'a, &'new str, u8> { + v + } + fn values_val<'a, 'new>(v: Values<'a, u8, &'static str>) -> Values<'a, u8, &'new str> { + v + } + fn drain<'new>( + d: Drain<'static, &'static str, &'static str>, + ) -> Drain<'new, &'new str, &'new str> { + d + } +} + +#[cfg(test)] +mod test_map { + use super::DefaultHashBuilder; + use super::Entry::{Occupied, Vacant}; + use super::EntryRef; + use super::{HashMap, RawEntryMut}; + use rand::{rngs::SmallRng, Rng, SeedableRng}; + use std::borrow::ToOwned; + use std::cell::RefCell; + use std::usize; + use std::vec::Vec; + + #[test] + fn test_zero_capacities() { + type HM = HashMap<i32, i32>; + + let m = HM::new(); + assert_eq!(m.capacity(), 0); + + let m = HM::default(); + assert_eq!(m.capacity(), 0); + + let m = HM::with_hasher(DefaultHashBuilder::default()); + assert_eq!(m.capacity(), 0); + + let m = HM::with_capacity(0); + assert_eq!(m.capacity(), 0); + + let m = HM::with_capacity_and_hasher(0, DefaultHashBuilder::default()); + assert_eq!(m.capacity(), 0); + + let mut m = HM::new(); + m.insert(1, 1); + m.insert(2, 2); + m.remove(&1); + m.remove(&2); + m.shrink_to_fit(); + assert_eq!(m.capacity(), 0); + + let mut m = HM::new(); + m.reserve(0); + assert_eq!(m.capacity(), 0); + } + + #[test] + fn test_create_capacity_zero() { + let mut m = HashMap::with_capacity(0); + + assert!(m.insert(1, 1).is_none()); + + assert!(m.contains_key(&1)); + assert!(!m.contains_key(&0)); + } + + #[test] + fn test_insert() { + let mut m = HashMap::new(); + assert_eq!(m.len(), 0); + assert!(m.insert(1, 2).is_none()); + assert_eq!(m.len(), 1); + assert!(m.insert(2, 4).is_none()); + assert_eq!(m.len(), 2); + assert_eq!(*m.get(&1).unwrap(), 2); + assert_eq!(*m.get(&2).unwrap(), 4); + } + + #[test] + fn test_clone() { + let mut m = HashMap::new(); + assert_eq!(m.len(), 0); + assert!(m.insert(1, 2).is_none()); + assert_eq!(m.len(), 1); + assert!(m.insert(2, 4).is_none()); + assert_eq!(m.len(), 2); + #[allow(clippy::redundant_clone)] + let m2 = m.clone(); + assert_eq!(*m2.get(&1).unwrap(), 2); + assert_eq!(*m2.get(&2).unwrap(), 4); + assert_eq!(m2.len(), 2); + } + + #[test] + fn test_clone_from() { + let mut m = HashMap::new(); + let mut m2 = HashMap::new(); + assert_eq!(m.len(), 0); + assert!(m.insert(1, 2).is_none()); + assert_eq!(m.len(), 1); + assert!(m.insert(2, 4).is_none()); + assert_eq!(m.len(), 2); + m2.clone_from(&m); + assert_eq!(*m2.get(&1).unwrap(), 2); + assert_eq!(*m2.get(&2).unwrap(), 4); + assert_eq!(m2.len(), 2); + } + + thread_local! { static DROP_VECTOR: RefCell<Vec<i32>> = RefCell::new(Vec::new()) } + + #[derive(Hash, PartialEq, Eq)] + struct Droppable { + k: usize, + } + + impl Droppable { + fn new(k: usize) -> Droppable { + DROP_VECTOR.with(|slot| { + slot.borrow_mut()[k] += 1; + }); + + Droppable { k } + } + } + + impl Drop for Droppable { + fn drop(&mut self) { + DROP_VECTOR.with(|slot| { + slot.borrow_mut()[self.k] -= 1; + }); + } + } + + impl Clone for Droppable { + fn clone(&self) -> Self { + Droppable::new(self.k) + } + } + + #[test] + fn test_drops() { + DROP_VECTOR.with(|slot| { + *slot.borrow_mut() = vec![0; 200]; + }); + + { + let mut m = HashMap::new(); + + DROP_VECTOR.with(|v| { + for i in 0..200 { + assert_eq!(v.borrow()[i], 0); + } + }); + + for i in 0..100 { + let d1 = Droppable::new(i); + let d2 = Droppable::new(i + 100); + m.insert(d1, d2); + } + + DROP_VECTOR.with(|v| { + for i in 0..200 { + assert_eq!(v.borrow()[i], 1); + } + }); + + for i in 0..50 { + let k = Droppable::new(i); + let v = m.remove(&k); + + assert!(v.is_some()); + + DROP_VECTOR.with(|v| { + assert_eq!(v.borrow()[i], 1); + assert_eq!(v.borrow()[i + 100], 1); + }); + } + + DROP_VECTOR.with(|v| { + for i in 0..50 { + assert_eq!(v.borrow()[i], 0); + assert_eq!(v.borrow()[i + 100], 0); + } + + for i in 50..100 { + assert_eq!(v.borrow()[i], 1); + assert_eq!(v.borrow()[i + 100], 1); + } + }); + } + + DROP_VECTOR.with(|v| { + for i in 0..200 { + assert_eq!(v.borrow()[i], 0); + } + }); + } + + #[test] + fn test_into_iter_drops() { + DROP_VECTOR.with(|v| { + *v.borrow_mut() = vec![0; 200]; + }); + + let hm = { + let mut hm = HashMap::new(); + + DROP_VECTOR.with(|v| { + for i in 0..200 { + assert_eq!(v.borrow()[i], 0); + } + }); + + for i in 0..100 { + let d1 = Droppable::new(i); + let d2 = Droppable::new(i + 100); + hm.insert(d1, d2); + } + + DROP_VECTOR.with(|v| { + for i in 0..200 { + assert_eq!(v.borrow()[i], 1); + } + }); + + hm + }; + + // By the way, ensure that cloning doesn't screw up the dropping. + drop(hm.clone()); + + { + let mut half = hm.into_iter().take(50); + + DROP_VECTOR.with(|v| { + for i in 0..200 { + assert_eq!(v.borrow()[i], 1); + } + }); + + #[allow(clippy::let_underscore_drop)] // kind-of a false positive + for _ in half.by_ref() {} + + DROP_VECTOR.with(|v| { + let nk = (0..100).filter(|&i| v.borrow()[i] == 1).count(); + + let nv = (0..100).filter(|&i| v.borrow()[i + 100] == 1).count(); + + assert_eq!(nk, 50); + assert_eq!(nv, 50); + }); + }; + + DROP_VECTOR.with(|v| { + for i in 0..200 { + assert_eq!(v.borrow()[i], 0); + } + }); + } + + #[test] + fn test_empty_remove() { + let mut m: HashMap<i32, bool> = HashMap::new(); + assert_eq!(m.remove(&0), None); + } + + #[test] + fn test_empty_entry() { + let mut m: HashMap<i32, bool> = HashMap::new(); + match m.entry(0) { + Occupied(_) => panic!(), + Vacant(_) => {} + } + assert!(*m.entry(0).or_insert(true)); + assert_eq!(m.len(), 1); + } + + #[test] + fn test_empty_entry_ref() { + let mut m: HashMap<std::string::String, bool> = HashMap::new(); + match m.entry_ref("poneyland") { + EntryRef::Occupied(_) => panic!(), + EntryRef::Vacant(_) => {} + } + assert!(*m.entry_ref("poneyland").or_insert(true)); + assert_eq!(m.len(), 1); + } + + #[test] + fn test_empty_iter() { + let mut m: HashMap<i32, bool> = HashMap::new(); + assert_eq!(m.drain().next(), None); + assert_eq!(m.keys().next(), None); + assert_eq!(m.values().next(), None); + assert_eq!(m.values_mut().next(), None); + assert_eq!(m.iter().next(), None); + assert_eq!(m.iter_mut().next(), None); + assert_eq!(m.len(), 0); + assert!(m.is_empty()); + assert_eq!(m.into_iter().next(), None); + } + + #[test] + #[cfg_attr(miri, ignore)] // FIXME: takes too long + fn test_lots_of_insertions() { + let mut m = HashMap::new(); + + // Try this a few times to make sure we never screw up the hashmap's + // internal state. + for _ in 0..10 { + assert!(m.is_empty()); + + for i in 1..1001 { + assert!(m.insert(i, i).is_none()); + + for j in 1..=i { + let r = m.get(&j); + assert_eq!(r, Some(&j)); + } + + for j in i + 1..1001 { + let r = m.get(&j); + assert_eq!(r, None); + } + } + + for i in 1001..2001 { + assert!(!m.contains_key(&i)); + } + + // remove forwards + for i in 1..1001 { + assert!(m.remove(&i).is_some()); + + for j in 1..=i { + assert!(!m.contains_key(&j)); + } + + for j in i + 1..1001 { + assert!(m.contains_key(&j)); + } + } + + for i in 1..1001 { + assert!(!m.contains_key(&i)); + } + + for i in 1..1001 { + assert!(m.insert(i, i).is_none()); + } + + // remove backwards + for i in (1..1001).rev() { + assert!(m.remove(&i).is_some()); + + for j in i..1001 { + assert!(!m.contains_key(&j)); + } + + for j in 1..i { + assert!(m.contains_key(&j)); + } + } + } + } + + #[test] + fn test_find_mut() { + let mut m = HashMap::new(); + assert!(m.insert(1, 12).is_none()); + assert!(m.insert(2, 8).is_none()); + assert!(m.insert(5, 14).is_none()); + let new = 100; + match m.get_mut(&5) { + None => panic!(), + Some(x) => *x = new, + } + assert_eq!(m.get(&5), Some(&new)); + } + + #[test] + fn test_insert_overwrite() { + let mut m = HashMap::new(); + assert!(m.insert(1, 2).is_none()); + assert_eq!(*m.get(&1).unwrap(), 2); + assert!(m.insert(1, 3).is_some()); + assert_eq!(*m.get(&1).unwrap(), 3); + } + + #[test] + fn test_insert_conflicts() { + let mut m = HashMap::with_capacity(4); + assert!(m.insert(1, 2).is_none()); + assert!(m.insert(5, 3).is_none()); + assert!(m.insert(9, 4).is_none()); + assert_eq!(*m.get(&9).unwrap(), 4); + assert_eq!(*m.get(&5).unwrap(), 3); + assert_eq!(*m.get(&1).unwrap(), 2); + } + + #[test] + fn test_conflict_remove() { + let mut m = HashMap::with_capacity(4); + assert!(m.insert(1, 2).is_none()); + assert_eq!(*m.get(&1).unwrap(), 2); + assert!(m.insert(5, 3).is_none()); + assert_eq!(*m.get(&1).unwrap(), 2); + assert_eq!(*m.get(&5).unwrap(), 3); + assert!(m.insert(9, 4).is_none()); + assert_eq!(*m.get(&1).unwrap(), 2); + assert_eq!(*m.get(&5).unwrap(), 3); + assert_eq!(*m.get(&9).unwrap(), 4); + assert!(m.remove(&1).is_some()); + assert_eq!(*m.get(&9).unwrap(), 4); + assert_eq!(*m.get(&5).unwrap(), 3); + } + + #[test] + fn test_insert_unique_unchecked() { + let mut map = HashMap::new(); + let (k1, v1) = map.insert_unique_unchecked(10, 11); + assert_eq!((&10, &mut 11), (k1, v1)); + let (k2, v2) = map.insert_unique_unchecked(20, 21); + assert_eq!((&20, &mut 21), (k2, v2)); + assert_eq!(Some(&11), map.get(&10)); + assert_eq!(Some(&21), map.get(&20)); + assert_eq!(None, map.get(&30)); + } + + #[test] + fn test_is_empty() { + let mut m = HashMap::with_capacity(4); + assert!(m.insert(1, 2).is_none()); + assert!(!m.is_empty()); + assert!(m.remove(&1).is_some()); + assert!(m.is_empty()); + } + + #[test] + fn test_remove() { + let mut m = HashMap::new(); + m.insert(1, 2); + assert_eq!(m.remove(&1), Some(2)); + assert_eq!(m.remove(&1), None); + } + + #[test] + fn test_remove_entry() { + let mut m = HashMap::new(); + m.insert(1, 2); + assert_eq!(m.remove_entry(&1), Some((1, 2))); + assert_eq!(m.remove(&1), None); + } + + #[test] + fn test_iterate() { + let mut m = HashMap::with_capacity(4); + for i in 0..32 { + assert!(m.insert(i, i * 2).is_none()); + } + assert_eq!(m.len(), 32); + + let mut observed: u32 = 0; + + for (k, v) in &m { + assert_eq!(*v, *k * 2); + observed |= 1 << *k; + } + assert_eq!(observed, 0xFFFF_FFFF); + } + + #[test] + fn test_keys() { + let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')]; + let map: HashMap<_, _> = vec.into_iter().collect(); + let keys: Vec<_> = map.keys().copied().collect(); + assert_eq!(keys.len(), 3); + assert!(keys.contains(&1)); + assert!(keys.contains(&2)); + assert!(keys.contains(&3)); + } + + #[test] + fn test_values() { + let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')]; + let map: HashMap<_, _> = vec.into_iter().collect(); + let values: Vec<_> = map.values().copied().collect(); + assert_eq!(values.len(), 3); + assert!(values.contains(&'a')); + assert!(values.contains(&'b')); + assert!(values.contains(&'c')); + } + + #[test] + fn test_values_mut() { + let vec = vec![(1, 1), (2, 2), (3, 3)]; + let mut map: HashMap<_, _> = vec.into_iter().collect(); + for value in map.values_mut() { + *value *= 2; + } + let values: Vec<_> = map.values().copied().collect(); + assert_eq!(values.len(), 3); + assert!(values.contains(&2)); + assert!(values.contains(&4)); + assert!(values.contains(&6)); + } + + #[test] + fn test_into_keys() { + let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')]; + let map: HashMap<_, _> = vec.into_iter().collect(); + let keys: Vec<_> = map.into_keys().collect(); + + assert_eq!(keys.len(), 3); + assert!(keys.contains(&1)); + assert!(keys.contains(&2)); + assert!(keys.contains(&3)); + } + + #[test] + fn test_into_values() { + let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')]; + let map: HashMap<_, _> = vec.into_iter().collect(); + let values: Vec<_> = map.into_values().collect(); + + assert_eq!(values.len(), 3); + assert!(values.contains(&'a')); + assert!(values.contains(&'b')); + assert!(values.contains(&'c')); + } + + #[test] + fn test_find() { + let mut m = HashMap::new(); + assert!(m.get(&1).is_none()); + m.insert(1, 2); + match m.get(&1) { + None => panic!(), + Some(v) => assert_eq!(*v, 2), + } + } + + #[test] + fn test_eq() { + let mut m1 = HashMap::new(); + m1.insert(1, 2); + m1.insert(2, 3); + m1.insert(3, 4); + + let mut m2 = HashMap::new(); + m2.insert(1, 2); + m2.insert(2, 3); + + assert!(m1 != m2); + + m2.insert(3, 4); + + assert_eq!(m1, m2); + } + + #[test] + fn test_show() { + let mut map = HashMap::new(); + let empty: HashMap<i32, i32> = HashMap::new(); + + map.insert(1, 2); + map.insert(3, 4); + + let map_str = format!("{:?}", map); + + assert!(map_str == "{1: 2, 3: 4}" || map_str == "{3: 4, 1: 2}"); + assert_eq!(format!("{:?}", empty), "{}"); + } + + #[test] + fn test_expand() { + let mut m = HashMap::new(); + + assert_eq!(m.len(), 0); + assert!(m.is_empty()); + + let mut i = 0; + let old_raw_cap = m.raw_capacity(); + while old_raw_cap == m.raw_capacity() { + m.insert(i, i); + i += 1; + } + + assert_eq!(m.len(), i); + assert!(!m.is_empty()); + } + + #[test] + fn test_behavior_resize_policy() { + let mut m = HashMap::new(); + + assert_eq!(m.len(), 0); + assert_eq!(m.raw_capacity(), 1); + assert!(m.is_empty()); + + m.insert(0, 0); + m.remove(&0); + assert!(m.is_empty()); + let initial_raw_cap = m.raw_capacity(); + m.reserve(initial_raw_cap); + let raw_cap = m.raw_capacity(); + + assert_eq!(raw_cap, initial_raw_cap * 2); + + let mut i = 0; + for _ in 0..raw_cap * 3 / 4 { + m.insert(i, i); + i += 1; + } + // three quarters full + + assert_eq!(m.len(), i); + assert_eq!(m.raw_capacity(), raw_cap); + + for _ in 0..raw_cap / 4 { + m.insert(i, i); + i += 1; + } + // half full + + let new_raw_cap = m.raw_capacity(); + assert_eq!(new_raw_cap, raw_cap * 2); + + for _ in 0..raw_cap / 2 - 1 { + i -= 1; + m.remove(&i); + assert_eq!(m.raw_capacity(), new_raw_cap); + } + // A little more than one quarter full. + m.shrink_to_fit(); + assert_eq!(m.raw_capacity(), raw_cap); + // again, a little more than half full + for _ in 0..raw_cap / 2 { + i -= 1; + m.remove(&i); + } + m.shrink_to_fit(); + + assert_eq!(m.len(), i); + assert!(!m.is_empty()); + assert_eq!(m.raw_capacity(), initial_raw_cap); + } + + #[test] + fn test_reserve_shrink_to_fit() { + let mut m = HashMap::new(); + m.insert(0, 0); + m.remove(&0); + assert!(m.capacity() >= m.len()); + for i in 0..128 { + m.insert(i, i); + } + m.reserve(256); + + let usable_cap = m.capacity(); + for i in 128..(128 + 256) { + m.insert(i, i); + assert_eq!(m.capacity(), usable_cap); + } + + for i in 100..(128 + 256) { + assert_eq!(m.remove(&i), Some(i)); + } + m.shrink_to_fit(); + + assert_eq!(m.len(), 100); + assert!(!m.is_empty()); + assert!(m.capacity() >= m.len()); + + for i in 0..100 { + assert_eq!(m.remove(&i), Some(i)); + } + m.shrink_to_fit(); + m.insert(0, 0); + + assert_eq!(m.len(), 1); + assert!(m.capacity() >= m.len()); + assert_eq!(m.remove(&0), Some(0)); + } + + #[test] + fn test_from_iter() { + let xs = [(1, 1), (2, 2), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; + + let map: HashMap<_, _> = xs.iter().copied().collect(); + + for &(k, v) in &xs { + assert_eq!(map.get(&k), Some(&v)); + } + + assert_eq!(map.iter().len(), xs.len() - 1); + } + + #[test] + fn test_size_hint() { + let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; + + let map: HashMap<_, _> = xs.iter().copied().collect(); + + let mut iter = map.iter(); + + for _ in iter.by_ref().take(3) {} + + assert_eq!(iter.size_hint(), (3, Some(3))); + } + + #[test] + fn test_iter_len() { + let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; + + let map: HashMap<_, _> = xs.iter().copied().collect(); + + let mut iter = map.iter(); + + for _ in iter.by_ref().take(3) {} + + assert_eq!(iter.len(), 3); + } + + #[test] + fn test_mut_size_hint() { + let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; + + let mut map: HashMap<_, _> = xs.iter().copied().collect(); + + let mut iter = map.iter_mut(); + + for _ in iter.by_ref().take(3) {} + + assert_eq!(iter.size_hint(), (3, Some(3))); + } + + #[test] + fn test_iter_mut_len() { + let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]; + + let mut map: HashMap<_, _> = xs.iter().copied().collect(); + + let mut iter = map.iter_mut(); + + for _ in iter.by_ref().take(3) {} + + assert_eq!(iter.len(), 3); + } + + #[test] + fn test_index() { + let mut map = HashMap::new(); + + map.insert(1, 2); + map.insert(2, 1); + map.insert(3, 4); + + assert_eq!(map[&2], 1); + } + + #[test] + #[should_panic] + fn test_index_nonexistent() { + let mut map = HashMap::new(); + + map.insert(1, 2); + map.insert(2, 1); + map.insert(3, 4); + + #[allow(clippy::no_effect)] // false positive lint + map[&4]; + } + + #[test] + fn test_entry() { + let xs = [(1, 10), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)]; + + let mut map: HashMap<_, _> = xs.iter().copied().collect(); + + // Existing key (insert) + match map.entry(1) { + Vacant(_) => unreachable!(), + Occupied(mut view) => { + assert_eq!(view.get(), &10); + assert_eq!(view.insert(100), 10); + } + } + assert_eq!(map.get(&1).unwrap(), &100); + assert_eq!(map.len(), 6); + + // Existing key (update) + match map.entry(2) { + Vacant(_) => unreachable!(), + Occupied(mut view) => { + let v = view.get_mut(); + let new_v = (*v) * 10; + *v = new_v; + } + } + assert_eq!(map.get(&2).unwrap(), &200); + assert_eq!(map.len(), 6); + + // Existing key (take) + match map.entry(3) { + Vacant(_) => unreachable!(), + Occupied(view) => { + assert_eq!(view.remove(), 30); + } + } + assert_eq!(map.get(&3), None); + assert_eq!(map.len(), 5); + + // Inexistent key (insert) + match map.entry(10) { + Occupied(_) => unreachable!(), + Vacant(view) => { + assert_eq!(*view.insert(1000), 1000); + } + } + assert_eq!(map.get(&10).unwrap(), &1000); + assert_eq!(map.len(), 6); + } + + #[test] + fn test_entry_ref() { + let xs = [ + ("One".to_owned(), 10), + ("Two".to_owned(), 20), + ("Three".to_owned(), 30), + ("Four".to_owned(), 40), + ("Five".to_owned(), 50), + ("Six".to_owned(), 60), + ]; + + let mut map: HashMap<_, _> = xs.iter().cloned().collect(); + + // Existing key (insert) + match map.entry_ref("One") { + EntryRef::Vacant(_) => unreachable!(), + EntryRef::Occupied(mut view) => { + assert_eq!(view.get(), &10); + assert_eq!(view.insert(100), 10); + } + } + assert_eq!(map.get("One").unwrap(), &100); + assert_eq!(map.len(), 6); + + // Existing key (update) + match map.entry_ref("Two") { + EntryRef::Vacant(_) => unreachable!(), + EntryRef::Occupied(mut view) => { + let v = view.get_mut(); + let new_v = (*v) * 10; + *v = new_v; + } + } + assert_eq!(map.get("Two").unwrap(), &200); + assert_eq!(map.len(), 6); + + // Existing key (take) + match map.entry_ref("Three") { + EntryRef::Vacant(_) => unreachable!(), + EntryRef::Occupied(view) => { + assert_eq!(view.remove(), 30); + } + } + assert_eq!(map.get("Three"), None); + assert_eq!(map.len(), 5); + + // Inexistent key (insert) + match map.entry_ref("Ten") { + EntryRef::Occupied(_) => unreachable!(), + EntryRef::Vacant(view) => { + assert_eq!(*view.insert(1000), 1000); + } + } + assert_eq!(map.get("Ten").unwrap(), &1000); + assert_eq!(map.len(), 6); + } + + #[test] + fn test_entry_take_doesnt_corrupt() { + #![allow(deprecated)] //rand + // Test for #19292 + fn check(m: &HashMap<i32, ()>) { + for k in m.keys() { + assert!(m.contains_key(k), "{} is in keys() but not in the map?", k); + } + } + + let mut m = HashMap::new(); + + let mut rng = { + let seed = u64::from_le_bytes(*b"testseed"); + SmallRng::seed_from_u64(seed) + }; + + // Populate the map with some items. + for _ in 0..50 { + let x = rng.gen_range(-10..10); + m.insert(x, ()); + } + + for _ in 0..1000 { + let x = rng.gen_range(-10..10); + match m.entry(x) { + Vacant(_) => {} + Occupied(e) => { + e.remove(); + } + } + + check(&m); + } + } + + #[test] + fn test_entry_ref_take_doesnt_corrupt() { + #![allow(deprecated)] //rand + // Test for #19292 + fn check(m: &HashMap<std::string::String, ()>) { + for k in m.keys() { + assert!(m.contains_key(k), "{} is in keys() but not in the map?", k); + } + } + + let mut m = HashMap::new(); + + let mut rng = { + let seed = u64::from_le_bytes(*b"testseed"); + SmallRng::seed_from_u64(seed) + }; + + // Populate the map with some items. + for _ in 0..50 { + let mut x = std::string::String::with_capacity(1); + x.push(rng.gen_range('a'..='z')); + m.insert(x, ()); + } + + for _ in 0..1000 { + let mut x = std::string::String::with_capacity(1); + x.push(rng.gen_range('a'..='z')); + match m.entry_ref(x.as_str()) { + EntryRef::Vacant(_) => {} + EntryRef::Occupied(e) => { + e.remove(); + } + } + + check(&m); + } + } + + #[test] + fn test_extend_ref_k_ref_v() { + let mut a = HashMap::new(); + a.insert(1, "one"); + let mut b = HashMap::new(); + b.insert(2, "two"); + b.insert(3, "three"); + + a.extend(&b); + + assert_eq!(a.len(), 3); + assert_eq!(a[&1], "one"); + assert_eq!(a[&2], "two"); + assert_eq!(a[&3], "three"); + } + + #[test] + fn test_extend_ref_kv_tuple() { + use std::ops::AddAssign; + let mut a = HashMap::new(); + a.insert(0, 0); + + fn create_arr<T: AddAssign<T> + Copy, const N: usize>(start: T, step: T) -> [(T, T); N] { + let mut outs: [(T, T); N] = [(start, start); N]; + let mut element = step; + outs.iter_mut().skip(1).for_each(|(k, v)| { + *k += element; + *v += element; + element += step; + }); + outs + } + + let for_iter: Vec<_> = (0..100).map(|i| (i, i)).collect(); + let iter = for_iter.iter(); + let vec: Vec<_> = (100..200).map(|i| (i, i)).collect(); + a.extend(iter); + a.extend(&vec); + a.extend(&create_arr::<i32, 100>(200, 1)); + + assert_eq!(a.len(), 300); + + for item in 0..300 { + assert_eq!(a[&item], item); + } + } + + #[test] + fn test_capacity_not_less_than_len() { + let mut a = HashMap::new(); + let mut item = 0; + + for _ in 0..116 { + a.insert(item, 0); + item += 1; + } + + assert!(a.capacity() > a.len()); + + let free = a.capacity() - a.len(); + for _ in 0..free { + a.insert(item, 0); + item += 1; + } + + assert_eq!(a.len(), a.capacity()); + + // Insert at capacity should cause allocation. + a.insert(item, 0); + assert!(a.capacity() > a.len()); + } + + #[test] + fn test_occupied_entry_key() { + let mut a = HashMap::new(); + let key = "hello there"; + let value = "value goes here"; + assert!(a.is_empty()); + a.insert(key, value); + assert_eq!(a.len(), 1); + assert_eq!(a[key], value); + + match a.entry(key) { + Vacant(_) => panic!(), + Occupied(e) => assert_eq!(key, *e.key()), + } + assert_eq!(a.len(), 1); + assert_eq!(a[key], value); + } + + #[test] + fn test_occupied_entry_ref_key() { + let mut a = HashMap::new(); + let key = "hello there"; + let value = "value goes here"; + assert!(a.is_empty()); + a.insert(key.to_owned(), value); + assert_eq!(a.len(), 1); + assert_eq!(a[key], value); + + match a.entry_ref(key) { + EntryRef::Vacant(_) => panic!(), + EntryRef::Occupied(e) => assert_eq!(key, e.key()), + } + assert_eq!(a.len(), 1); + assert_eq!(a[key], value); + } + + #[test] + fn test_vacant_entry_key() { + let mut a = HashMap::new(); + let key = "hello there"; + let value = "value goes here"; + + assert!(a.is_empty()); + match a.entry(key) { + Occupied(_) => panic!(), + Vacant(e) => { + assert_eq!(key, *e.key()); + e.insert(value); + } + } + assert_eq!(a.len(), 1); + assert_eq!(a[key], value); + } + + #[test] + fn test_vacant_entry_ref_key() { + let mut a: HashMap<std::string::String, &str> = HashMap::new(); + let key = "hello there"; + let value = "value goes here"; + + assert!(a.is_empty()); + match a.entry_ref(key) { + EntryRef::Occupied(_) => panic!(), + EntryRef::Vacant(e) => { + assert_eq!(key, e.key()); + e.insert(value); + } + } + assert_eq!(a.len(), 1); + assert_eq!(a[key], value); + } + + #[test] + fn test_occupied_entry_replace_entry_with() { + let mut a = HashMap::new(); + + let key = "a key"; + let value = "an initial value"; + let new_value = "a new value"; + + let entry = a.entry(key).insert(value).replace_entry_with(|k, v| { + assert_eq!(k, &key); + assert_eq!(v, value); + Some(new_value) + }); + + match entry { + Occupied(e) => { + assert_eq!(e.key(), &key); + assert_eq!(e.get(), &new_value); + } + Vacant(_) => panic!(), + } + + assert_eq!(a[key], new_value); + assert_eq!(a.len(), 1); + + let entry = match a.entry(key) { + Occupied(e) => e.replace_entry_with(|k, v| { + assert_eq!(k, &key); + assert_eq!(v, new_value); + None + }), + Vacant(_) => panic!(), + }; + + match entry { + Vacant(e) => assert_eq!(e.key(), &key), + Occupied(_) => panic!(), + } + + assert!(!a.contains_key(key)); + assert_eq!(a.len(), 0); + } + + #[test] + fn test_occupied_entry_ref_replace_entry_with() { + let mut a: HashMap<std::string::String, &str> = HashMap::new(); + + let key = "a key"; + let value = "an initial value"; + let new_value = "a new value"; + + let entry = a.entry_ref(key).insert(value).replace_entry_with(|k, v| { + assert_eq!(k, key); + assert_eq!(v, value); + Some(new_value) + }); + + match entry { + EntryRef::Occupied(e) => { + assert_eq!(e.key(), key); + assert_eq!(e.get(), &new_value); + } + EntryRef::Vacant(_) => panic!(), + } + + assert_eq!(a[key], new_value); + assert_eq!(a.len(), 1); + + let entry = match a.entry_ref(key) { + EntryRef::Occupied(e) => e.replace_entry_with(|k, v| { + assert_eq!(k, key); + assert_eq!(v, new_value); + None + }), + EntryRef::Vacant(_) => panic!(), + }; + + match entry { + EntryRef::Vacant(e) => assert_eq!(e.key(), key), + EntryRef::Occupied(_) => panic!(), + } + + assert!(!a.contains_key(key)); + assert_eq!(a.len(), 0); + } + + #[test] + fn test_entry_and_replace_entry_with() { + let mut a = HashMap::new(); + + let key = "a key"; + let value = "an initial value"; + let new_value = "a new value"; + + let entry = a.entry(key).and_replace_entry_with(|_, _| panic!()); + + match entry { + Vacant(e) => assert_eq!(e.key(), &key), + Occupied(_) => panic!(), + } + + a.insert(key, value); + + let entry = a.entry(key).and_replace_entry_with(|k, v| { + assert_eq!(k, &key); + assert_eq!(v, value); + Some(new_value) + }); + + match entry { + Occupied(e) => { + assert_eq!(e.key(), &key); + assert_eq!(e.get(), &new_value); + } + Vacant(_) => panic!(), + } + + assert_eq!(a[key], new_value); + assert_eq!(a.len(), 1); + + let entry = a.entry(key).and_replace_entry_with(|k, v| { + assert_eq!(k, &key); + assert_eq!(v, new_value); + None + }); + + match entry { + Vacant(e) => assert_eq!(e.key(), &key), + Occupied(_) => panic!(), + } + + assert!(!a.contains_key(key)); + assert_eq!(a.len(), 0); + } + + #[test] + fn test_entry_ref_and_replace_entry_with() { + let mut a = HashMap::new(); + + let key = "a key"; + let value = "an initial value"; + let new_value = "a new value"; + + let entry = a.entry_ref(key).and_replace_entry_with(|_, _| panic!()); + + match entry { + EntryRef::Vacant(e) => assert_eq!(e.key(), key), + EntryRef::Occupied(_) => panic!(), + } + + a.insert(key.to_owned(), value); + + let entry = a.entry_ref(key).and_replace_entry_with(|k, v| { + assert_eq!(k, key); + assert_eq!(v, value); + Some(new_value) + }); + + match entry { + EntryRef::Occupied(e) => { + assert_eq!(e.key(), key); + assert_eq!(e.get(), &new_value); + } + EntryRef::Vacant(_) => panic!(), + } + + assert_eq!(a[key], new_value); + assert_eq!(a.len(), 1); + + let entry = a.entry_ref(key).and_replace_entry_with(|k, v| { + assert_eq!(k, key); + assert_eq!(v, new_value); + None + }); + + match entry { + EntryRef::Vacant(e) => assert_eq!(e.key(), key), + EntryRef::Occupied(_) => panic!(), + } + + assert!(!a.contains_key(key)); + assert_eq!(a.len(), 0); + } + + #[test] + fn test_raw_occupied_entry_replace_entry_with() { + let mut a = HashMap::new(); + + let key = "a key"; + let value = "an initial value"; + let new_value = "a new value"; + + let entry = a + .raw_entry_mut() + .from_key(&key) + .insert(key, value) + .replace_entry_with(|k, v| { + assert_eq!(k, &key); + assert_eq!(v, value); + Some(new_value) + }); + + match entry { + RawEntryMut::Occupied(e) => { + assert_eq!(e.key(), &key); + assert_eq!(e.get(), &new_value); + } + RawEntryMut::Vacant(_) => panic!(), + } + + assert_eq!(a[key], new_value); + assert_eq!(a.len(), 1); + + let entry = match a.raw_entry_mut().from_key(&key) { + RawEntryMut::Occupied(e) => e.replace_entry_with(|k, v| { + assert_eq!(k, &key); + assert_eq!(v, new_value); + None + }), + RawEntryMut::Vacant(_) => panic!(), + }; + + match entry { + RawEntryMut::Vacant(_) => {} + RawEntryMut::Occupied(_) => panic!(), + } + + assert!(!a.contains_key(key)); + assert_eq!(a.len(), 0); + } + + #[test] + fn test_raw_entry_and_replace_entry_with() { + let mut a = HashMap::new(); + + let key = "a key"; + let value = "an initial value"; + let new_value = "a new value"; + + let entry = a + .raw_entry_mut() + .from_key(&key) + .and_replace_entry_with(|_, _| panic!()); + + match entry { + RawEntryMut::Vacant(_) => {} + RawEntryMut::Occupied(_) => panic!(), + } + + a.insert(key, value); + + let entry = a + .raw_entry_mut() + .from_key(&key) + .and_replace_entry_with(|k, v| { + assert_eq!(k, &key); + assert_eq!(v, value); + Some(new_value) + }); + + match entry { + RawEntryMut::Occupied(e) => { + assert_eq!(e.key(), &key); + assert_eq!(e.get(), &new_value); + } + RawEntryMut::Vacant(_) => panic!(), + } + + assert_eq!(a[key], new_value); + assert_eq!(a.len(), 1); + + let entry = a + .raw_entry_mut() + .from_key(&key) + .and_replace_entry_with(|k, v| { + assert_eq!(k, &key); + assert_eq!(v, new_value); + None + }); + + match entry { + RawEntryMut::Vacant(_) => {} + RawEntryMut::Occupied(_) => panic!(), + } + + assert!(!a.contains_key(key)); + assert_eq!(a.len(), 0); + } + + #[test] + fn test_replace_entry_with_doesnt_corrupt() { + #![allow(deprecated)] //rand + // Test for #19292 + fn check(m: &HashMap<i32, ()>) { + for k in m.keys() { + assert!(m.contains_key(k), "{} is in keys() but not in the map?", k); + } + } + + let mut m = HashMap::new(); + + let mut rng = { + let seed = u64::from_le_bytes(*b"testseed"); + SmallRng::seed_from_u64(seed) + }; + + // Populate the map with some items. + for _ in 0..50 { + let x = rng.gen_range(-10..10); + m.insert(x, ()); + } + + for _ in 0..1000 { + let x = rng.gen_range(-10..10); + m.entry(x).and_replace_entry_with(|_, _| None); + check(&m); + } + } + + #[test] + fn test_replace_entry_ref_with_doesnt_corrupt() { + #![allow(deprecated)] //rand + // Test for #19292 + fn check(m: &HashMap<std::string::String, ()>) { + for k in m.keys() { + assert!(m.contains_key(k), "{} is in keys() but not in the map?", k); + } + } + + let mut m = HashMap::new(); + + let mut rng = { + let seed = u64::from_le_bytes(*b"testseed"); + SmallRng::seed_from_u64(seed) + }; + + // Populate the map with some items. + for _ in 0..50 { + let mut x = std::string::String::with_capacity(1); + x.push(rng.gen_range('a'..='z')); + m.insert(x, ()); + } + + for _ in 0..1000 { + let mut x = std::string::String::with_capacity(1); + x.push(rng.gen_range('a'..='z')); + m.entry_ref(x.as_str()).and_replace_entry_with(|_, _| None); + check(&m); + } + } + + #[test] + fn test_retain() { + let mut map: HashMap<i32, i32> = (0..100).map(|x| (x, x * 10)).collect(); + + map.retain(|&k, _| k % 2 == 0); + assert_eq!(map.len(), 50); + assert_eq!(map[&2], 20); + assert_eq!(map[&4], 40); + assert_eq!(map[&6], 60); + } + + #[test] + fn test_drain_filter() { + { + let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x * 10)).collect(); + let drained = map.drain_filter(|&k, _| k % 2 == 0); + let mut out = drained.collect::<Vec<_>>(); + out.sort_unstable(); + assert_eq!(vec![(0, 0), (2, 20), (4, 40), (6, 60)], out); + assert_eq!(map.len(), 4); + } + { + let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x * 10)).collect(); + drop(map.drain_filter(|&k, _| k % 2 == 0)); + assert_eq!(map.len(), 4); + } + } + + #[test] + #[cfg_attr(miri, ignore)] // FIXME: no OOM signalling (https://github.com/rust-lang/miri/issues/613) + fn test_try_reserve() { + use crate::TryReserveError::{AllocError, CapacityOverflow}; + + const MAX_USIZE: usize = usize::MAX; + + let mut empty_bytes: HashMap<u8, u8> = HashMap::new(); + + if let Err(CapacityOverflow) = empty_bytes.try_reserve(MAX_USIZE) { + } else { + panic!("usize::MAX should trigger an overflow!"); + } + + if let Err(AllocError { .. }) = empty_bytes.try_reserve(MAX_USIZE / 16) { + } else { + // This may succeed if there is enough free memory. Attempt to + // allocate a few more hashmaps to ensure the allocation will fail. + let mut empty_bytes2: HashMap<u8, u8> = HashMap::new(); + let _ = empty_bytes2.try_reserve(MAX_USIZE / 16); + let mut empty_bytes3: HashMap<u8, u8> = HashMap::new(); + let _ = empty_bytes3.try_reserve(MAX_USIZE / 16); + let mut empty_bytes4: HashMap<u8, u8> = HashMap::new(); + if let Err(AllocError { .. }) = empty_bytes4.try_reserve(MAX_USIZE / 16) { + } else { + panic!("usize::MAX / 8 should trigger an OOM!"); + } + } + } + + #[test] + fn test_raw_entry() { + use super::RawEntryMut::{Occupied, Vacant}; + + let xs = [(1_i32, 10_i32), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)]; + + let mut map: HashMap<_, _> = xs.iter().copied().collect(); + + let compute_hash = |map: &HashMap<i32, i32>, k: i32| -> u64 { + super::make_insert_hash::<i32, _>(map.hasher(), &k) + }; + + // Existing key (insert) + match map.raw_entry_mut().from_key(&1) { + Vacant(_) => unreachable!(), + Occupied(mut view) => { + assert_eq!(view.get(), &10); + assert_eq!(view.insert(100), 10); + } + } + let hash1 = compute_hash(&map, 1); + assert_eq!(map.raw_entry().from_key(&1).unwrap(), (&1, &100)); + assert_eq!( + map.raw_entry().from_hash(hash1, |k| *k == 1).unwrap(), + (&1, &100) + ); + assert_eq!( + map.raw_entry().from_key_hashed_nocheck(hash1, &1).unwrap(), + (&1, &100) + ); + assert_eq!(map.len(), 6); + + // Existing key (update) + match map.raw_entry_mut().from_key(&2) { + Vacant(_) => unreachable!(), + Occupied(mut view) => { + let v = view.get_mut(); + let new_v = (*v) * 10; + *v = new_v; + } + } + let hash2 = compute_hash(&map, 2); + assert_eq!(map.raw_entry().from_key(&2).unwrap(), (&2, &200)); + assert_eq!( + map.raw_entry().from_hash(hash2, |k| *k == 2).unwrap(), + (&2, &200) + ); + assert_eq!( + map.raw_entry().from_key_hashed_nocheck(hash2, &2).unwrap(), + (&2, &200) + ); + assert_eq!(map.len(), 6); + + // Existing key (take) + let hash3 = compute_hash(&map, 3); + match map.raw_entry_mut().from_key_hashed_nocheck(hash3, &3) { + Vacant(_) => unreachable!(), + Occupied(view) => { + assert_eq!(view.remove_entry(), (3, 30)); + } + } + assert_eq!(map.raw_entry().from_key(&3), None); + assert_eq!(map.raw_entry().from_hash(hash3, |k| *k == 3), None); + assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash3, &3), None); + assert_eq!(map.len(), 5); + + // Nonexistent key (insert) + match map.raw_entry_mut().from_key(&10) { + Occupied(_) => unreachable!(), + Vacant(view) => { + assert_eq!(view.insert(10, 1000), (&mut 10, &mut 1000)); + } + } + assert_eq!(map.raw_entry().from_key(&10).unwrap(), (&10, &1000)); + assert_eq!(map.len(), 6); + + // Ensure all lookup methods produce equivalent results. + for k in 0..12 { + let hash = compute_hash(&map, k); + let v = map.get(&k).copied(); + let kv = v.as_ref().map(|v| (&k, v)); + + assert_eq!(map.raw_entry().from_key(&k), kv); + assert_eq!(map.raw_entry().from_hash(hash, |q| *q == k), kv); + assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv); + + match map.raw_entry_mut().from_key(&k) { + Occupied(o) => assert_eq!(Some(o.get_key_value()), kv), + Vacant(_) => assert_eq!(v, None), + } + match map.raw_entry_mut().from_key_hashed_nocheck(hash, &k) { + Occupied(o) => assert_eq!(Some(o.get_key_value()), kv), + Vacant(_) => assert_eq!(v, None), + } + match map.raw_entry_mut().from_hash(hash, |q| *q == k) { + Occupied(o) => assert_eq!(Some(o.get_key_value()), kv), + Vacant(_) => assert_eq!(v, None), + } + } + } + + #[test] + fn test_key_without_hash_impl() { + #[derive(Debug)] + struct IntWrapper(u64); + + let mut m: HashMap<IntWrapper, (), ()> = HashMap::default(); + { + assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_none()); + } + { + let vacant_entry = match m.raw_entry_mut().from_hash(0, |k| k.0 == 0) { + RawEntryMut::Occupied(..) => panic!("Found entry for key 0"), + RawEntryMut::Vacant(e) => e, + }; + vacant_entry.insert_with_hasher(0, IntWrapper(0), (), |k| k.0); + } + { + assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_some()); + assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_none()); + assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none()); + } + { + let vacant_entry = match m.raw_entry_mut().from_hash(1, |k| k.0 == 1) { + RawEntryMut::Occupied(..) => panic!("Found entry for key 1"), + RawEntryMut::Vacant(e) => e, + }; + vacant_entry.insert_with_hasher(1, IntWrapper(1), (), |k| k.0); + } + { + assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_some()); + assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_some()); + assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none()); + } + { + let occupied_entry = match m.raw_entry_mut().from_hash(0, |k| k.0 == 0) { + RawEntryMut::Occupied(e) => e, + RawEntryMut::Vacant(..) => panic!("Couldn't find entry for key 0"), + }; + occupied_entry.remove(); + } + assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_none()); + assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_some()); + assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none()); + } + + #[test] + #[cfg(feature = "raw")] + fn test_into_iter_refresh() { + #[cfg(miri)] + const N: usize = 32; + #[cfg(not(miri))] + const N: usize = 128; + + let mut rng = rand::thread_rng(); + for n in 0..N { + let mut map = HashMap::new(); + for i in 0..n { + assert!(map.insert(i, 2 * i).is_none()); + } + let hash_builder = map.hasher().clone(); + + let mut it = unsafe { map.table.iter() }; + assert_eq!(it.len(), n); + + let mut i = 0; + let mut left = n; + let mut removed = Vec::new(); + loop { + // occasionally remove some elements + if i < n && rng.gen_bool(0.1) { + let hash_value = super::make_insert_hash(&hash_builder, &i); + + unsafe { + let e = map.table.find(hash_value, |q| q.0.eq(&i)); + if let Some(e) = e { + it.reflect_remove(&e); + let t = map.table.remove(e); + removed.push(t); + left -= 1; + } else { + assert!(removed.contains(&(i, 2 * i)), "{} not in {:?}", i, removed); + let e = map.table.insert( + hash_value, + (i, 2 * i), + super::make_hasher::<usize, _, usize, _>(&hash_builder), + ); + it.reflect_insert(&e); + if let Some(p) = removed.iter().position(|e| e == &(i, 2 * i)) { + removed.swap_remove(p); + } + left += 1; + } + } + } + + let e = it.next(); + if e.is_none() { + break; + } + assert!(i < n); + let t = unsafe { e.unwrap().as_ref() }; + assert!(!removed.contains(t)); + let (key, value) = t; + assert_eq!(*value, 2 * key); + i += 1; + } + assert!(i <= n); + + // just for safety: + assert_eq!(map.table.len(), left); + } + } + + #[test] + fn test_const_with_hasher() { + use core::hash::BuildHasher; + use std::collections::hash_map::DefaultHasher; + + #[derive(Clone)] + struct MyHasher; + impl BuildHasher for MyHasher { + type Hasher = DefaultHasher; + + fn build_hasher(&self) -> DefaultHasher { + DefaultHasher::new() + } + } + + const EMPTY_MAP: HashMap<u32, std::string::String, MyHasher> = + HashMap::with_hasher(MyHasher); + + let mut map = EMPTY_MAP; + map.insert(17, "seventeen".to_owned()); + assert_eq!("seventeen", map[&17]); + } + + #[test] + fn test_get_each_mut() { + let mut map = HashMap::new(); + map.insert("foo".to_owned(), 0); + map.insert("bar".to_owned(), 10); + map.insert("baz".to_owned(), 20); + map.insert("qux".to_owned(), 30); + + let xs = map.get_many_mut(["foo", "qux"]); + assert_eq!(xs, Some([&mut 0, &mut 30])); + + let xs = map.get_many_mut(["foo", "dud"]); + assert_eq!(xs, None); + + let xs = map.get_many_mut(["foo", "foo"]); + assert_eq!(xs, None); + + let ys = map.get_many_key_value_mut(["bar", "baz"]); + assert_eq!( + ys, + Some([(&"bar".to_owned(), &mut 10), (&"baz".to_owned(), &mut 20),]), + ); + + let ys = map.get_many_key_value_mut(["bar", "dip"]); + assert_eq!(ys, None); + + let ys = map.get_many_key_value_mut(["baz", "baz"]); + assert_eq!(ys, None); + } + + #[test] + #[should_panic = "panic in drop"] + fn test_clone_from_double_drop() { + #[derive(Clone)] + struct CheckedDrop { + panic_in_drop: bool, + dropped: bool, + } + impl Drop for CheckedDrop { + fn drop(&mut self) { + if self.panic_in_drop { + self.dropped = true; + panic!("panic in drop"); + } + if self.dropped { + panic!("double drop"); + } + self.dropped = true; + } + } + const DISARMED: CheckedDrop = CheckedDrop { + panic_in_drop: false, + dropped: false, + }; + const ARMED: CheckedDrop = CheckedDrop { + panic_in_drop: true, + dropped: false, + }; + + let mut map1 = HashMap::new(); + map1.insert(1, DISARMED); + map1.insert(2, DISARMED); + map1.insert(3, DISARMED); + map1.insert(4, DISARMED); + + let mut map2 = HashMap::new(); + map2.insert(1, DISARMED); + map2.insert(2, ARMED); + map2.insert(3, DISARMED); + map2.insert(4, DISARMED); + + map2.clone_from(&map1); + } +} diff --git a/vendor/hashbrown/src/raw/alloc.rs b/vendor/hashbrown/src/raw/alloc.rs new file mode 100644 index 000000000..ba09ea9de --- /dev/null +++ b/vendor/hashbrown/src/raw/alloc.rs @@ -0,0 +1,73 @@ +pub(crate) use self::inner::{do_alloc, Allocator, Global}; + +#[cfg(feature = "nightly")] +mod inner { + use crate::alloc::alloc::Layout; + pub use crate::alloc::alloc::{Allocator, Global}; + use core::ptr::NonNull; + + #[allow(clippy::map_err_ignore)] + pub fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { + match alloc.allocate(layout) { + Ok(ptr) => Ok(ptr.as_non_null_ptr()), + Err(_) => Err(()), + } + } + + #[cfg(feature = "bumpalo")] + unsafe impl Allocator for crate::BumpWrapper<'_> { + #[inline] + fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, core::alloc::AllocError> { + match self.0.try_alloc_layout(layout) { + Ok(ptr) => Ok(NonNull::slice_from_raw_parts(ptr, layout.size())), + Err(_) => Err(core::alloc::AllocError), + } + } + #[inline] + unsafe fn deallocate(&self, _ptr: NonNull<u8>, _layout: Layout) {} + } +} + +#[cfg(not(feature = "nightly"))] +mod inner { + use crate::alloc::alloc::{alloc, dealloc, Layout}; + use core::ptr::NonNull; + + #[allow(clippy::missing_safety_doc)] // not exposed outside of this crate + pub unsafe trait Allocator { + fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()>; + unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout); + } + + #[derive(Copy, Clone)] + pub struct Global; + unsafe impl Allocator for Global { + #[inline] + fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()> { + unsafe { NonNull::new(alloc(layout)).ok_or(()) } + } + #[inline] + unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) { + dealloc(ptr.as_ptr(), layout); + } + } + impl Default for Global { + #[inline] + fn default() -> Self { + Global + } + } + + pub fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { + alloc.allocate(layout) + } + + #[cfg(feature = "bumpalo")] + unsafe impl Allocator for crate::BumpWrapper<'_> { + #[allow(clippy::map_err_ignore)] + fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()> { + self.0.try_alloc_layout(layout).map_err(|_| ()) + } + unsafe fn deallocate(&self, _ptr: NonNull<u8>, _layout: Layout) {} + } +} diff --git a/vendor/hashbrown/src/raw/bitmask.rs b/vendor/hashbrown/src/raw/bitmask.rs new file mode 100644 index 000000000..7d4f9fc38 --- /dev/null +++ b/vendor/hashbrown/src/raw/bitmask.rs @@ -0,0 +1,122 @@ +use super::imp::{BitMaskWord, BITMASK_MASK, BITMASK_STRIDE}; +#[cfg(feature = "nightly")] +use core::intrinsics; + +/// A bit mask which contains the result of a `Match` operation on a `Group` and +/// allows iterating through them. +/// +/// The bit mask is arranged so that low-order bits represent lower memory +/// addresses for group match results. +/// +/// For implementation reasons, the bits in the set may be sparsely packed, so +/// that there is only one bit-per-byte used (the high bit, 7). If this is the +/// case, `BITMASK_STRIDE` will be 8 to indicate a divide-by-8 should be +/// performed on counts/indices to normalize this difference. `BITMASK_MASK` is +/// similarly a mask of all the actually-used bits. +#[derive(Copy, Clone)] +pub struct BitMask(pub BitMaskWord); + +#[allow(clippy::use_self)] +impl BitMask { + /// Returns a new `BitMask` with all bits inverted. + #[inline] + #[must_use] + pub fn invert(self) -> Self { + BitMask(self.0 ^ BITMASK_MASK) + } + + /// Flip the bit in the mask for the entry at the given index. + /// + /// Returns the bit's previous state. + #[inline] + #[allow(clippy::cast_ptr_alignment)] + #[cfg(feature = "raw")] + pub unsafe fn flip(&mut self, index: usize) -> bool { + // NOTE: The + BITMASK_STRIDE - 1 is to set the high bit. + let mask = 1 << (index * BITMASK_STRIDE + BITMASK_STRIDE - 1); + self.0 ^= mask; + // The bit was set if the bit is now 0. + self.0 & mask == 0 + } + + /// Returns a new `BitMask` with the lowest bit removed. + #[inline] + #[must_use] + pub fn remove_lowest_bit(self) -> Self { + BitMask(self.0 & (self.0 - 1)) + } + /// Returns whether the `BitMask` has at least one set bit. + #[inline] + pub fn any_bit_set(self) -> bool { + self.0 != 0 + } + + /// Returns the first set bit in the `BitMask`, if there is one. + #[inline] + pub fn lowest_set_bit(self) -> Option<usize> { + if self.0 == 0 { + None + } else { + Some(unsafe { self.lowest_set_bit_nonzero() }) + } + } + + /// Returns the first set bit in the `BitMask`, if there is one. The + /// bitmask must not be empty. + #[inline] + #[cfg(feature = "nightly")] + pub unsafe fn lowest_set_bit_nonzero(self) -> usize { + intrinsics::cttz_nonzero(self.0) as usize / BITMASK_STRIDE + } + #[inline] + #[cfg(not(feature = "nightly"))] + pub unsafe fn lowest_set_bit_nonzero(self) -> usize { + self.trailing_zeros() + } + + /// Returns the number of trailing zeroes in the `BitMask`. + #[inline] + pub fn trailing_zeros(self) -> usize { + // ARM doesn't have a trailing_zeroes instruction, and instead uses + // reverse_bits (RBIT) + leading_zeroes (CLZ). However older ARM + // versions (pre-ARMv7) don't have RBIT and need to emulate it + // instead. Since we only have 1 bit set in each byte on ARM, we can + // use swap_bytes (REV) + leading_zeroes instead. + if cfg!(target_arch = "arm") && BITMASK_STRIDE % 8 == 0 { + self.0.swap_bytes().leading_zeros() as usize / BITMASK_STRIDE + } else { + self.0.trailing_zeros() as usize / BITMASK_STRIDE + } + } + + /// Returns the number of leading zeroes in the `BitMask`. + #[inline] + pub fn leading_zeros(self) -> usize { + self.0.leading_zeros() as usize / BITMASK_STRIDE + } +} + +impl IntoIterator for BitMask { + type Item = usize; + type IntoIter = BitMaskIter; + + #[inline] + fn into_iter(self) -> BitMaskIter { + BitMaskIter(self) + } +} + +/// Iterator over the contents of a `BitMask`, returning the indices of set +/// bits. +pub struct BitMaskIter(BitMask); + +impl Iterator for BitMaskIter { + type Item = usize; + + #[inline] + fn next(&mut self) -> Option<usize> { + let bit = self.0.lowest_set_bit()?; + self.0 = self.0.remove_lowest_bit(); + Some(bit) + } +} diff --git a/vendor/hashbrown/src/raw/generic.rs b/vendor/hashbrown/src/raw/generic.rs new file mode 100644 index 000000000..b4d31e62c --- /dev/null +++ b/vendor/hashbrown/src/raw/generic.rs @@ -0,0 +1,154 @@ +use super::bitmask::BitMask; +use super::EMPTY; +use core::{mem, ptr}; + +// Use the native word size as the group size. Using a 64-bit group size on +// a 32-bit architecture will just end up being more expensive because +// shifts and multiplies will need to be emulated. +#[cfg(any( + target_pointer_width = "64", + target_arch = "aarch64", + target_arch = "x86_64", + target_arch = "wasm32", +))] +type GroupWord = u64; +#[cfg(all( + target_pointer_width = "32", + not(target_arch = "aarch64"), + not(target_arch = "x86_64"), + not(target_arch = "wasm32"), +))] +type GroupWord = u32; + +pub type BitMaskWord = GroupWord; +pub const BITMASK_STRIDE: usize = 8; +// We only care about the highest bit of each byte for the mask. +#[allow(clippy::cast_possible_truncation, clippy::unnecessary_cast)] +pub const BITMASK_MASK: BitMaskWord = 0x8080_8080_8080_8080_u64 as GroupWord; + +/// Helper function to replicate a byte across a `GroupWord`. +#[inline] +fn repeat(byte: u8) -> GroupWord { + GroupWord::from_ne_bytes([byte; Group::WIDTH]) +} + +/// Abstraction over a group of control bytes which can be scanned in +/// parallel. +/// +/// This implementation uses a word-sized integer. +#[derive(Copy, Clone)] +pub struct Group(GroupWord); + +// We perform all operations in the native endianness, and convert to +// little-endian just before creating a BitMask. The can potentially +// enable the compiler to eliminate unnecessary byte swaps if we are +// only checking whether a BitMask is empty. +#[allow(clippy::use_self)] +impl Group { + /// Number of bytes in the group. + pub const WIDTH: usize = mem::size_of::<Self>(); + + /// Returns a full group of empty bytes, suitable for use as the initial + /// value for an empty hash table. + /// + /// This is guaranteed to be aligned to the group size. + #[inline] + pub const fn static_empty() -> &'static [u8; Group::WIDTH] { + #[repr(C)] + struct AlignedBytes { + _align: [Group; 0], + bytes: [u8; Group::WIDTH], + } + const ALIGNED_BYTES: AlignedBytes = AlignedBytes { + _align: [], + bytes: [EMPTY; Group::WIDTH], + }; + &ALIGNED_BYTES.bytes + } + + /// Loads a group of bytes starting at the given address. + #[inline] + #[allow(clippy::cast_ptr_alignment)] // unaligned load + pub unsafe fn load(ptr: *const u8) -> Self { + Group(ptr::read_unaligned(ptr.cast())) + } + + /// Loads a group of bytes starting at the given address, which must be + /// aligned to `mem::align_of::<Group>()`. + #[inline] + #[allow(clippy::cast_ptr_alignment)] + pub unsafe fn load_aligned(ptr: *const u8) -> Self { + // FIXME: use align_offset once it stabilizes + debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); + Group(ptr::read(ptr.cast())) + } + + /// Stores the group of bytes to the given address, which must be + /// aligned to `mem::align_of::<Group>()`. + #[inline] + #[allow(clippy::cast_ptr_alignment)] + pub unsafe fn store_aligned(self, ptr: *mut u8) { + // FIXME: use align_offset once it stabilizes + debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); + ptr::write(ptr.cast(), self.0); + } + + /// Returns a `BitMask` indicating all bytes in the group which *may* + /// have the given value. + /// + /// This function may return a false positive in certain cases where + /// the byte in the group differs from the searched value only in its + /// lowest bit. This is fine because: + /// - This never happens for `EMPTY` and `DELETED`, only full entries. + /// - The check for key equality will catch these. + /// - This only happens if there is at least 1 true match. + /// - The chance of this happening is very low (< 1% chance per byte). + #[inline] + pub fn match_byte(self, byte: u8) -> BitMask { + // This algorithm is derived from + // https://graphics.stanford.edu/~seander/bithacks.html##ValueInWord + let cmp = self.0 ^ repeat(byte); + BitMask((cmp.wrapping_sub(repeat(0x01)) & !cmp & repeat(0x80)).to_le()) + } + + /// Returns a `BitMask` indicating all bytes in the group which are + /// `EMPTY`. + #[inline] + pub fn match_empty(self) -> BitMask { + // If the high bit is set, then the byte must be either: + // 1111_1111 (EMPTY) or 1000_0000 (DELETED). + // So we can just check if the top two bits are 1 by ANDing them. + BitMask((self.0 & (self.0 << 1) & repeat(0x80)).to_le()) + } + + /// Returns a `BitMask` indicating all bytes in the group which are + /// `EMPTY` or `DELETED`. + #[inline] + pub fn match_empty_or_deleted(self) -> BitMask { + // A byte is EMPTY or DELETED iff the high bit is set + BitMask((self.0 & repeat(0x80)).to_le()) + } + + /// Returns a `BitMask` indicating all bytes in the group which are full. + #[inline] + pub fn match_full(self) -> BitMask { + self.match_empty_or_deleted().invert() + } + + /// Performs the following transformation on all bytes in the group: + /// - `EMPTY => EMPTY` + /// - `DELETED => EMPTY` + /// - `FULL => DELETED` + #[inline] + pub fn convert_special_to_empty_and_full_to_deleted(self) -> Self { + // Map high_bit = 1 (EMPTY or DELETED) to 1111_1111 + // and high_bit = 0 (FULL) to 1000_0000 + // + // Here's this logic expanded to concrete values: + // let full = 1000_0000 (true) or 0000_0000 (false) + // !1000_0000 + 1 = 0111_1111 + 1 = 1000_0000 (no carry) + // !0000_0000 + 0 = 1111_1111 + 0 = 1111_1111 (no carry) + let full = !self.0 & repeat(0x80); + Group(!full + (full >> 7)) + } +} diff --git a/vendor/hashbrown/src/raw/mod.rs b/vendor/hashbrown/src/raw/mod.rs new file mode 100644 index 000000000..211b818a5 --- /dev/null +++ b/vendor/hashbrown/src/raw/mod.rs @@ -0,0 +1,2460 @@ +use crate::alloc::alloc::{handle_alloc_error, Layout}; +use crate::scopeguard::{guard, ScopeGuard}; +use crate::TryReserveError; +use core::iter::FusedIterator; +use core::marker::PhantomData; +use core::mem; +use core::mem::ManuallyDrop; +use core::mem::MaybeUninit; +use core::ptr::NonNull; +use core::{hint, ptr}; + +cfg_if! { + // Use the SSE2 implementation if possible: it allows us to scan 16 buckets + // at once instead of 8. We don't bother with AVX since it would require + // runtime dispatch and wouldn't gain us much anyways: the probability of + // finding a match drops off drastically after the first few buckets. + // + // I attempted an implementation on ARM using NEON instructions, but it + // turns out that most NEON instructions have multi-cycle latency, which in + // the end outweighs any gains over the generic implementation. + if #[cfg(all( + target_feature = "sse2", + any(target_arch = "x86", target_arch = "x86_64"), + not(miri) + ))] { + mod sse2; + use sse2 as imp; + } else { + #[path = "generic.rs"] + mod generic; + use generic as imp; + } +} + +mod alloc; +pub(crate) use self::alloc::{do_alloc, Allocator, Global}; + +mod bitmask; + +use self::bitmask::{BitMask, BitMaskIter}; +use self::imp::Group; + +// Branch prediction hint. This is currently only available on nightly but it +// consistently improves performance by 10-15%. +#[cfg(feature = "nightly")] +use core::intrinsics::{likely, unlikely}; + +// On stable we can use #[cold] to get a equivalent effect: this attributes +// suggests that the function is unlikely to be called +#[cfg(not(feature = "nightly"))] +#[inline] +#[cold] +fn cold() {} + +#[cfg(not(feature = "nightly"))] +#[inline] +fn likely(b: bool) -> bool { + if !b { + cold(); + } + b +} +#[cfg(not(feature = "nightly"))] +#[inline] +fn unlikely(b: bool) -> bool { + if b { + cold(); + } + b +} + +#[inline] +unsafe fn offset_from<T>(to: *const T, from: *const T) -> usize { + to.offset_from(from) as usize +} + +/// Whether memory allocation errors should return an error or abort. +#[derive(Copy, Clone)] +enum Fallibility { + Fallible, + Infallible, +} + +impl Fallibility { + /// Error to return on capacity overflow. + #[cfg_attr(feature = "inline-more", inline)] + fn capacity_overflow(self) -> TryReserveError { + match self { + Fallibility::Fallible => TryReserveError::CapacityOverflow, + Fallibility::Infallible => panic!("Hash table capacity overflow"), + } + } + + /// Error to return on allocation error. + #[cfg_attr(feature = "inline-more", inline)] + fn alloc_err(self, layout: Layout) -> TryReserveError { + match self { + Fallibility::Fallible => TryReserveError::AllocError { layout }, + Fallibility::Infallible => handle_alloc_error(layout), + } + } +} + +/// Control byte value for an empty bucket. +const EMPTY: u8 = 0b1111_1111; + +/// Control byte value for a deleted bucket. +const DELETED: u8 = 0b1000_0000; + +/// Checks whether a control byte represents a full bucket (top bit is clear). +#[inline] +fn is_full(ctrl: u8) -> bool { + ctrl & 0x80 == 0 +} + +/// Checks whether a control byte represents a special value (top bit is set). +#[inline] +fn is_special(ctrl: u8) -> bool { + ctrl & 0x80 != 0 +} + +/// Checks whether a special control value is EMPTY (just check 1 bit). +#[inline] +fn special_is_empty(ctrl: u8) -> bool { + debug_assert!(is_special(ctrl)); + ctrl & 0x01 != 0 +} + +/// Primary hash function, used to select the initial bucket to probe from. +#[inline] +#[allow(clippy::cast_possible_truncation)] +fn h1(hash: u64) -> usize { + // On 32-bit platforms we simply ignore the higher hash bits. + hash as usize +} + +/// Secondary hash function, saved in the low 7 bits of the control byte. +#[inline] +#[allow(clippy::cast_possible_truncation)] +fn h2(hash: u64) -> u8 { + // Grab the top 7 bits of the hash. While the hash is normally a full 64-bit + // value, some hash functions (such as FxHash) produce a usize result + // instead, which means that the top 32 bits are 0 on 32-bit platforms. + let hash_len = usize::min(mem::size_of::<usize>(), mem::size_of::<u64>()); + let top7 = hash >> (hash_len * 8 - 7); + (top7 & 0x7f) as u8 // truncation +} + +/// Probe sequence based on triangular numbers, which is guaranteed (since our +/// table size is a power of two) to visit every group of elements exactly once. +/// +/// A triangular probe has us jump by 1 more group every time. So first we +/// jump by 1 group (meaning we just continue our linear scan), then 2 groups +/// (skipping over 1 group), then 3 groups (skipping over 2 groups), and so on. +/// +/// Proof that the probe will visit every group in the table: +/// <https://fgiesen.wordpress.com/2015/02/22/triangular-numbers-mod-2n/> +struct ProbeSeq { + pos: usize, + stride: usize, +} + +impl ProbeSeq { + #[inline] + fn move_next(&mut self, bucket_mask: usize) { + // We should have found an empty bucket by now and ended the probe. + debug_assert!( + self.stride <= bucket_mask, + "Went past end of probe sequence" + ); + + self.stride += Group::WIDTH; + self.pos += self.stride; + self.pos &= bucket_mask; + } +} + +/// Returns the number of buckets needed to hold the given number of items, +/// taking the maximum load factor into account. +/// +/// Returns `None` if an overflow occurs. +// Workaround for emscripten bug emscripten-core/emscripten-fastcomp#258 +#[cfg_attr(target_os = "emscripten", inline(never))] +#[cfg_attr(not(target_os = "emscripten"), inline)] +fn capacity_to_buckets(cap: usize) -> Option<usize> { + debug_assert_ne!(cap, 0); + + // For small tables we require at least 1 empty bucket so that lookups are + // guaranteed to terminate if an element doesn't exist in the table. + if cap < 8 { + // We don't bother with a table size of 2 buckets since that can only + // hold a single element. Instead we skip directly to a 4 bucket table + // which can hold 3 elements. + return Some(if cap < 4 { 4 } else { 8 }); + } + + // Otherwise require 1/8 buckets to be empty (87.5% load) + // + // Be careful when modifying this, calculate_layout relies on the + // overflow check here. + let adjusted_cap = cap.checked_mul(8)? / 7; + + // Any overflows will have been caught by the checked_mul. Also, any + // rounding errors from the division above will be cleaned up by + // next_power_of_two (which can't overflow because of the previous division). + Some(adjusted_cap.next_power_of_two()) +} + +/// Returns the maximum effective capacity for the given bucket mask, taking +/// the maximum load factor into account. +#[inline] +fn bucket_mask_to_capacity(bucket_mask: usize) -> usize { + if bucket_mask < 8 { + // For tables with 1/2/4/8 buckets, we always reserve one empty slot. + // Keep in mind that the bucket mask is one less than the bucket count. + bucket_mask + } else { + // For larger tables we reserve 12.5% of the slots as empty. + ((bucket_mask + 1) / 8) * 7 + } +} + +/// Helper which allows the max calculation for ctrl_align to be statically computed for each T +/// while keeping the rest of `calculate_layout_for` independent of `T` +#[derive(Copy, Clone)] +struct TableLayout { + size: usize, + ctrl_align: usize, +} + +impl TableLayout { + #[inline] + fn new<T>() -> Self { + let layout = Layout::new::<T>(); + Self { + size: layout.size(), + ctrl_align: usize::max(layout.align(), Group::WIDTH), + } + } + + #[inline] + fn calculate_layout_for(self, buckets: usize) -> Option<(Layout, usize)> { + debug_assert!(buckets.is_power_of_two()); + + let TableLayout { size, ctrl_align } = self; + // Manual layout calculation since Layout methods are not yet stable. + let ctrl_offset = + size.checked_mul(buckets)?.checked_add(ctrl_align - 1)? & !(ctrl_align - 1); + let len = ctrl_offset.checked_add(buckets + Group::WIDTH)?; + + Some(( + unsafe { Layout::from_size_align_unchecked(len, ctrl_align) }, + ctrl_offset, + )) + } +} + +/// Returns a Layout which describes the allocation required for a hash table, +/// and the offset of the control bytes in the allocation. +/// (the offset is also one past last element of buckets) +/// +/// Returns `None` if an overflow occurs. +#[cfg_attr(feature = "inline-more", inline)] +fn calculate_layout<T>(buckets: usize) -> Option<(Layout, usize)> { + TableLayout::new::<T>().calculate_layout_for(buckets) +} + +/// A reference to a hash table bucket containing a `T`. +/// +/// This is usually just a pointer to the element itself. However if the element +/// is a ZST, then we instead track the index of the element in the table so +/// that `erase` works properly. +pub struct Bucket<T> { + // Actually it is pointer to next element than element itself + // this is needed to maintain pointer arithmetic invariants + // keeping direct pointer to element introduces difficulty. + // Using `NonNull` for variance and niche layout + ptr: NonNull<T>, +} + +// This Send impl is needed for rayon support. This is safe since Bucket is +// never exposed in a public API. +unsafe impl<T> Send for Bucket<T> {} + +impl<T> Clone for Bucket<T> { + #[inline] + fn clone(&self) -> Self { + Self { ptr: self.ptr } + } +} + +impl<T> Bucket<T> { + #[inline] + unsafe fn from_base_index(base: NonNull<T>, index: usize) -> Self { + let ptr = if mem::size_of::<T>() == 0 { + // won't overflow because index must be less than length + (index + 1) as *mut T + } else { + base.as_ptr().sub(index) + }; + Self { + ptr: NonNull::new_unchecked(ptr), + } + } + #[inline] + unsafe fn to_base_index(&self, base: NonNull<T>) -> usize { + if mem::size_of::<T>() == 0 { + self.ptr.as_ptr() as usize - 1 + } else { + offset_from(base.as_ptr(), self.ptr.as_ptr()) + } + } + #[inline] + pub fn as_ptr(&self) -> *mut T { + if mem::size_of::<T>() == 0 { + // Just return an arbitrary ZST pointer which is properly aligned + mem::align_of::<T>() as *mut T + } else { + unsafe { self.ptr.as_ptr().sub(1) } + } + } + #[inline] + unsafe fn next_n(&self, offset: usize) -> Self { + let ptr = if mem::size_of::<T>() == 0 { + (self.ptr.as_ptr() as usize + offset) as *mut T + } else { + self.ptr.as_ptr().sub(offset) + }; + Self { + ptr: NonNull::new_unchecked(ptr), + } + } + #[cfg_attr(feature = "inline-more", inline)] + pub unsafe fn drop(&self) { + self.as_ptr().drop_in_place(); + } + #[inline] + pub unsafe fn read(&self) -> T { + self.as_ptr().read() + } + #[inline] + pub unsafe fn write(&self, val: T) { + self.as_ptr().write(val); + } + #[inline] + pub unsafe fn as_ref<'a>(&self) -> &'a T { + &*self.as_ptr() + } + #[inline] + pub unsafe fn as_mut<'a>(&self) -> &'a mut T { + &mut *self.as_ptr() + } + #[cfg(feature = "raw")] + #[inline] + pub unsafe fn copy_from_nonoverlapping(&self, other: &Self) { + self.as_ptr().copy_from_nonoverlapping(other.as_ptr(), 1); + } +} + +/// A raw hash table with an unsafe API. +pub struct RawTable<T, A: Allocator + Clone = Global> { + table: RawTableInner<A>, + // Tell dropck that we own instances of T. + marker: PhantomData<T>, +} + +/// Non-generic part of `RawTable` which allows functions to be instantiated only once regardless +/// of how many different key-value types are used. +struct RawTableInner<A> { + // Mask to get an index from a hash value. The value is one less than the + // number of buckets in the table. + bucket_mask: usize, + + // [Padding], T1, T2, ..., Tlast, C1, C2, ... + // ^ points here + ctrl: NonNull<u8>, + + // Number of elements that can be inserted before we need to grow the table + growth_left: usize, + + // Number of elements in the table, only really used by len() + items: usize, + + alloc: A, +} + +impl<T> RawTable<T, Global> { + /// Creates a new empty hash table without allocating any memory. + /// + /// In effect this returns a table with exactly 1 bucket. However we can + /// leave the data pointer dangling since that bucket is never written to + /// due to our load factor forcing us to always have at least 1 free bucket. + #[inline] + pub const fn new() -> Self { + Self { + table: RawTableInner::new_in(Global), + marker: PhantomData, + } + } + + /// Attempts to allocate a new hash table with at least enough capacity + /// for inserting the given number of elements without reallocating. + #[cfg(feature = "raw")] + pub fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError> { + Self::try_with_capacity_in(capacity, Global) + } + + /// Allocates a new hash table with at least enough capacity for inserting + /// the given number of elements without reallocating. + pub fn with_capacity(capacity: usize) -> Self { + Self::with_capacity_in(capacity, Global) + } +} + +impl<T, A: Allocator + Clone> RawTable<T, A> { + /// Creates a new empty hash table without allocating any memory, using the + /// given allocator. + /// + /// In effect this returns a table with exactly 1 bucket. However we can + /// leave the data pointer dangling since that bucket is never written to + /// due to our load factor forcing us to always have at least 1 free bucket. + #[inline] + pub fn new_in(alloc: A) -> Self { + Self { + table: RawTableInner::new_in(alloc), + marker: PhantomData, + } + } + + /// Allocates a new hash table with the given number of buckets. + /// + /// The control bytes are left uninitialized. + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn new_uninitialized( + alloc: A, + buckets: usize, + fallibility: Fallibility, + ) -> Result<Self, TryReserveError> { + debug_assert!(buckets.is_power_of_two()); + + Ok(Self { + table: RawTableInner::new_uninitialized( + alloc, + TableLayout::new::<T>(), + buckets, + fallibility, + )?, + marker: PhantomData, + }) + } + + /// Attempts to allocate a new hash table with at least enough capacity + /// for inserting the given number of elements without reallocating. + fn fallible_with_capacity( + alloc: A, + capacity: usize, + fallibility: Fallibility, + ) -> Result<Self, TryReserveError> { + Ok(Self { + table: RawTableInner::fallible_with_capacity( + alloc, + TableLayout::new::<T>(), + capacity, + fallibility, + )?, + marker: PhantomData, + }) + } + + /// Attempts to allocate a new hash table using the given allocator, with at least enough + /// capacity for inserting the given number of elements without reallocating. + #[cfg(feature = "raw")] + pub fn try_with_capacity_in(capacity: usize, alloc: A) -> Result<Self, TryReserveError> { + Self::fallible_with_capacity(alloc, capacity, Fallibility::Fallible) + } + + /// Allocates a new hash table using the given allocator, with at least enough capacity for + /// inserting the given number of elements without reallocating. + pub fn with_capacity_in(capacity: usize, alloc: A) -> Self { + // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. + match Self::fallible_with_capacity(alloc, capacity, Fallibility::Infallible) { + Ok(capacity) => capacity, + Err(_) => unsafe { hint::unreachable_unchecked() }, + } + } + + /// Returns a reference to the underlying allocator. + #[inline] + pub fn allocator(&self) -> &A { + &self.table.alloc + } + + /// Deallocates the table without dropping any entries. + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn free_buckets(&mut self) { + self.table.free_buckets(TableLayout::new::<T>()); + } + + /// Returns pointer to one past last element of data table. + #[inline] + pub unsafe fn data_end(&self) -> NonNull<T> { + NonNull::new_unchecked(self.table.ctrl.as_ptr().cast()) + } + + /// Returns pointer to start of data table. + #[inline] + #[cfg(feature = "nightly")] + pub unsafe fn data_start(&self) -> *mut T { + self.data_end().as_ptr().wrapping_sub(self.buckets()) + } + + /// Returns the index of a bucket from a `Bucket`. + #[inline] + pub unsafe fn bucket_index(&self, bucket: &Bucket<T>) -> usize { + bucket.to_base_index(self.data_end()) + } + + /// Returns a pointer to an element in the table. + #[inline] + pub unsafe fn bucket(&self, index: usize) -> Bucket<T> { + debug_assert_ne!(self.table.bucket_mask, 0); + debug_assert!(index < self.buckets()); + Bucket::from_base_index(self.data_end(), index) + } + + /// Erases an element from the table without dropping it. + #[cfg_attr(feature = "inline-more", inline)] + #[deprecated(since = "0.8.1", note = "use erase or remove instead")] + pub unsafe fn erase_no_drop(&mut self, item: &Bucket<T>) { + let index = self.bucket_index(item); + self.table.erase(index); + } + + /// Erases an element from the table, dropping it in place. + #[cfg_attr(feature = "inline-more", inline)] + #[allow(clippy::needless_pass_by_value)] + #[allow(deprecated)] + pub unsafe fn erase(&mut self, item: Bucket<T>) { + // Erase the element from the table first since drop might panic. + self.erase_no_drop(&item); + item.drop(); + } + + /// Finds and erases an element from the table, dropping it in place. + /// Returns true if an element was found. + #[cfg(feature = "raw")] + #[cfg_attr(feature = "inline-more", inline)] + pub fn erase_entry(&mut self, hash: u64, eq: impl FnMut(&T) -> bool) -> bool { + // Avoid `Option::map` because it bloats LLVM IR. + if let Some(bucket) = self.find(hash, eq) { + unsafe { + self.erase(bucket); + } + true + } else { + false + } + } + + /// Removes an element from the table, returning it. + #[cfg_attr(feature = "inline-more", inline)] + #[allow(clippy::needless_pass_by_value)] + #[allow(deprecated)] + pub unsafe fn remove(&mut self, item: Bucket<T>) -> T { + self.erase_no_drop(&item); + item.read() + } + + /// Finds and removes an element from the table, returning it. + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove_entry(&mut self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<T> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.find(hash, eq) { + Some(bucket) => Some(unsafe { self.remove(bucket) }), + None => None, + } + } + + /// Marks all table buckets as empty without dropping their contents. + #[cfg_attr(feature = "inline-more", inline)] + pub fn clear_no_drop(&mut self) { + self.table.clear_no_drop(); + } + + /// Removes all elements from the table without freeing the backing memory. + #[cfg_attr(feature = "inline-more", inline)] + pub fn clear(&mut self) { + // Ensure that the table is reset even if one of the drops panic + let mut self_ = guard(self, |self_| self_.clear_no_drop()); + unsafe { + self_.drop_elements(); + } + } + + unsafe fn drop_elements(&mut self) { + if mem::needs_drop::<T>() && !self.is_empty() { + for item in self.iter() { + item.drop(); + } + } + } + + /// Shrinks the table to fit `max(self.len(), min_size)` elements. + #[cfg_attr(feature = "inline-more", inline)] + pub fn shrink_to(&mut self, min_size: usize, hasher: impl Fn(&T) -> u64) { + // Calculate the minimal number of elements that we need to reserve + // space for. + let min_size = usize::max(self.table.items, min_size); + if min_size == 0 { + *self = Self::new_in(self.table.alloc.clone()); + return; + } + + // Calculate the number of buckets that we need for this number of + // elements. If the calculation overflows then the requested bucket + // count must be larger than what we have right and nothing needs to be + // done. + let min_buckets = match capacity_to_buckets(min_size) { + Some(buckets) => buckets, + None => return, + }; + + // If we have more buckets than we need, shrink the table. + if min_buckets < self.buckets() { + // Fast path if the table is empty + if self.table.items == 0 { + *self = Self::with_capacity_in(min_size, self.table.alloc.clone()); + } else { + // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. + if self + .resize(min_size, hasher, Fallibility::Infallible) + .is_err() + { + unsafe { hint::unreachable_unchecked() } + } + } + } + } + + /// Ensures that at least `additional` items can be inserted into the table + /// without reallocation. + #[cfg_attr(feature = "inline-more", inline)] + pub fn reserve(&mut self, additional: usize, hasher: impl Fn(&T) -> u64) { + if additional > self.table.growth_left { + // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. + if self + .reserve_rehash(additional, hasher, Fallibility::Infallible) + .is_err() + { + unsafe { hint::unreachable_unchecked() } + } + } + } + + /// Tries to ensure that at least `additional` items can be inserted into + /// the table without reallocation. + #[cfg_attr(feature = "inline-more", inline)] + pub fn try_reserve( + &mut self, + additional: usize, + hasher: impl Fn(&T) -> u64, + ) -> Result<(), TryReserveError> { + if additional > self.table.growth_left { + self.reserve_rehash(additional, hasher, Fallibility::Fallible) + } else { + Ok(()) + } + } + + /// Out-of-line slow path for `reserve` and `try_reserve`. + #[cold] + #[inline(never)] + fn reserve_rehash( + &mut self, + additional: usize, + hasher: impl Fn(&T) -> u64, + fallibility: Fallibility, + ) -> Result<(), TryReserveError> { + unsafe { + self.table.reserve_rehash_inner( + additional, + &|table, index| hasher(table.bucket::<T>(index).as_ref()), + fallibility, + TableLayout::new::<T>(), + if mem::needs_drop::<T>() { + Some(mem::transmute(ptr::drop_in_place::<T> as unsafe fn(*mut T))) + } else { + None + }, + ) + } + } + + /// Allocates a new table of a different size and moves the contents of the + /// current table into it. + fn resize( + &mut self, + capacity: usize, + hasher: impl Fn(&T) -> u64, + fallibility: Fallibility, + ) -> Result<(), TryReserveError> { + unsafe { + self.table.resize_inner( + capacity, + &|table, index| hasher(table.bucket::<T>(index).as_ref()), + fallibility, + TableLayout::new::<T>(), + ) + } + } + + /// Inserts a new element into the table, and returns its raw bucket. + /// + /// This does not check if the given element already exists in the table. + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(&mut self, hash: u64, value: T, hasher: impl Fn(&T) -> u64) -> Bucket<T> { + unsafe { + let mut index = self.table.find_insert_slot(hash); + + // We can avoid growing the table once we have reached our load + // factor if we are replacing a tombstone. This works since the + // number of EMPTY slots does not change in this case. + let old_ctrl = *self.table.ctrl(index); + if unlikely(self.table.growth_left == 0 && special_is_empty(old_ctrl)) { + self.reserve(1, hasher); + index = self.table.find_insert_slot(hash); + } + + self.table.record_item_insert_at(index, old_ctrl, hash); + + let bucket = self.bucket(index); + bucket.write(value); + bucket + } + } + + /// Attempts to insert a new element without growing the table and return its raw bucket. + /// + /// Returns an `Err` containing the given element if inserting it would require growing the + /// table. + /// + /// This does not check if the given element already exists in the table. + #[cfg(feature = "raw")] + #[cfg_attr(feature = "inline-more", inline)] + pub fn try_insert_no_grow(&mut self, hash: u64, value: T) -> Result<Bucket<T>, T> { + unsafe { + match self.table.prepare_insert_no_grow(hash) { + Ok(index) => { + let bucket = self.bucket(index); + bucket.write(value); + Ok(bucket) + } + Err(()) => Err(value), + } + } + } + + /// Inserts a new element into the table, and returns a mutable reference to it. + /// + /// This does not check if the given element already exists in the table. + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert_entry(&mut self, hash: u64, value: T, hasher: impl Fn(&T) -> u64) -> &mut T { + unsafe { self.insert(hash, value, hasher).as_mut() } + } + + /// Inserts a new element into the table, without growing the table. + /// + /// There must be enough space in the table to insert the new element. + /// + /// This does not check if the given element already exists in the table. + #[cfg_attr(feature = "inline-more", inline)] + #[cfg(any(feature = "raw", feature = "rustc-internal-api"))] + pub unsafe fn insert_no_grow(&mut self, hash: u64, value: T) -> Bucket<T> { + let (index, old_ctrl) = self.table.prepare_insert_slot(hash); + let bucket = self.table.bucket(index); + + // If we are replacing a DELETED entry then we don't need to update + // the load counter. + self.table.growth_left -= special_is_empty(old_ctrl) as usize; + + bucket.write(value); + self.table.items += 1; + bucket + } + + /// Temporary removes a bucket, applying the given function to the removed + /// element and optionally put back the returned value in the same bucket. + /// + /// Returns `true` if the bucket still contains an element + /// + /// This does not check if the given bucket is actually occupied. + #[cfg_attr(feature = "inline-more", inline)] + pub unsafe fn replace_bucket_with<F>(&mut self, bucket: Bucket<T>, f: F) -> bool + where + F: FnOnce(T) -> Option<T>, + { + let index = self.bucket_index(&bucket); + let old_ctrl = *self.table.ctrl(index); + debug_assert!(is_full(old_ctrl)); + let old_growth_left = self.table.growth_left; + let item = self.remove(bucket); + if let Some(new_item) = f(item) { + self.table.growth_left = old_growth_left; + self.table.set_ctrl(index, old_ctrl); + self.table.items += 1; + self.bucket(index).write(new_item); + true + } else { + false + } + } + + /// Searches for an element in the table. + #[inline] + pub fn find(&self, hash: u64, mut eq: impl FnMut(&T) -> bool) -> Option<Bucket<T>> { + let result = self.table.find_inner(hash, &mut |index| unsafe { + eq(self.bucket(index).as_ref()) + }); + + // Avoid `Option::map` because it bloats LLVM IR. + match result { + Some(index) => Some(unsafe { self.bucket(index) }), + None => None, + } + } + + /// Gets a reference to an element in the table. + #[inline] + pub fn get(&self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<&T> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.find(hash, eq) { + Some(bucket) => Some(unsafe { bucket.as_ref() }), + None => None, + } + } + + /// Gets a mutable reference to an element in the table. + #[inline] + pub fn get_mut(&mut self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<&mut T> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.find(hash, eq) { + Some(bucket) => Some(unsafe { bucket.as_mut() }), + None => None, + } + } + + /// Attempts to get mutable references to `N` entries in the table at once. + /// + /// Returns an array of length `N` with the results of each query. + /// + /// At most one mutable reference will be returned to any entry. `None` will be returned if any + /// of the hashes are duplicates. `None` will be returned if the hash is not found. + /// + /// The `eq` argument should be a closure such that `eq(i, k)` returns true if `k` is equal to + /// the `i`th key to be looked up. + pub fn get_many_mut<const N: usize>( + &mut self, + hashes: [u64; N], + eq: impl FnMut(usize, &T) -> bool, + ) -> Option<[&'_ mut T; N]> { + unsafe { + let ptrs = self.get_many_mut_pointers(hashes, eq)?; + + for (i, &cur) in ptrs.iter().enumerate() { + if ptrs[..i].iter().any(|&prev| ptr::eq::<T>(prev, cur)) { + return None; + } + } + // All bucket are distinct from all previous buckets so we're clear to return the result + // of the lookup. + + // TODO use `MaybeUninit::array_assume_init` here instead once that's stable. + Some(mem::transmute_copy(&ptrs)) + } + } + + pub unsafe fn get_many_unchecked_mut<const N: usize>( + &mut self, + hashes: [u64; N], + eq: impl FnMut(usize, &T) -> bool, + ) -> Option<[&'_ mut T; N]> { + let ptrs = self.get_many_mut_pointers(hashes, eq)?; + Some(mem::transmute_copy(&ptrs)) + } + + unsafe fn get_many_mut_pointers<const N: usize>( + &mut self, + hashes: [u64; N], + mut eq: impl FnMut(usize, &T) -> bool, + ) -> Option<[*mut T; N]> { + // TODO use `MaybeUninit::uninit_array` here instead once that's stable. + let mut outs: MaybeUninit<[*mut T; N]> = MaybeUninit::uninit(); + let outs_ptr = outs.as_mut_ptr(); + + for (i, &hash) in hashes.iter().enumerate() { + let cur = self.find(hash, |k| eq(i, k))?; + *(*outs_ptr).get_unchecked_mut(i) = cur.as_mut(); + } + + // TODO use `MaybeUninit::array_assume_init` here instead once that's stable. + Some(outs.assume_init()) + } + + /// Returns the number of elements the map can hold without reallocating. + /// + /// This number is a lower bound; the table might be able to hold + /// more, but is guaranteed to be able to hold at least this many. + #[inline] + pub fn capacity(&self) -> usize { + self.table.items + self.table.growth_left + } + + /// Returns the number of elements in the table. + #[inline] + pub fn len(&self) -> usize { + self.table.items + } + + /// Returns `true` if the table contains no elements. + #[inline] + pub fn is_empty(&self) -> bool { + self.len() == 0 + } + + /// Returns the number of buckets in the table. + #[inline] + pub fn buckets(&self) -> usize { + self.table.bucket_mask + 1 + } + + /// Returns an iterator over every element in the table. It is up to + /// the caller to ensure that the `RawTable` outlives the `RawIter`. + /// Because we cannot make the `next` method unsafe on the `RawIter` + /// struct, we have to make the `iter` method unsafe. + #[inline] + pub unsafe fn iter(&self) -> RawIter<T> { + let data = Bucket::from_base_index(self.data_end(), 0); + RawIter { + iter: RawIterRange::new(self.table.ctrl.as_ptr(), data, self.table.buckets()), + items: self.table.items, + } + } + + /// Returns an iterator over occupied buckets that could match a given hash. + /// + /// `RawTable` only stores 7 bits of the hash value, so this iterator may + /// return items that have a hash value different than the one provided. You + /// should always validate the returned values before using them. + /// + /// It is up to the caller to ensure that the `RawTable` outlives the + /// `RawIterHash`. Because we cannot make the `next` method unsafe on the + /// `RawIterHash` struct, we have to make the `iter_hash` method unsafe. + #[cfg_attr(feature = "inline-more", inline)] + #[cfg(feature = "raw")] + pub unsafe fn iter_hash(&self, hash: u64) -> RawIterHash<'_, T, A> { + RawIterHash::new(self, hash) + } + + /// Returns an iterator which removes all elements from the table without + /// freeing the memory. + #[cfg_attr(feature = "inline-more", inline)] + pub fn drain(&mut self) -> RawDrain<'_, T, A> { + unsafe { + let iter = self.iter(); + self.drain_iter_from(iter) + } + } + + /// Returns an iterator which removes all elements from the table without + /// freeing the memory. + /// + /// Iteration starts at the provided iterator's current location. + /// + /// It is up to the caller to ensure that the iterator is valid for this + /// `RawTable` and covers all items that remain in the table. + #[cfg_attr(feature = "inline-more", inline)] + pub unsafe fn drain_iter_from(&mut self, iter: RawIter<T>) -> RawDrain<'_, T, A> { + debug_assert_eq!(iter.len(), self.len()); + RawDrain { + iter, + table: ManuallyDrop::new(mem::replace(self, Self::new_in(self.table.alloc.clone()))), + orig_table: NonNull::from(self), + marker: PhantomData, + } + } + + /// Returns an iterator which consumes all elements from the table. + /// + /// Iteration starts at the provided iterator's current location. + /// + /// It is up to the caller to ensure that the iterator is valid for this + /// `RawTable` and covers all items that remain in the table. + pub unsafe fn into_iter_from(self, iter: RawIter<T>) -> RawIntoIter<T, A> { + debug_assert_eq!(iter.len(), self.len()); + + let alloc = self.table.alloc.clone(); + let allocation = self.into_allocation(); + RawIntoIter { + iter, + allocation, + marker: PhantomData, + alloc, + } + } + + /// Converts the table into a raw allocation. The contents of the table + /// should be dropped using a `RawIter` before freeing the allocation. + #[cfg_attr(feature = "inline-more", inline)] + pub(crate) fn into_allocation(self) -> Option<(NonNull<u8>, Layout)> { + let alloc = if self.table.is_empty_singleton() { + None + } else { + // Avoid `Option::unwrap_or_else` because it bloats LLVM IR. + let (layout, ctrl_offset) = match calculate_layout::<T>(self.table.buckets()) { + Some(lco) => lco, + None => unsafe { hint::unreachable_unchecked() }, + }; + Some(( + unsafe { NonNull::new_unchecked(self.table.ctrl.as_ptr().sub(ctrl_offset)) }, + layout, + )) + }; + mem::forget(self); + alloc + } +} + +unsafe impl<T, A: Allocator + Clone> Send for RawTable<T, A> +where + T: Send, + A: Send, +{ +} +unsafe impl<T, A: Allocator + Clone> Sync for RawTable<T, A> +where + T: Sync, + A: Sync, +{ +} + +impl<A> RawTableInner<A> { + #[inline] + const fn new_in(alloc: A) -> Self { + Self { + // Be careful to cast the entire slice to a raw pointer. + ctrl: unsafe { NonNull::new_unchecked(Group::static_empty() as *const _ as *mut u8) }, + bucket_mask: 0, + items: 0, + growth_left: 0, + alloc, + } + } +} + +impl<A: Allocator + Clone> RawTableInner<A> { + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn new_uninitialized( + alloc: A, + table_layout: TableLayout, + buckets: usize, + fallibility: Fallibility, + ) -> Result<Self, TryReserveError> { + debug_assert!(buckets.is_power_of_two()); + + // Avoid `Option::ok_or_else` because it bloats LLVM IR. + let (layout, ctrl_offset) = match table_layout.calculate_layout_for(buckets) { + Some(lco) => lco, + None => return Err(fallibility.capacity_overflow()), + }; + + // We need an additional check to ensure that the allocation doesn't + // exceed `isize::MAX`. We can skip this check on 64-bit systems since + // such allocations will never succeed anyways. + // + // This mirrors what Vec does in the standard library. + if mem::size_of::<usize>() < 8 && layout.size() > isize::MAX as usize { + return Err(fallibility.capacity_overflow()); + } + + let ptr: NonNull<u8> = match do_alloc(&alloc, layout) { + Ok(block) => block.cast(), + Err(_) => return Err(fallibility.alloc_err(layout)), + }; + + let ctrl = NonNull::new_unchecked(ptr.as_ptr().add(ctrl_offset)); + Ok(Self { + ctrl, + bucket_mask: buckets - 1, + items: 0, + growth_left: bucket_mask_to_capacity(buckets - 1), + alloc, + }) + } + + #[inline] + fn fallible_with_capacity( + alloc: A, + table_layout: TableLayout, + capacity: usize, + fallibility: Fallibility, + ) -> Result<Self, TryReserveError> { + if capacity == 0 { + Ok(Self::new_in(alloc)) + } else { + unsafe { + let buckets = + capacity_to_buckets(capacity).ok_or_else(|| fallibility.capacity_overflow())?; + + let result = Self::new_uninitialized(alloc, table_layout, buckets, fallibility)?; + result.ctrl(0).write_bytes(EMPTY, result.num_ctrl_bytes()); + + Ok(result) + } + } + } + + /// Searches for an empty or deleted bucket which is suitable for inserting + /// a new element and sets the hash for that slot. + /// + /// There must be at least 1 empty bucket in the table. + #[inline] + unsafe fn prepare_insert_slot(&self, hash: u64) -> (usize, u8) { + let index = self.find_insert_slot(hash); + let old_ctrl = *self.ctrl(index); + self.set_ctrl_h2(index, hash); + (index, old_ctrl) + } + + /// Searches for an empty or deleted bucket which is suitable for inserting + /// a new element. + /// + /// There must be at least 1 empty bucket in the table. + #[inline] + fn find_insert_slot(&self, hash: u64) -> usize { + let mut probe_seq = self.probe_seq(hash); + loop { + unsafe { + let group = Group::load(self.ctrl(probe_seq.pos)); + if let Some(bit) = group.match_empty_or_deleted().lowest_set_bit() { + let result = (probe_seq.pos + bit) & self.bucket_mask; + + // In tables smaller than the group width, trailing control + // bytes outside the range of the table are filled with + // EMPTY entries. These will unfortunately trigger a + // match, but once masked may point to a full bucket that + // is already occupied. We detect this situation here and + // perform a second scan starting at the beginning of the + // table. This second scan is guaranteed to find an empty + // slot (due to the load factor) before hitting the trailing + // control bytes (containing EMPTY). + if unlikely(is_full(*self.ctrl(result))) { + debug_assert!(self.bucket_mask < Group::WIDTH); + debug_assert_ne!(probe_seq.pos, 0); + return Group::load_aligned(self.ctrl(0)) + .match_empty_or_deleted() + .lowest_set_bit_nonzero(); + } + + return result; + } + } + probe_seq.move_next(self.bucket_mask); + } + } + + /// Searches for an element in the table. This uses dynamic dispatch to reduce the amount of + /// code generated, but it is eliminated by LLVM optimizations. + #[inline] + fn find_inner(&self, hash: u64, eq: &mut dyn FnMut(usize) -> bool) -> Option<usize> { + let h2_hash = h2(hash); + let mut probe_seq = self.probe_seq(hash); + + loop { + let group = unsafe { Group::load(self.ctrl(probe_seq.pos)) }; + + for bit in group.match_byte(h2_hash) { + let index = (probe_seq.pos + bit) & self.bucket_mask; + + if likely(eq(index)) { + return Some(index); + } + } + + if likely(group.match_empty().any_bit_set()) { + return None; + } + + probe_seq.move_next(self.bucket_mask); + } + } + + #[allow(clippy::mut_mut)] + #[inline] + unsafe fn prepare_rehash_in_place(&mut self) { + // Bulk convert all full control bytes to DELETED, and all DELETED + // control bytes to EMPTY. This effectively frees up all buckets + // containing a DELETED entry. + for i in (0..self.buckets()).step_by(Group::WIDTH) { + let group = Group::load_aligned(self.ctrl(i)); + let group = group.convert_special_to_empty_and_full_to_deleted(); + group.store_aligned(self.ctrl(i)); + } + + // Fix up the trailing control bytes. See the comments in set_ctrl + // for the handling of tables smaller than the group width. + if self.buckets() < Group::WIDTH { + self.ctrl(0) + .copy_to(self.ctrl(Group::WIDTH), self.buckets()); + } else { + self.ctrl(0) + .copy_to(self.ctrl(self.buckets()), Group::WIDTH); + } + } + + #[inline] + unsafe fn bucket<T>(&self, index: usize) -> Bucket<T> { + debug_assert_ne!(self.bucket_mask, 0); + debug_assert!(index < self.buckets()); + Bucket::from_base_index(self.data_end(), index) + } + + #[inline] + unsafe fn bucket_ptr(&self, index: usize, size_of: usize) -> *mut u8 { + debug_assert_ne!(self.bucket_mask, 0); + debug_assert!(index < self.buckets()); + let base: *mut u8 = self.data_end().as_ptr(); + base.sub((index + 1) * size_of) + } + + #[inline] + unsafe fn data_end<T>(&self) -> NonNull<T> { + NonNull::new_unchecked(self.ctrl.as_ptr().cast()) + } + + /// Returns an iterator-like object for a probe sequence on the table. + /// + /// This iterator never terminates, but is guaranteed to visit each bucket + /// group exactly once. The loop using `probe_seq` must terminate upon + /// reaching a group containing an empty bucket. + #[inline] + fn probe_seq(&self, hash: u64) -> ProbeSeq { + ProbeSeq { + pos: h1(hash) & self.bucket_mask, + stride: 0, + } + } + + /// Returns the index of a bucket for which a value must be inserted if there is enough rooom + /// in the table, otherwise returns error + #[cfg(feature = "raw")] + #[inline] + unsafe fn prepare_insert_no_grow(&mut self, hash: u64) -> Result<usize, ()> { + let index = self.find_insert_slot(hash); + let old_ctrl = *self.ctrl(index); + if unlikely(self.growth_left == 0 && special_is_empty(old_ctrl)) { + Err(()) + } else { + self.record_item_insert_at(index, old_ctrl, hash); + Ok(index) + } + } + + #[inline] + unsafe fn record_item_insert_at(&mut self, index: usize, old_ctrl: u8, hash: u64) { + self.growth_left -= usize::from(special_is_empty(old_ctrl)); + self.set_ctrl_h2(index, hash); + self.items += 1; + } + + #[inline] + fn is_in_same_group(&self, i: usize, new_i: usize, hash: u64) -> bool { + let probe_seq_pos = self.probe_seq(hash).pos; + let probe_index = + |pos: usize| (pos.wrapping_sub(probe_seq_pos) & self.bucket_mask) / Group::WIDTH; + probe_index(i) == probe_index(new_i) + } + + /// Sets a control byte to the hash, and possibly also the replicated control byte at + /// the end of the array. + #[inline] + unsafe fn set_ctrl_h2(&self, index: usize, hash: u64) { + self.set_ctrl(index, h2(hash)); + } + + #[inline] + unsafe fn replace_ctrl_h2(&self, index: usize, hash: u64) -> u8 { + let prev_ctrl = *self.ctrl(index); + self.set_ctrl_h2(index, hash); + prev_ctrl + } + + /// Sets a control byte, and possibly also the replicated control byte at + /// the end of the array. + #[inline] + unsafe fn set_ctrl(&self, index: usize, ctrl: u8) { + // Replicate the first Group::WIDTH control bytes at the end of + // the array without using a branch: + // - If index >= Group::WIDTH then index == index2. + // - Otherwise index2 == self.bucket_mask + 1 + index. + // + // The very last replicated control byte is never actually read because + // we mask the initial index for unaligned loads, but we write it + // anyways because it makes the set_ctrl implementation simpler. + // + // If there are fewer buckets than Group::WIDTH then this code will + // replicate the buckets at the end of the trailing group. For example + // with 2 buckets and a group size of 4, the control bytes will look + // like this: + // + // Real | Replicated + // --------------------------------------------- + // | [A] | [B] | [EMPTY] | [EMPTY] | [A] | [B] | + // --------------------------------------------- + let index2 = ((index.wrapping_sub(Group::WIDTH)) & self.bucket_mask) + Group::WIDTH; + + *self.ctrl(index) = ctrl; + *self.ctrl(index2) = ctrl; + } + + /// Returns a pointer to a control byte. + #[inline] + unsafe fn ctrl(&self, index: usize) -> *mut u8 { + debug_assert!(index < self.num_ctrl_bytes()); + self.ctrl.as_ptr().add(index) + } + + #[inline] + fn buckets(&self) -> usize { + self.bucket_mask + 1 + } + + #[inline] + fn num_ctrl_bytes(&self) -> usize { + self.bucket_mask + 1 + Group::WIDTH + } + + #[inline] + fn is_empty_singleton(&self) -> bool { + self.bucket_mask == 0 + } + + #[allow(clippy::mut_mut)] + #[inline] + unsafe fn prepare_resize( + &self, + table_layout: TableLayout, + capacity: usize, + fallibility: Fallibility, + ) -> Result<crate::scopeguard::ScopeGuard<Self, impl FnMut(&mut Self)>, TryReserveError> { + debug_assert!(self.items <= capacity); + + // Allocate and initialize the new table. + let mut new_table = RawTableInner::fallible_with_capacity( + self.alloc.clone(), + table_layout, + capacity, + fallibility, + )?; + new_table.growth_left -= self.items; + new_table.items = self.items; + + // The hash function may panic, in which case we simply free the new + // table without dropping any elements that may have been copied into + // it. + // + // This guard is also used to free the old table on success, see + // the comment at the bottom of this function. + Ok(guard(new_table, move |self_| { + if !self_.is_empty_singleton() { + self_.free_buckets(table_layout); + } + })) + } + + /// Reserves or rehashes to make room for `additional` more elements. + /// + /// This uses dynamic dispatch to reduce the amount of + /// code generated, but it is eliminated by LLVM optimizations when inlined. + #[allow(clippy::inline_always)] + #[inline(always)] + unsafe fn reserve_rehash_inner( + &mut self, + additional: usize, + hasher: &dyn Fn(&mut Self, usize) -> u64, + fallibility: Fallibility, + layout: TableLayout, + drop: Option<fn(*mut u8)>, + ) -> Result<(), TryReserveError> { + // Avoid `Option::ok_or_else` because it bloats LLVM IR. + let new_items = match self.items.checked_add(additional) { + Some(new_items) => new_items, + None => return Err(fallibility.capacity_overflow()), + }; + let full_capacity = bucket_mask_to_capacity(self.bucket_mask); + if new_items <= full_capacity / 2 { + // Rehash in-place without re-allocating if we have plenty of spare + // capacity that is locked up due to DELETED entries. + self.rehash_in_place(hasher, layout.size, drop); + Ok(()) + } else { + // Otherwise, conservatively resize to at least the next size up + // to avoid churning deletes into frequent rehashes. + self.resize_inner( + usize::max(new_items, full_capacity + 1), + hasher, + fallibility, + layout, + ) + } + } + + /// Allocates a new table of a different size and moves the contents of the + /// current table into it. + /// + /// This uses dynamic dispatch to reduce the amount of + /// code generated, but it is eliminated by LLVM optimizations when inlined. + #[allow(clippy::inline_always)] + #[inline(always)] + unsafe fn resize_inner( + &mut self, + capacity: usize, + hasher: &dyn Fn(&mut Self, usize) -> u64, + fallibility: Fallibility, + layout: TableLayout, + ) -> Result<(), TryReserveError> { + let mut new_table = self.prepare_resize(layout, capacity, fallibility)?; + + // Copy all elements to the new table. + for i in 0..self.buckets() { + if !is_full(*self.ctrl(i)) { + continue; + } + + // This may panic. + let hash = hasher(self, i); + + // We can use a simpler version of insert() here since: + // - there are no DELETED entries. + // - we know there is enough space in the table. + // - all elements are unique. + let (index, _) = new_table.prepare_insert_slot(hash); + + ptr::copy_nonoverlapping( + self.bucket_ptr(i, layout.size), + new_table.bucket_ptr(index, layout.size), + layout.size, + ); + } + + // We successfully copied all elements without panicking. Now replace + // self with the new table. The old table will have its memory freed but + // the items will not be dropped (since they have been moved into the + // new table). + mem::swap(self, &mut new_table); + + Ok(()) + } + + /// Rehashes the contents of the table in place (i.e. without changing the + /// allocation). + /// + /// If `hasher` panics then some the table's contents may be lost. + /// + /// This uses dynamic dispatch to reduce the amount of + /// code generated, but it is eliminated by LLVM optimizations when inlined. + #[allow(clippy::inline_always)] + #[cfg_attr(feature = "inline-more", inline(always))] + #[cfg_attr(not(feature = "inline-more"), inline)] + unsafe fn rehash_in_place( + &mut self, + hasher: &dyn Fn(&mut Self, usize) -> u64, + size_of: usize, + drop: Option<fn(*mut u8)>, + ) { + // If the hash function panics then properly clean up any elements + // that we haven't rehashed yet. We unfortunately can't preserve the + // element since we lost their hash and have no way of recovering it + // without risking another panic. + self.prepare_rehash_in_place(); + + let mut guard = guard(self, move |self_| { + if let Some(drop) = drop { + for i in 0..self_.buckets() { + if *self_.ctrl(i) == DELETED { + self_.set_ctrl(i, EMPTY); + drop(self_.bucket_ptr(i, size_of)); + self_.items -= 1; + } + } + } + self_.growth_left = bucket_mask_to_capacity(self_.bucket_mask) - self_.items; + }); + + // At this point, DELETED elements are elements that we haven't + // rehashed yet. Find them and re-insert them at their ideal + // position. + 'outer: for i in 0..guard.buckets() { + if *guard.ctrl(i) != DELETED { + continue; + } + + let i_p = guard.bucket_ptr(i, size_of); + + 'inner: loop { + // Hash the current item + let hash = hasher(*guard, i); + + // Search for a suitable place to put it + let new_i = guard.find_insert_slot(hash); + let new_i_p = guard.bucket_ptr(new_i, size_of); + + // Probing works by scanning through all of the control + // bytes in groups, which may not be aligned to the group + // size. If both the new and old position fall within the + // same unaligned group, then there is no benefit in moving + // it and we can just continue to the next item. + if likely(guard.is_in_same_group(i, new_i, hash)) { + guard.set_ctrl_h2(i, hash); + continue 'outer; + } + + // We are moving the current item to a new position. Write + // our H2 to the control byte of the new position. + let prev_ctrl = guard.replace_ctrl_h2(new_i, hash); + if prev_ctrl == EMPTY { + guard.set_ctrl(i, EMPTY); + // If the target slot is empty, simply move the current + // element into the new slot and clear the old control + // byte. + ptr::copy_nonoverlapping(i_p, new_i_p, size_of); + continue 'outer; + } else { + // If the target slot is occupied, swap the two elements + // and then continue processing the element that we just + // swapped into the old slot. + debug_assert_eq!(prev_ctrl, DELETED); + ptr::swap_nonoverlapping(i_p, new_i_p, size_of); + continue 'inner; + } + } + } + + guard.growth_left = bucket_mask_to_capacity(guard.bucket_mask) - guard.items; + + mem::forget(guard); + } + + #[inline] + unsafe fn free_buckets(&mut self, table_layout: TableLayout) { + // Avoid `Option::unwrap_or_else` because it bloats LLVM IR. + let (layout, ctrl_offset) = match table_layout.calculate_layout_for(self.buckets()) { + Some(lco) => lco, + None => hint::unreachable_unchecked(), + }; + self.alloc.deallocate( + NonNull::new_unchecked(self.ctrl.as_ptr().sub(ctrl_offset)), + layout, + ); + } + + /// Marks all table buckets as empty without dropping their contents. + #[inline] + fn clear_no_drop(&mut self) { + if !self.is_empty_singleton() { + unsafe { + self.ctrl(0).write_bytes(EMPTY, self.num_ctrl_bytes()); + } + } + self.items = 0; + self.growth_left = bucket_mask_to_capacity(self.bucket_mask); + } + + #[inline] + unsafe fn erase(&mut self, index: usize) { + debug_assert!(is_full(*self.ctrl(index))); + let index_before = index.wrapping_sub(Group::WIDTH) & self.bucket_mask; + let empty_before = Group::load(self.ctrl(index_before)).match_empty(); + let empty_after = Group::load(self.ctrl(index)).match_empty(); + + // If we are inside a continuous block of Group::WIDTH full or deleted + // cells then a probe window may have seen a full block when trying to + // insert. We therefore need to keep that block non-empty so that + // lookups will continue searching to the next probe window. + // + // Note that in this context `leading_zeros` refers to the bytes at the + // end of a group, while `trailing_zeros` refers to the bytes at the + // beginning of a group. + let ctrl = if empty_before.leading_zeros() + empty_after.trailing_zeros() >= Group::WIDTH { + DELETED + } else { + self.growth_left += 1; + EMPTY + }; + self.set_ctrl(index, ctrl); + self.items -= 1; + } +} + +impl<T: Clone, A: Allocator + Clone> Clone for RawTable<T, A> { + fn clone(&self) -> Self { + if self.table.is_empty_singleton() { + Self::new_in(self.table.alloc.clone()) + } else { + unsafe { + // Avoid `Result::ok_or_else` because it bloats LLVM IR. + let new_table = match Self::new_uninitialized( + self.table.alloc.clone(), + self.table.buckets(), + Fallibility::Infallible, + ) { + Ok(table) => table, + Err(_) => hint::unreachable_unchecked(), + }; + + // If cloning fails then we need to free the allocation for the + // new table. However we don't run its drop since its control + // bytes are not initialized yet. + let mut guard = guard(ManuallyDrop::new(new_table), |new_table| { + new_table.free_buckets(); + }); + + guard.clone_from_spec(self); + + // Disarm the scope guard and return the newly created table. + ManuallyDrop::into_inner(ScopeGuard::into_inner(guard)) + } + } + } + + fn clone_from(&mut self, source: &Self) { + if source.table.is_empty_singleton() { + *self = Self::new_in(self.table.alloc.clone()); + } else { + unsafe { + // Make sure that if any panics occurs, we clear the table and + // leave it in an empty state. + let mut self_ = guard(self, |self_| { + self_.clear_no_drop(); + }); + + // First, drop all our elements without clearing the control + // bytes. If this panics then the scope guard will clear the + // table, leaking any elements that were not dropped yet. + // + // This leak is unavoidable: we can't try dropping more elements + // since this could lead to another panic and abort the process. + self_.drop_elements(); + + // If necessary, resize our table to match the source. + if self_.buckets() != source.buckets() { + // Skip our drop by using ptr::write. + if !self_.table.is_empty_singleton() { + self_.free_buckets(); + } + (&mut **self_ as *mut Self).write( + // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. + match Self::new_uninitialized( + self_.table.alloc.clone(), + source.buckets(), + Fallibility::Infallible, + ) { + Ok(table) => table, + Err(_) => hint::unreachable_unchecked(), + }, + ); + } + + self_.clone_from_spec(source); + + // Disarm the scope guard if cloning was successful. + ScopeGuard::into_inner(self_); + } + } + } +} + +/// Specialization of `clone_from` for `Copy` types +trait RawTableClone { + unsafe fn clone_from_spec(&mut self, source: &Self); +} +impl<T: Clone, A: Allocator + Clone> RawTableClone for RawTable<T, A> { + default_fn! { + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn clone_from_spec(&mut self, source: &Self) { + self.clone_from_impl(source); + } + } +} +#[cfg(feature = "nightly")] +impl<T: Copy, A: Allocator + Clone> RawTableClone for RawTable<T, A> { + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn clone_from_spec(&mut self, source: &Self) { + source + .table + .ctrl(0) + .copy_to_nonoverlapping(self.table.ctrl(0), self.table.num_ctrl_bytes()); + source + .data_start() + .copy_to_nonoverlapping(self.data_start(), self.table.buckets()); + + self.table.items = source.table.items; + self.table.growth_left = source.table.growth_left; + } +} + +impl<T: Clone, A: Allocator + Clone> RawTable<T, A> { + /// Common code for clone and clone_from. Assumes: + /// - `self.buckets() == source.buckets()`. + /// - Any existing elements have been dropped. + /// - The control bytes are not initialized yet. + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn clone_from_impl(&mut self, source: &Self) { + // Copy the control bytes unchanged. We do this in a single pass + source + .table + .ctrl(0) + .copy_to_nonoverlapping(self.table.ctrl(0), self.table.num_ctrl_bytes()); + + // The cloning of elements may panic, in which case we need + // to make sure we drop only the elements that have been + // cloned so far. + let mut guard = guard((0, &mut *self), |(index, self_)| { + if mem::needs_drop::<T>() && !self_.is_empty() { + for i in 0..=*index { + if is_full(*self_.table.ctrl(i)) { + self_.bucket(i).drop(); + } + } + } + }); + + for from in source.iter() { + let index = source.bucket_index(&from); + let to = guard.1.bucket(index); + to.write(from.as_ref().clone()); + + // Update the index in case we need to unwind. + guard.0 = index; + } + + // Successfully cloned all items, no need to clean up. + mem::forget(guard); + + self.table.items = source.table.items; + self.table.growth_left = source.table.growth_left; + } + + /// Variant of `clone_from` to use when a hasher is available. + #[cfg(feature = "raw")] + pub fn clone_from_with_hasher(&mut self, source: &Self, hasher: impl Fn(&T) -> u64) { + // If we have enough capacity in the table, just clear it and insert + // elements one by one. We don't do this if we have the same number of + // buckets as the source since we can just copy the contents directly + // in that case. + if self.table.buckets() != source.table.buckets() + && bucket_mask_to_capacity(self.table.bucket_mask) >= source.len() + { + self.clear(); + + let guard_self = guard(&mut *self, |self_| { + // Clear the partially copied table if a panic occurs, otherwise + // items and growth_left will be out of sync with the contents + // of the table. + self_.clear(); + }); + + unsafe { + for item in source.iter() { + // This may panic. + let item = item.as_ref().clone(); + let hash = hasher(&item); + + // We can use a simpler version of insert() here since: + // - there are no DELETED entries. + // - we know there is enough space in the table. + // - all elements are unique. + let (index, _) = guard_self.table.prepare_insert_slot(hash); + guard_self.bucket(index).write(item); + } + } + + // Successfully cloned all items, no need to clean up. + mem::forget(guard_self); + + self.table.items = source.table.items; + self.table.growth_left -= source.table.items; + } else { + self.clone_from(source); + } + } +} + +impl<T, A: Allocator + Clone + Default> Default for RawTable<T, A> { + #[inline] + fn default() -> Self { + Self::new_in(Default::default()) + } +} + +#[cfg(feature = "nightly")] +unsafe impl<#[may_dangle] T, A: Allocator + Clone> Drop for RawTable<T, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + if !self.table.is_empty_singleton() { + unsafe { + self.drop_elements(); + self.free_buckets(); + } + } + } +} +#[cfg(not(feature = "nightly"))] +impl<T, A: Allocator + Clone> Drop for RawTable<T, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + if !self.table.is_empty_singleton() { + unsafe { + self.drop_elements(); + self.free_buckets(); + } + } + } +} + +impl<T, A: Allocator + Clone> IntoIterator for RawTable<T, A> { + type Item = T; + type IntoIter = RawIntoIter<T, A>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_iter(self) -> RawIntoIter<T, A> { + unsafe { + let iter = self.iter(); + self.into_iter_from(iter) + } + } +} + +/// Iterator over a sub-range of a table. Unlike `RawIter` this iterator does +/// not track an item count. +pub(crate) struct RawIterRange<T> { + // Mask of full buckets in the current group. Bits are cleared from this + // mask as each element is processed. + current_group: BitMask, + + // Pointer to the buckets for the current group. + data: Bucket<T>, + + // Pointer to the next group of control bytes, + // Must be aligned to the group size. + next_ctrl: *const u8, + + // Pointer one past the last control byte of this range. + end: *const u8, +} + +impl<T> RawIterRange<T> { + /// Returns a `RawIterRange` covering a subset of a table. + /// + /// The control byte address must be aligned to the group size. + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn new(ctrl: *const u8, data: Bucket<T>, len: usize) -> Self { + debug_assert_ne!(len, 0); + debug_assert_eq!(ctrl as usize % Group::WIDTH, 0); + let end = ctrl.add(len); + + // Load the first group and advance ctrl to point to the next group + let current_group = Group::load_aligned(ctrl).match_full(); + let next_ctrl = ctrl.add(Group::WIDTH); + + Self { + current_group, + data, + next_ctrl, + end, + } + } + + /// Splits a `RawIterRange` into two halves. + /// + /// Returns `None` if the remaining range is smaller than or equal to the + /// group width. + #[cfg_attr(feature = "inline-more", inline)] + #[cfg(feature = "rayon")] + pub(crate) fn split(mut self) -> (Self, Option<RawIterRange<T>>) { + unsafe { + if self.end <= self.next_ctrl { + // Nothing to split if the group that we are current processing + // is the last one. + (self, None) + } else { + // len is the remaining number of elements after the group that + // we are currently processing. It must be a multiple of the + // group size (small tables are caught by the check above). + let len = offset_from(self.end, self.next_ctrl); + debug_assert_eq!(len % Group::WIDTH, 0); + + // Split the remaining elements into two halves, but round the + // midpoint down in case there is an odd number of groups + // remaining. This ensures that: + // - The tail is at least 1 group long. + // - The split is roughly even considering we still have the + // current group to process. + let mid = (len / 2) & !(Group::WIDTH - 1); + + let tail = Self::new( + self.next_ctrl.add(mid), + self.data.next_n(Group::WIDTH).next_n(mid), + len - mid, + ); + debug_assert_eq!( + self.data.next_n(Group::WIDTH).next_n(mid).ptr, + tail.data.ptr + ); + debug_assert_eq!(self.end, tail.end); + self.end = self.next_ctrl.add(mid); + debug_assert_eq!(self.end.add(Group::WIDTH), tail.next_ctrl); + (self, Some(tail)) + } + } + } + + /// # Safety + /// If DO_CHECK_PTR_RANGE is false, caller must ensure that we never try to iterate + /// after yielding all elements. + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn next_impl<const DO_CHECK_PTR_RANGE: bool>(&mut self) -> Option<Bucket<T>> { + loop { + if let Some(index) = self.current_group.lowest_set_bit() { + self.current_group = self.current_group.remove_lowest_bit(); + return Some(self.data.next_n(index)); + } + + if DO_CHECK_PTR_RANGE && self.next_ctrl >= self.end { + return None; + } + + // We might read past self.end up to the next group boundary, + // but this is fine because it only occurs on tables smaller + // than the group size where the trailing control bytes are all + // EMPTY. On larger tables self.end is guaranteed to be aligned + // to the group size (since tables are power-of-two sized). + self.current_group = Group::load_aligned(self.next_ctrl).match_full(); + self.data = self.data.next_n(Group::WIDTH); + self.next_ctrl = self.next_ctrl.add(Group::WIDTH); + } + } +} + +// We make raw iterators unconditionally Send and Sync, and let the PhantomData +// in the actual iterator implementations determine the real Send/Sync bounds. +unsafe impl<T> Send for RawIterRange<T> {} +unsafe impl<T> Sync for RawIterRange<T> {} + +impl<T> Clone for RawIterRange<T> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Self { + data: self.data.clone(), + next_ctrl: self.next_ctrl, + current_group: self.current_group, + end: self.end, + } + } +} + +impl<T> Iterator for RawIterRange<T> { + type Item = Bucket<T>; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<Bucket<T>> { + unsafe { + // SAFETY: We set checker flag to true. + self.next_impl::<true>() + } + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + // We don't have an item count, so just guess based on the range size. + let remaining_buckets = if self.end > self.next_ctrl { + unsafe { offset_from(self.end, self.next_ctrl) } + } else { + 0 + }; + + // Add a group width to include the group we are currently processing. + (0, Some(Group::WIDTH + remaining_buckets)) + } +} + +impl<T> FusedIterator for RawIterRange<T> {} + +/// Iterator which returns a raw pointer to every full bucket in the table. +/// +/// For maximum flexibility this iterator is not bound by a lifetime, but you +/// must observe several rules when using it: +/// - You must not free the hash table while iterating (including via growing/shrinking). +/// - It is fine to erase a bucket that has been yielded by the iterator. +/// - Erasing a bucket that has not yet been yielded by the iterator may still +/// result in the iterator yielding that bucket (unless `reflect_remove` is called). +/// - It is unspecified whether an element inserted after the iterator was +/// created will be yielded by that iterator (unless `reflect_insert` is called). +/// - The order in which the iterator yields bucket is unspecified and may +/// change in the future. +pub struct RawIter<T> { + pub(crate) iter: RawIterRange<T>, + items: usize, +} + +impl<T> RawIter<T> { + /// Refresh the iterator so that it reflects a removal from the given bucket. + /// + /// For the iterator to remain valid, this method must be called once + /// for each removed bucket before `next` is called again. + /// + /// This method should be called _before_ the removal is made. It is not necessary to call this + /// method if you are removing an item that this iterator yielded in the past. + #[cfg(feature = "raw")] + pub fn reflect_remove(&mut self, b: &Bucket<T>) { + self.reflect_toggle_full(b, false); + } + + /// Refresh the iterator so that it reflects an insertion into the given bucket. + /// + /// For the iterator to remain valid, this method must be called once + /// for each insert before `next` is called again. + /// + /// This method does not guarantee that an insertion of a bucket with a greater + /// index than the last one yielded will be reflected in the iterator. + /// + /// This method should be called _after_ the given insert is made. + #[cfg(feature = "raw")] + pub fn reflect_insert(&mut self, b: &Bucket<T>) { + self.reflect_toggle_full(b, true); + } + + /// Refresh the iterator so that it reflects a change to the state of the given bucket. + #[cfg(feature = "raw")] + fn reflect_toggle_full(&mut self, b: &Bucket<T>, is_insert: bool) { + unsafe { + if b.as_ptr() > self.iter.data.as_ptr() { + // The iterator has already passed the bucket's group. + // So the toggle isn't relevant to this iterator. + return; + } + + if self.iter.next_ctrl < self.iter.end + && b.as_ptr() <= self.iter.data.next_n(Group::WIDTH).as_ptr() + { + // The iterator has not yet reached the bucket's group. + // We don't need to reload anything, but we do need to adjust the item count. + + if cfg!(debug_assertions) { + // Double-check that the user isn't lying to us by checking the bucket state. + // To do that, we need to find its control byte. We know that self.iter.data is + // at self.iter.next_ctrl - Group::WIDTH, so we work from there: + let offset = offset_from(self.iter.data.as_ptr(), b.as_ptr()); + let ctrl = self.iter.next_ctrl.sub(Group::WIDTH).add(offset); + // This method should be called _before_ a removal, or _after_ an insert, + // so in both cases the ctrl byte should indicate that the bucket is full. + assert!(is_full(*ctrl)); + } + + if is_insert { + self.items += 1; + } else { + self.items -= 1; + } + + return; + } + + // The iterator is at the bucket group that the toggled bucket is in. + // We need to do two things: + // + // - Determine if the iterator already yielded the toggled bucket. + // If it did, we're done. + // - Otherwise, update the iterator cached group so that it won't + // yield a to-be-removed bucket, or _will_ yield a to-be-added bucket. + // We'll also need to update the item count accordingly. + if let Some(index) = self.iter.current_group.lowest_set_bit() { + let next_bucket = self.iter.data.next_n(index); + if b.as_ptr() > next_bucket.as_ptr() { + // The toggled bucket is "before" the bucket the iterator would yield next. We + // therefore don't need to do anything --- the iterator has already passed the + // bucket in question. + // + // The item count must already be correct, since a removal or insert "prior" to + // the iterator's position wouldn't affect the item count. + } else { + // The removed bucket is an upcoming bucket. We need to make sure it does _not_ + // get yielded, and also that it's no longer included in the item count. + // + // NOTE: We can't just reload the group here, both since that might reflect + // inserts we've already passed, and because that might inadvertently unset the + // bits for _other_ removals. If we do that, we'd have to also decrement the + // item count for those other bits that we unset. But the presumably subsequent + // call to reflect for those buckets might _also_ decrement the item count. + // Instead, we _just_ flip the bit for the particular bucket the caller asked + // us to reflect. + let our_bit = offset_from(self.iter.data.as_ptr(), b.as_ptr()); + let was_full = self.iter.current_group.flip(our_bit); + debug_assert_ne!(was_full, is_insert); + + if is_insert { + self.items += 1; + } else { + self.items -= 1; + } + + if cfg!(debug_assertions) { + if b.as_ptr() == next_bucket.as_ptr() { + // The removed bucket should no longer be next + debug_assert_ne!(self.iter.current_group.lowest_set_bit(), Some(index)); + } else { + // We should not have changed what bucket comes next. + debug_assert_eq!(self.iter.current_group.lowest_set_bit(), Some(index)); + } + } + } + } else { + // We must have already iterated past the removed item. + } + } + } + + unsafe fn drop_elements(&mut self) { + if mem::needs_drop::<T>() && self.len() != 0 { + for item in self { + item.drop(); + } + } + } +} + +impl<T> Clone for RawIter<T> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Self { + iter: self.iter.clone(), + items: self.items, + } + } +} + +impl<T> Iterator for RawIter<T> { + type Item = Bucket<T>; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<Bucket<T>> { + // Inner iterator iterates over buckets + // so it can do unnecessary work if we already yielded all items. + if self.items == 0 { + return None; + } + + let nxt = unsafe { + // SAFETY: We check number of items to yield using `items` field. + self.iter.next_impl::<false>() + }; + + if nxt.is_some() { + self.items -= 1; + } + + nxt + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + (self.items, Some(self.items)) + } +} + +impl<T> ExactSizeIterator for RawIter<T> {} +impl<T> FusedIterator for RawIter<T> {} + +/// Iterator which consumes a table and returns elements. +pub struct RawIntoIter<T, A: Allocator + Clone = Global> { + iter: RawIter<T>, + allocation: Option<(NonNull<u8>, Layout)>, + marker: PhantomData<T>, + alloc: A, +} + +impl<T, A: Allocator + Clone> RawIntoIter<T, A> { + #[cfg_attr(feature = "inline-more", inline)] + pub fn iter(&self) -> RawIter<T> { + self.iter.clone() + } +} + +unsafe impl<T, A: Allocator + Clone> Send for RawIntoIter<T, A> +where + T: Send, + A: Send, +{ +} +unsafe impl<T, A: Allocator + Clone> Sync for RawIntoIter<T, A> +where + T: Sync, + A: Sync, +{ +} + +#[cfg(feature = "nightly")] +unsafe impl<#[may_dangle] T, A: Allocator + Clone> Drop for RawIntoIter<T, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + unsafe { + // Drop all remaining elements + self.iter.drop_elements(); + + // Free the table + if let Some((ptr, layout)) = self.allocation { + self.alloc.deallocate(ptr, layout); + } + } + } +} +#[cfg(not(feature = "nightly"))] +impl<T, A: Allocator + Clone> Drop for RawIntoIter<T, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + unsafe { + // Drop all remaining elements + self.iter.drop_elements(); + + // Free the table + if let Some((ptr, layout)) = self.allocation { + self.alloc.deallocate(ptr, layout); + } + } + } +} + +impl<T, A: Allocator + Clone> Iterator for RawIntoIter<T, A> { + type Item = T; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<T> { + unsafe { Some(self.iter.next()?.read()) } + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + self.iter.size_hint() + } +} + +impl<T, A: Allocator + Clone> ExactSizeIterator for RawIntoIter<T, A> {} +impl<T, A: Allocator + Clone> FusedIterator for RawIntoIter<T, A> {} + +/// Iterator which consumes elements without freeing the table storage. +pub struct RawDrain<'a, T, A: Allocator + Clone = Global> { + iter: RawIter<T>, + + // The table is moved into the iterator for the duration of the drain. This + // ensures that an empty table is left if the drain iterator is leaked + // without dropping. + table: ManuallyDrop<RawTable<T, A>>, + orig_table: NonNull<RawTable<T, A>>, + + // We don't use a &'a mut RawTable<T> because we want RawDrain to be + // covariant over T. + marker: PhantomData<&'a RawTable<T, A>>, +} + +impl<T, A: Allocator + Clone> RawDrain<'_, T, A> { + #[cfg_attr(feature = "inline-more", inline)] + pub fn iter(&self) -> RawIter<T> { + self.iter.clone() + } +} + +unsafe impl<T, A: Allocator + Copy> Send for RawDrain<'_, T, A> +where + T: Send, + A: Send, +{ +} +unsafe impl<T, A: Allocator + Copy> Sync for RawDrain<'_, T, A> +where + T: Sync, + A: Sync, +{ +} + +impl<T, A: Allocator + Clone> Drop for RawDrain<'_, T, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + unsafe { + // Drop all remaining elements. Note that this may panic. + self.iter.drop_elements(); + + // Reset the contents of the table now that all elements have been + // dropped. + self.table.clear_no_drop(); + + // Move the now empty table back to its original location. + self.orig_table + .as_ptr() + .copy_from_nonoverlapping(&*self.table, 1); + } + } +} + +impl<T, A: Allocator + Clone> Iterator for RawDrain<'_, T, A> { + type Item = T; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<T> { + unsafe { + let item = self.iter.next()?; + Some(item.read()) + } + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + self.iter.size_hint() + } +} + +impl<T, A: Allocator + Clone> ExactSizeIterator for RawDrain<'_, T, A> {} +impl<T, A: Allocator + Clone> FusedIterator for RawDrain<'_, T, A> {} + +/// Iterator over occupied buckets that could match a given hash. +/// +/// `RawTable` only stores 7 bits of the hash value, so this iterator may return +/// items that have a hash value different than the one provided. You should +/// always validate the returned values before using them. +pub struct RawIterHash<'a, T, A: Allocator + Clone = Global> { + inner: RawIterHashInner<'a, A>, + _marker: PhantomData<T>, +} + +struct RawIterHashInner<'a, A: Allocator + Clone> { + table: &'a RawTableInner<A>, + + // The top 7 bits of the hash. + h2_hash: u8, + + // The sequence of groups to probe in the search. + probe_seq: ProbeSeq, + + group: Group, + + // The elements within the group with a matching h2-hash. + bitmask: BitMaskIter, +} + +impl<'a, T, A: Allocator + Clone> RawIterHash<'a, T, A> { + #[cfg_attr(feature = "inline-more", inline)] + #[cfg(feature = "raw")] + fn new(table: &'a RawTable<T, A>, hash: u64) -> Self { + RawIterHash { + inner: RawIterHashInner::new(&table.table, hash), + _marker: PhantomData, + } + } +} +impl<'a, A: Allocator + Clone> RawIterHashInner<'a, A> { + #[cfg_attr(feature = "inline-more", inline)] + #[cfg(feature = "raw")] + fn new(table: &'a RawTableInner<A>, hash: u64) -> Self { + unsafe { + let h2_hash = h2(hash); + let probe_seq = table.probe_seq(hash); + let group = Group::load(table.ctrl(probe_seq.pos)); + let bitmask = group.match_byte(h2_hash).into_iter(); + + RawIterHashInner { + table, + h2_hash, + probe_seq, + group, + bitmask, + } + } + } +} + +impl<'a, T, A: Allocator + Clone> Iterator for RawIterHash<'a, T, A> { + type Item = Bucket<T>; + + fn next(&mut self) -> Option<Bucket<T>> { + unsafe { + match self.inner.next() { + Some(index) => Some(self.inner.table.bucket(index)), + None => None, + } + } + } +} + +impl<'a, A: Allocator + Clone> Iterator for RawIterHashInner<'a, A> { + type Item = usize; + + fn next(&mut self) -> Option<Self::Item> { + unsafe { + loop { + if let Some(bit) = self.bitmask.next() { + let index = (self.probe_seq.pos + bit) & self.table.bucket_mask; + return Some(index); + } + if likely(self.group.match_empty().any_bit_set()) { + return None; + } + self.probe_seq.move_next(self.table.bucket_mask); + self.group = Group::load(self.table.ctrl(self.probe_seq.pos)); + self.bitmask = self.group.match_byte(self.h2_hash).into_iter(); + } + } + } +} + +#[cfg(test)] +mod test_map { + use super::*; + + fn rehash_in_place<T>(table: &mut RawTable<T>, hasher: impl Fn(&T) -> u64) { + unsafe { + table.table.rehash_in_place( + &|table, index| hasher(table.bucket::<T>(index).as_ref()), + mem::size_of::<T>(), + if mem::needs_drop::<T>() { + Some(mem::transmute(ptr::drop_in_place::<T> as unsafe fn(*mut T))) + } else { + None + }, + ); + } + } + + #[test] + fn rehash() { + let mut table = RawTable::new(); + let hasher = |i: &u64| *i; + for i in 0..100 { + table.insert(i, i, hasher); + } + + for i in 0..100 { + unsafe { + assert_eq!(table.find(i, |x| *x == i).map(|b| b.read()), Some(i)); + } + assert!(table.find(i + 100, |x| *x == i + 100).is_none()); + } + + rehash_in_place(&mut table, hasher); + + for i in 0..100 { + unsafe { + assert_eq!(table.find(i, |x| *x == i).map(|b| b.read()), Some(i)); + } + assert!(table.find(i + 100, |x| *x == i + 100).is_none()); + } + } +} diff --git a/vendor/hashbrown/src/raw/sse2.rs b/vendor/hashbrown/src/raw/sse2.rs new file mode 100644 index 000000000..a0bf6da80 --- /dev/null +++ b/vendor/hashbrown/src/raw/sse2.rs @@ -0,0 +1,146 @@ +use super::bitmask::BitMask; +use super::EMPTY; +use core::mem; + +#[cfg(target_arch = "x86")] +use core::arch::x86; +#[cfg(target_arch = "x86_64")] +use core::arch::x86_64 as x86; + +pub type BitMaskWord = u16; +pub const BITMASK_STRIDE: usize = 1; +pub const BITMASK_MASK: BitMaskWord = 0xffff; + +/// Abstraction over a group of control bytes which can be scanned in +/// parallel. +/// +/// This implementation uses a 128-bit SSE value. +#[derive(Copy, Clone)] +pub struct Group(x86::__m128i); + +// FIXME: https://github.com/rust-lang/rust-clippy/issues/3859 +#[allow(clippy::use_self)] +impl Group { + /// Number of bytes in the group. + pub const WIDTH: usize = mem::size_of::<Self>(); + + /// Returns a full group of empty bytes, suitable for use as the initial + /// value for an empty hash table. + /// + /// This is guaranteed to be aligned to the group size. + #[inline] + #[allow(clippy::items_after_statements)] + pub const fn static_empty() -> &'static [u8; Group::WIDTH] { + #[repr(C)] + struct AlignedBytes { + _align: [Group; 0], + bytes: [u8; Group::WIDTH], + } + const ALIGNED_BYTES: AlignedBytes = AlignedBytes { + _align: [], + bytes: [EMPTY; Group::WIDTH], + }; + &ALIGNED_BYTES.bytes + } + + /// Loads a group of bytes starting at the given address. + #[inline] + #[allow(clippy::cast_ptr_alignment)] // unaligned load + pub unsafe fn load(ptr: *const u8) -> Self { + Group(x86::_mm_loadu_si128(ptr.cast())) + } + + /// Loads a group of bytes starting at the given address, which must be + /// aligned to `mem::align_of::<Group>()`. + #[inline] + #[allow(clippy::cast_ptr_alignment)] + pub unsafe fn load_aligned(ptr: *const u8) -> Self { + // FIXME: use align_offset once it stabilizes + debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); + Group(x86::_mm_load_si128(ptr.cast())) + } + + /// Stores the group of bytes to the given address, which must be + /// aligned to `mem::align_of::<Group>()`. + #[inline] + #[allow(clippy::cast_ptr_alignment)] + pub unsafe fn store_aligned(self, ptr: *mut u8) { + // FIXME: use align_offset once it stabilizes + debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); + x86::_mm_store_si128(ptr.cast(), self.0); + } + + /// Returns a `BitMask` indicating all bytes in the group which have + /// the given value. + #[inline] + pub fn match_byte(self, byte: u8) -> BitMask { + #[allow( + clippy::cast_possible_wrap, // byte: u8 as i8 + // byte: i32 as u16 + // note: _mm_movemask_epi8 returns a 16-bit mask in a i32, the + // upper 16-bits of the i32 are zeroed: + clippy::cast_sign_loss, + clippy::cast_possible_truncation + )] + unsafe { + let cmp = x86::_mm_cmpeq_epi8(self.0, x86::_mm_set1_epi8(byte as i8)); + BitMask(x86::_mm_movemask_epi8(cmp) as u16) + } + } + + /// Returns a `BitMask` indicating all bytes in the group which are + /// `EMPTY`. + #[inline] + pub fn match_empty(self) -> BitMask { + self.match_byte(EMPTY) + } + + /// Returns a `BitMask` indicating all bytes in the group which are + /// `EMPTY` or `DELETED`. + #[inline] + pub fn match_empty_or_deleted(self) -> BitMask { + #[allow( + // byte: i32 as u16 + // note: _mm_movemask_epi8 returns a 16-bit mask in a i32, the + // upper 16-bits of the i32 are zeroed: + clippy::cast_sign_loss, + clippy::cast_possible_truncation + )] + unsafe { + // A byte is EMPTY or DELETED iff the high bit is set + BitMask(x86::_mm_movemask_epi8(self.0) as u16) + } + } + + /// Returns a `BitMask` indicating all bytes in the group which are full. + #[inline] + pub fn match_full(&self) -> BitMask { + self.match_empty_or_deleted().invert() + } + + /// Performs the following transformation on all bytes in the group: + /// - `EMPTY => EMPTY` + /// - `DELETED => EMPTY` + /// - `FULL => DELETED` + #[inline] + pub fn convert_special_to_empty_and_full_to_deleted(self) -> Self { + // Map high_bit = 1 (EMPTY or DELETED) to 1111_1111 + // and high_bit = 0 (FULL) to 1000_0000 + // + // Here's this logic expanded to concrete values: + // let special = 0 > byte = 1111_1111 (true) or 0000_0000 (false) + // 1111_1111 | 1000_0000 = 1111_1111 + // 0000_0000 | 1000_0000 = 1000_0000 + #[allow( + clippy::cast_possible_wrap, // byte: 0x80_u8 as i8 + )] + unsafe { + let zero = x86::_mm_setzero_si128(); + let special = x86::_mm_cmpgt_epi8(zero, self.0); + Group(x86::_mm_or_si128( + special, + x86::_mm_set1_epi8(0x80_u8 as i8), + )) + } + } +} diff --git a/vendor/hashbrown/src/rustc_entry.rs b/vendor/hashbrown/src/rustc_entry.rs new file mode 100644 index 000000000..2e8459526 --- /dev/null +++ b/vendor/hashbrown/src/rustc_entry.rs @@ -0,0 +1,630 @@ +use self::RustcEntry::*; +use crate::map::{make_insert_hash, Drain, HashMap, IntoIter, Iter, IterMut}; +use crate::raw::{Allocator, Bucket, Global, RawTable}; +use core::fmt::{self, Debug}; +use core::hash::{BuildHasher, Hash}; +use core::mem; + +impl<K, V, S, A> HashMap<K, V, S, A> +where + K: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + /// Gets the given key's corresponding entry in the map for in-place manipulation. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut letters = HashMap::new(); + /// + /// for ch in "a short treatise on fungi".chars() { + /// let counter = letters.rustc_entry(ch).or_insert(0); + /// *counter += 1; + /// } + /// + /// assert_eq!(letters[&'s'], 2); + /// assert_eq!(letters[&'t'], 3); + /// assert_eq!(letters[&'u'], 1); + /// assert_eq!(letters.get(&'y'), None); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn rustc_entry(&mut self, key: K) -> RustcEntry<'_, K, V, A> { + let hash = make_insert_hash(&self.hash_builder, &key); + if let Some(elem) = self.table.find(hash, |q| q.0.eq(&key)) { + RustcEntry::Occupied(RustcOccupiedEntry { + key: Some(key), + elem, + table: &mut self.table, + }) + } else { + // Ideally we would put this in VacantEntry::insert, but Entry is not + // generic over the BuildHasher and adding a generic parameter would be + // a breaking change. + self.reserve(1); + + RustcEntry::Vacant(RustcVacantEntry { + hash, + key, + table: &mut self.table, + }) + } + } +} + +/// A view into a single entry in a map, which may either be vacant or occupied. +/// +/// This `enum` is constructed from the [`rustc_entry`] method on [`HashMap`]. +/// +/// [`HashMap`]: struct.HashMap.html +/// [`rustc_entry`]: struct.HashMap.html#method.rustc_entry +pub enum RustcEntry<'a, K, V, A = Global> +where + A: Allocator + Clone, +{ + /// An occupied entry. + Occupied(RustcOccupiedEntry<'a, K, V, A>), + + /// A vacant entry. + Vacant(RustcVacantEntry<'a, K, V, A>), +} + +impl<K: Debug, V: Debug, A: Allocator + Clone> Debug for RustcEntry<'_, K, V, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(), + Occupied(ref o) => f.debug_tuple("Entry").field(o).finish(), + } + } +} + +/// A view into an occupied entry in a `HashMap`. +/// It is part of the [`RustcEntry`] enum. +/// +/// [`RustcEntry`]: enum.RustcEntry.html +pub struct RustcOccupiedEntry<'a, K, V, A = Global> +where + A: Allocator + Clone, +{ + key: Option<K>, + elem: Bucket<(K, V)>, + table: &'a mut RawTable<(K, V), A>, +} + +unsafe impl<K, V, A> Send for RustcOccupiedEntry<'_, K, V, A> +where + K: Send, + V: Send, + A: Allocator + Clone + Send, +{ +} +unsafe impl<K, V, A> Sync for RustcOccupiedEntry<'_, K, V, A> +where + K: Sync, + V: Sync, + A: Allocator + Clone + Sync, +{ +} + +impl<K: Debug, V: Debug, A: Allocator + Clone> Debug for RustcOccupiedEntry<'_, K, V, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("OccupiedEntry") + .field("key", self.key()) + .field("value", self.get()) + .finish() + } +} + +/// A view into a vacant entry in a `HashMap`. +/// It is part of the [`RustcEntry`] enum. +/// +/// [`RustcEntry`]: enum.RustcEntry.html +pub struct RustcVacantEntry<'a, K, V, A = Global> +where + A: Allocator + Clone, +{ + hash: u64, + key: K, + table: &'a mut RawTable<(K, V), A>, +} + +impl<K: Debug, V, A: Allocator + Clone> Debug for RustcVacantEntry<'_, K, V, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("VacantEntry").field(self.key()).finish() + } +} + +impl<'a, K, V, A: Allocator + Clone> RustcEntry<'a, K, V, A> { + /// Sets the value of the entry, and returns a RustcOccupiedEntry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// let entry = map.rustc_entry("horseyland").insert(37); + /// + /// assert_eq!(entry.key(), &"horseyland"); + /// ``` + pub fn insert(self, value: V) -> RustcOccupiedEntry<'a, K, V, A> { + match self { + Vacant(entry) => entry.insert_entry(value), + Occupied(mut entry) => { + entry.insert(value); + entry + } + } + } + + /// Ensures a value is in the entry by inserting the default if empty, and returns + /// a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// map.rustc_entry("poneyland").or_insert(3); + /// assert_eq!(map["poneyland"], 3); + /// + /// *map.rustc_entry("poneyland").or_insert(10) *= 2; + /// assert_eq!(map["poneyland"], 6); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert(self, default: V) -> &'a mut V + where + K: Hash, + { + match self { + Occupied(entry) => entry.into_mut(), + Vacant(entry) => entry.insert(default), + } + } + + /// Ensures a value is in the entry by inserting the result of the default function if empty, + /// and returns a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, String> = HashMap::new(); + /// let s = "hoho".to_string(); + /// + /// map.rustc_entry("poneyland").or_insert_with(|| s); + /// + /// assert_eq!(map["poneyland"], "hoho".to_string()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V + where + K: Hash, + { + match self { + Occupied(entry) => entry.into_mut(), + Vacant(entry) => entry.insert(default()), + } + } + + /// Returns a reference to this entry's key. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// assert_eq!(map.rustc_entry("poneyland").key(), &"poneyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &K { + match *self { + Occupied(ref entry) => entry.key(), + Vacant(ref entry) => entry.key(), + } + } + + /// Provides in-place mutable access to an occupied entry before any + /// potential inserts into the map. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// map.rustc_entry("poneyland") + /// .and_modify(|e| { *e += 1 }) + /// .or_insert(42); + /// assert_eq!(map["poneyland"], 42); + /// + /// map.rustc_entry("poneyland") + /// .and_modify(|e| { *e += 1 }) + /// .or_insert(42); + /// assert_eq!(map["poneyland"], 43); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn and_modify<F>(self, f: F) -> Self + where + F: FnOnce(&mut V), + { + match self { + Occupied(mut entry) => { + f(entry.get_mut()); + Occupied(entry) + } + Vacant(entry) => Vacant(entry), + } + } +} + +impl<'a, K, V: Default, A: Allocator + Clone> RustcEntry<'a, K, V, A> { + /// Ensures a value is in the entry by inserting the default value if empty, + /// and returns a mutable reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// # fn main() { + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, Option<u32>> = HashMap::new(); + /// map.rustc_entry("poneyland").or_default(); + /// + /// assert_eq!(map["poneyland"], None); + /// # } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_default(self) -> &'a mut V + where + K: Hash, + { + match self { + Occupied(entry) => entry.into_mut(), + Vacant(entry) => entry.insert(Default::default()), + } + } +} + +impl<'a, K, V, A: Allocator + Clone> RustcOccupiedEntry<'a, K, V, A> { + /// Gets a reference to the key in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.rustc_entry("poneyland").or_insert(12); + /// assert_eq!(map.rustc_entry("poneyland").key(), &"poneyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &K { + unsafe { &self.elem.as_ref().0 } + } + + /// Take the ownership of the key and value from the map. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.rustc_entry("poneyland").or_insert(12); + /// + /// if let RustcEntry::Occupied(o) = map.rustc_entry("poneyland") { + /// // We delete the entry from the map. + /// o.remove_entry(); + /// } + /// + /// assert_eq!(map.contains_key("poneyland"), false); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove_entry(self) -> (K, V) { + unsafe { self.table.remove(self.elem) } + } + + /// Gets a reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.rustc_entry("poneyland").or_insert(12); + /// + /// if let RustcEntry::Occupied(o) = map.rustc_entry("poneyland") { + /// assert_eq!(o.get(), &12); + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get(&self) -> &V { + unsafe { &self.elem.as_ref().1 } + } + + /// Gets a mutable reference to the value in the entry. + /// + /// If you need a reference to the `RustcOccupiedEntry` which may outlive the + /// destruction of the `RustcEntry` value, see [`into_mut`]. + /// + /// [`into_mut`]: #method.into_mut + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.rustc_entry("poneyland").or_insert(12); + /// + /// assert_eq!(map["poneyland"], 12); + /// if let RustcEntry::Occupied(mut o) = map.rustc_entry("poneyland") { + /// *o.get_mut() += 10; + /// assert_eq!(*o.get(), 22); + /// + /// // We can use the same RustcEntry multiple times. + /// *o.get_mut() += 2; + /// } + /// + /// assert_eq!(map["poneyland"], 24); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_mut(&mut self) -> &mut V { + unsafe { &mut self.elem.as_mut().1 } + } + + /// Converts the RustcOccupiedEntry into a mutable reference to the value in the entry + /// with a lifetime bound to the map itself. + /// + /// If you need multiple references to the `RustcOccupiedEntry`, see [`get_mut`]. + /// + /// [`get_mut`]: #method.get_mut + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.rustc_entry("poneyland").or_insert(12); + /// + /// assert_eq!(map["poneyland"], 12); + /// if let RustcEntry::Occupied(o) = map.rustc_entry("poneyland") { + /// *o.into_mut() += 10; + /// } + /// + /// assert_eq!(map["poneyland"], 22); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_mut(self) -> &'a mut V { + unsafe { &mut self.elem.as_mut().1 } + } + + /// Sets the value of the entry, and returns the entry's old value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.rustc_entry("poneyland").or_insert(12); + /// + /// if let RustcEntry::Occupied(mut o) = map.rustc_entry("poneyland") { + /// assert_eq!(o.insert(15), 12); + /// } + /// + /// assert_eq!(map["poneyland"], 15); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(&mut self, value: V) -> V { + mem::replace(self.get_mut(), value) + } + + /// Takes the value out of the entry, and returns it. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// map.rustc_entry("poneyland").or_insert(12); + /// + /// if let RustcEntry::Occupied(o) = map.rustc_entry("poneyland") { + /// assert_eq!(o.remove(), 12); + /// } + /// + /// assert_eq!(map.contains_key("poneyland"), false); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove(self) -> V { + self.remove_entry().1 + } + + /// Replaces the entry, returning the old key and value. The new key in the hash map will be + /// the key used to create this entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{RustcEntry, HashMap}; + /// use std::rc::Rc; + /// + /// let mut map: HashMap<Rc<String>, u32> = HashMap::new(); + /// map.insert(Rc::new("Stringthing".to_string()), 15); + /// + /// let my_key = Rc::new("Stringthing".to_string()); + /// + /// if let RustcEntry::Occupied(entry) = map.rustc_entry(my_key) { + /// // Also replace the key with a handle to our other key. + /// let (old_key, old_value): (Rc<String>, u32) = entry.replace_entry(16); + /// } + /// + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_entry(self, value: V) -> (K, V) { + let entry = unsafe { self.elem.as_mut() }; + + let old_key = mem::replace(&mut entry.0, self.key.unwrap()); + let old_value = mem::replace(&mut entry.1, value); + + (old_key, old_value) + } + + /// Replaces the key in the hash map with the key used to create this entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_map::{RustcEntry, HashMap}; + /// use std::rc::Rc; + /// + /// let mut map: HashMap<Rc<String>, u32> = HashMap::new(); + /// let mut known_strings: Vec<Rc<String>> = Vec::new(); + /// + /// // Initialise known strings, run program, etc. + /// + /// reclaim_memory(&mut map, &known_strings); + /// + /// fn reclaim_memory(map: &mut HashMap<Rc<String>, u32>, known_strings: &[Rc<String>] ) { + /// for s in known_strings { + /// if let RustcEntry::Occupied(entry) = map.rustc_entry(s.clone()) { + /// // Replaces the entry's key with our version of it in `known_strings`. + /// entry.replace_key(); + /// } + /// } + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace_key(self) -> K { + let entry = unsafe { self.elem.as_mut() }; + mem::replace(&mut entry.0, self.key.unwrap()) + } +} + +impl<'a, K, V, A: Allocator + Clone> RustcVacantEntry<'a, K, V, A> { + /// Gets a reference to the key that would be used when inserting a value + /// through the `RustcVacantEntry`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// assert_eq!(map.rustc_entry("poneyland").key(), &"poneyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn key(&self) -> &K { + &self.key + } + + /// Take ownership of the key. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// if let RustcEntry::Vacant(v) = map.rustc_entry("poneyland") { + /// v.into_key(); + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_key(self) -> K { + self.key + } + + /// Sets the value of the entry with the RustcVacantEntry's key, + /// and returns a mutable reference to it. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// if let RustcEntry::Vacant(o) = map.rustc_entry("poneyland") { + /// o.insert(37); + /// } + /// assert_eq!(map["poneyland"], 37); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self, value: V) -> &'a mut V { + unsafe { + let bucket = self.table.insert_no_grow(self.hash, (self.key, value)); + &mut bucket.as_mut().1 + } + } + + /// Sets the value of the entry with the RustcVacantEntry's key, + /// and returns a RustcOccupiedEntry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use hashbrown::hash_map::RustcEntry; + /// + /// let mut map: HashMap<&str, u32> = HashMap::new(); + /// + /// if let RustcEntry::Vacant(v) = map.rustc_entry("poneyland") { + /// let o = v.insert_entry(37); + /// assert_eq!(o.get(), &37); + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert_entry(self, value: V) -> RustcOccupiedEntry<'a, K, V, A> { + let bucket = unsafe { self.table.insert_no_grow(self.hash, (self.key, value)) }; + RustcOccupiedEntry { + key: None, + elem: bucket, + table: self.table, + } + } +} + +impl<K, V> IterMut<'_, K, V> { + /// Returns a iterator of references over the remaining items. + #[cfg_attr(feature = "inline-more", inline)] + pub fn rustc_iter(&self) -> Iter<'_, K, V> { + self.iter() + } +} + +impl<K, V> IntoIter<K, V> { + /// Returns a iterator of references over the remaining items. + #[cfg_attr(feature = "inline-more", inline)] + pub fn rustc_iter(&self) -> Iter<'_, K, V> { + self.iter() + } +} + +impl<K, V> Drain<'_, K, V> { + /// Returns a iterator of references over the remaining items. + #[cfg_attr(feature = "inline-more", inline)] + pub fn rustc_iter(&self) -> Iter<'_, K, V> { + self.iter() + } +} diff --git a/vendor/hashbrown/src/scopeguard.rs b/vendor/hashbrown/src/scopeguard.rs new file mode 100644 index 000000000..f85e6ab0e --- /dev/null +++ b/vendor/hashbrown/src/scopeguard.rs @@ -0,0 +1,74 @@ +// Extracted from the scopeguard crate +use core::{ + mem, + ops::{Deref, DerefMut}, + ptr, +}; + +pub struct ScopeGuard<T, F> +where + F: FnMut(&mut T), +{ + dropfn: F, + value: T, +} + +#[inline] +pub fn guard<T, F>(value: T, dropfn: F) -> ScopeGuard<T, F> +where + F: FnMut(&mut T), +{ + ScopeGuard { dropfn, value } +} + +impl<T, F> ScopeGuard<T, F> +where + F: FnMut(&mut T), +{ + #[inline] + pub fn into_inner(guard: Self) -> T { + // Cannot move out of Drop-implementing types, so + // ptr::read the value and forget the guard. + unsafe { + let value = ptr::read(&guard.value); + // read the closure so that it is dropped, and assign it to a local + // variable to ensure that it is only dropped after the guard has + // been forgotten. (In case the Drop impl of the closure, or that + // of any consumed captured variable, panics). + let _dropfn = ptr::read(&guard.dropfn); + mem::forget(guard); + value + } + } +} + +impl<T, F> Deref for ScopeGuard<T, F> +where + F: FnMut(&mut T), +{ + type Target = T; + #[inline] + fn deref(&self) -> &T { + &self.value + } +} + +impl<T, F> DerefMut for ScopeGuard<T, F> +where + F: FnMut(&mut T), +{ + #[inline] + fn deref_mut(&mut self) -> &mut T { + &mut self.value + } +} + +impl<T, F> Drop for ScopeGuard<T, F> +where + F: FnMut(&mut T), +{ + #[inline] + fn drop(&mut self) { + (self.dropfn)(&mut self.value); + } +} diff --git a/vendor/hashbrown/src/set.rs b/vendor/hashbrown/src/set.rs new file mode 100644 index 000000000..2a4dcea52 --- /dev/null +++ b/vendor/hashbrown/src/set.rs @@ -0,0 +1,2790 @@ +use crate::TryReserveError; +use alloc::borrow::ToOwned; +use core::borrow::Borrow; +use core::fmt; +use core::hash::{BuildHasher, Hash}; +use core::iter::{Chain, FromIterator, FusedIterator}; +use core::mem; +use core::ops::{BitAnd, BitOr, BitXor, Sub}; + +use super::map::{self, ConsumeAllOnDrop, DefaultHashBuilder, DrainFilterInner, HashMap, Keys}; +use crate::raw::{Allocator, Global}; + +// Future Optimization (FIXME!) +// ============================= +// +// Iteration over zero sized values is a noop. There is no need +// for `bucket.val` in the case of HashSet. I suppose we would need HKT +// to get rid of it properly. + +/// A hash set implemented as a `HashMap` where the value is `()`. +/// +/// As with the [`HashMap`] type, a `HashSet` requires that the elements +/// implement the [`Eq`] and [`Hash`] traits. This can frequently be achieved by +/// using `#[derive(PartialEq, Eq, Hash)]`. If you implement these yourself, +/// it is important that the following property holds: +/// +/// ```text +/// k1 == k2 -> hash(k1) == hash(k2) +/// ``` +/// +/// In other words, if two keys are equal, their hashes must be equal. +/// +/// +/// It is a logic error for an item to be modified in such a way that the +/// item's hash, as determined by the [`Hash`] trait, or its equality, as +/// determined by the [`Eq`] trait, changes while it is in the set. This is +/// normally only possible through [`Cell`], [`RefCell`], global state, I/O, or +/// unsafe code. +/// +/// It is also a logic error for the [`Hash`] implementation of a key to panic. +/// This is generally only possible if the trait is implemented manually. If a +/// panic does occur then the contents of the `HashSet` may become corrupted and +/// some items may be dropped from the table. +/// +/// # Examples +/// +/// ``` +/// use hashbrown::HashSet; +/// // Type inference lets us omit an explicit type signature (which +/// // would be `HashSet<String>` in this example). +/// let mut books = HashSet::new(); +/// +/// // Add some books. +/// books.insert("A Dance With Dragons".to_string()); +/// books.insert("To Kill a Mockingbird".to_string()); +/// books.insert("The Odyssey".to_string()); +/// books.insert("The Great Gatsby".to_string()); +/// +/// // Check for a specific one. +/// if !books.contains("The Winds of Winter") { +/// println!("We have {} books, but The Winds of Winter ain't one.", +/// books.len()); +/// } +/// +/// // Remove a book. +/// books.remove("The Odyssey"); +/// +/// // Iterate over everything. +/// for book in &books { +/// println!("{}", book); +/// } +/// ``` +/// +/// The easiest way to use `HashSet` with a custom type is to derive +/// [`Eq`] and [`Hash`]. We must also derive [`PartialEq`]. This will in the +/// future be implied by [`Eq`]. +/// +/// ``` +/// use hashbrown::HashSet; +/// #[derive(Hash, Eq, PartialEq, Debug)] +/// struct Viking { +/// name: String, +/// power: usize, +/// } +/// +/// let mut vikings = HashSet::new(); +/// +/// vikings.insert(Viking { name: "Einar".to_string(), power: 9 }); +/// vikings.insert(Viking { name: "Einar".to_string(), power: 9 }); +/// vikings.insert(Viking { name: "Olaf".to_string(), power: 4 }); +/// vikings.insert(Viking { name: "Harald".to_string(), power: 8 }); +/// +/// // Use derived implementation to print the vikings. +/// for x in &vikings { +/// println!("{:?}", x); +/// } +/// ``` +/// +/// A `HashSet` with fixed list of elements can be initialized from an array: +/// +/// ``` +/// use hashbrown::HashSet; +/// +/// let viking_names: HashSet<&'static str> = +/// [ "Einar", "Olaf", "Harald" ].iter().cloned().collect(); +/// // use the values stored in the set +/// ``` +/// +/// [`Cell`]: https://doc.rust-lang.org/std/cell/struct.Cell.html +/// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html +/// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html +/// [`HashMap`]: struct.HashMap.html +/// [`PartialEq`]: https://doc.rust-lang.org/std/cmp/trait.PartialEq.html +/// [`RefCell`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html +pub struct HashSet<T, S = DefaultHashBuilder, A: Allocator + Clone = Global> { + pub(crate) map: HashMap<T, (), S, A>, +} + +impl<T: Clone, S: Clone, A: Allocator + Clone> Clone for HashSet<T, S, A> { + fn clone(&self) -> Self { + HashSet { + map: self.map.clone(), + } + } + + fn clone_from(&mut self, source: &Self) { + self.map.clone_from(&source.map); + } +} + +#[cfg(feature = "ahash")] +impl<T> HashSet<T, DefaultHashBuilder> { + /// Creates an empty `HashSet`. + /// + /// The hash set is initially created with a capacity of 0, so it will not allocate until it + /// is first inserted into. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let set: HashSet<i32> = HashSet::new(); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn new() -> Self { + Self { + map: HashMap::new(), + } + } + + /// Creates an empty `HashSet` with the specified capacity. + /// + /// The hash set will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash set will not allocate. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let set: HashSet<i32> = HashSet::with_capacity(10); + /// assert!(set.capacity() >= 10); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_capacity(capacity: usize) -> Self { + Self { + map: HashMap::with_capacity(capacity), + } + } +} + +#[cfg(feature = "ahash")] +impl<T: Hash + Eq, A: Allocator + Clone> HashSet<T, DefaultHashBuilder, A> { + /// Creates an empty `HashSet`. + /// + /// The hash set is initially created with a capacity of 0, so it will not allocate until it + /// is first inserted into. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let set: HashSet<i32> = HashSet::new(); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn new_in(alloc: A) -> Self { + Self { + map: HashMap::new_in(alloc), + } + } + + /// Creates an empty `HashSet` with the specified capacity. + /// + /// The hash set will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash set will not allocate. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let set: HashSet<i32> = HashSet::with_capacity(10); + /// assert!(set.capacity() >= 10); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_capacity_in(capacity: usize, alloc: A) -> Self { + Self { + map: HashMap::with_capacity_in(capacity, alloc), + } + } +} + +impl<T, S, A: Allocator + Clone> HashSet<T, S, A> { + /// Returns the number of elements the set can hold without reallocating. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let set: HashSet<i32> = HashSet::with_capacity(100); + /// assert!(set.capacity() >= 100); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn capacity(&self) -> usize { + self.map.capacity() + } + + /// An iterator visiting all elements in arbitrary order. + /// The iterator element type is `&'a T`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let mut set = HashSet::new(); + /// set.insert("a"); + /// set.insert("b"); + /// + /// // Will print in an arbitrary order. + /// for x in set.iter() { + /// println!("{}", x); + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn iter(&self) -> Iter<'_, T> { + Iter { + iter: self.map.keys(), + } + } + + /// Returns the number of elements in the set. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut v = HashSet::new(); + /// assert_eq!(v.len(), 0); + /// v.insert(1); + /// assert_eq!(v.len(), 1); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn len(&self) -> usize { + self.map.len() + } + + /// Returns `true` if the set contains no elements. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut v = HashSet::new(); + /// assert!(v.is_empty()); + /// v.insert(1); + /// assert!(!v.is_empty()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn is_empty(&self) -> bool { + self.map.is_empty() + } + + /// Clears the set, returning all elements in an iterator. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// assert!(!set.is_empty()); + /// + /// // print 1, 2, 3 in an arbitrary order + /// for i in set.drain() { + /// println!("{}", i); + /// } + /// + /// assert!(set.is_empty()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn drain(&mut self) -> Drain<'_, T, A> { + Drain { + iter: self.map.drain(), + } + } + + /// Retains only the elements specified by the predicate. + /// + /// In other words, remove all elements `e` such that `f(&e)` returns `false`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let xs = [1,2,3,4,5,6]; + /// let mut set: HashSet<i32> = xs.iter().cloned().collect(); + /// set.retain(|&k| k % 2 == 0); + /// assert_eq!(set.len(), 3); + /// ``` + pub fn retain<F>(&mut self, mut f: F) + where + F: FnMut(&T) -> bool, + { + self.map.retain(|k, _| f(k)); + } + + /// Drains elements which are true under the given predicate, + /// and returns an iterator over the removed items. + /// + /// In other words, move all elements `e` such that `f(&e)` returns `true` out + /// into another iterator. + /// + /// When the returned DrainedFilter is dropped, any remaining elements that satisfy + /// the predicate are dropped from the set. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<i32> = (0..8).collect(); + /// let drained: HashSet<i32> = set.drain_filter(|v| v % 2 == 0).collect(); + /// + /// let mut evens = drained.into_iter().collect::<Vec<_>>(); + /// let mut odds = set.into_iter().collect::<Vec<_>>(); + /// evens.sort(); + /// odds.sort(); + /// + /// assert_eq!(evens, vec![0, 2, 4, 6]); + /// assert_eq!(odds, vec![1, 3, 5, 7]); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn drain_filter<F>(&mut self, f: F) -> DrainFilter<'_, T, F, A> + where + F: FnMut(&T) -> bool, + { + DrainFilter { + f, + inner: DrainFilterInner { + iter: unsafe { self.map.table.iter() }, + table: &mut self.map.table, + }, + } + } + + /// Clears the set, removing all values. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut v = HashSet::new(); + /// v.insert(1); + /// v.clear(); + /// assert!(v.is_empty()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn clear(&mut self) { + self.map.clear(); + } +} + +impl<T, S> HashSet<T, S, Global> { + /// Creates a new empty hash set which will use the given hasher to hash + /// keys. + /// + /// The hash set is also created with the default initial capacity. + /// + /// Warning: `hasher` is normally randomly generated, and + /// is designed to allow `HashSet`s to be resistant to attacks that + /// cause many collisions and very poor performance. Setting it + /// manually using this function can expose a DoS attack vector. + /// + /// The `hash_builder` passed should implement the [`BuildHasher`] trait for + /// the HashMap to be useful, see its documentation for details. + /// + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let s = DefaultHashBuilder::default(); + /// let mut set = HashSet::with_hasher(s); + /// set.insert(2); + /// ``` + /// + /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html + #[cfg_attr(feature = "inline-more", inline)] + pub const fn with_hasher(hasher: S) -> Self { + Self { + map: HashMap::with_hasher(hasher), + } + } + + /// Creates an empty `HashSet` with the specified capacity, using + /// `hasher` to hash the keys. + /// + /// The hash set will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash set will not allocate. + /// + /// Warning: `hasher` is normally randomly generated, and + /// is designed to allow `HashSet`s to be resistant to attacks that + /// cause many collisions and very poor performance. Setting it + /// manually using this function can expose a DoS attack vector. + /// + /// The `hash_builder` passed should implement the [`BuildHasher`] trait for + /// the HashMap to be useful, see its documentation for details. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let s = DefaultHashBuilder::default(); + /// let mut set = HashSet::with_capacity_and_hasher(10, s); + /// set.insert(1); + /// ``` + /// + /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> Self { + Self { + map: HashMap::with_capacity_and_hasher(capacity, hasher), + } + } +} + +impl<T, S, A> HashSet<T, S, A> +where + A: Allocator + Clone, +{ + /// Returns a reference to the underlying allocator. + #[inline] + pub fn allocator(&self) -> &A { + self.map.allocator() + } + + /// Creates a new empty hash set which will use the given hasher to hash + /// keys. + /// + /// The hash set is also created with the default initial capacity. + /// + /// Warning: `hasher` is normally randomly generated, and + /// is designed to allow `HashSet`s to be resistant to attacks that + /// cause many collisions and very poor performance. Setting it + /// manually using this function can expose a DoS attack vector. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let s = DefaultHashBuilder::default(); + /// let mut set = HashSet::with_hasher(s); + /// set.insert(2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_hasher_in(hasher: S, alloc: A) -> Self { + Self { + map: HashMap::with_hasher_in(hasher, alloc), + } + } + + /// Creates an empty `HashSet` with the specified capacity, using + /// `hasher` to hash the keys. + /// + /// The hash set will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash set will not allocate. + /// + /// Warning: `hasher` is normally randomly generated, and + /// is designed to allow `HashSet`s to be resistant to attacks that + /// cause many collisions and very poor performance. Setting it + /// manually using this function can expose a DoS attack vector. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let s = DefaultHashBuilder::default(); + /// let mut set = HashSet::with_capacity_and_hasher(10, s); + /// set.insert(1); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn with_capacity_and_hasher_in(capacity: usize, hasher: S, alloc: A) -> Self { + Self { + map: HashMap::with_capacity_and_hasher_in(capacity, hasher, alloc), + } + } + + /// Returns a reference to the set's [`BuildHasher`]. + /// + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// use hashbrown::hash_map::DefaultHashBuilder; + /// + /// let hasher = DefaultHashBuilder::default(); + /// let set: HashSet<i32> = HashSet::with_hasher(hasher); + /// let hasher: &DefaultHashBuilder = set.hasher(); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn hasher(&self) -> &S { + self.map.hasher() + } +} + +impl<T, S, A> HashSet<T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + /// Reserves capacity for at least `additional` more elements to be inserted + /// in the `HashSet`. The collection may reserve more space to avoid + /// frequent reallocations. + /// + /// # Panics + /// + /// Panics if the new allocation size overflows `usize`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let mut set: HashSet<i32> = HashSet::new(); + /// set.reserve(10); + /// assert!(set.capacity() >= 10); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn reserve(&mut self, additional: usize) { + self.map.reserve(additional); + } + + /// Tries to reserve capacity for at least `additional` more elements to be inserted + /// in the given `HashSet<K,V>`. The collection may reserve more space to avoid + /// frequent reallocations. + /// + /// # Errors + /// + /// If the capacity overflows, or the allocator reports a failure, then an error + /// is returned. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let mut set: HashSet<i32> = HashSet::new(); + /// set.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> { + self.map.try_reserve(additional) + } + + /// Shrinks the capacity of the set as much as possible. It will drop + /// down as much as possible while maintaining the internal rules + /// and possibly leaving some space in accordance with the resize policy. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set = HashSet::with_capacity(100); + /// set.insert(1); + /// set.insert(2); + /// assert!(set.capacity() >= 100); + /// set.shrink_to_fit(); + /// assert!(set.capacity() >= 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn shrink_to_fit(&mut self) { + self.map.shrink_to_fit(); + } + + /// Shrinks the capacity of the set with a lower limit. It will drop + /// down no lower than the supplied limit while maintaining the internal rules + /// and possibly leaving some space in accordance with the resize policy. + /// + /// Panics if the current capacity is smaller than the supplied + /// minimum capacity. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set = HashSet::with_capacity(100); + /// set.insert(1); + /// set.insert(2); + /// assert!(set.capacity() >= 100); + /// set.shrink_to(10); + /// assert!(set.capacity() >= 10); + /// set.shrink_to(0); + /// assert!(set.capacity() >= 2); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn shrink_to(&mut self, min_capacity: usize) { + self.map.shrink_to(min_capacity); + } + + /// Visits the values representing the difference, + /// i.e., the values that are in `self` but not in `other`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); + /// + /// // Can be seen as `a - b`. + /// for x in a.difference(&b) { + /// println!("{}", x); // Print 1 + /// } + /// + /// let diff: HashSet<_> = a.difference(&b).collect(); + /// assert_eq!(diff, [1].iter().collect()); + /// + /// // Note that difference is not symmetric, + /// // and `b - a` means something else: + /// let diff: HashSet<_> = b.difference(&a).collect(); + /// assert_eq!(diff, [4].iter().collect()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn difference<'a>(&'a self, other: &'a Self) -> Difference<'a, T, S, A> { + Difference { + iter: self.iter(), + other, + } + } + + /// Visits the values representing the symmetric difference, + /// i.e., the values that are in `self` or in `other` but not in both. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); + /// + /// // Print 1, 4 in arbitrary order. + /// for x in a.symmetric_difference(&b) { + /// println!("{}", x); + /// } + /// + /// let diff1: HashSet<_> = a.symmetric_difference(&b).collect(); + /// let diff2: HashSet<_> = b.symmetric_difference(&a).collect(); + /// + /// assert_eq!(diff1, diff2); + /// assert_eq!(diff1, [1, 4].iter().collect()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn symmetric_difference<'a>(&'a self, other: &'a Self) -> SymmetricDifference<'a, T, S, A> { + SymmetricDifference { + iter: self.difference(other).chain(other.difference(self)), + } + } + + /// Visits the values representing the intersection, + /// i.e., the values that are both in `self` and `other`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); + /// + /// // Print 2, 3 in arbitrary order. + /// for x in a.intersection(&b) { + /// println!("{}", x); + /// } + /// + /// let intersection: HashSet<_> = a.intersection(&b).collect(); + /// assert_eq!(intersection, [2, 3].iter().collect()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn intersection<'a>(&'a self, other: &'a Self) -> Intersection<'a, T, S, A> { + let (smaller, larger) = if self.len() <= other.len() { + (self, other) + } else { + (other, self) + }; + Intersection { + iter: smaller.iter(), + other: larger, + } + } + + /// Visits the values representing the union, + /// i.e., all the values in `self` or `other`, without duplicates. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); + /// + /// // Print 1, 2, 3, 4 in arbitrary order. + /// for x in a.union(&b) { + /// println!("{}", x); + /// } + /// + /// let union: HashSet<_> = a.union(&b).collect(); + /// assert_eq!(union, [1, 2, 3, 4].iter().collect()); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn union<'a>(&'a self, other: &'a Self) -> Union<'a, T, S, A> { + // We'll iterate one set in full, and only the remaining difference from the other. + // Use the smaller set for the difference in order to reduce hash lookups. + let (smaller, larger) = if self.len() <= other.len() { + (self, other) + } else { + (other, self) + }; + Union { + iter: larger.iter().chain(smaller.difference(larger)), + } + } + + /// Returns `true` if the set contains a value. + /// + /// The value may be any borrowed form of the set's value type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the value type. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// assert_eq!(set.contains(&1), true); + /// assert_eq!(set.contains(&4), false); + /// ``` + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + #[cfg_attr(feature = "inline-more", inline)] + pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool + where + T: Borrow<Q>, + Q: Hash + Eq, + { + self.map.contains_key(value) + } + + /// Returns a reference to the value in the set, if any, that is equal to the given value. + /// + /// The value may be any borrowed form of the set's value type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the value type. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// assert_eq!(set.get(&2), Some(&2)); + /// assert_eq!(set.get(&4), None); + /// ``` + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + #[cfg_attr(feature = "inline-more", inline)] + pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T> + where + T: Borrow<Q>, + Q: Hash + Eq, + { + // Avoid `Option::map` because it bloats LLVM IR. + match self.map.get_key_value(value) { + Some((k, _)) => Some(k), + None => None, + } + } + + /// Inserts the given `value` into the set if it is not present, then + /// returns a reference to the value in the set. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// assert_eq!(set.len(), 3); + /// assert_eq!(set.get_or_insert(2), &2); + /// assert_eq!(set.get_or_insert(100), &100); + /// assert_eq!(set.len(), 4); // 100 was inserted + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_or_insert(&mut self, value: T) -> &T { + // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with + // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`. + self.map + .raw_entry_mut() + .from_key(&value) + .or_insert(value, ()) + .0 + } + + /// Inserts an owned copy of the given `value` into the set if it is not + /// present, then returns a reference to the value in the set. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<String> = ["cat", "dog", "horse"] + /// .iter().map(|&pet| pet.to_owned()).collect(); + /// + /// assert_eq!(set.len(), 3); + /// for &pet in &["cat", "dog", "fish"] { + /// let value = set.get_or_insert_owned(pet); + /// assert_eq!(value, pet); + /// } + /// assert_eq!(set.len(), 4); // a new "fish" was inserted + /// ``` + #[inline] + pub fn get_or_insert_owned<Q: ?Sized>(&mut self, value: &Q) -> &T + where + T: Borrow<Q>, + Q: Hash + Eq + ToOwned<Owned = T>, + { + // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with + // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`. + self.map + .raw_entry_mut() + .from_key(value) + .or_insert_with(|| (value.to_owned(), ())) + .0 + } + + /// Inserts a value computed from `f` into the set if the given `value` is + /// not present, then returns a reference to the value in the set. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<String> = ["cat", "dog", "horse"] + /// .iter().map(|&pet| pet.to_owned()).collect(); + /// + /// assert_eq!(set.len(), 3); + /// for &pet in &["cat", "dog", "fish"] { + /// let value = set.get_or_insert_with(pet, str::to_owned); + /// assert_eq!(value, pet); + /// } + /// assert_eq!(set.len(), 4); // a new "fish" was inserted + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get_or_insert_with<Q: ?Sized, F>(&mut self, value: &Q, f: F) -> &T + where + T: Borrow<Q>, + Q: Hash + Eq, + F: FnOnce(&Q) -> T, + { + // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with + // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`. + self.map + .raw_entry_mut() + .from_key(value) + .or_insert_with(|| (f(value), ())) + .0 + } + + /// Gets the given value's corresponding entry in the set for in-place manipulation. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// use hashbrown::hash_set::Entry::*; + /// + /// let mut singles = HashSet::new(); + /// let mut dupes = HashSet::new(); + /// + /// for ch in "a short treatise on fungi".chars() { + /// if let Vacant(dupe_entry) = dupes.entry(ch) { + /// // We haven't already seen a duplicate, so + /// // check if we've at least seen it once. + /// match singles.entry(ch) { + /// Vacant(single_entry) => { + /// // We found a new character for the first time. + /// single_entry.insert() + /// } + /// Occupied(single_entry) => { + /// // We've already seen this once, "move" it to dupes. + /// single_entry.remove(); + /// dupe_entry.insert(); + /// } + /// } + /// } + /// } + /// + /// assert!(!singles.contains(&'t') && dupes.contains(&'t')); + /// assert!(singles.contains(&'u') && !dupes.contains(&'u')); + /// assert!(!singles.contains(&'v') && !dupes.contains(&'v')); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn entry(&mut self, value: T) -> Entry<'_, T, S, A> { + match self.map.entry(value) { + map::Entry::Occupied(entry) => Entry::Occupied(OccupiedEntry { inner: entry }), + map::Entry::Vacant(entry) => Entry::Vacant(VacantEntry { inner: entry }), + } + } + + /// Returns `true` if `self` has no elements in common with `other`. + /// This is equivalent to checking for an empty intersection. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let mut b = HashSet::new(); + /// + /// assert_eq!(a.is_disjoint(&b), true); + /// b.insert(4); + /// assert_eq!(a.is_disjoint(&b), true); + /// b.insert(1); + /// assert_eq!(a.is_disjoint(&b), false); + /// ``` + pub fn is_disjoint(&self, other: &Self) -> bool { + self.iter().all(|v| !other.contains(v)) + } + + /// Returns `true` if the set is a subset of another, + /// i.e., `other` contains at least all the values in `self`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let sup: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let mut set = HashSet::new(); + /// + /// assert_eq!(set.is_subset(&sup), true); + /// set.insert(2); + /// assert_eq!(set.is_subset(&sup), true); + /// set.insert(4); + /// assert_eq!(set.is_subset(&sup), false); + /// ``` + pub fn is_subset(&self, other: &Self) -> bool { + self.len() <= other.len() && self.iter().all(|v| other.contains(v)) + } + + /// Returns `true` if the set is a superset of another, + /// i.e., `self` contains at least all the values in `other`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let sub: HashSet<_> = [1, 2].iter().cloned().collect(); + /// let mut set = HashSet::new(); + /// + /// assert_eq!(set.is_superset(&sub), false); + /// + /// set.insert(0); + /// set.insert(1); + /// assert_eq!(set.is_superset(&sub), false); + /// + /// set.insert(2); + /// assert_eq!(set.is_superset(&sub), true); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn is_superset(&self, other: &Self) -> bool { + other.is_subset(self) + } + + /// Adds a value to the set. + /// + /// If the set did not have this value present, `true` is returned. + /// + /// If the set did have this value present, `false` is returned. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set = HashSet::new(); + /// + /// assert_eq!(set.insert(2), true); + /// assert_eq!(set.insert(2), false); + /// assert_eq!(set.len(), 1); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(&mut self, value: T) -> bool { + self.map.insert(value, ()).is_none() + } + + /// Insert a value the set without checking if the value already exists in the set. + /// + /// Returns a reference to the value just inserted. + /// + /// This operation is safe if a value does not exist in the set. + /// + /// However, if a value exists in the set already, the behavior is unspecified: + /// this operation may panic, loop forever, or any following operation with the set + /// may panic, loop forever or return arbitrary result. + /// + /// That said, this operation (and following operations) are guaranteed to + /// not violate memory safety. + /// + /// This operation is faster than regular insert, because it does not perform + /// lookup before insertion. + /// + /// This operation is useful during initial population of the set. + /// For example, when constructing a set from another set, we know + /// that values are unique. + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert_unique_unchecked(&mut self, value: T) -> &T { + self.map.insert_unique_unchecked(value, ()).0 + } + + /// Adds a value to the set, replacing the existing value, if any, that is equal to the given + /// one. Returns the replaced value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set = HashSet::new(); + /// set.insert(Vec::<i32>::new()); + /// + /// assert_eq!(set.get(&[][..]).unwrap().capacity(), 0); + /// set.replace(Vec::with_capacity(10)); + /// assert_eq!(set.get(&[][..]).unwrap().capacity(), 10); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace(&mut self, value: T) -> Option<T> { + match self.map.entry(value) { + map::Entry::Occupied(occupied) => Some(occupied.replace_key()), + map::Entry::Vacant(vacant) => { + vacant.insert(()); + None + } + } + } + + /// Removes a value from the set. Returns whether the value was + /// present in the set. + /// + /// The value may be any borrowed form of the set's value type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the value type. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set = HashSet::new(); + /// + /// set.insert(2); + /// assert_eq!(set.remove(&2), true); + /// assert_eq!(set.remove(&2), false); + /// ``` + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool + where + T: Borrow<Q>, + Q: Hash + Eq, + { + self.map.remove(value).is_some() + } + + /// Removes and returns the value in the set, if any, that is equal to the given one. + /// + /// The value may be any borrowed form of the set's value type, but + /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for + /// the value type. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// assert_eq!(set.take(&2), Some(2)); + /// assert_eq!(set.take(&2), None); + /// ``` + /// + /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html + /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html + #[cfg_attr(feature = "inline-more", inline)] + pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T> + where + T: Borrow<Q>, + Q: Hash + Eq, + { + // Avoid `Option::map` because it bloats LLVM IR. + match self.map.remove_entry(value) { + Some((k, _)) => Some(k), + None => None, + } + } +} + +impl<T, S, A> PartialEq for HashSet<T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + fn eq(&self, other: &Self) -> bool { + if self.len() != other.len() { + return false; + } + + self.iter().all(|key| other.contains(key)) + } +} + +impl<T, S, A> Eq for HashSet<T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ +} + +impl<T, S, A> fmt::Debug for HashSet<T, S, A> +where + T: fmt::Debug, + A: Allocator + Clone, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_set().entries(self.iter()).finish() + } +} + +impl<T, S, A> From<HashMap<T, (), S, A>> for HashSet<T, S, A> +where + A: Allocator + Clone, +{ + fn from(map: HashMap<T, (), S, A>) -> Self { + Self { map } + } +} + +impl<T, S, A> FromIterator<T> for HashSet<T, S, A> +where + T: Eq + Hash, + S: BuildHasher + Default, + A: Default + Allocator + Clone, +{ + #[cfg_attr(feature = "inline-more", inline)] + fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self { + let mut set = Self::with_hasher_in(Default::default(), Default::default()); + set.extend(iter); + set + } +} + +// The default hasher is used to match the std implementation signature +#[cfg(feature = "ahash")] +impl<T, A, const N: usize> From<[T; N]> for HashSet<T, DefaultHashBuilder, A> +where + T: Eq + Hash, + A: Default + Allocator + Clone, +{ + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let set1 = HashSet::from([1, 2, 3, 4]); + /// let set2: HashSet<_> = [1, 2, 3, 4].into(); + /// assert_eq!(set1, set2); + /// ``` + fn from(arr: [T; N]) -> Self { + arr.into_iter().collect() + } +} + +impl<T, S, A> Extend<T> for HashSet<T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + #[cfg_attr(feature = "inline-more", inline)] + fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) { + self.map.extend(iter.into_iter().map(|k| (k, ()))); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_one(&mut self, k: T) { + self.map.insert(k, ()); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_reserve(&mut self, additional: usize) { + Extend::<(T, ())>::extend_reserve(&mut self.map, additional); + } +} + +impl<'a, T, S, A> Extend<&'a T> for HashSet<T, S, A> +where + T: 'a + Eq + Hash + Copy, + S: BuildHasher, + A: Allocator + Clone, +{ + #[cfg_attr(feature = "inline-more", inline)] + fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) { + self.extend(iter.into_iter().copied()); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_one(&mut self, k: &'a T) { + self.map.insert(*k, ()); + } + + #[inline] + #[cfg(feature = "nightly")] + fn extend_reserve(&mut self, additional: usize) { + Extend::<(T, ())>::extend_reserve(&mut self.map, additional); + } +} + +impl<T, S, A> Default for HashSet<T, S, A> +where + S: Default, + A: Default + Allocator + Clone, +{ + /// Creates an empty `HashSet<T, S>` with the `Default` value for the hasher. + #[cfg_attr(feature = "inline-more", inline)] + fn default() -> Self { + Self { + map: HashMap::default(), + } + } +} + +impl<T, S, A> BitOr<&HashSet<T, S, A>> for &HashSet<T, S, A> +where + T: Eq + Hash + Clone, + S: BuildHasher + Default, + A: Allocator + Clone, +{ + type Output = HashSet<T, S>; + + /// Returns the union of `self` and `rhs` as a new `HashSet<T, S>`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); + /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); + /// + /// let set = &a | &b; + /// + /// let mut i = 0; + /// let expected = [1, 2, 3, 4, 5]; + /// for x in &set { + /// assert!(expected.contains(x)); + /// i += 1; + /// } + /// assert_eq!(i, expected.len()); + /// ``` + fn bitor(self, rhs: &HashSet<T, S, A>) -> HashSet<T, S> { + self.union(rhs).cloned().collect() + } +} + +impl<T, S, A> BitAnd<&HashSet<T, S, A>> for &HashSet<T, S, A> +where + T: Eq + Hash + Clone, + S: BuildHasher + Default, + A: Allocator + Clone, +{ + type Output = HashSet<T, S>; + + /// Returns the intersection of `self` and `rhs` as a new `HashSet<T, S>`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); + /// let b: HashSet<_> = vec![2, 3, 4].into_iter().collect(); + /// + /// let set = &a & &b; + /// + /// let mut i = 0; + /// let expected = [2, 3]; + /// for x in &set { + /// assert!(expected.contains(x)); + /// i += 1; + /// } + /// assert_eq!(i, expected.len()); + /// ``` + fn bitand(self, rhs: &HashSet<T, S, A>) -> HashSet<T, S> { + self.intersection(rhs).cloned().collect() + } +} + +impl<T, S> BitXor<&HashSet<T, S>> for &HashSet<T, S> +where + T: Eq + Hash + Clone, + S: BuildHasher + Default, +{ + type Output = HashSet<T, S>; + + /// Returns the symmetric difference of `self` and `rhs` as a new `HashSet<T, S>`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); + /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); + /// + /// let set = &a ^ &b; + /// + /// let mut i = 0; + /// let expected = [1, 2, 4, 5]; + /// for x in &set { + /// assert!(expected.contains(x)); + /// i += 1; + /// } + /// assert_eq!(i, expected.len()); + /// ``` + fn bitxor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { + self.symmetric_difference(rhs).cloned().collect() + } +} + +impl<T, S> Sub<&HashSet<T, S>> for &HashSet<T, S> +where + T: Eq + Hash + Clone, + S: BuildHasher + Default, +{ + type Output = HashSet<T, S>; + + /// Returns the difference of `self` and `rhs` as a new `HashSet<T, S>`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); + /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); + /// + /// let set = &a - &b; + /// + /// let mut i = 0; + /// let expected = [1, 2]; + /// for x in &set { + /// assert!(expected.contains(x)); + /// i += 1; + /// } + /// assert_eq!(i, expected.len()); + /// ``` + fn sub(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { + self.difference(rhs).cloned().collect() + } +} + +/// An iterator over the items of a `HashSet`. +/// +/// This `struct` is created by the [`iter`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`HashSet`]: struct.HashSet.html +/// [`iter`]: struct.HashSet.html#method.iter +pub struct Iter<'a, K> { + iter: Keys<'a, K, ()>, +} + +/// An owning iterator over the items of a `HashSet`. +/// +/// This `struct` is created by the [`into_iter`] method on [`HashSet`] +/// (provided by the `IntoIterator` trait). See its documentation for more. +/// +/// [`HashSet`]: struct.HashSet.html +/// [`into_iter`]: struct.HashSet.html#method.into_iter +pub struct IntoIter<K, A: Allocator + Clone = Global> { + iter: map::IntoIter<K, (), A>, +} + +/// A draining iterator over the items of a `HashSet`. +/// +/// This `struct` is created by the [`drain`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`HashSet`]: struct.HashSet.html +/// [`drain`]: struct.HashSet.html#method.drain +pub struct Drain<'a, K, A: Allocator + Clone = Global> { + iter: map::Drain<'a, K, (), A>, +} + +/// A draining iterator over entries of a `HashSet` which don't satisfy the predicate `f`. +/// +/// This `struct` is created by the [`drain_filter`] method on [`HashSet`]. See its +/// documentation for more. +/// +/// [`drain_filter`]: struct.HashSet.html#method.drain_filter +/// [`HashSet`]: struct.HashSet.html +pub struct DrainFilter<'a, K, F, A: Allocator + Clone = Global> +where + F: FnMut(&K) -> bool, +{ + f: F, + inner: DrainFilterInner<'a, K, (), A>, +} + +/// A lazy iterator producing elements in the intersection of `HashSet`s. +/// +/// This `struct` is created by the [`intersection`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`HashSet`]: struct.HashSet.html +/// [`intersection`]: struct.HashSet.html#method.intersection +pub struct Intersection<'a, T, S, A: Allocator + Clone = Global> { + // iterator of the first set + iter: Iter<'a, T>, + // the second set + other: &'a HashSet<T, S, A>, +} + +/// A lazy iterator producing elements in the difference of `HashSet`s. +/// +/// This `struct` is created by the [`difference`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`HashSet`]: struct.HashSet.html +/// [`difference`]: struct.HashSet.html#method.difference +pub struct Difference<'a, T, S, A: Allocator + Clone = Global> { + // iterator of the first set + iter: Iter<'a, T>, + // the second set + other: &'a HashSet<T, S, A>, +} + +/// A lazy iterator producing elements in the symmetric difference of `HashSet`s. +/// +/// This `struct` is created by the [`symmetric_difference`] method on +/// [`HashSet`]. See its documentation for more. +/// +/// [`HashSet`]: struct.HashSet.html +/// [`symmetric_difference`]: struct.HashSet.html#method.symmetric_difference +pub struct SymmetricDifference<'a, T, S, A: Allocator + Clone = Global> { + iter: Chain<Difference<'a, T, S, A>, Difference<'a, T, S, A>>, +} + +/// A lazy iterator producing elements in the union of `HashSet`s. +/// +/// This `struct` is created by the [`union`] method on [`HashSet`]. +/// See its documentation for more. +/// +/// [`HashSet`]: struct.HashSet.html +/// [`union`]: struct.HashSet.html#method.union +pub struct Union<'a, T, S, A: Allocator + Clone = Global> { + iter: Chain<Iter<'a, T>, Difference<'a, T, S, A>>, +} + +impl<'a, T, S, A: Allocator + Clone> IntoIterator for &'a HashSet<T, S, A> { + type Item = &'a T; + type IntoIter = Iter<'a, T>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_iter(self) -> Iter<'a, T> { + self.iter() + } +} + +impl<T, S, A: Allocator + Clone> IntoIterator for HashSet<T, S, A> { + type Item = T; + type IntoIter = IntoIter<T, A>; + + /// Creates a consuming iterator, that is, one that moves each value out + /// of the set in arbitrary order. The set cannot be used after calling + /// this. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// let mut set = HashSet::new(); + /// set.insert("a".to_string()); + /// set.insert("b".to_string()); + /// + /// // Not possible to collect to a Vec<String> with a regular `.iter()`. + /// let v: Vec<String> = set.into_iter().collect(); + /// + /// // Will print in an arbitrary order. + /// for x in &v { + /// println!("{}", x); + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + fn into_iter(self) -> IntoIter<T, A> { + IntoIter { + iter: self.map.into_iter(), + } + } +} + +impl<K> Clone for Iter<'_, K> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Iter { + iter: self.iter.clone(), + } + } +} +impl<'a, K> Iterator for Iter<'a, K> { + type Item = &'a K; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<&'a K> { + self.iter.next() + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.iter.size_hint() + } +} +impl<'a, K> ExactSizeIterator for Iter<'a, K> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.iter.len() + } +} +impl<K> FusedIterator for Iter<'_, K> {} + +impl<K: fmt::Debug> fmt::Debug for Iter<'_, K> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.clone()).finish() + } +} + +impl<K, A: Allocator + Clone> Iterator for IntoIter<K, A> { + type Item = K; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<K> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.iter.next() { + Some((k, _)) => Some(k), + None => None, + } + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.iter.size_hint() + } +} +impl<K, A: Allocator + Clone> ExactSizeIterator for IntoIter<K, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.iter.len() + } +} +impl<K, A: Allocator + Clone> FusedIterator for IntoIter<K, A> {} + +impl<K: fmt::Debug, A: Allocator + Clone> fmt::Debug for IntoIter<K, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let entries_iter = self.iter.iter().map(|(k, _)| k); + f.debug_list().entries(entries_iter).finish() + } +} + +impl<K, A: Allocator + Clone> Iterator for Drain<'_, K, A> { + type Item = K; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<K> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.iter.next() { + Some((k, _)) => Some(k), + None => None, + } + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.iter.size_hint() + } +} +impl<K, A: Allocator + Clone> ExactSizeIterator for Drain<'_, K, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn len(&self) -> usize { + self.iter.len() + } +} +impl<K, A: Allocator + Clone> FusedIterator for Drain<'_, K, A> {} + +impl<K: fmt::Debug, A: Allocator + Clone> fmt::Debug for Drain<'_, K, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let entries_iter = self.iter.iter().map(|(k, _)| k); + f.debug_list().entries(entries_iter).finish() + } +} + +impl<'a, K, F, A: Allocator + Clone> Drop for DrainFilter<'a, K, F, A> +where + F: FnMut(&K) -> bool, +{ + #[cfg_attr(feature = "inline-more", inline)] + fn drop(&mut self) { + while let Some(item) = self.next() { + let guard = ConsumeAllOnDrop(self); + drop(item); + mem::forget(guard); + } + } +} + +impl<K, F, A: Allocator + Clone> Iterator for DrainFilter<'_, K, F, A> +where + F: FnMut(&K) -> bool, +{ + type Item = K; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<Self::Item> { + let f = &mut self.f; + let (k, _) = self.inner.next(&mut |k, _| f(k))?; + Some(k) + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + (0, self.inner.iter.size_hint().1) + } +} + +impl<K, F, A: Allocator + Clone> FusedIterator for DrainFilter<'_, K, F, A> where + F: FnMut(&K) -> bool +{ +} + +impl<T, S, A: Allocator + Clone> Clone for Intersection<'_, T, S, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Intersection { + iter: self.iter.clone(), + ..*self + } + } +} + +impl<'a, T, S, A> Iterator for Intersection<'a, T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + type Item = &'a T; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<&'a T> { + loop { + let elt = self.iter.next()?; + if self.other.contains(elt) { + return Some(elt); + } + } + } + + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + let (_, upper) = self.iter.size_hint(); + (0, upper) + } +} + +impl<T, S, A> fmt::Debug for Intersection<'_, T, S, A> +where + T: fmt::Debug + Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.clone()).finish() + } +} + +impl<T, S, A> FusedIterator for Intersection<'_, T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ +} + +impl<T, S, A: Allocator + Clone> Clone for Difference<'_, T, S, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Difference { + iter: self.iter.clone(), + ..*self + } + } +} + +impl<'a, T, S, A> Iterator for Difference<'a, T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + type Item = &'a T; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<&'a T> { + loop { + let elt = self.iter.next()?; + if !self.other.contains(elt) { + return Some(elt); + } + } + } + + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + let (_, upper) = self.iter.size_hint(); + (0, upper) + } +} + +impl<T, S, A> FusedIterator for Difference<'_, T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ +} + +impl<T, S, A> fmt::Debug for Difference<'_, T, S, A> +where + T: fmt::Debug + Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.clone()).finish() + } +} + +impl<T, S, A: Allocator + Clone> Clone for SymmetricDifference<'_, T, S, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + SymmetricDifference { + iter: self.iter.clone(), + } + } +} + +impl<'a, T, S, A> Iterator for SymmetricDifference<'a, T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + type Item = &'a T; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<&'a T> { + self.iter.next() + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.iter.size_hint() + } +} + +impl<T, S, A> FusedIterator for SymmetricDifference<'_, T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ +} + +impl<T, S, A> fmt::Debug for SymmetricDifference<'_, T, S, A> +where + T: fmt::Debug + Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.clone()).finish() + } +} + +impl<T, S, A: Allocator + Clone> Clone for Union<'_, T, S, A> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Union { + iter: self.iter.clone(), + } + } +} + +impl<T, S, A> FusedIterator for Union<'_, T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ +} + +impl<T, S, A> fmt::Debug for Union<'_, T, S, A> +where + T: fmt::Debug + Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.clone()).finish() + } +} + +impl<'a, T, S, A> Iterator for Union<'a, T, S, A> +where + T: Eq + Hash, + S: BuildHasher, + A: Allocator + Clone, +{ + type Item = &'a T; + + #[cfg_attr(feature = "inline-more", inline)] + fn next(&mut self) -> Option<&'a T> { + self.iter.next() + } + #[cfg_attr(feature = "inline-more", inline)] + fn size_hint(&self) -> (usize, Option<usize>) { + self.iter.size_hint() + } +} + +/// A view into a single entry in a set, which may either be vacant or occupied. +/// +/// This `enum` is constructed from the [`entry`] method on [`HashSet`]. +/// +/// [`HashSet`]: struct.HashSet.html +/// [`entry`]: struct.HashSet.html#method.entry +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_set::{Entry, HashSet, OccupiedEntry}; +/// +/// let mut set = HashSet::new(); +/// set.extend(["a", "b", "c"]); +/// assert_eq!(set.len(), 3); +/// +/// // Existing value (insert) +/// let entry: Entry<_, _> = set.entry("a"); +/// let _raw_o: OccupiedEntry<_, _> = entry.insert(); +/// assert_eq!(set.len(), 3); +/// // Nonexistent value (insert) +/// set.entry("d").insert(); +/// +/// // Existing value (or_insert) +/// set.entry("b").or_insert(); +/// // Nonexistent value (or_insert) +/// set.entry("e").or_insert(); +/// +/// println!("Our HashSet: {:?}", set); +/// +/// let mut vec: Vec<_> = set.iter().copied().collect(); +/// // The `Iter` iterator produces items in arbitrary order, so the +/// // items must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, ["a", "b", "c", "d", "e"]); +/// ``` +pub enum Entry<'a, T, S, A = Global> +where + A: Allocator + Clone, +{ + /// An occupied entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_set::{Entry, HashSet}; + /// let mut set: HashSet<_> = ["a", "b"].into(); + /// + /// match set.entry("a") { + /// Entry::Vacant(_) => unreachable!(), + /// Entry::Occupied(_) => { } + /// } + /// ``` + Occupied(OccupiedEntry<'a, T, S, A>), + + /// A vacant entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_set::{Entry, HashSet}; + /// let mut set: HashSet<&str> = HashSet::new(); + /// + /// match set.entry("a") { + /// Entry::Occupied(_) => unreachable!(), + /// Entry::Vacant(_) => { } + /// } + /// ``` + Vacant(VacantEntry<'a, T, S, A>), +} + +impl<T: fmt::Debug, S, A: Allocator + Clone> fmt::Debug for Entry<'_, T, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + Entry::Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(), + Entry::Occupied(ref o) => f.debug_tuple("Entry").field(o).finish(), + } + } +} + +/// A view into an occupied entry in a `HashSet`. +/// It is part of the [`Entry`] enum. +/// +/// [`Entry`]: enum.Entry.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_set::{Entry, HashSet, OccupiedEntry}; +/// +/// let mut set = HashSet::new(); +/// set.extend(["a", "b", "c"]); +/// +/// let _entry_o: OccupiedEntry<_, _> = set.entry("a").insert(); +/// assert_eq!(set.len(), 3); +/// +/// // Existing key +/// match set.entry("a") { +/// Entry::Vacant(_) => unreachable!(), +/// Entry::Occupied(view) => { +/// assert_eq!(view.get(), &"a"); +/// } +/// } +/// +/// assert_eq!(set.len(), 3); +/// +/// // Existing key (take) +/// match set.entry("c") { +/// Entry::Vacant(_) => unreachable!(), +/// Entry::Occupied(view) => { +/// assert_eq!(view.remove(), "c"); +/// } +/// } +/// assert_eq!(set.get(&"c"), None); +/// assert_eq!(set.len(), 2); +/// ``` +pub struct OccupiedEntry<'a, T, S, A: Allocator + Clone = Global> { + inner: map::OccupiedEntry<'a, T, (), S, A>, +} + +impl<T: fmt::Debug, S, A: Allocator + Clone> fmt::Debug for OccupiedEntry<'_, T, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("OccupiedEntry") + .field("value", self.get()) + .finish() + } +} + +/// A view into a vacant entry in a `HashSet`. +/// It is part of the [`Entry`] enum. +/// +/// [`Entry`]: enum.Entry.html +/// +/// # Examples +/// +/// ``` +/// use hashbrown::hash_set::{Entry, HashSet, VacantEntry}; +/// +/// let mut set = HashSet::<&str>::new(); +/// +/// let entry_v: VacantEntry<_, _> = match set.entry("a") { +/// Entry::Vacant(view) => view, +/// Entry::Occupied(_) => unreachable!(), +/// }; +/// entry_v.insert(); +/// assert!(set.contains("a") && set.len() == 1); +/// +/// // Nonexistent key (insert) +/// match set.entry("b") { +/// Entry::Vacant(view) => view.insert(), +/// Entry::Occupied(_) => unreachable!(), +/// } +/// assert!(set.contains("b") && set.len() == 2); +/// ``` +pub struct VacantEntry<'a, T, S, A: Allocator + Clone = Global> { + inner: map::VacantEntry<'a, T, (), S, A>, +} + +impl<T: fmt::Debug, S, A: Allocator + Clone> fmt::Debug for VacantEntry<'_, T, S, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("VacantEntry").field(self.get()).finish() + } +} + +impl<'a, T, S, A: Allocator + Clone> Entry<'a, T, S, A> { + /// Sets the value of the entry, and returns an OccupiedEntry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<&str> = HashSet::new(); + /// let entry = set.entry("horseyland").insert(); + /// + /// assert_eq!(entry.get(), &"horseyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self) -> OccupiedEntry<'a, T, S, A> + where + T: Hash, + S: BuildHasher, + { + match self { + Entry::Occupied(entry) => entry, + Entry::Vacant(entry) => entry.insert_entry(), + } + } + + /// Ensures a value is in the entry by inserting if it was vacant. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<&str> = HashSet::new(); + /// + /// // nonexistent key + /// set.entry("poneyland").or_insert(); + /// assert!(set.contains("poneyland")); + /// + /// // existing key + /// set.entry("poneyland").or_insert(); + /// assert!(set.contains("poneyland")); + /// assert_eq!(set.len(), 1); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn or_insert(self) + where + T: Hash, + S: BuildHasher, + { + if let Entry::Vacant(entry) = self { + entry.insert(); + } + } + + /// Returns a reference to this entry's value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<&str> = HashSet::new(); + /// set.entry("poneyland").or_insert(); + /// // existing key + /// assert_eq!(set.entry("poneyland").get(), &"poneyland"); + /// // nonexistent key + /// assert_eq!(set.entry("horseland").get(), &"horseland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get(&self) -> &T { + match *self { + Entry::Occupied(ref entry) => entry.get(), + Entry::Vacant(ref entry) => entry.get(), + } + } +} + +impl<T, S, A: Allocator + Clone> OccupiedEntry<'_, T, S, A> { + /// Gets a reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_set::{Entry, HashSet}; + /// + /// let mut set: HashSet<&str> = HashSet::new(); + /// set.entry("poneyland").or_insert(); + /// + /// match set.entry("poneyland") { + /// Entry::Vacant(_) => panic!(), + /// Entry::Occupied(entry) => assert_eq!(entry.get(), &"poneyland"), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get(&self) -> &T { + self.inner.key() + } + + /// Takes the value out of the entry, and returns it. + /// Keeps the allocated memory for reuse. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// use hashbrown::hash_set::Entry; + /// + /// let mut set: HashSet<&str> = HashSet::new(); + /// // The set is empty + /// assert!(set.is_empty() && set.capacity() == 0); + /// + /// set.entry("poneyland").or_insert(); + /// let capacity_before_remove = set.capacity(); + /// + /// if let Entry::Occupied(o) = set.entry("poneyland") { + /// assert_eq!(o.remove(), "poneyland"); + /// } + /// + /// assert_eq!(set.contains("poneyland"), false); + /// // Now set hold none elements but capacity is equal to the old one + /// assert!(set.len() == 0 && set.capacity() == capacity_before_remove); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove(self) -> T { + self.inner.remove_entry().0 + } + + /// Replaces the entry, returning the old value. The new value in the hash map will be + /// the value used to create this entry. + /// + /// # Panics + /// + /// Will panic if this OccupiedEntry was created through [`Entry::insert`]. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_set::{Entry, HashSet}; + /// use std::rc::Rc; + /// + /// let mut set: HashSet<Rc<String>> = HashSet::new(); + /// let key_one = Rc::new("Stringthing".to_string()); + /// let key_two = Rc::new("Stringthing".to_string()); + /// + /// set.insert(key_one.clone()); + /// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1); + /// + /// match set.entry(key_two.clone()) { + /// Entry::Occupied(entry) => { + /// let old_key: Rc<String> = entry.replace(); + /// assert!(Rc::ptr_eq(&key_one, &old_key)); + /// } + /// Entry::Vacant(_) => panic!(), + /// } + /// + /// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2); + /// assert!(set.contains(&"Stringthing".to_owned())); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn replace(self) -> T { + self.inner.replace_key() + } +} + +impl<'a, T, S, A: Allocator + Clone> VacantEntry<'a, T, S, A> { + /// Gets a reference to the value that would be used when inserting + /// through the `VacantEntry`. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// + /// let mut set: HashSet<&str> = HashSet::new(); + /// assert_eq!(set.entry("poneyland").get(), &"poneyland"); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn get(&self) -> &T { + self.inner.key() + } + + /// Take ownership of the value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::hash_set::{Entry, HashSet}; + /// + /// let mut set: HashSet<&str> = HashSet::new(); + /// + /// match set.entry("poneyland") { + /// Entry::Occupied(_) => panic!(), + /// Entry::Vacant(v) => assert_eq!(v.into_value(), "poneyland"), + /// } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn into_value(self) -> T { + self.inner.into_key() + } + + /// Sets the value of the entry with the VacantEntry's value. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashSet; + /// use hashbrown::hash_set::Entry; + /// + /// let mut set: HashSet<&str> = HashSet::new(); + /// + /// if let Entry::Vacant(o) = set.entry("poneyland") { + /// o.insert(); + /// } + /// assert!(set.contains("poneyland")); + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn insert(self) + where + T: Hash, + S: BuildHasher, + { + self.inner.insert(()); + } + + #[cfg_attr(feature = "inline-more", inline)] + fn insert_entry(self) -> OccupiedEntry<'a, T, S, A> + where + T: Hash, + S: BuildHasher, + { + OccupiedEntry { + inner: self.inner.insert_entry(()), + } + } +} + +#[allow(dead_code)] +fn assert_covariance() { + fn set<'new>(v: HashSet<&'static str>) -> HashSet<&'new str> { + v + } + fn iter<'a, 'new>(v: Iter<'a, &'static str>) -> Iter<'a, &'new str> { + v + } + fn into_iter<'new, A: Allocator + Clone>( + v: IntoIter<&'static str, A>, + ) -> IntoIter<&'new str, A> { + v + } + fn difference<'a, 'new, A: Allocator + Clone>( + v: Difference<'a, &'static str, DefaultHashBuilder, A>, + ) -> Difference<'a, &'new str, DefaultHashBuilder, A> { + v + } + fn symmetric_difference<'a, 'new, A: Allocator + Clone>( + v: SymmetricDifference<'a, &'static str, DefaultHashBuilder, A>, + ) -> SymmetricDifference<'a, &'new str, DefaultHashBuilder, A> { + v + } + fn intersection<'a, 'new, A: Allocator + Clone>( + v: Intersection<'a, &'static str, DefaultHashBuilder, A>, + ) -> Intersection<'a, &'new str, DefaultHashBuilder, A> { + v + } + fn union<'a, 'new, A: Allocator + Clone>( + v: Union<'a, &'static str, DefaultHashBuilder, A>, + ) -> Union<'a, &'new str, DefaultHashBuilder, A> { + v + } + fn drain<'new, A: Allocator + Clone>( + d: Drain<'static, &'static str, A>, + ) -> Drain<'new, &'new str, A> { + d + } +} + +#[cfg(test)] +mod test_set { + use super::super::map::DefaultHashBuilder; + use super::HashSet; + use std::vec::Vec; + + #[test] + fn test_zero_capacities() { + type HS = HashSet<i32>; + + let s = HS::new(); + assert_eq!(s.capacity(), 0); + + let s = HS::default(); + assert_eq!(s.capacity(), 0); + + let s = HS::with_hasher(DefaultHashBuilder::default()); + assert_eq!(s.capacity(), 0); + + let s = HS::with_capacity(0); + assert_eq!(s.capacity(), 0); + + let s = HS::with_capacity_and_hasher(0, DefaultHashBuilder::default()); + assert_eq!(s.capacity(), 0); + + let mut s = HS::new(); + s.insert(1); + s.insert(2); + s.remove(&1); + s.remove(&2); + s.shrink_to_fit(); + assert_eq!(s.capacity(), 0); + + let mut s = HS::new(); + s.reserve(0); + assert_eq!(s.capacity(), 0); + } + + #[test] + fn test_disjoint() { + let mut xs = HashSet::new(); + let mut ys = HashSet::new(); + assert!(xs.is_disjoint(&ys)); + assert!(ys.is_disjoint(&xs)); + assert!(xs.insert(5)); + assert!(ys.insert(11)); + assert!(xs.is_disjoint(&ys)); + assert!(ys.is_disjoint(&xs)); + assert!(xs.insert(7)); + assert!(xs.insert(19)); + assert!(xs.insert(4)); + assert!(ys.insert(2)); + assert!(ys.insert(-11)); + assert!(xs.is_disjoint(&ys)); + assert!(ys.is_disjoint(&xs)); + assert!(ys.insert(7)); + assert!(!xs.is_disjoint(&ys)); + assert!(!ys.is_disjoint(&xs)); + } + + #[test] + fn test_subset_and_superset() { + let mut a = HashSet::new(); + assert!(a.insert(0)); + assert!(a.insert(5)); + assert!(a.insert(11)); + assert!(a.insert(7)); + + let mut b = HashSet::new(); + assert!(b.insert(0)); + assert!(b.insert(7)); + assert!(b.insert(19)); + assert!(b.insert(250)); + assert!(b.insert(11)); + assert!(b.insert(200)); + + assert!(!a.is_subset(&b)); + assert!(!a.is_superset(&b)); + assert!(!b.is_subset(&a)); + assert!(!b.is_superset(&a)); + + assert!(b.insert(5)); + + assert!(a.is_subset(&b)); + assert!(!a.is_superset(&b)); + assert!(!b.is_subset(&a)); + assert!(b.is_superset(&a)); + } + + #[test] + fn test_iterate() { + let mut a = HashSet::new(); + for i in 0..32 { + assert!(a.insert(i)); + } + let mut observed: u32 = 0; + for k in &a { + observed |= 1 << *k; + } + assert_eq!(observed, 0xFFFF_FFFF); + } + + #[test] + fn test_intersection() { + let mut a = HashSet::new(); + let mut b = HashSet::new(); + + assert!(a.insert(11)); + assert!(a.insert(1)); + assert!(a.insert(3)); + assert!(a.insert(77)); + assert!(a.insert(103)); + assert!(a.insert(5)); + assert!(a.insert(-5)); + + assert!(b.insert(2)); + assert!(b.insert(11)); + assert!(b.insert(77)); + assert!(b.insert(-9)); + assert!(b.insert(-42)); + assert!(b.insert(5)); + assert!(b.insert(3)); + + let mut i = 0; + let expected = [3, 5, 11, 77]; + for x in a.intersection(&b) { + assert!(expected.contains(x)); + i += 1; + } + assert_eq!(i, expected.len()); + } + + #[test] + fn test_difference() { + let mut a = HashSet::new(); + let mut b = HashSet::new(); + + assert!(a.insert(1)); + assert!(a.insert(3)); + assert!(a.insert(5)); + assert!(a.insert(9)); + assert!(a.insert(11)); + + assert!(b.insert(3)); + assert!(b.insert(9)); + + let mut i = 0; + let expected = [1, 5, 11]; + for x in a.difference(&b) { + assert!(expected.contains(x)); + i += 1; + } + assert_eq!(i, expected.len()); + } + + #[test] + fn test_symmetric_difference() { + let mut a = HashSet::new(); + let mut b = HashSet::new(); + + assert!(a.insert(1)); + assert!(a.insert(3)); + assert!(a.insert(5)); + assert!(a.insert(9)); + assert!(a.insert(11)); + + assert!(b.insert(-2)); + assert!(b.insert(3)); + assert!(b.insert(9)); + assert!(b.insert(14)); + assert!(b.insert(22)); + + let mut i = 0; + let expected = [-2, 1, 5, 11, 14, 22]; + for x in a.symmetric_difference(&b) { + assert!(expected.contains(x)); + i += 1; + } + assert_eq!(i, expected.len()); + } + + #[test] + fn test_union() { + let mut a = HashSet::new(); + let mut b = HashSet::new(); + + assert!(a.insert(1)); + assert!(a.insert(3)); + assert!(a.insert(5)); + assert!(a.insert(9)); + assert!(a.insert(11)); + assert!(a.insert(16)); + assert!(a.insert(19)); + assert!(a.insert(24)); + + assert!(b.insert(-2)); + assert!(b.insert(1)); + assert!(b.insert(5)); + assert!(b.insert(9)); + assert!(b.insert(13)); + assert!(b.insert(19)); + + let mut i = 0; + let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24]; + for x in a.union(&b) { + assert!(expected.contains(x)); + i += 1; + } + assert_eq!(i, expected.len()); + } + + #[test] + fn test_from_map() { + let mut a = crate::HashMap::new(); + a.insert(1, ()); + a.insert(2, ()); + a.insert(3, ()); + a.insert(4, ()); + + let a: HashSet<_> = a.into(); + + assert_eq!(a.len(), 4); + assert!(a.contains(&1)); + assert!(a.contains(&2)); + assert!(a.contains(&3)); + assert!(a.contains(&4)); + } + + #[test] + fn test_from_iter() { + let xs = [1, 2, 2, 3, 4, 5, 6, 7, 8, 9]; + + let set: HashSet<_> = xs.iter().copied().collect(); + + for x in &xs { + assert!(set.contains(x)); + } + + assert_eq!(set.iter().len(), xs.len() - 1); + } + + #[test] + fn test_move_iter() { + let hs = { + let mut hs = HashSet::new(); + + hs.insert('a'); + hs.insert('b'); + + hs + }; + + let v = hs.into_iter().collect::<Vec<char>>(); + assert!(v == ['a', 'b'] || v == ['b', 'a']); + } + + #[test] + fn test_eq() { + // These constants once happened to expose a bug in insert(). + // I'm keeping them around to prevent a regression. + let mut s1 = HashSet::new(); + + s1.insert(1); + s1.insert(2); + s1.insert(3); + + let mut s2 = HashSet::new(); + + s2.insert(1); + s2.insert(2); + + assert!(s1 != s2); + + s2.insert(3); + + assert_eq!(s1, s2); + } + + #[test] + fn test_show() { + let mut set = HashSet::new(); + let empty = HashSet::<i32>::new(); + + set.insert(1); + set.insert(2); + + let set_str = format!("{:?}", set); + + assert!(set_str == "{1, 2}" || set_str == "{2, 1}"); + assert_eq!(format!("{:?}", empty), "{}"); + } + + #[test] + fn test_trivial_drain() { + let mut s = HashSet::<i32>::new(); + for _ in s.drain() {} + assert!(s.is_empty()); + drop(s); + + let mut s = HashSet::<i32>::new(); + drop(s.drain()); + assert!(s.is_empty()); + } + + #[test] + fn test_drain() { + let mut s: HashSet<_> = (1..100).collect(); + + // try this a bunch of times to make sure we don't screw up internal state. + for _ in 0..20 { + assert_eq!(s.len(), 99); + + { + let mut last_i = 0; + let mut d = s.drain(); + for (i, x) in d.by_ref().take(50).enumerate() { + last_i = i; + assert!(x != 0); + } + assert_eq!(last_i, 49); + } + + for _ in &s { + panic!("s should be empty!"); + } + + // reset to try again. + s.extend(1..100); + } + } + + #[test] + fn test_replace() { + use core::hash; + + #[derive(Debug)] + struct Foo(&'static str, i32); + + impl PartialEq for Foo { + fn eq(&self, other: &Self) -> bool { + self.0 == other.0 + } + } + + impl Eq for Foo {} + + impl hash::Hash for Foo { + fn hash<H: hash::Hasher>(&self, h: &mut H) { + self.0.hash(h); + } + } + + let mut s = HashSet::new(); + assert_eq!(s.replace(Foo("a", 1)), None); + assert_eq!(s.len(), 1); + assert_eq!(s.replace(Foo("a", 2)), Some(Foo("a", 1))); + assert_eq!(s.len(), 1); + + let mut it = s.iter(); + assert_eq!(it.next(), Some(&Foo("a", 2))); + assert_eq!(it.next(), None); + } + + #[test] + fn test_extend_ref() { + let mut a = HashSet::new(); + a.insert(1); + + a.extend(&[2, 3, 4]); + + assert_eq!(a.len(), 4); + assert!(a.contains(&1)); + assert!(a.contains(&2)); + assert!(a.contains(&3)); + assert!(a.contains(&4)); + + let mut b = HashSet::new(); + b.insert(5); + b.insert(6); + + a.extend(&b); + + assert_eq!(a.len(), 6); + assert!(a.contains(&1)); + assert!(a.contains(&2)); + assert!(a.contains(&3)); + assert!(a.contains(&4)); + assert!(a.contains(&5)); + assert!(a.contains(&6)); + } + + #[test] + fn test_retain() { + let xs = [1, 2, 3, 4, 5, 6]; + let mut set: HashSet<i32> = xs.iter().copied().collect(); + set.retain(|&k| k % 2 == 0); + assert_eq!(set.len(), 3); + assert!(set.contains(&2)); + assert!(set.contains(&4)); + assert!(set.contains(&6)); + } + + #[test] + fn test_drain_filter() { + { + let mut set: HashSet<i32> = (0..8).collect(); + let drained = set.drain_filter(|&k| k % 2 == 0); + let mut out = drained.collect::<Vec<_>>(); + out.sort_unstable(); + assert_eq!(vec![0, 2, 4, 6], out); + assert_eq!(set.len(), 4); + } + { + let mut set: HashSet<i32> = (0..8).collect(); + drop(set.drain_filter(|&k| k % 2 == 0)); + assert_eq!(set.len(), 4, "Removes non-matching items on drop"); + } + } + + #[test] + fn test_const_with_hasher() { + use core::hash::BuildHasher; + use std::collections::hash_map::DefaultHasher; + + #[derive(Clone)] + struct MyHasher; + impl BuildHasher for MyHasher { + type Hasher = DefaultHasher; + + fn build_hasher(&self) -> DefaultHasher { + DefaultHasher::new() + } + } + + const EMPTY_SET: HashSet<u32, MyHasher> = HashSet::with_hasher(MyHasher); + + let mut set = EMPTY_SET; + set.insert(19); + assert!(set.contains(&19)); + } + + #[test] + fn rehash_in_place() { + let mut set = HashSet::new(); + + for i in 0..224 { + set.insert(i); + } + + assert_eq!( + set.capacity(), + 224, + "The set must be at or close to capacity to trigger a re hashing" + ); + + for i in 100..1400 { + set.remove(&(i - 100)); + set.insert(i); + } + } +} |