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Diffstat (limited to 'vendor/hashbrown/src/set.rs')
-rw-r--r-- | vendor/hashbrown/src/set.rs | 2790 |
1 files changed, 2790 insertions, 0 deletions
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); + } + } +} |