use crate::raw::{ Allocator, Bucket, Global, RawDrain, RawExtractIf, RawIntoIter, RawIter, RawTable, }; use crate::{Equivalent, 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 = core::hash::BuildHasherDefault; /// 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` 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 { pub(crate) hash_builder: S, pub(crate) table: RawTable<(K, V), A>, } impl Clone for HashMap { 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(hash_builder: &S) -> impl Fn(&(Q, V)) -> u64 + '_ where Q: Hash, S: BuildHasher, { move |val| make_hash::(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(k: &Q) -> impl Fn(&(K, V)) -> bool + '_ where Q: ?Sized + Equivalent, { move |x| k.equivalent(&x.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(k: &Q) -> impl Fn(&K) -> bool + '_ where Q: ?Sized + Equivalent, { move |x| k.equivalent(x) } #[cfg(not(feature = "nightly"))] #[cfg_attr(feature = "inline-more", inline)] pub(crate) fn make_hash(hash_builder: &S, val: &Q) -> u64 where 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(hash_builder: &S, val: &Q) -> u64 where Q: Hash + ?Sized, S: BuildHasher, { hash_builder.hash_one(val) } #[cfg(feature = "ahash")] impl HashMap { /// 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. /// /// # HashDoS resistance /// /// The `hash_builder` normally use a fixed key by default and that does /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. /// Users who require HashDoS resistance should explicitly use /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] /// as the hasher when creating a [`HashMap`], for example with /// [`with_hasher`](HashMap::with_hasher) method. /// /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// /// # 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. /// /// # HashDoS resistance /// /// The `hash_builder` normally use a fixed key by default and that does /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. /// Users who require HashDoS resistance should explicitly use /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] /// as the hasher when creating a [`HashMap`], for example with /// [`with_capacity_and_hasher`](HashMap::with_capacity_and_hasher) method. /// /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// /// # 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 HashMap { /// 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. /// /// # HashDoS resistance /// /// The `hash_builder` normally use a fixed key by default and that does /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. /// Users who require HashDoS resistance should explicitly use /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] /// as the hasher when creating a [`HashMap`], for example with /// [`with_hasher_in`](HashMap::with_hasher_in) method. /// /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// /// # Examples /// /// ``` /// use hashbrown::HashMap; /// use bumpalo::Bump; /// /// let bump = Bump::new(); /// let mut map = HashMap::new_in(&bump); /// /// // The created HashMap holds none elements /// assert_eq!(map.len(), 0); /// /// // The created HashMap also doesn't allocate memory /// assert_eq!(map.capacity(), 0); /// /// // Now we insert element inside created HashMap /// map.insert("One", 1); /// // We can see that the HashMap holds 1 element /// assert_eq!(map.len(), 1); /// // And it also allocates some capacity /// assert!(map.capacity() > 1); /// ``` #[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. /// /// # HashDoS resistance /// /// The `hash_builder` normally use a fixed key by default and that does /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. /// Users who require HashDoS resistance should explicitly use /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] /// as the hasher when creating a [`HashMap`], for example with /// [`with_capacity_and_hasher_in`](HashMap::with_capacity_and_hasher_in) method. /// /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// /// # Examples /// /// ``` /// use hashbrown::HashMap; /// use bumpalo::Bump; /// /// let bump = Bump::new(); /// let mut map = HashMap::with_capacity_in(5, &bump); /// /// // The created HashMap holds none elements /// assert_eq!(map.len(), 0); /// // But it can hold at least 5 elements without reallocating /// let empty_map_capacity = map.capacity(); /// assert!(empty_map_capacity >= 5); /// /// // Now we insert some 5 elements inside created HashMap /// map.insert("One", 1); /// map.insert("Two", 2); /// map.insert("Three", 3); /// map.insert("Four", 4); /// map.insert("Five", 5); /// /// // We can see that the HashMap holds 5 elements /// assert_eq!(map.len(), 5); /// // But its capacity isn't changed /// assert_eq!(map.capacity(), empty_map_capacity) /// ``` #[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 HashMap { /// 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. /// /// # HashDoS resistance /// /// The `hash_builder` normally use a fixed key by default and that does /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. /// Users who require HashDoS resistance should explicitly use /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] /// as the hasher when creating a [`HashMap`]. /// /// The `hash_builder` passed should implement the [`BuildHasher`] trait for /// the HashMap to be useful, see its documentation for details. /// /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html /// /// # 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); /// ``` #[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. /// /// # HashDoS resistance /// /// The `hash_builder` normally use a fixed key by default and that does /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. /// Users who require HashDoS resistance should explicitly use /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] /// as the hasher when creating a [`HashMap`]. /// /// The `hash_builder` passed should implement the [`BuildHasher`] trait for /// the HashMap to be useful, see its documentation for details. /// /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html /// /// # 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); /// ``` #[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 HashMap { /// 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 hash map is initially created with a capacity of 0, so it will not allocate until it /// is first inserted into. /// /// # HashDoS resistance /// /// The `hash_builder` normally use a fixed key by default and that does /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. /// Users who require HashDoS resistance should explicitly use /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] /// as the hasher when creating a [`HashMap`]. /// /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// /// # 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 const 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. /// /// # HashDoS resistance /// /// The `hash_builder` normally use a fixed key by default and that does /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. /// Users who require HashDoS resistance should explicitly use /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] /// as the hasher when creating a [`HashMap`]. /// /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// /// # 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 = 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` 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 = 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 = 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 = 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 = (0..8).map(|x|(x, x*10)).collect(); /// assert_eq!(map.len(), 8); /// /// map.retain(|&k, _| k % 2 == 0); /// /// // We can see, that the number of elements inside map is changed. /// assert_eq!(map.len(), 4); /// /// 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(&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 `extract_if` lets you mutate every value in the filter closure, regardless of /// whether you choose to keep or remove it. /// /// If the returned `ExtractIf` is not exhausted, e.g. because it is dropped without iterating /// or the iteration short-circuits, then the remaining elements will be retained. /// Use [`retain()`] with a negated predicate if you do not need the returned iterator. /// /// Keeps the allocated memory for reuse. /// /// [`retain()`]: HashMap::retain /// /// # Examples /// /// ``` /// use hashbrown::HashMap; /// /// let mut map: HashMap = (0..8).map(|x| (x, x)).collect(); /// /// let drained: HashMap = map.extract_if(|k, _v| k % 2 == 0).collect(); /// /// let mut evens = drained.keys().cloned().collect::>(); /// let mut odds = map.keys().cloned().collect::>(); /// evens.sort(); /// odds.sort(); /// /// assert_eq!(evens, vec![0, 2, 4, 6]); /// assert_eq!(odds, vec![1, 3, 5, 7]); /// /// let mut map: HashMap = (0..8).map(|x| (x, x)).collect(); /// /// { // Iterator is dropped without being consumed. /// let d = map.extract_if(|k, _v| k % 2 != 0); /// } /// /// // ExtractIf was not exhausted, therefore no elements were drained. /// assert_eq!(map.len(), 8); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn extract_if(&mut self, f: F) -> ExtractIf<'_, K, V, F, A> where F: FnMut(&K, &mut V) -> bool, { ExtractIf { f, inner: RawExtractIf { 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 { 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 = 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 { IntoValues { inner: self.into_iter(), } } } impl HashMap where K: Eq + Hash, S: BuildHasher, A: Allocator, { /// 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 capacity exceeds [`isize::MAX`] bytes and [`abort`] the program /// in case of allocation error. Use [`try_reserve`](HashMap::try_reserve) instead /// if you want to handle memory allocation failure. /// /// [`isize::MAX`]: https://doc.rust-lang.org/std/primitive.isize.html /// [`abort`]: https://doc.rust-lang.org/alloc/alloc/fn.handle_alloc_error.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::<_, V, S>(&self.hash_builder)); } /// Tries to reserve capacity for at least `additional` more elements to be inserted /// in the given `HashMap`. 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 = 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::<_, 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 = 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::<_, 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 = 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::<_, 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_hash::(&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 = 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 Q: Hash + Equivalent, { let hash = make_hash::(&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(&self, k: &Q) -> Option<&V> where Q: Hash + Equivalent, { // Avoid `Option::map` because it bloats LLVM IR. match self.get_inner(k) { Some((_, 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(&self, k: &Q) -> Option<(&K, &V)> where Q: Hash + Equivalent, { // Avoid `Option::map` because it bloats LLVM IR. match self.get_inner(k) { Some((key, value)) => Some((key, value)), None => None, } } #[inline] fn get_inner(&self, k: &Q) -> Option<&(K, V)> where Q: Hash + Equivalent, { if self.table.is_empty() { None } else { let hash = make_hash::(&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(&mut self, k: &Q) -> Option<(&K, &mut V)> where Q: Hash + Equivalent, { // 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(&self, k: &Q) -> bool where Q: Hash + Equivalent, { 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(&mut self, k: &Q) -> Option<&mut V> where Q: Hash + Equivalent, { // 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(&mut self, k: &Q) -> Option<&mut (K, V)> where Q: Hash + Equivalent, { if self.table.is_empty() { None } else { let hash = make_hash::(&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(&mut self, ks: [&Q; N]) -> Option<[&'_ mut V; N]> where Q: Hash + Equivalent, { 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( &mut self, ks: [&Q; N], ) -> Option<[&'_ mut V; N]> where Q: Hash + Equivalent, { 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( &mut self, ks: [&Q; N], ) -> Option<[(&'_ K, &'_ mut V); N]> where Q: Hash + Equivalent, { 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( &mut self, ks: [&Q; N], ) -> Option<[(&'_ K, &'_ mut V); N]> where Q: Hash + Equivalent, { self.get_many_unchecked_mut_inner(ks) .map(|res| res.map(|(k, v)| (&*k, v))) } fn get_many_mut_inner( &mut self, ks: [&Q; N], ) -> Option<[&'_ mut (K, V); N]> where Q: Hash + Equivalent, { let hashes = self.build_hashes_inner(ks); self.table .get_many_mut(hashes, |i, (k, _)| ks[i].equivalent(k)) } unsafe fn get_many_unchecked_mut_inner( &mut self, ks: [&Q; N], ) -> Option<[&'_ mut (K, V); N]> where Q: Hash + Equivalent, { let hashes = self.build_hashes_inner(ks); self.table .get_many_unchecked_mut(hashes, |i, (k, _)| ks[i].equivalent(k)) } fn build_hashes_inner(&self, ks: [&Q; N]) -> [u64; N] where Q: Hash + Equivalent, { let mut hashes = [0_u64; N]; for i in 0..N { hashes[i] = make_hash::(&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 { let hash = make_hash::(&self.hash_builder, &k); let hasher = make_hasher::<_, V, S>(&self.hash_builder); match self .table .find_or_find_insert_slot(hash, equivalent_key(&k), hasher) { Ok(bucket) => Some(mem::replace(unsafe { &mut bucket.as_mut().1 }, v)), Err(slot) => { unsafe { self.table.insert_in_slot(hash, slot, (k, v)); } 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_hash::(&self.hash_builder, &k); let bucket = self .table .insert(hash, (k, v), make_hasher::<_, 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"); /// /// assert_eq!(map.remove(&1), Some("a")); /// assert_eq!(map.remove(&1), None); /// /// // Now map holds none elements /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove(&mut self, k: &Q) -> Option where Q: Hash + Equivalent, { // 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"); /// /// assert_eq!(map.remove_entry(&1), Some((1, "a"))); /// assert_eq!(map.remove(&1), None); /// /// // Now map hold none elements /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove_entry(&mut self, k: &Q) -> Option<(K, V)> where Q: Hash + Equivalent, { let hash = make_hash::(&self.hash_builder, k); self.table.remove_entry(hash, equivalent_key(k)) } } impl HashMap { /// 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(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(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 reference to the [`RawTable`] used underneath [`HashMap`]. /// This function is only available if the `raw` feature of the crate is enabled. /// /// See [`raw_table_mut`] for more. /// /// [`raw_table_mut`]: Self::raw_table_mut #[cfg(feature = "raw")] #[cfg_attr(feature = "inline-more", inline)] pub fn raw_table(&self) -> &RawTable<(K, V), A> { &self.table } /// 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 this function is safe, but using the raw hash table API 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`]: crate::raw::RawTable /// [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( /// map: &mut HashMap, /// hash: u64, /// is_match: F, /// ) -> Option<(K, V)> /// where /// F: Fn(&(K, V)) -> bool, /// { /// let raw_table = map.raw_table_mut(); /// match raw_table.find(hash, is_match) { /// Some(bucket) => Some(unsafe { raw_table.remove(bucket).0 }), /// None => None, /// } /// } /// /// fn compute_hash(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(&mut self) -> &mut RawTable<(K, V), A> { &mut self.table } } impl PartialEq for HashMap where K: Eq + Hash, V: PartialEq, S: BuildHasher, A: Allocator, { 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 Eq for HashMap where K: Eq + Hash, V: Eq, S: BuildHasher, A: Allocator, { } impl Debug for HashMap where K: Debug, V: Debug, A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_map().entries(self.iter()).finish() } } impl Default for HashMap where S: Default, A: Default + Allocator, { /// Creates an empty `HashMap`, 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 = Default::default(); /// assert_eq!(map.capacity(), 0); /// let map: HashMap = 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 Index<&Q> for HashMap where K: Eq + Hash, Q: Hash + Equivalent, S: BuildHasher, A: Allocator, { 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 From<[(K, V); N]> for HashMap where K: Eq + Hash, A: Default + Allocator, { /// # 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 Clone for Iter<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] fn clone(&self) -> Self { Iter { inner: self.inner.clone(), marker: PhantomData, } } } impl 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 Send for IterMut<'_, K, V> {} impl 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 { inner: RawIntoIter<(K, V), A>, } impl IntoIter { /// 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 { inner: IntoIter, } impl Iterator for IntoKeys { type Item = K; #[inline] fn next(&mut self) -> Option { self.inner.next().map(|(k, _)| k) } #[inline] fn size_hint(&self) -> (usize, Option) { self.inner.size_hint() } } impl ExactSizeIterator for IntoKeys { #[inline] fn len(&self) -> usize { self.inner.len() } } impl FusedIterator for IntoKeys {} impl fmt::Debug for IntoKeys { 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 { inner: IntoIter, } impl Iterator for IntoValues { type Item = V; #[inline] fn next(&mut self) -> Option { self.inner.next().map(|(_, v)| v) } #[inline] fn size_hint(&self) -> (usize, Option) { self.inner.size_hint() } } impl ExactSizeIterator for IntoValues { #[inline] fn len(&self) -> usize { self.inner.len() } } impl FusedIterator for IntoValues {} impl fmt::Debug for IntoValues { 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 Clone for Keys<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] fn clone(&self) -> Self { Keys { inner: self.inner.clone(), } } } impl 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 Clone for Values<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] fn clone(&self) -> Self { Values { inner: self.inner.clone(), } } } impl 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 = Global> { inner: RawDrain<'a, (K, V), A>, } impl 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 [`extract_if`] method on [`HashMap`]. See its /// documentation for more. /// /// [`extract_if`]: struct.HashMap.html#method.extract_if /// [`HashMap`]: struct.HashMap.html /// /// # Examples /// /// ``` /// use hashbrown::HashMap; /// /// let mut map: HashMap = [(1, "a"), (2, "b"), (3, "c")].into(); /// /// let mut extract_if = map.extract_if(|k, _v| k % 2 != 0); /// let mut vec = vec![extract_if.next(), extract_if.next()]; /// /// // The `ExtractIf` 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!(extract_if.next(), None); /// assert_eq!(extract_if.next(), None); /// drop(extract_if); /// /// assert_eq!(map.len(), 1); /// ``` #[must_use = "Iterators are lazy unless consumed"] pub struct ExtractIf<'a, K, V, F, A: Allocator = Global> where F: FnMut(&K, &mut V) -> bool, { f: F, inner: RawExtractIf<'a, (K, V), A>, } impl Iterator for ExtractIf<'_, K, V, F, A> where F: FnMut(&K, &mut V) -> bool, A: Allocator, { type Item = (K, V); #[cfg_attr(feature = "inline-more", inline)] fn next(&mut self) -> Option { self.inner.next(|&mut (ref k, ref mut v)| (self.f)(k, v)) } #[inline] fn size_hint(&self) -> (usize, Option) { (0, self.inner.iter.size_hint().1) } } impl FusedIterator for ExtractIf<'_, K, V, F> where F: FnMut(&K, &mut V) -> bool {} /// 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(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 = Global> { map: &'a mut HashMap, } /// 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(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 = 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(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 = Global> { elem: Bucket<(K, V)>, table: &'a mut RawTable<(K, V), A>, hash_builder: &'a S, } unsafe impl Send for RawOccupiedEntryMut<'_, K, V, S, A> where K: Send, V: Send, S: Send, A: Send + Allocator, { } unsafe impl Sync for RawOccupiedEntryMut<'_, K, V, S, A> where K: Sync, V: Sync, S: Sync, A: Sync + Allocator, { } /// 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(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 = 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(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 = Global> { map: &'a HashMap, } impl<'a, K, V, S, A: Allocator> 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(self, k: &Q) -> RawEntryMut<'a, K, V, S, A> where S: BuildHasher, Q: Hash + Equivalent, { let hash = make_hash::(&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(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(self, hash: u64, k: &Q) -> RawEntryMut<'a, K, V, S, A> where Q: Equivalent, { self.from_hash(hash, equivalent(k)) } } impl<'a, K, V, S, A: Allocator> 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(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(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(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> 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(self, k: &Q) -> Option<(&'a K, &'a V)> where S: BuildHasher, Q: Hash + Equivalent, { let hash = make_hash::(&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(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(self, hash: u64, k: &Q) -> Option<(&'a K, &'a V)> where Q: Equivalent, { self.from_hash(hash, equivalent(k)) } #[cfg_attr(feature = "inline-more", inline)] fn search(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((key, 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(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(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> 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(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(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(self, f: F) -> Self where F: FnOnce(&K, V) -> Option, { match self { RawEntryMut::Occupied(entry) => entry.replace_entry_with(f), RawEntryMut::Vacant(_) => self, } } } impl<'a, K, V, S, A: Allocator> 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, 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, 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 (key, 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, 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, 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, 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).0 } } /// 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(self, f: F) -> RawEntryMut<'a, K, V, S, A> where F: FnOnce(&K, V) -> Option, { 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> 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_hash::(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(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::<_, 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(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( 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_hash::(self.hash_builder, &key); let elem = self.table.insert( hash, (key, value), make_hasher::<_, V, S>(self.hash_builder), ); RawOccupiedEntryMut { elem, table: self.table, hash_builder: self.hash_builder, } } } impl Debug for RawEntryBuilderMut<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("RawEntryBuilder").finish() } } impl 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 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 Debug for RawVacantEntryMut<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("RawVacantEntryMut").finish() } } impl 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, { /// 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 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 = DefaultHashBuilder, A: Allocator = Global> { hash: u64, key: Option, elem: Bucket<(K, V)>, table: &'a mut HashMap, } unsafe impl Send for OccupiedEntry<'_, K, V, S, A> where K: Send, V: Send, S: Send, A: Send + Allocator, { } unsafe impl Sync for OccupiedEntry<'_, K, V, S, A> where K: Sync, V: Sync, S: Sync, A: Sync + Allocator, { } impl 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 = DefaultHashBuilder, A: Allocator = Global> { hash: u64, key: K, table: &'a mut HashMap, } impl 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, { /// 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 = HashMap::new(); /// /// match map.entry_ref("a") { /// EntryRef::Occupied(_) => unreachable!(), /// EntryRef::Vacant(_) => { } /// } /// ``` Vacant(VacantEntryRef<'a, 'b, K, Q, V, S, A>), } impl, Q: ?Sized + Debug, V: Debug, S, A: Allocator> 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: ?Sized> AsRef 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 = Global> { hash: u64, key: Option>, elem: Bucket<(K, V)>, table: &'a mut HashMap, } 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, { } 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, { } impl, Q: ?Sized + Debug, V: Debug, S, A: Allocator> 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().borrow()) .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::::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 = Global> { hash: u64, key: KeyOrRef<'b, K, Q>, table: &'a mut HashMap, } impl, Q: ?Sized + Debug, V, S, A: Allocator> 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 = 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 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> 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> IntoIterator for &'a HashMap { 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> IntoIterator for &'a mut HashMap { 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::>(); /// // 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 IntoIterator for HashMap { type Item = (K, V); type IntoIter = IntoIter; /// 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 { 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) { self.inner.size_hint() } } impl ExactSizeIterator for Iter<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } impl 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) { self.inner.size_hint() } } impl ExactSizeIterator for IterMut<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } impl FusedIterator for IterMut<'_, K, V> {} impl 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 Iterator for IntoIter { 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) { self.inner.size_hint() } } impl ExactSizeIterator for IntoIter { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } impl FusedIterator for IntoIter {} impl fmt::Debug for IntoIter { 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) { self.inner.size_hint() } } impl ExactSizeIterator for Keys<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } impl 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) { self.inner.size_hint() } } impl ExactSizeIterator for Values<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } impl 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) { self.inner.size_hint() } } impl ExactSizeIterator for ValuesMut<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } impl FusedIterator for ValuesMut<'_, K, V> {} impl 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> 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) { self.inner.size_hint() } } impl ExactSizeIterator for Drain<'_, K, V, A> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } impl FusedIterator for Drain<'_, K, V, A> {} impl fmt::Debug for Drain<'_, K, V, A> where K: fmt::Debug, V: fmt::Debug, A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list().entries(self.iter()).finish() } } impl<'a, K, V, S, A: Allocator> 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 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 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(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(self, f: F) -> Self where F: FnOnce(&K, V) -> Option, { match self { Entry::Occupied(entry) => entry.replace_entry_with(f), Entry::Vacant(_) => self, } } } impl<'a, K, V: Default, S, A: Allocator> 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> = 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> 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); /// /// 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 /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove_entry(self) -> (K, V) { unsafe { self.table.table.remove(self.elem).0 } } /// 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); /// /// 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 /// assert!(map.is_empty()); /// ``` #[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, 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, 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, usize> = HashMap::with_capacity(6); /// let mut keys_one: Vec> = Vec::with_capacity(6); /// let mut keys_two: Vec> = 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, usize>, keys: &[Rc]) { /// 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(self, f: F) -> Entry<'a, K, V, S, A> where F: FnOnce(&K, V) -> Option, { 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> 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::<_, 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::<_, 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> 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 = 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 = 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 = 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 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 an access to the borrower form of the key. /// /// # Examples /// /// ``` /// use hashbrown::HashMap; /// /// let mut map: HashMap = 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 V>(self, default: F) -> &'a mut V where K: Hash + Borrow + 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 = 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, { match *self { EntryRef::Occupied(ref entry) => entry.key().borrow(), 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 = 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(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 = 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(self, f: F) -> Self where F: FnOnce(&K, V) -> Option, { match self { EntryRef::Occupied(entry) => entry.replace_entry_with(f), EntryRef::Vacant(_) => self, } } } impl<'a, 'b, K, Q: ?Sized, V: Default, S, A: Allocator> 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> = 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> 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 = 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) -> &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::EntryRef; /// /// let mut map: HashMap = HashMap::new(); /// // The map is empty /// assert!(map.is_empty() && map.capacity() == 0); /// /// map.entry_ref("poneyland").or_insert(12); /// /// 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.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove_entry(self) -> (K, V) { unsafe { self.table.table.remove(self.elem).0 } } /// Gets a reference to the value in the entry. /// /// # Examples /// /// ``` /// use hashbrown::HashMap; /// use hashbrown::hash_map::EntryRef; /// /// let mut map: HashMap = 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 = 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 = 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 = 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 = HashMap::new(); /// // The map is empty /// assert!(map.is_empty() && map.capacity() == 0); /// /// map.entry_ref("poneyland").or_insert(12); /// /// 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.is_empty()); /// ``` #[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 OccupiedEntryRef was created through [`EntryRef::insert`]. /// /// # Examples /// /// ``` /// use hashbrown::hash_map::{EntryRef, HashMap}; /// use std::rc::Rc; /// /// let mut map: HashMap, u32> = HashMap::new(); /// let key: Rc = 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, 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 OccupiedEntryRef was created through [`EntryRef::insert`]. /// /// # Examples /// /// ``` /// use hashbrown::hash_map::{EntryRef, HashMap}; /// use std::rc::Rc; /// /// let mut map: HashMap, usize> = HashMap::with_capacity(6); /// let mut keys: Vec> = Vec::with_capacity(6); /// /// for (value, key) in ["a", "b", "c", "d", "e", "f"].into_iter().enumerate() { /// let rc_key: Rc = 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, usize>, keys: &[Rc]) { /// 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 = 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(self, f: F) -> EntryRef<'a, 'b, K, Q, V, S, A> where F: FnOnce(&K, V) -> Option, { 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(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> 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 = 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, { self.key.as_ref() } /// Take ownership of the key. /// /// # Examples /// /// ``` /// use hashbrown::hash_map::{EntryRef, HashMap}; /// /// let mut map: HashMap = 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 = 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::<_, 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::<_, V, S>(&self.table.hash_builder), ); OccupiedEntryRef { hash: self.hash, key: None, elem, table: self.table, } } } impl FromIterator<(K, V)> for HashMap where K: Eq + Hash, S: BuildHasher + Default, A: Default + Allocator, { #[cfg_attr(feature = "inline-more", inline)] fn from_iter>(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 Extend<(K, V)> for HashMap where K: Eq + Hash, S: BuildHasher, A: Allocator, { /// Inserts all new key-values from the iterator to existing `HashMap`. /// 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>(&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 where K: Eq + Hash + Copy, V: Copy, S: BuildHasher, A: Allocator, { /// Inserts all new key-values from the iterator to existing `HashMap`. /// 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>(&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 where K: Eq + Hash + Copy, V: Copy, S: BuildHasher, A: Allocator, { /// Inserts all new key-values from the iterator to existing `HashMap`. /// 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>(&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) -> HashMap { 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>( v: IntoIter<&'static str, u8, A>, ) -> IntoIter<&'new str, u8, A> { v } fn into_iter_val<'new, A: Allocator>( v: IntoIter, ) -> IntoIter { 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 alloc::string::{String, ToString}; use alloc::sync::Arc; use allocator_api2::alloc::{AllocError, Allocator, Global}; use core::alloc::Layout; use core::ptr::NonNull; use core::sync::atomic::{AtomicI8, Ordering}; 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; 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> = 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); } }); 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 = HashMap::new(); assert_eq!(m.remove(&0), None); } #[test] fn test_empty_entry() { let mut m: HashMap = 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 = 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 = 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 = 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) { for k in m.keys() { assert!(m.contains_key(k), "{k} is in keys() but not in the map?"); } } 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) { for k in m.keys() { assert!(m.contains_key(k), "{k} is in keys() but not in the map?"); } } 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] #[allow(clippy::needless_borrow)] fn test_extend_ref_kv_tuple() { use std::ops::AddAssign; let mut a = HashMap::new(); a.insert(0, 0); fn create_arr + 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::(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 = 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 = 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) { for k in m.keys() { assert!(m.contains_key(k), "{k} is in keys() but not in the map?"); } } 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) { for k in m.keys() { assert!(m.contains_key(k), "{k} is in keys() but not in the map?"); } } 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 = (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_extract_if() { { let mut map: HashMap = (0..8).map(|x| (x, x * 10)).collect(); let drained = map.extract_if(|&k, _| k % 2 == 0); let mut out = drained.collect::>(); out.sort_unstable(); assert_eq!(vec![(0, 0), (2, 20), (4, 40), (6, 60)], out); assert_eq!(map.len(), 4); } { let mut map: HashMap = (0..8).map(|x| (x, x * 10)).collect(); map.extract_if(|&k, _| k % 2 == 0).for_each(drop); 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_ISIZE: usize = isize::MAX as usize; let mut empty_bytes: HashMap = HashMap::new(); if let Err(CapacityOverflow) = empty_bytes.try_reserve(usize::MAX) { } else { panic!("usize::MAX should trigger an overflow!"); } if let Err(CapacityOverflow) = empty_bytes.try_reserve(MAX_ISIZE) { } else { panic!("isize::MAX should trigger an overflow!"); } if let Err(AllocError { .. }) = empty_bytes.try_reserve(MAX_ISIZE / 5) { } 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 = HashMap::new(); let _ = empty_bytes2.try_reserve(MAX_ISIZE / 5); let mut empty_bytes3: HashMap = HashMap::new(); let _ = empty_bytes3.try_reserve(MAX_ISIZE / 5); let mut empty_bytes4: HashMap = HashMap::new(); if let Err(AllocError { .. }) = empty_bytes4.try_reserve(MAX_ISIZE / 5) { } else { panic!("isize::MAX / 5 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, k: i32| -> u64 { super::make_hash::(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 = 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_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).0; removed.push(t); left -= 1; } else { assert!(removed.contains(&(i, 2 * i)), "{i} not in {removed:?}"); let e = map.table.insert( hash_value, (i, 2 * i), super::make_hasher::<_, 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 = 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); } #[test] #[should_panic = "panic in clone"] fn test_clone_from_memory_leaks() { use ::alloc::vec::Vec; struct CheckedClone { panic_in_clone: bool, need_drop: Vec, } impl Clone for CheckedClone { fn clone(&self) -> Self { if self.panic_in_clone { panic!("panic in clone") } Self { panic_in_clone: self.panic_in_clone, need_drop: self.need_drop.clone(), } } } let mut map1 = HashMap::new(); map1.insert( 1, CheckedClone { panic_in_clone: false, need_drop: vec![0, 1, 2], }, ); map1.insert( 2, CheckedClone { panic_in_clone: false, need_drop: vec![3, 4, 5], }, ); map1.insert( 3, CheckedClone { panic_in_clone: true, need_drop: vec![6, 7, 8], }, ); let _map2 = map1.clone(); } struct MyAllocInner { drop_count: Arc, } #[derive(Clone)] struct MyAlloc { _inner: Arc, } impl MyAlloc { fn new(drop_count: Arc) -> Self { MyAlloc { _inner: Arc::new(MyAllocInner { drop_count }), } } } impl Drop for MyAllocInner { fn drop(&mut self) { println!("MyAlloc freed."); self.drop_count.fetch_sub(1, Ordering::SeqCst); } } unsafe impl Allocator for MyAlloc { fn allocate(&self, layout: Layout) -> std::result::Result, AllocError> { let g = Global; g.allocate(layout) } unsafe fn deallocate(&self, ptr: NonNull, layout: Layout) { let g = Global; g.deallocate(ptr, layout) } } #[test] fn test_hashmap_into_iter_bug() { let dropped: Arc = Arc::new(AtomicI8::new(1)); { let mut map = HashMap::with_capacity_in(10, MyAlloc::new(dropped.clone())); for i in 0..10 { map.entry(i).or_insert_with(|| "i".to_string()); } for (k, v) in map { println!("{}, {}", k, v); } } // All allocator clones should already be dropped. assert_eq!(dropped.load(Ordering::SeqCst), 0); } #[derive(Debug)] struct CheckedCloneDrop { panic_in_clone: bool, panic_in_drop: bool, dropped: bool, data: T, } impl CheckedCloneDrop { fn new(panic_in_clone: bool, panic_in_drop: bool, data: T) -> Self { CheckedCloneDrop { panic_in_clone, panic_in_drop, dropped: false, data, } } } impl Clone for CheckedCloneDrop { fn clone(&self) -> Self { if self.panic_in_clone { panic!("panic in clone") } Self { panic_in_clone: self.panic_in_clone, panic_in_drop: self.panic_in_drop, dropped: self.dropped, data: self.data.clone(), } } } impl Drop for CheckedCloneDrop { 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; } } /// Return hashmap with predefined distribution of elements. /// All elements will be located in the same order as elements /// returned by iterator. /// /// This function does not panic, but returns an error as a `String` /// to distinguish between a test panic and an error in the input data. fn get_test_map( iter: I, mut fun: impl FnMut(u64) -> T, alloc: A, ) -> Result, DefaultHashBuilder, A>, String> where I: Iterator + Clone + ExactSizeIterator, A: Allocator, T: PartialEq + core::fmt::Debug, { use crate::scopeguard::guard; let mut map: HashMap, _, A> = HashMap::with_capacity_in(iter.size_hint().0, alloc); { let mut guard = guard(&mut map, |map| { for (_, value) in map.iter_mut() { value.panic_in_drop = false } }); let mut count = 0; // Hash and Key must be equal to each other for controlling the elements placement. for (panic_in_clone, panic_in_drop) in iter.clone() { if core::mem::needs_drop::() && panic_in_drop { return Err(String::from( "panic_in_drop can be set with a type that doesn't need to be dropped", )); } guard.table.insert( count, ( count, CheckedCloneDrop::new(panic_in_clone, panic_in_drop, fun(count)), ), |(k, _)| *k, ); count += 1; } // Let's check that all elements are located as we wanted let mut check_count = 0; for ((key, value), (panic_in_clone, panic_in_drop)) in guard.iter().zip(iter) { if *key != check_count { return Err(format!( "key != check_count,\nkey: `{}`,\ncheck_count: `{}`", key, check_count )); } if value.dropped || value.panic_in_clone != panic_in_clone || value.panic_in_drop != panic_in_drop || value.data != fun(check_count) { return Err(format!( "Value is not equal to expected,\nvalue: `{:?}`,\nexpected: \ `CheckedCloneDrop {{ panic_in_clone: {}, panic_in_drop: {}, dropped: {}, data: {:?} }}`", value, panic_in_clone, panic_in_drop, false, fun(check_count) )); } check_count += 1; } if guard.len() != check_count as usize { return Err(format!( "map.len() != check_count,\nmap.len(): `{}`,\ncheck_count: `{}`", guard.len(), check_count )); } if count != check_count { return Err(format!( "count != check_count,\ncount: `{}`,\ncheck_count: `{}`", count, check_count )); } core::mem::forget(guard); } Ok(map) } const DISARMED: bool = false; const ARMED: bool = true; const ARMED_FLAGS: [bool; 8] = [ DISARMED, DISARMED, DISARMED, ARMED, DISARMED, DISARMED, DISARMED, DISARMED, ]; const DISARMED_FLAGS: [bool; 8] = [ DISARMED, DISARMED, DISARMED, DISARMED, DISARMED, DISARMED, DISARMED, DISARMED, ]; #[test] #[should_panic = "panic in clone"] fn test_clone_memory_leaks_and_double_drop_one() { let dropped: Arc = Arc::new(AtomicI8::new(2)); { assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len()); let map: HashMap>, DefaultHashBuilder, MyAlloc> = match get_test_map( ARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), |n| vec![n], MyAlloc::new(dropped.clone()), ) { Ok(map) => map, Err(msg) => panic!("{msg}"), }; // Clone should normally clone a few elements, and then (when the // clone function panics), deallocate both its own memory, memory // of `dropped: Arc` and the memory of already cloned // elements (Vec memory inside CheckedCloneDrop). let _map2 = map.clone(); } } #[test] #[should_panic = "panic in drop"] fn test_clone_memory_leaks_and_double_drop_two() { let dropped: Arc = Arc::new(AtomicI8::new(2)); { assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len()); let map: HashMap, DefaultHashBuilder, _> = match get_test_map( DISARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), |n| n, MyAlloc::new(dropped.clone()), ) { Ok(map) => map, Err(msg) => panic!("{msg}"), }; let mut map2 = match get_test_map( DISARMED_FLAGS.into_iter().zip(ARMED_FLAGS), |n| n, MyAlloc::new(dropped.clone()), ) { Ok(map) => map, Err(msg) => panic!("{msg}"), }; // The `clone_from` should try to drop the elements of `map2` without // double drop and leaking the allocator. Elements that have not been // dropped leak their memory. map2.clone_from(&map); } } /// We check that we have a working table if the clone operation from another /// thread ended in a panic (when buckets of maps are equal to each other). #[test] fn test_catch_panic_clone_from_when_len_is_equal() { use std::thread; let dropped: Arc = Arc::new(AtomicI8::new(2)); { assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len()); let mut map = match get_test_map( DISARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), |n| vec![n], MyAlloc::new(dropped.clone()), ) { Ok(map) => map, Err(msg) => panic!("{msg}"), }; thread::scope(|s| { let result: thread::ScopedJoinHandle<'_, String> = s.spawn(|| { let scope_map = match get_test_map(ARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), |n| vec![n * 2], MyAlloc::new(dropped.clone())) { Ok(map) => map, Err(msg) => return msg, }; if map.table.buckets() != scope_map.table.buckets() { return format!( "map.table.buckets() != scope_map.table.buckets(),\nleft: `{}`,\nright: `{}`", map.table.buckets(), scope_map.table.buckets() ); } map.clone_from(&scope_map); "We must fail the cloning!!!".to_owned() }); if let Ok(msg) = result.join() { panic!("{msg}") } }); // Let's check that all iterators work fine and do not return elements // (especially `RawIterRange`, which does not depend on the number of // elements in the table, but looks directly at the control bytes) // // SAFETY: We know for sure that `RawTable` will outlive // the returned `RawIter / RawIterRange` iterator. assert_eq!(map.len(), 0); assert_eq!(map.iter().count(), 0); assert_eq!(unsafe { map.table.iter().count() }, 0); assert_eq!(unsafe { map.table.iter().iter.count() }, 0); for idx in 0..map.table.buckets() { let idx = idx as u64; assert!( map.table.find(idx, |(k, _)| *k == idx).is_none(), "Index: {idx}" ); } } // All allocator clones should already be dropped. assert_eq!(dropped.load(Ordering::SeqCst), 0); } /// We check that we have a working table if the clone operation from another /// thread ended in a panic (when buckets of maps are not equal to each other). #[test] fn test_catch_panic_clone_from_when_len_is_not_equal() { use std::thread; let dropped: Arc = Arc::new(AtomicI8::new(2)); { assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len()); let mut map = match get_test_map( [DISARMED].into_iter().zip([DISARMED]), |n| vec![n], MyAlloc::new(dropped.clone()), ) { Ok(map) => map, Err(msg) => panic!("{msg}"), }; thread::scope(|s| { let result: thread::ScopedJoinHandle<'_, String> = s.spawn(|| { let scope_map = match get_test_map( ARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), |n| vec![n * 2], MyAlloc::new(dropped.clone()), ) { Ok(map) => map, Err(msg) => return msg, }; if map.table.buckets() == scope_map.table.buckets() { return format!( "map.table.buckets() == scope_map.table.buckets(): `{}`", map.table.buckets() ); } map.clone_from(&scope_map); "We must fail the cloning!!!".to_owned() }); if let Ok(msg) = result.join() { panic!("{msg}") } }); // Let's check that all iterators work fine and do not return elements // (especially `RawIterRange`, which does not depend on the number of // elements in the table, but looks directly at the control bytes) // // SAFETY: We know for sure that `RawTable` will outlive // the returned `RawIter / RawIterRange` iterator. assert_eq!(map.len(), 0); assert_eq!(map.iter().count(), 0); assert_eq!(unsafe { map.table.iter().count() }, 0); assert_eq!(unsafe { map.table.iter().iter.count() }, 0); for idx in 0..map.table.buckets() { let idx = idx as u64; assert!( map.table.find(idx, |(k, _)| *k == idx).is_none(), "Index: {idx}" ); } } // All allocator clones should already be dropped. assert_eq!(dropped.load(Ordering::SeqCst), 0); } }