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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::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<ahash::AHasher>;
/// Dummy default hasher for `HashMap`.
#[cfg(not(feature = "ahash"))]
pub enum DefaultHashBuilder {}
/// A hash map implemented with quadratic probing and SIMD lookup.
///
/// The default hashing algorithm is currently [`AHash`], though this is
/// subject to change at any point in the future. This hash function is very
/// fast for all types of keys, but this algorithm will typically *not* protect
/// against attacks such as HashDoS.
///
/// The hashing algorithm can be replaced on a per-`HashMap` basis using the
/// [`default`], [`with_hasher`], and [`with_capacity_and_hasher`] methods. Many
/// alternative algorithms are available on crates.io, such as the [`fnv`] crate.
///
/// It is required that the keys implement the [`Eq`] and [`Hash`] traits, although
/// this can frequently be achieved by using `#[derive(PartialEq, Eq, Hash)]`.
/// If you implement these yourself, it is important that the following
/// property holds:
///
/// ```text
/// k1 == k2 -> hash(k1) == hash(k2)
/// ```
///
/// In other words, if two keys are equal, their hashes must be equal.
///
/// It is a logic error for a key to be modified in such a way that the key's
/// hash, as determined by the [`Hash`] trait, or its equality, as determined by
/// the [`Eq`] trait, changes while it is in the map. This is normally only
/// possible through [`Cell`], [`RefCell`], global state, I/O, or unsafe code.
///
/// It is also a logic error for the [`Hash`] implementation of a key to panic.
/// This is generally only possible if the trait is implemented manually. If a
/// panic does occur then the contents of the `HashMap` may become corrupted and
/// some items may be dropped from the table.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// // Type inference lets us omit an explicit type signature (which
/// // would be `HashMap<String, String>` in this example).
/// let mut book_reviews = HashMap::new();
///
/// // Review some books.
/// book_reviews.insert(
/// "Adventures of Huckleberry Finn".to_string(),
/// "My favorite book.".to_string(),
/// );
/// book_reviews.insert(
/// "Grimms' Fairy Tales".to_string(),
/// "Masterpiece.".to_string(),
/// );
/// book_reviews.insert(
/// "Pride and Prejudice".to_string(),
/// "Very enjoyable.".to_string(),
/// );
/// book_reviews.insert(
/// "The Adventures of Sherlock Holmes".to_string(),
/// "Eye lyked it alot.".to_string(),
/// );
///
/// // Check for a specific one.
/// // When collections store owned values (String), they can still be
/// // queried using references (&str).
/// if !book_reviews.contains_key("Les Misérables") {
/// println!("We've got {} reviews, but Les Misérables ain't one.",
/// book_reviews.len());
/// }
///
/// // oops, this review has a lot of spelling mistakes, let's delete it.
/// book_reviews.remove("The Adventures of Sherlock Holmes");
///
/// // Look up the values associated with some keys.
/// let to_find = ["Pride and Prejudice", "Alice's Adventure in Wonderland"];
/// for &book in &to_find {
/// match book_reviews.get(book) {
/// Some(review) => println!("{}: {}", book, review),
/// None => println!("{} is unreviewed.", book)
/// }
/// }
///
/// // Look up the value for a key (will panic if the key is not found).
/// println!("Review for Jane: {}", book_reviews["Pride and Prejudice"]);
///
/// // Iterate over everything.
/// for (book, review) in &book_reviews {
/// println!("{}: \"{}\"", book, review);
/// }
/// ```
///
/// `HashMap` also implements an [`Entry API`](#method.entry), which allows
/// for more complex methods of getting, setting, updating and removing keys and
/// their values:
///
/// ```
/// use hashbrown::HashMap;
///
/// // type inference lets us omit an explicit type signature (which
/// // would be `HashMap<&str, u8>` in this example).
/// let mut player_stats = HashMap::new();
///
/// fn random_stat_buff() -> u8 {
/// // could actually return some random value here - let's just return
/// // some fixed value for now
/// 42
/// }
///
/// // insert a key only if it doesn't already exist
/// player_stats.entry("health").or_insert(100);
///
/// // insert a key using a function that provides a new value only if it
/// // doesn't already exist
/// player_stats.entry("defence").or_insert_with(random_stat_buff);
///
/// // update a key, guarding against the key possibly not being set
/// let stat = player_stats.entry("attack").or_insert(100);
/// *stat += random_stat_buff();
/// ```
///
/// The easiest way to use `HashMap` with a custom key type is to derive [`Eq`] and [`Hash`].
/// We must also derive [`PartialEq`].
///
/// [`default`]: #method.default
/// [`with_hasher`]: #method.with_hasher
/// [`with_capacity_and_hasher`]: #method.with_capacity_and_hasher
///
/// ```
/// 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)]
/// .into_iter().collect();
/// // use the values stored in map
/// ```
pub struct HashMap<K, V, S = DefaultHashBuilder, A: Allocator = Global> {
pub(crate) hash_builder: S,
pub(crate) table: RawTable<(K, V), A>,
}
impl<K: Clone, V: Clone, S: Clone, A: Allocator + Clone> Clone for HashMap<K, V, S, A> {
fn clone(&self) -> Self {
HashMap {
hash_builder: self.hash_builder.clone(),
table: self.table.clone(),
}
}
fn clone_from(&mut self, source: &Self) {
self.table.clone_from(&source.table);
// Update hash_builder only if we successfully cloned all elements.
self.hash_builder.clone_from(&source.hash_builder);
}
}
/// Ensures that a single closure type across uses of this which, in turn prevents multiple
/// instances of any functions like RawTable::reserve from being generated
#[cfg_attr(feature = "inline-more", inline)]
pub(crate) fn make_hasher<Q, V, S>(hash_builder: &S) -> impl Fn(&(Q, V)) -> u64 + '_
where
Q: Hash,
S: BuildHasher,
{
move |val| make_hash::<Q, S>(hash_builder, &val.0)
}
/// Ensures that a single closure type across uses of this which, in turn prevents multiple
/// instances of any functions like RawTable::reserve from being generated
#[cfg_attr(feature = "inline-more", inline)]
fn equivalent_key<Q, K, V>(k: &Q) -> impl Fn(&(K, V)) -> bool + '_
where
Q: ?Sized + Equivalent<K>,
{
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<Q, K>(k: &Q) -> impl Fn(&K) -> bool + '_
where
Q: ?Sized + Equivalent<K>,
{
move |x| k.equivalent(x)
}
#[cfg(not(feature = "nightly"))]
#[cfg_attr(feature = "inline-more", inline)]
pub(crate) fn make_hash<Q, S>(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<Q, S>(hash_builder: &S, val: &Q) -> u64
where
Q: Hash + ?Sized,
S: BuildHasher,
{
hash_builder.hash_one(val)
}
#[cfg(feature = "ahash")]
impl<K, V> HashMap<K, V, DefaultHashBuilder> {
/// Creates an empty `HashMap`.
///
/// The hash map is initially created with a capacity of 0, so it will not allocate until it
/// is first inserted into.
///
/// # 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.
///
/// [`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.
///
/// [`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<K, V, A: Allocator> HashMap<K, V, DefaultHashBuilder, A> {
/// Creates an empty `HashMap` using the given allocator.
///
/// The hash map is initially created with a capacity of 0, so it will not allocate until it
/// is first inserted into.
///
/// # 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.
///
/// [`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.
///
/// [`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<K, V, S> HashMap<K, V, S> {
/// Creates an empty `HashMap` which will use the given hash builder to hash
/// keys.
///
/// The hash map is initially created with a capacity of 0, so it will not
/// allocate until it is first inserted into.
///
/// # 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.
///
/// [`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);
/// 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.
///
/// [`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);
/// 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<K, V, S, A: Allocator> HashMap<K, V, S, A> {
/// Returns a reference to the underlying allocator.
#[inline]
pub fn allocator(&self) -> &A {
self.table.allocator()
}
/// Creates an empty `HashMap` which will use the given hash builder to hash
/// keys. It will be allocated with the given allocator.
///
/// The 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`].
///
/// [`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`].
///
/// [`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`].
///
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::DefaultHashBuilder;
///
/// let hasher = DefaultHashBuilder::default();
/// let map: HashMap<i32, i32> = HashMap::with_hasher(hasher);
/// let hasher: &DefaultHashBuilder = map.hasher();
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn hasher(&self) -> &S {
&self.hash_builder
}
/// Returns the number of elements the map can hold without reallocating.
///
/// This number is a lower bound; the `HashMap<K, V>` might be able to hold
/// more, but is guaranteed to be able to hold at least this many.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// let map: HashMap<i32, i32> = HashMap::with_capacity(100);
/// assert_eq!(map.len(), 0);
/// assert!(map.capacity() >= 100);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn capacity(&self) -> usize {
self.table.capacity()
}
/// An iterator visiting all keys in arbitrary order.
/// The iterator element type is `&'a K`.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
/// assert_eq!(map.len(), 3);
/// let mut vec: Vec<&str> = Vec::new();
///
/// for key in map.keys() {
/// println!("{}", key);
/// vec.push(*key);
/// }
///
/// // The `Keys` iterator produces keys in arbitrary order, so the
/// // keys must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, ["a", "b", "c"]);
///
/// assert_eq!(map.len(), 3);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn keys(&self) -> Keys<'_, K, V> {
Keys { inner: self.iter() }
}
/// An iterator visiting all values in arbitrary order.
/// The iterator element type is `&'a V`.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
/// assert_eq!(map.len(), 3);
/// let mut vec: Vec<i32> = Vec::new();
///
/// for val in map.values() {
/// println!("{}", val);
/// vec.push(*val);
/// }
///
/// // The `Values` iterator produces values in arbitrary order, so the
/// // values must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [1, 2, 3]);
///
/// assert_eq!(map.len(), 3);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn values(&self) -> Values<'_, K, V> {
Values { inner: self.iter() }
}
/// An iterator visiting all values mutably in arbitrary order.
/// The iterator element type is `&'a mut V`.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
///
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// for val in map.values_mut() {
/// *val = *val + 10;
/// }
///
/// assert_eq!(map.len(), 3);
/// let mut vec: Vec<i32> = Vec::new();
///
/// for val in map.values() {
/// println!("{}", val);
/// vec.push(*val);
/// }
///
/// // The `Values` iterator produces values in arbitrary order, so the
/// // values must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [11, 12, 13]);
///
/// assert_eq!(map.len(), 3);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> {
ValuesMut {
inner: self.iter_mut(),
}
}
/// An iterator visiting all key-value pairs in arbitrary order.
/// The iterator element type is `(&'a K, &'a V)`.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
/// assert_eq!(map.len(), 3);
/// let mut vec: Vec<(&str, i32)> = Vec::new();
///
/// for (key, val) in map.iter() {
/// println!("key: {} val: {}", key, val);
/// vec.push((*key, *val));
/// }
///
/// // The `Iter` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [("a", 1), ("b", 2), ("c", 3)]);
///
/// assert_eq!(map.len(), 3);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn iter(&self) -> Iter<'_, K, V> {
// Here we tie the lifetime of self to the iter.
unsafe {
Iter {
inner: self.table.iter(),
marker: PhantomData,
}
}
}
/// An iterator visiting all key-value pairs in arbitrary order,
/// with mutable references to the values.
/// The iterator element type is `(&'a K, &'a mut V)`.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// // Update all values
/// for (_, val) in map.iter_mut() {
/// *val *= 2;
/// }
///
/// assert_eq!(map.len(), 3);
/// let mut vec: Vec<(&str, i32)> = Vec::new();
///
/// for (key, val) in &map {
/// println!("key: {} val: {}", key, val);
/// vec.push((*key, *val));
/// }
///
/// // The `Iter` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [("a", 2), ("b", 4), ("c", 6)]);
///
/// assert_eq!(map.len(), 3);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn iter_mut(&mut self) -> IterMut<'_, K, V> {
// Here we tie the lifetime of self to the iter.
unsafe {
IterMut {
inner: self.table.iter(),
marker: PhantomData,
}
}
}
#[cfg(test)]
#[cfg_attr(feature = "inline-more", inline)]
fn raw_capacity(&self) -> usize {
self.table.buckets()
}
/// Returns the number of elements in the map.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut a = HashMap::new();
/// assert_eq!(a.len(), 0);
/// a.insert(1, "a");
/// assert_eq!(a.len(), 1);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn len(&self) -> usize {
self.table.len()
}
/// Returns `true` if the map contains no elements.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut a = HashMap::new();
/// assert!(a.is_empty());
/// a.insert(1, "a");
/// assert!(!a.is_empty());
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// Clears the map, returning all key-value pairs as an iterator. Keeps the
/// allocated memory for reuse.
///
/// If the returned iterator is dropped before being fully consumed, it
/// drops the remaining key-value pairs. The returned iterator keeps a
/// mutable borrow on the vector to optimize its implementation.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut a = HashMap::new();
/// a.insert(1, "a");
/// a.insert(2, "b");
/// let capacity_before_drain = a.capacity();
///
/// for (k, v) in a.drain().take(1) {
/// assert!(k == 1 || k == 2);
/// assert!(v == "a" || v == "b");
/// }
///
/// // As we can see, the map is empty and contains no element.
/// assert!(a.is_empty() && a.len() == 0);
/// // But map capacity is equal to old one.
/// assert_eq!(a.capacity(), capacity_before_drain);
///
/// let mut a = HashMap::new();
/// a.insert(1, "a");
/// a.insert(2, "b");
///
/// { // Iterator is dropped without being consumed.
/// let d = a.drain();
/// }
///
/// // But the map is empty even if we do not use Drain iterator.
/// assert!(a.is_empty());
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn drain(&mut self) -> Drain<'_, K, V, A> {
Drain {
inner: self.table.drain(),
}
}
/// Retains only the elements specified by the predicate. Keeps the
/// allocated memory for reuse.
///
/// In other words, remove all pairs `(k, v)` such that `f(&k, &mut v)` returns `false`.
/// The elements are visited in unsorted (and unspecified) order.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<i32, i32> = (0..8).map(|x|(x, x*10)).collect();
/// assert_eq!(map.len(), 8);
///
/// 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<F>(&mut self, mut f: F)
where
F: FnMut(&K, &mut V) -> bool,
{
// Here we only use `iter` as a temporary, preventing use-after-free
unsafe {
for item in self.table.iter() {
let &mut (ref key, ref mut value) = item.as_mut();
if !f(key, value) {
self.table.erase(item);
}
}
}
}
/// Drains elements which are true under the given predicate,
/// and returns an iterator over the removed items.
///
/// In other words, move all pairs `(k, v)` such that `f(&k, &mut v)` returns `true` out
/// into another iterator.
///
/// Note that `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<i32, i32> = (0..8).map(|x| (x, x)).collect();
///
/// let drained: HashMap<i32, i32> = map.extract_if(|k, _v| k % 2 == 0).collect();
///
/// let mut evens = drained.keys().cloned().collect::<Vec<_>>();
/// let mut odds = map.keys().cloned().collect::<Vec<_>>();
/// evens.sort();
/// odds.sort();
///
/// assert_eq!(evens, vec![0, 2, 4, 6]);
/// assert_eq!(odds, vec![1, 3, 5, 7]);
///
/// let mut map: HashMap<i32, i32> = (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<F>(&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<K, V, A> {
IntoKeys {
inner: self.into_iter(),
}
}
/// Creates a consuming iterator visiting all the values in arbitrary order.
/// The map cannot be used after calling this.
/// The iterator element type is `V`.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// let mut vec: Vec<i32> = map.into_values().collect();
///
/// // The `IntoValues` iterator produces values in arbitrary order, so
/// // the values must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [1, 2, 3]);
/// ```
#[inline]
pub fn into_values(self) -> IntoValues<K, V, A> {
IntoValues {
inner: self.into_iter(),
}
}
}
impl<K, V, S, A> HashMap<K, V, S, A>
where
K: Eq + Hash,
S: BuildHasher,
A: Allocator,
{
/// 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.
///
///
/// # 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<K,V>`. The collection may reserve more space to avoid
/// frequent reallocations.
///
/// # Errors
///
/// If the capacity overflows, or the allocator reports a failure, then an error
/// is returned.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, isize> = HashMap::new();
/// // Map is empty and doesn't allocate memory
/// assert_eq!(map.capacity(), 0);
///
/// map.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?");
///
/// // And now map can hold at least 10 elements
/// assert!(map.capacity() >= 10);
/// ```
/// If the capacity overflows, or the allocator reports a failure, then an error
/// is returned:
/// ```
/// # fn test() {
/// use hashbrown::HashMap;
/// use hashbrown::TryReserveError;
/// let mut map: HashMap<i32, i32> = HashMap::new();
///
/// match map.try_reserve(usize::MAX) {
/// Err(error) => match error {
/// TryReserveError::CapacityOverflow => {}
/// _ => panic!("TryReserveError::AllocError ?"),
/// },
/// _ => panic!(),
/// }
/// # }
/// # fn main() {
/// # #[cfg(not(miri))]
/// # test()
/// # }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
self.table
.try_reserve(additional, make_hasher::<_, V, S>(&self.hash_builder))
}
/// Shrinks the capacity of the map as much as possible. It will drop
/// down as much as possible while maintaining the internal rules
/// and possibly leaving some space in accordance with the resize policy.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<i32, i32> = HashMap::with_capacity(100);
/// map.insert(1, 2);
/// map.insert(3, 4);
/// assert!(map.capacity() >= 100);
/// map.shrink_to_fit();
/// assert!(map.capacity() >= 2);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn shrink_to_fit(&mut self) {
self.table
.shrink_to(0, make_hasher::<_, V, S>(&self.hash_builder));
}
/// Shrinks the capacity of the map with a lower limit. It will drop
/// down no lower than the supplied limit while maintaining the internal rules
/// and possibly leaving some space in accordance with the resize policy.
///
/// This function does nothing if the current capacity is smaller than the
/// supplied minimum capacity.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<i32, i32> = HashMap::with_capacity(100);
/// map.insert(1, 2);
/// map.insert(3, 4);
/// assert!(map.capacity() >= 100);
/// map.shrink_to(10);
/// assert!(map.capacity() >= 10);
/// map.shrink_to(0);
/// assert!(map.capacity() >= 2);
/// map.shrink_to(10);
/// assert!(map.capacity() >= 2);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn shrink_to(&mut self, min_capacity: usize) {
self.table
.shrink_to(min_capacity, make_hasher::<_, 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::<K, S>(&self.hash_builder, &key);
if let Some(elem) = self.table.find(hash, equivalent_key(&key)) {
Entry::Occupied(OccupiedEntry {
hash,
key: Some(key),
elem,
table: self,
})
} else {
Entry::Vacant(VacantEntry {
hash,
key,
table: self,
})
}
}
/// Gets the given key's corresponding entry by reference in the map for in-place manipulation.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut words: HashMap<String, usize> = HashMap::new();
/// let source = ["poneyland", "horseyland", "poneyland", "poneyland"];
/// for (i, &s) in source.iter().enumerate() {
/// let counter = words.entry_ref(s).or_insert(0);
/// *counter += 1;
/// }
///
/// assert_eq!(words["poneyland"], 3);
/// assert_eq!(words["horseyland"], 1);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn entry_ref<'a, 'b, Q: ?Sized>(&'a mut self, key: &'b Q) -> EntryRef<'a, 'b, K, Q, V, S, A>
where
Q: Hash + Equivalent<K>,
{
let hash = make_hash::<Q, S>(&self.hash_builder, key);
if let Some(elem) = self.table.find(hash, equivalent_key(key)) {
EntryRef::Occupied(OccupiedEntryRef {
hash,
key: Some(KeyOrRef::Borrowed(key)),
elem,
table: self,
})
} else {
EntryRef::Vacant(VacantEntryRef {
hash,
key: KeyOrRef::Borrowed(key),
table: self,
})
}
}
/// Returns a reference to the value corresponding to the key.
///
/// The key may be any borrowed form of the map's key type, but
/// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
/// the key type.
///
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.get(&1), Some(&"a"));
/// assert_eq!(map.get(&2), None);
/// ```
#[inline]
pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V>
where
Q: Hash + Equivalent<K>,
{
// 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.
///
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.get_key_value(&1), Some((&1, &"a")));
/// assert_eq!(map.get_key_value(&2), None);
/// ```
#[inline]
pub fn get_key_value<Q: ?Sized>(&self, k: &Q) -> Option<(&K, &V)>
where
Q: Hash + Equivalent<K>,
{
// 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<Q: ?Sized>(&self, k: &Q) -> Option<&(K, V)>
where
Q: Hash + Equivalent<K>,
{
if self.table.is_empty() {
None
} else {
let hash = make_hash::<Q, S>(&self.hash_builder, k);
self.table.get(hash, equivalent_key(k))
}
}
/// Returns the key-value pair corresponding to the supplied key, with a mutable reference to value.
///
/// The supplied key may be any borrowed form of the map's key type, but
/// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
/// the key type.
///
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// let (k, v) = map.get_key_value_mut(&1).unwrap();
/// assert_eq!(k, &1);
/// assert_eq!(v, &mut "a");
/// *v = "b";
/// assert_eq!(map.get_key_value_mut(&1), Some((&1, &mut "b")));
/// assert_eq!(map.get_key_value_mut(&2), None);
/// ```
#[inline]
pub fn get_key_value_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<(&K, &mut V)>
where
Q: Hash + Equivalent<K>,
{
// 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.
///
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.contains_key(&1), true);
/// assert_eq!(map.contains_key(&2), false);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool
where
Q: Hash + Equivalent<K>,
{
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.
///
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// if let Some(x) = map.get_mut(&1) {
/// *x = "b";
/// }
/// assert_eq!(map[&1], "b");
///
/// assert_eq!(map.get_mut(&2), None);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V>
where
Q: Hash + Equivalent<K>,
{
// Avoid `Option::map` because it bloats LLVM IR.
match self.get_inner_mut(k) {
Some(&mut (_, ref mut v)) => Some(v),
None => None,
}
}
#[inline]
fn get_inner_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut (K, V)>
where
Q: Hash + Equivalent<K>,
{
if self.table.is_empty() {
None
} else {
let hash = make_hash::<Q, S>(&self.hash_builder, k);
self.table.get_mut(hash, equivalent_key(k))
}
}
/// Attempts to get mutable references to `N` values in the map at once.
///
/// Returns an array of length `N` with the results of each query. For soundness, at most one
/// mutable reference will be returned to any value. `None` will be returned if any of the
/// keys are duplicates or missing.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut libraries = HashMap::new();
/// libraries.insert("Bodleian Library".to_string(), 1602);
/// libraries.insert("Athenæum".to_string(), 1807);
/// libraries.insert("Herzogin-Anna-Amalia-Bibliothek".to_string(), 1691);
/// libraries.insert("Library of Congress".to_string(), 1800);
///
/// let got = libraries.get_many_mut([
/// "Athenæum",
/// "Library of Congress",
/// ]);
/// assert_eq!(
/// got,
/// Some([
/// &mut 1807,
/// &mut 1800,
/// ]),
/// );
///
/// // Missing keys result in None
/// let got = libraries.get_many_mut([
/// "Athenæum",
/// "New York Public Library",
/// ]);
/// assert_eq!(got, None);
///
/// // Duplicate keys result in None
/// let got = libraries.get_many_mut([
/// "Athenæum",
/// "Athenæum",
/// ]);
/// assert_eq!(got, None);
/// ```
pub fn get_many_mut<Q: ?Sized, const N: usize>(&mut self, ks: [&Q; N]) -> Option<[&'_ mut V; N]>
where
Q: Hash + Equivalent<K>,
{
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.
///
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut libraries = HashMap::new();
/// libraries.insert("Bodleian Library".to_string(), 1602);
/// libraries.insert("Athenæum".to_string(), 1807);
/// libraries.insert("Herzogin-Anna-Amalia-Bibliothek".to_string(), 1691);
/// libraries.insert("Library of Congress".to_string(), 1800);
///
/// let got = libraries.get_many_mut([
/// "Athenæum",
/// "Library of Congress",
/// ]);
/// assert_eq!(
/// got,
/// Some([
/// &mut 1807,
/// &mut 1800,
/// ]),
/// );
///
/// // Missing keys result in None
/// let got = libraries.get_many_mut([
/// "Athenæum",
/// "New York Public Library",
/// ]);
/// assert_eq!(got, None);
/// ```
pub unsafe fn get_many_unchecked_mut<Q: ?Sized, const N: usize>(
&mut self,
ks: [&Q; N],
) -> Option<[&'_ mut V; N]>
where
Q: Hash + Equivalent<K>,
{
self.get_many_unchecked_mut_inner(ks)
.map(|res| res.map(|(_, v)| v))
}
/// Attempts to get mutable references to `N` values in the map at once, with immutable
/// references to the corresponding keys.
///
/// Returns an array of length `N` with the results of each query. For soundness, at most one
/// mutable reference will be returned to any value. `None` will be returned if any of the keys
/// are duplicates or missing.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut libraries = HashMap::new();
/// libraries.insert("Bodleian Library".to_string(), 1602);
/// libraries.insert("Athenæum".to_string(), 1807);
/// libraries.insert("Herzogin-Anna-Amalia-Bibliothek".to_string(), 1691);
/// libraries.insert("Library of Congress".to_string(), 1800);
///
/// let got = libraries.get_many_key_value_mut([
/// "Bodleian Library",
/// "Herzogin-Anna-Amalia-Bibliothek",
/// ]);
/// assert_eq!(
/// got,
/// Some([
/// (&"Bodleian Library".to_string(), &mut 1602),
/// (&"Herzogin-Anna-Amalia-Bibliothek".to_string(), &mut 1691),
/// ]),
/// );
/// // Missing keys result in None
/// let got = libraries.get_many_key_value_mut([
/// "Bodleian Library",
/// "Gewandhaus",
/// ]);
/// assert_eq!(got, None);
///
/// // Duplicate keys result in None
/// let got = libraries.get_many_key_value_mut([
/// "Bodleian Library",
/// "Herzogin-Anna-Amalia-Bibliothek",
/// "Herzogin-Anna-Amalia-Bibliothek",
/// ]);
/// assert_eq!(got, None);
/// ```
pub fn get_many_key_value_mut<Q: ?Sized, const N: usize>(
&mut self,
ks: [&Q; N],
) -> Option<[(&'_ K, &'_ mut V); N]>
where
Q: Hash + Equivalent<K>,
{
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.
///
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut libraries = HashMap::new();
/// libraries.insert("Bodleian Library".to_string(), 1602);
/// libraries.insert("Athenæum".to_string(), 1807);
/// libraries.insert("Herzogin-Anna-Amalia-Bibliothek".to_string(), 1691);
/// libraries.insert("Library of Congress".to_string(), 1800);
///
/// let got = libraries.get_many_key_value_mut([
/// "Bodleian Library",
/// "Herzogin-Anna-Amalia-Bibliothek",
/// ]);
/// assert_eq!(
/// got,
/// Some([
/// (&"Bodleian Library".to_string(), &mut 1602),
/// (&"Herzogin-Anna-Amalia-Bibliothek".to_string(), &mut 1691),
/// ]),
/// );
/// // Missing keys result in None
/// let got = libraries.get_many_key_value_mut([
/// "Bodleian Library",
/// "Gewandhaus",
/// ]);
/// assert_eq!(got, None);
/// ```
pub unsafe fn get_many_key_value_unchecked_mut<Q: ?Sized, const N: usize>(
&mut self,
ks: [&Q; N],
) -> Option<[(&'_ K, &'_ mut V); N]>
where
Q: Hash + Equivalent<K>,
{
self.get_many_unchecked_mut_inner(ks)
.map(|res| res.map(|(k, v)| (&*k, v)))
}
fn get_many_mut_inner<Q: ?Sized, const N: usize>(
&mut self,
ks: [&Q; N],
) -> Option<[&'_ mut (K, V); N]>
where
Q: Hash + Equivalent<K>,
{
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<Q: ?Sized, const N: usize>(
&mut self,
ks: [&Q; N],
) -> Option<[&'_ mut (K, V); N]>
where
Q: Hash + Equivalent<K>,
{
let hashes = self.build_hashes_inner(ks);
self.table
.get_many_unchecked_mut(hashes, |i, (k, _)| ks[i].equivalent(k))
}
fn build_hashes_inner<Q: ?Sized, const N: usize>(&self, ks: [&Q; N]) -> [u64; N]
where
Q: Hash + Equivalent<K>,
{
let mut hashes = [0_u64; N];
for i in 0..N {
hashes[i] = make_hash::<Q, S>(&self.hash_builder, ks[i]);
}
hashes
}
/// Inserts a key-value pair into the map.
///
/// If the map did not have this key present, [`None`] is returned.
///
/// If the map did have this key present, the value is updated, and the old
/// value is returned. The key is not updated, though; this matters for
/// types that can be `==` without being identical. See the [`std::collections`]
/// [module-level documentation] for more.
///
/// [module-level documentation]: https://doc.rust-lang.org/std/collections/index.html#insert-and-complex-keys
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// assert_eq!(map.insert(37, "a"), None);
/// assert_eq!(map.is_empty(), false);
///
/// map.insert(37, "b");
/// assert_eq!(map.insert(37, "c"), Some("b"));
/// assert_eq!(map[&37], "c");
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn insert(&mut self, k: K, v: V) -> Option<V> {
let hash = make_hash::<K, S>(&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::<K, S>(&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.
///
///
/// # 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<Q: ?Sized>(&mut self, k: &Q) -> Option<V>
where
Q: Hash + Equivalent<K>,
{
// 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.
///
///
/// # 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<Q: ?Sized>(&mut self, k: &Q) -> Option<(K, V)>
where
Q: Hash + Equivalent<K>,
{
let hash = make_hash::<Q, S>(&self.hash_builder, k);
self.table.remove_entry(hash, equivalent_key(k))
}
}
impl<K, V, S, A: Allocator> HashMap<K, V, S, A> {
/// Creates a raw entry builder for the HashMap.
///
/// Raw entries provide the lowest level of control for searching and
/// manipulating a map. They must be manually initialized with a hash and
/// then manually searched. After this, insertions into a vacant entry
/// still require an owned key to be provided.
///
/// Raw entries are useful for such exotic situations as:
///
/// * Hash memoization
/// * Deferring the creation of an owned key until it is known to be required
/// * Using a search key that doesn't work with the Borrow trait
/// * Using custom comparison logic without newtype wrappers
///
/// Because raw entries provide much more low-level control, it's much easier
/// to put the HashMap into an inconsistent state which, while memory-safe,
/// will cause the map to produce seemingly random results. Higher-level and
/// more foolproof APIs like `entry` should be preferred when possible.
///
/// In particular, the hash used to initialized the raw entry must still be
/// consistent with the hash of the key that is ultimately stored in the entry.
/// This is because implementations of HashMap may need to recompute hashes
/// when resizing, at which point only the keys are available.
///
/// Raw entries give mutable access to the keys. This must not be used
/// to modify how the key would compare or hash, as the map will not re-evaluate
/// where the key should go, meaning the keys may become "lost" if their
/// location does not reflect their state. For instance, if you change a key
/// so that the map now contains keys which compare equal, search may start
/// acting erratically, with two keys randomly masking each other. Implementations
/// are free to assume this doesn't happen (within the limits of memory-safety).
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map = HashMap::new();
/// map.extend([("a", 100), ("b", 200), ("c", 300)]);
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// // Existing key (insert and update)
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => unreachable!(),
/// RawEntryMut::Occupied(mut view) => {
/// assert_eq!(view.get(), &100);
/// let v = view.get_mut();
/// let new_v = (*v) * 10;
/// *v = new_v;
/// assert_eq!(view.insert(1111), 1000);
/// }
/// }
///
/// assert_eq!(map[&"a"], 1111);
/// assert_eq!(map.len(), 3);
///
/// // Existing key (take)
/// let hash = compute_hash(map.hasher(), &"c");
/// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &"c") {
/// RawEntryMut::Vacant(_) => unreachable!(),
/// RawEntryMut::Occupied(view) => {
/// assert_eq!(view.remove_entry(), ("c", 300));
/// }
/// }
/// assert_eq!(map.raw_entry().from_key(&"c"), None);
/// assert_eq!(map.len(), 2);
///
/// // Nonexistent key (insert and update)
/// let key = "d";
/// let hash = compute_hash(map.hasher(), &key);
/// match map.raw_entry_mut().from_hash(hash, |q| *q == key) {
/// RawEntryMut::Occupied(_) => unreachable!(),
/// RawEntryMut::Vacant(view) => {
/// let (k, value) = view.insert("d", 4000);
/// assert_eq!((*k, *value), ("d", 4000));
/// *value = 40000;
/// }
/// }
/// assert_eq!(map[&"d"], 40000);
/// assert_eq!(map.len(), 3);
///
/// match map.raw_entry_mut().from_hash(hash, |q| *q == key) {
/// RawEntryMut::Vacant(_) => unreachable!(),
/// RawEntryMut::Occupied(view) => {
/// assert_eq!(view.remove_entry(), ("d", 40000));
/// }
/// }
/// assert_eq!(map.get(&"d"), None);
/// assert_eq!(map.len(), 2);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn raw_entry_mut(&mut self) -> RawEntryBuilderMut<'_, K, V, S, A> {
RawEntryBuilderMut { map: self }
}
/// Creates a raw immutable entry builder for the HashMap.
///
/// Raw entries provide the lowest level of control for searching and
/// manipulating a map. They must be manually initialized with a hash and
/// then manually searched.
///
/// This is useful for
/// * Hash memoization
/// * Using a search key that doesn't work with the Borrow trait
/// * Using custom comparison logic without newtype wrappers
///
/// Unless you are in such a situation, higher-level and more foolproof APIs like
/// `get` should be preferred.
///
/// Immutable raw entries have very limited use; you might instead want `raw_entry_mut`.
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.extend([("a", 100), ("b", 200), ("c", 300)]);
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// for k in ["a", "b", "c", "d", "e", "f"] {
/// let hash = compute_hash(map.hasher(), k);
/// let v = map.get(&k).cloned();
/// let kv = v.as_ref().map(|v| (&k, v));
///
/// println!("Key: {} and value: {:?}", k, v);
///
/// assert_eq!(map.raw_entry().from_key(&k), kv);
/// assert_eq!(map.raw_entry().from_hash(hash, |q| *q == k), kv);
/// assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv);
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn raw_entry(&self) -> RawEntryBuilder<'_, K, V, S, A> {
RawEntryBuilder { map: self }
}
/// Returns a 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
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::HashMap;
///
/// let mut map = HashMap::new();
/// map.extend([("a", 10), ("b", 20), ("c", 30)]);
/// assert_eq!(map.len(), 3);
///
/// // Let's imagine that we have a value and a hash of the key, but not the key itself.
/// // However, if you want to remove the value from the map by hash and value, and you
/// // know exactly that the value is unique, then you can create a function like this:
/// fn remove_by_hash<K, V, S, F>(
/// map: &mut HashMap<K, V, S>,
/// hash: u64,
/// is_match: F,
/// ) -> Option<(K, V)>
/// where
/// F: Fn(&(K, V)) -> bool,
/// {
/// let raw_table = map.raw_table_mut();
/// match raw_table.find(hash, is_match) {
/// Some(bucket) => Some(unsafe { raw_table.remove(bucket).0 }),
/// None => None,
/// }
/// }
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let hash = compute_hash(map.hasher(), "a");
/// assert_eq!(remove_by_hash(&mut map, hash, |(_, v)| *v == 10), Some(("a", 10)));
/// assert_eq!(map.get(&"a"), None);
/// assert_eq!(map.len(), 2);
/// ```
#[cfg(feature = "raw")]
#[cfg_attr(feature = "inline-more", inline)]
pub fn raw_table_mut(&mut self) -> &mut RawTable<(K, V), A> {
&mut self.table
}
}
impl<K, V, S, A> PartialEq for HashMap<K, V, S, A>
where
K: Eq + Hash,
V: PartialEq,
S: BuildHasher,
A: Allocator,
{
fn eq(&self, other: &Self) -> bool {
if self.len() != other.len() {
return false;
}
self.iter()
.all(|(key, value)| other.get(key).map_or(false, |v| *value == *v))
}
}
impl<K, V, S, A> Eq for HashMap<K, V, S, A>
where
K: Eq + Hash,
V: Eq,
S: BuildHasher,
A: Allocator,
{
}
impl<K, V, S, A> Debug for HashMap<K, V, S, A>
where
K: Debug,
V: Debug,
A: Allocator,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_map().entries(self.iter()).finish()
}
}
impl<K, V, S, A> Default for HashMap<K, V, S, A>
where
S: Default,
A: Default + Allocator,
{
/// Creates an empty `HashMap<K, V, S, A>`, with the `Default` value for the hasher and allocator.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use std::collections::hash_map::RandomState;
///
/// // You can specify all types of HashMap, including hasher and allocator.
/// // Created map is empty and don't allocate memory
/// let map: HashMap<u32, String> = Default::default();
/// assert_eq!(map.capacity(), 0);
/// let map: HashMap<u32, String, RandomState> = HashMap::default();
/// assert_eq!(map.capacity(), 0);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
fn default() -> Self {
Self::with_hasher_in(Default::default(), Default::default())
}
}
impl<K, Q: ?Sized, V, S, A> Index<&Q> for HashMap<K, V, S, A>
where
K: Eq + Hash,
Q: Hash + Equivalent<K>,
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<K, V, A, const N: usize> From<[(K, V); N]> for HashMap<K, V, DefaultHashBuilder, A>
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<K, V> Clone for Iter<'_, K, V> {
#[cfg_attr(feature = "inline-more", inline)]
fn clone(&self) -> Self {
Iter {
inner: self.inner.clone(),
marker: PhantomData,
}
}
}
impl<K: Debug, V: Debug> fmt::Debug for Iter<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
/// A mutable iterator over the entries of a `HashMap` in arbitrary order.
/// The iterator element type is `(&'a K, &'a mut V)`.
///
/// This `struct` is created by the [`iter_mut`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`iter_mut`]: struct.HashMap.html#method.iter_mut
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<_, _> = [(1, "One".to_owned()), (2, "Two".into())].into();
///
/// let mut iter = map.iter_mut();
/// iter.next().map(|(_, v)| v.push_str(" Mississippi"));
/// iter.next().map(|(_, v)| v.push_str(" Mississippi"));
///
/// // It is fused iterator
/// assert_eq!(iter.next(), None);
/// assert_eq!(iter.next(), None);
///
/// assert_eq!(map.get(&1).unwrap(), &"One Mississippi".to_owned());
/// assert_eq!(map.get(&2).unwrap(), &"Two Mississippi".to_owned());
/// ```
pub struct IterMut<'a, K, V> {
inner: RawIter<(K, V)>,
// To ensure invariance with respect to V
marker: PhantomData<(&'a K, &'a mut V)>,
}
// We override the default Send impl which has K: Sync instead of K: Send. Both
// are correct, but this one is more general since it allows keys which
// implement Send but not Sync.
unsafe impl<K: Send, V: Send> Send for IterMut<'_, K, V> {}
impl<K, V> IterMut<'_, K, V> {
/// Returns a iterator of references over the remaining items.
#[cfg_attr(feature = "inline-more", inline)]
pub(super) fn iter(&self) -> Iter<'_, K, V> {
Iter {
inner: self.inner.clone(),
marker: PhantomData,
}
}
}
/// An owning iterator over the entries of a `HashMap` in arbitrary order.
/// The iterator element type is `(K, V)`.
///
/// This `struct` is created by the [`into_iter`] method on [`HashMap`]
/// (provided by the [`IntoIterator`] trait). See its documentation for more.
/// The map cannot be used after calling that method.
///
/// [`into_iter`]: struct.HashMap.html#method.into_iter
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into();
///
/// let mut iter = map.into_iter();
/// let mut vec = vec![iter.next(), iter.next(), iter.next()];
///
/// // The `IntoIter` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [Some((1, "a")), Some((2, "b")), Some((3, "c"))]);
///
/// // It is fused iterator
/// assert_eq!(iter.next(), None);
/// assert_eq!(iter.next(), None);
/// ```
pub struct IntoIter<K, V, A: Allocator = Global> {
inner: RawIntoIter<(K, V), A>,
}
impl<K, V, A: Allocator> IntoIter<K, V, A> {
/// Returns a iterator of references over the remaining items.
#[cfg_attr(feature = "inline-more", inline)]
pub(super) fn iter(&self) -> Iter<'_, K, V> {
Iter {
inner: self.inner.iter(),
marker: PhantomData,
}
}
}
/// An owning iterator over the keys of a `HashMap` in arbitrary order.
/// The iterator element type is `K`.
///
/// This `struct` is created by the [`into_keys`] method on [`HashMap`].
/// See its documentation for more.
/// The map cannot be used after calling that method.
///
/// [`into_keys`]: struct.HashMap.html#method.into_keys
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into();
///
/// let mut keys = map.into_keys();
/// let mut vec = vec![keys.next(), keys.next(), keys.next()];
///
/// // The `IntoKeys` iterator produces keys in arbitrary order, so the
/// // keys must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [Some(1), Some(2), Some(3)]);
///
/// // It is fused iterator
/// assert_eq!(keys.next(), None);
/// assert_eq!(keys.next(), None);
/// ```
pub struct IntoKeys<K, V, A: Allocator = Global> {
inner: IntoIter<K, V, A>,
}
impl<K, V, A: Allocator> Iterator for IntoKeys<K, V, A> {
type Item = K;
#[inline]
fn next(&mut self) -> Option<K> {
self.inner.next().map(|(k, _)| k)
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[inline]
fn fold<B, F>(self, init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, |acc, (k, _)| f(acc, k))
}
}
impl<K, V, A: Allocator> ExactSizeIterator for IntoKeys<K, V, A> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V, A: Allocator> FusedIterator for IntoKeys<K, V, A> {}
impl<K: Debug, V: Debug, A: Allocator> fmt::Debug for IntoKeys<K, V, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list()
.entries(self.inner.iter().map(|(k, _)| k))
.finish()
}
}
/// An owning iterator over the values of a `HashMap` in arbitrary order.
/// The iterator element type is `V`.
///
/// This `struct` is created by the [`into_values`] method on [`HashMap`].
/// See its documentation for more. The map cannot be used after calling that method.
///
/// [`into_values`]: struct.HashMap.html#method.into_values
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into();
///
/// let mut values = map.into_values();
/// let mut vec = vec![values.next(), values.next(), values.next()];
///
/// // The `IntoValues` iterator produces values in arbitrary order, so
/// // the values must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [Some("a"), Some("b"), Some("c")]);
///
/// // It is fused iterator
/// assert_eq!(values.next(), None);
/// assert_eq!(values.next(), None);
/// ```
pub struct IntoValues<K, V, A: Allocator = Global> {
inner: IntoIter<K, V, A>,
}
impl<K, V, A: Allocator> Iterator for IntoValues<K, V, A> {
type Item = V;
#[inline]
fn next(&mut self) -> Option<V> {
self.inner.next().map(|(_, v)| v)
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[inline]
fn fold<B, F>(self, init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, |acc, (_, v)| f(acc, v))
}
}
impl<K, V, A: Allocator> ExactSizeIterator for IntoValues<K, V, A> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V, A: Allocator> FusedIterator for IntoValues<K, V, A> {}
impl<K, V: Debug, A: Allocator> fmt::Debug for IntoValues<K, V, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list()
.entries(self.inner.iter().map(|(_, v)| v))
.finish()
}
}
/// An iterator over the keys of a `HashMap` in arbitrary order.
/// The iterator element type is `&'a K`.
///
/// This `struct` is created by the [`keys`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`keys`]: struct.HashMap.html#method.keys
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into();
///
/// let mut keys = map.keys();
/// let mut vec = vec![keys.next(), keys.next(), keys.next()];
///
/// // The `Keys` iterator produces keys in arbitrary order, so the
/// // keys must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [Some(&1), Some(&2), Some(&3)]);
///
/// // It is fused iterator
/// assert_eq!(keys.next(), None);
/// assert_eq!(keys.next(), None);
/// ```
pub struct Keys<'a, K, V> {
inner: Iter<'a, K, V>,
}
// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
impl<K, V> Clone for Keys<'_, K, V> {
#[cfg_attr(feature = "inline-more", inline)]
fn clone(&self) -> Self {
Keys {
inner: self.inner.clone(),
}
}
}
impl<K: Debug, V> fmt::Debug for Keys<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
/// An iterator over the values of a `HashMap` in arbitrary order.
/// The iterator element type is `&'a V`.
///
/// This `struct` is created by the [`values`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`values`]: struct.HashMap.html#method.values
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into();
///
/// let mut values = map.values();
/// let mut vec = vec![values.next(), values.next(), values.next()];
///
/// // The `Values` iterator produces values in arbitrary order, so the
/// // values must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [Some(&"a"), Some(&"b"), Some(&"c")]);
///
/// // It is fused iterator
/// assert_eq!(values.next(), None);
/// assert_eq!(values.next(), None);
/// ```
pub struct Values<'a, K, V> {
inner: Iter<'a, K, V>,
}
// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
impl<K, V> Clone for Values<'_, K, V> {
#[cfg_attr(feature = "inline-more", inline)]
fn clone(&self) -> Self {
Values {
inner: self.inner.clone(),
}
}
}
impl<K, V: Debug> fmt::Debug for Values<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
/// A draining iterator over the entries of a `HashMap` in arbitrary
/// order. The iterator element type is `(K, V)`.
///
/// This `struct` is created by the [`drain`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`drain`]: struct.HashMap.html#method.drain
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into();
///
/// let mut drain_iter = map.drain();
/// let mut vec = vec![drain_iter.next(), drain_iter.next(), drain_iter.next()];
///
/// // The `Drain` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [Some((1, "a")), Some((2, "b")), Some((3, "c"))]);
///
/// // It is fused iterator
/// assert_eq!(drain_iter.next(), None);
/// assert_eq!(drain_iter.next(), None);
/// ```
pub struct Drain<'a, K, V, A: Allocator = Global> {
inner: RawDrain<'a, (K, V), A>,
}
impl<K, V, A: Allocator> 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<i32, &str> = [(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<K, V, F, A> 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::Item> {
self.inner.next(|&mut (ref k, ref mut v)| (self.f)(k, v))
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
(0, self.inner.iter.size_hint().1)
}
}
impl<K, V, F> 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<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let builder: RawEntryBuilderMut<_, _, _> = map.raw_entry_mut();
///
/// // Existing key
/// match builder.from_key(&6) {
/// Vacant(_) => unreachable!(),
/// Occupied(view) => assert_eq!(view.get(), &16),
/// }
///
/// for key in 0..12 {
/// let hash = compute_hash(map.hasher(), &key);
/// let value = map.get(&key).cloned();
/// let key_value = value.as_ref().map(|v| (&key, v));
///
/// println!("Key: {} and value: {:?}", key, value);
///
/// match map.raw_entry_mut().from_key(&key) {
/// Occupied(mut o) => assert_eq!(Some(o.get_key_value()), key_value),
/// Vacant(_) => assert_eq!(value, None),
/// }
/// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &key) {
/// Occupied(mut o) => assert_eq!(Some(o.get_key_value()), key_value),
/// Vacant(_) => assert_eq!(value, None),
/// }
/// match map.raw_entry_mut().from_hash(hash, |q| *q == key) {
/// Occupied(mut o) => assert_eq!(Some(o.get_key_value()), key_value),
/// Vacant(_) => assert_eq!(value, None),
/// }
/// }
///
/// assert_eq!(map.len(), 6);
/// ```
pub struct RawEntryBuilderMut<'a, K, V, S, A: Allocator = Global> {
map: &'a mut HashMap<K, V, S, A>,
}
/// A view into a single entry in a map, which may either be vacant or occupied.
///
/// This is a lower-level version of [`Entry`].
///
/// This `enum` is constructed through the [`raw_entry_mut`] method on [`HashMap`],
/// then calling one of the methods of that [`RawEntryBuilderMut`].
///
/// [`HashMap`]: struct.HashMap.html
/// [`Entry`]: enum.Entry.html
/// [`raw_entry_mut`]: struct.HashMap.html#method.raw_entry_mut
/// [`RawEntryBuilderMut`]: struct.RawEntryBuilderMut.html
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::hash_map::{HashMap, RawEntryMut, RawOccupiedEntryMut};
///
/// let mut map = HashMap::new();
/// map.extend([('a', 1), ('b', 2), ('c', 3)]);
/// assert_eq!(map.len(), 3);
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// // Existing key (insert)
/// let raw: RawEntryMut<_, _, _> = map.raw_entry_mut().from_key(&'a');
/// let _raw_o: RawOccupiedEntryMut<_, _, _> = raw.insert('a', 10);
/// assert_eq!(map.len(), 3);
///
/// // Nonexistent key (insert)
/// map.raw_entry_mut().from_key(&'d').insert('d', 40);
/// assert_eq!(map.len(), 4);
///
/// // Existing key (or_insert)
/// let hash = compute_hash(map.hasher(), &'b');
/// let kv = map
/// .raw_entry_mut()
/// .from_key_hashed_nocheck(hash, &'b')
/// .or_insert('b', 20);
/// assert_eq!(kv, (&mut 'b', &mut 2));
/// *kv.1 = 20;
/// assert_eq!(map.len(), 4);
///
/// // Nonexistent key (or_insert)
/// let hash = compute_hash(map.hasher(), &'e');
/// let kv = map
/// .raw_entry_mut()
/// .from_key_hashed_nocheck(hash, &'e')
/// .or_insert('e', 50);
/// assert_eq!(kv, (&mut 'e', &mut 50));
/// assert_eq!(map.len(), 5);
///
/// // Existing key (or_insert_with)
/// let hash = compute_hash(map.hasher(), &'c');
/// let kv = map
/// .raw_entry_mut()
/// .from_hash(hash, |q| q == &'c')
/// .or_insert_with(|| ('c', 30));
/// assert_eq!(kv, (&mut 'c', &mut 3));
/// *kv.1 = 30;
/// assert_eq!(map.len(), 5);
///
/// // Nonexistent key (or_insert_with)
/// let hash = compute_hash(map.hasher(), &'f');
/// let kv = map
/// .raw_entry_mut()
/// .from_hash(hash, |q| q == &'f')
/// .or_insert_with(|| ('f', 60));
/// assert_eq!(kv, (&mut 'f', &mut 60));
/// assert_eq!(map.len(), 6);
///
/// println!("Our HashMap: {:?}", map);
///
/// let mut vec: Vec<_> = map.iter().map(|(&k, &v)| (k, v)).collect();
/// // The `Iter` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [('a', 10), ('b', 20), ('c', 30), ('d', 40), ('e', 50), ('f', 60)]);
/// ```
pub enum RawEntryMut<'a, K, V, S, A: Allocator = Global> {
/// An occupied entry.
///
/// # Examples
///
/// ```
/// use hashbrown::{hash_map::RawEntryMut, HashMap};
/// let mut map: HashMap<_, _> = [("a", 100), ("b", 200)].into();
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => unreachable!(),
/// RawEntryMut::Occupied(_) => { }
/// }
/// ```
Occupied(RawOccupiedEntryMut<'a, K, V, S, A>),
/// A vacant entry.
///
/// # Examples
///
/// ```
/// use hashbrown::{hash_map::RawEntryMut, HashMap};
/// let mut map: HashMap<&str, i32> = HashMap::new();
///
/// match map.raw_entry_mut().from_key("a") {
/// RawEntryMut::Occupied(_) => unreachable!(),
/// RawEntryMut::Vacant(_) => { }
/// }
/// ```
Vacant(RawVacantEntryMut<'a, K, V, S, A>),
}
/// A view into an occupied entry in a `HashMap`.
/// It is part of the [`RawEntryMut`] enum.
///
/// [`RawEntryMut`]: enum.RawEntryMut.html
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::hash_map::{HashMap, RawEntryMut, RawOccupiedEntryMut};
///
/// let mut map = HashMap::new();
/// map.extend([("a", 10), ("b", 20), ("c", 30)]);
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let _raw_o: RawOccupiedEntryMut<_, _, _> = map.raw_entry_mut().from_key(&"a").insert("a", 100);
/// assert_eq!(map.len(), 3);
///
/// // Existing key (insert and update)
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => unreachable!(),
/// RawEntryMut::Occupied(mut view) => {
/// assert_eq!(view.get(), &100);
/// let v = view.get_mut();
/// let new_v = (*v) * 10;
/// *v = new_v;
/// assert_eq!(view.insert(1111), 1000);
/// }
/// }
///
/// assert_eq!(map[&"a"], 1111);
/// assert_eq!(map.len(), 3);
///
/// // Existing key (take)
/// let hash = compute_hash(map.hasher(), &"c");
/// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &"c") {
/// RawEntryMut::Vacant(_) => unreachable!(),
/// RawEntryMut::Occupied(view) => {
/// assert_eq!(view.remove_entry(), ("c", 30));
/// }
/// }
/// assert_eq!(map.raw_entry().from_key(&"c"), None);
/// assert_eq!(map.len(), 2);
///
/// let hash = compute_hash(map.hasher(), &"b");
/// match map.raw_entry_mut().from_hash(hash, |q| *q == "b") {
/// RawEntryMut::Vacant(_) => unreachable!(),
/// RawEntryMut::Occupied(view) => {
/// assert_eq!(view.remove_entry(), ("b", 20));
/// }
/// }
/// assert_eq!(map.get(&"b"), None);
/// assert_eq!(map.len(), 1);
/// ```
pub struct RawOccupiedEntryMut<'a, K, V, S, A: Allocator = Global> {
elem: Bucket<(K, V)>,
table: &'a mut RawTable<(K, V), A>,
hash_builder: &'a S,
}
unsafe impl<K, V, S, A> Send for RawOccupiedEntryMut<'_, K, V, S, A>
where
K: Send,
V: Send,
S: Send,
A: Send + Allocator,
{
}
unsafe impl<K, V, S, A> 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<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let raw_v: RawVacantEntryMut<_, _, _> = match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(view) => view,
/// RawEntryMut::Occupied(_) => unreachable!(),
/// };
/// raw_v.insert("a", 10);
/// assert!(map[&"a"] == 10 && map.len() == 1);
///
/// // Nonexistent key (insert and update)
/// let hash = compute_hash(map.hasher(), &"b");
/// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &"b") {
/// RawEntryMut::Occupied(_) => unreachable!(),
/// RawEntryMut::Vacant(view) => {
/// let (k, value) = view.insert("b", 2);
/// assert_eq!((*k, *value), ("b", 2));
/// *value = 20;
/// }
/// }
/// assert!(map[&"b"] == 20 && map.len() == 2);
///
/// let hash = compute_hash(map.hasher(), &"c");
/// match map.raw_entry_mut().from_hash(hash, |q| *q == "c") {
/// RawEntryMut::Occupied(_) => unreachable!(),
/// RawEntryMut::Vacant(view) => {
/// assert_eq!(view.insert("c", 30), (&mut "c", &mut 30));
/// }
/// }
/// assert!(map[&"c"] == 30 && map.len() == 3);
/// ```
pub struct RawVacantEntryMut<'a, K, V, S, A: Allocator = Global> {
table: &'a mut RawTable<(K, V), A>,
hash_builder: &'a S,
}
/// A builder for computing where in a [`HashMap`] a key-value pair would be stored.
///
/// See the [`HashMap::raw_entry`] docs for usage examples.
///
/// [`HashMap::raw_entry`]: struct.HashMap.html#method.raw_entry
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryBuilder};
/// use core::hash::{BuildHasher, Hash};
///
/// let mut map = HashMap::new();
/// map.extend([(1, 10), (2, 20), (3, 30)]);
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// for k in 0..6 {
/// let hash = compute_hash(map.hasher(), &k);
/// let v = map.get(&k).cloned();
/// let kv = v.as_ref().map(|v| (&k, v));
///
/// println!("Key: {} and value: {:?}", k, v);
/// let builder: RawEntryBuilder<_, _, _> = map.raw_entry();
/// assert_eq!(builder.from_key(&k), kv);
/// assert_eq!(map.raw_entry().from_hash(hash, |q| *q == k), kv);
/// assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv);
/// }
/// ```
pub struct RawEntryBuilder<'a, K, V, S, A: Allocator = Global> {
map: &'a HashMap<K, V, S, A>,
}
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<Q: ?Sized>(self, k: &Q) -> RawEntryMut<'a, K, V, S, A>
where
S: BuildHasher,
Q: Hash + Equivalent<K>,
{
let hash = make_hash::<Q, S>(&self.map.hash_builder, k);
self.from_key_hashed_nocheck(hash, k)
}
/// Creates a `RawEntryMut` from the given key and its hash.
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// let key = "a";
/// let hash = compute_hash(map.hasher(), &key);
/// let entry: RawEntryMut<&str, u32, _> = map.raw_entry_mut().from_key_hashed_nocheck(hash, &key);
/// entry.insert(key, 100);
/// assert_eq!(map[&"a"], 100);
/// ```
#[inline]
#[allow(clippy::wrong_self_convention)]
pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> RawEntryMut<'a, K, V, S, A>
where
Q: Equivalent<K>,
{
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<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// let key = "a";
/// let hash = compute_hash(map.hasher(), &key);
/// let entry: RawEntryMut<&str, u32, _> = map.raw_entry_mut().from_hash(hash, |k| k == &key);
/// entry.insert(key, 100);
/// assert_eq!(map[&"a"], 100);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
#[allow(clippy::wrong_self_convention)]
pub fn from_hash<F>(self, hash: u64, is_match: F) -> RawEntryMut<'a, K, V, S, A>
where
for<'b> F: FnMut(&'b K) -> bool,
{
self.search(hash, is_match)
}
#[cfg_attr(feature = "inline-more", inline)]
fn search<F>(self, hash: u64, mut is_match: F) -> RawEntryMut<'a, K, V, S, A>
where
for<'b> F: FnMut(&'b K) -> bool,
{
match self.map.table.find(hash, |(k, _)| is_match(k)) {
Some(elem) => RawEntryMut::Occupied(RawOccupiedEntryMut {
elem,
table: &mut self.map.table,
hash_builder: &self.map.hash_builder,
}),
None => RawEntryMut::Vacant(RawVacantEntryMut {
table: &mut self.map.table,
hash_builder: &self.map.hash_builder,
}),
}
}
}
impl<'a, K, V, S, A: Allocator> RawEntryBuilder<'a, K, V, S, A> {
/// Access an immutable entry by key.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
/// let key = "a";
/// assert_eq!(map.raw_entry().from_key(&key), Some((&"a", &100)));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
#[allow(clippy::wrong_self_convention)]
pub fn from_key<Q: ?Sized>(self, k: &Q) -> Option<(&'a K, &'a V)>
where
S: BuildHasher,
Q: Hash + Equivalent<K>,
{
let hash = make_hash::<Q, S>(&self.map.hash_builder, k);
self.from_key_hashed_nocheck(hash, k)
}
/// Access an immutable entry by a key and its hash.
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::HashMap;
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
/// let key = "a";
/// let hash = compute_hash(map.hasher(), &key);
/// assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &key), Some((&"a", &100)));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
#[allow(clippy::wrong_self_convention)]
pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> Option<(&'a K, &'a V)>
where
Q: Equivalent<K>,
{
self.from_hash(hash, equivalent(k))
}
#[cfg_attr(feature = "inline-more", inline)]
fn search<F>(self, hash: u64, mut is_match: F) -> Option<(&'a K, &'a V)>
where
F: FnMut(&K) -> bool,
{
match self.map.table.get(hash, |(k, _)| is_match(k)) {
Some((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<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
/// let key = "a";
/// let hash = compute_hash(map.hasher(), &key);
/// assert_eq!(map.raw_entry().from_hash(hash, |k| k == &key), Some((&"a", &100)));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
#[allow(clippy::wrong_self_convention)]
pub fn from_hash<F>(self, hash: u64, is_match: F) -> Option<(&'a K, &'a V)>
where
F: FnMut(&K) -> bool,
{
self.search(hash, is_match)
}
}
impl<'a, K, V, S, A: Allocator> RawEntryMut<'a, K, V, S, A> {
/// Sets the value of the entry, and returns a RawOccupiedEntryMut.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// let entry = map.raw_entry_mut().from_key("horseyland").insert("horseyland", 37);
///
/// assert_eq!(entry.remove_entry(), ("horseyland", 37));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn insert(self, key: K, value: V) -> RawOccupiedEntryMut<'a, K, V, S, A>
where
K: Hash,
S: BuildHasher,
{
match self {
RawEntryMut::Occupied(mut entry) => {
entry.insert(value);
entry
}
RawEntryMut::Vacant(entry) => entry.insert_entry(key, value),
}
}
/// Ensures a value is in the entry by inserting the default if empty, and returns
/// mutable references to the key and value in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 3);
/// assert_eq!(map["poneyland"], 3);
///
/// *map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 10).1 *= 2;
/// assert_eq!(map["poneyland"], 6);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn or_insert(self, default_key: K, default_val: V) -> (&'a mut K, &'a mut V)
where
K: Hash,
S: BuildHasher,
{
match self {
RawEntryMut::Occupied(entry) => entry.into_key_value(),
RawEntryMut::Vacant(entry) => entry.insert(default_key, default_val),
}
}
/// Ensures a value is in the entry by inserting the result of the default function if empty,
/// and returns mutable references to the key and value in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, String> = HashMap::new();
///
/// map.raw_entry_mut().from_key("poneyland").or_insert_with(|| {
/// ("poneyland", "hoho".to_string())
/// });
///
/// assert_eq!(map["poneyland"], "hoho".to_string());
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V)
where
F: FnOnce() -> (K, V),
K: Hash,
S: BuildHasher,
{
match self {
RawEntryMut::Occupied(entry) => entry.into_key_value(),
RawEntryMut::Vacant(entry) => {
let (k, v) = default();
entry.insert(k, v)
}
}
}
/// Provides in-place mutable access to an occupied entry before any
/// potential inserts into the map.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// map.raw_entry_mut()
/// .from_key("poneyland")
/// .and_modify(|_k, v| { *v += 1 })
/// .or_insert("poneyland", 42);
/// assert_eq!(map["poneyland"], 42);
///
/// map.raw_entry_mut()
/// .from_key("poneyland")
/// .and_modify(|_k, v| { *v += 1 })
/// .or_insert("poneyland", 0);
/// assert_eq!(map["poneyland"], 43);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn and_modify<F>(self, f: F) -> Self
where
F: FnOnce(&mut K, &mut V),
{
match self {
RawEntryMut::Occupied(mut entry) => {
{
let (k, v) = entry.get_key_value_mut();
f(k, v);
}
RawEntryMut::Occupied(entry)
}
RawEntryMut::Vacant(entry) => RawEntryMut::Vacant(entry),
}
}
/// Provides shared access to the key and owned access to the value of
/// an occupied entry and allows to replace or remove it based on the
/// value of the returned option.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::RawEntryMut;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// let entry = map
/// .raw_entry_mut()
/// .from_key("poneyland")
/// .and_replace_entry_with(|_k, _v| panic!());
///
/// match entry {
/// RawEntryMut::Vacant(_) => {},
/// RawEntryMut::Occupied(_) => panic!(),
/// }
///
/// map.insert("poneyland", 42);
///
/// let entry = map
/// .raw_entry_mut()
/// .from_key("poneyland")
/// .and_replace_entry_with(|k, v| {
/// assert_eq!(k, &"poneyland");
/// assert_eq!(v, 42);
/// Some(v + 1)
/// });
///
/// match entry {
/// RawEntryMut::Occupied(e) => {
/// assert_eq!(e.key(), &"poneyland");
/// assert_eq!(e.get(), &43);
/// },
/// RawEntryMut::Vacant(_) => panic!(),
/// }
///
/// assert_eq!(map["poneyland"], 43);
///
/// let entry = map
/// .raw_entry_mut()
/// .from_key("poneyland")
/// .and_replace_entry_with(|_k, _v| None);
///
/// match entry {
/// RawEntryMut::Vacant(_) => {},
/// RawEntryMut::Occupied(_) => panic!(),
/// }
///
/// assert!(!map.contains_key("poneyland"));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn and_replace_entry_with<F>(self, f: F) -> Self
where
F: FnOnce(&K, V) -> Option<V>,
{
match self {
RawEntryMut::Occupied(entry) => entry.replace_entry_with(f),
RawEntryMut::Vacant(_) => self,
}
}
}
impl<'a, K, V, S, A: Allocator> RawOccupiedEntryMut<'a, K, V, S, A> {
/// Gets a reference to the key in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(o) => assert_eq!(o.key(), &"a")
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn key(&self) -> &K {
unsafe { &self.elem.as_ref().0 }
}
/// Gets a mutable reference to the key in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
/// use std::rc::Rc;
///
/// let key_one = Rc::new("a");
/// let key_two = Rc::new("a");
///
/// let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
/// map.insert(key_one.clone(), 10);
///
/// assert_eq!(map[&key_one], 10);
/// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);
///
/// match map.raw_entry_mut().from_key(&key_one) {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(mut o) => {
/// *o.key_mut() = key_two.clone();
/// }
/// }
/// assert_eq!(map[&key_two], 10);
/// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn key_mut(&mut self) -> &mut K {
unsafe { &mut self.elem.as_mut().0 }
}
/// Converts the entry into a mutable reference to the key in the entry
/// with a lifetime bound to the map itself.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
/// use std::rc::Rc;
///
/// let key_one = Rc::new("a");
/// let key_two = Rc::new("a");
///
/// let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
/// map.insert(key_one.clone(), 10);
///
/// assert_eq!(map[&key_one], 10);
/// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);
///
/// let inside_key: &mut Rc<&str>;
///
/// match map.raw_entry_mut().from_key(&key_one) {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(o) => inside_key = o.into_key(),
/// }
/// *inside_key = key_two.clone();
///
/// assert_eq!(map[&key_two], 10);
/// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn into_key(self) -> &'a mut K {
unsafe { &mut self.elem.as_mut().0 }
}
/// Gets a reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(o) => assert_eq!(o.get(), &100),
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn get(&self) -> &V {
unsafe { &self.elem.as_ref().1 }
}
/// Converts the OccupiedEntry into a mutable reference to the value in the entry
/// with a lifetime bound to the map itself.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
///
/// let value: &mut u32;
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(o) => value = o.into_mut(),
/// }
/// *value += 900;
///
/// assert_eq!(map[&"a"], 1000);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn into_mut(self) -> &'a mut V {
unsafe { &mut self.elem.as_mut().1 }
}
/// Gets a mutable reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(mut o) => *o.get_mut() += 900,
/// }
///
/// assert_eq!(map[&"a"], 1000);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn get_mut(&mut self) -> &mut V {
unsafe { &mut self.elem.as_mut().1 }
}
/// Gets a reference to the key and value in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(o) => assert_eq!(o.get_key_value(), (&"a", &100)),
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn get_key_value(&self) -> (&K, &V) {
unsafe {
let (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<Rc<&str>, u32> = HashMap::new();
/// map.insert(key_one.clone(), 10);
///
/// assert_eq!(map[&key_one], 10);
/// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);
///
/// match map.raw_entry_mut().from_key(&key_one) {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(mut o) => {
/// let (inside_key, inside_value) = o.get_key_value_mut();
/// *inside_key = key_two.clone();
/// *inside_value = 100;
/// }
/// }
/// assert_eq!(map[&key_two], 100);
/// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn get_key_value_mut(&mut self) -> (&mut K, &mut V) {
unsafe {
let &mut (ref mut key, ref mut value) = self.elem.as_mut();
(key, value)
}
}
/// Converts the OccupiedEntry into a mutable reference to the key and value in the entry
/// with a lifetime bound to the map itself.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
/// use std::rc::Rc;
///
/// let key_one = Rc::new("a");
/// let key_two = Rc::new("a");
///
/// let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
/// map.insert(key_one.clone(), 10);
///
/// assert_eq!(map[&key_one], 10);
/// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);
///
/// let inside_key: &mut Rc<&str>;
/// let inside_value: &mut u32;
/// match map.raw_entry_mut().from_key(&key_one) {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(o) => {
/// let tuple = o.into_key_value();
/// inside_key = tuple.0;
/// inside_value = tuple.1;
/// }
/// }
/// *inside_key = key_two.clone();
/// *inside_value = 100;
/// assert_eq!(map[&key_two], 100);
/// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn into_key_value(self) -> (&'a mut K, &'a mut V) {
unsafe {
let &mut (ref mut key, ref mut value) = self.elem.as_mut();
(key, value)
}
}
/// Sets the value of the entry, and returns the entry's old value.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(mut o) => assert_eq!(o.insert(1000), 100),
/// }
///
/// assert_eq!(map[&"a"], 1000);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn insert(&mut self, value: V) -> V {
mem::replace(self.get_mut(), value)
}
/// Sets the value of the entry, and returns the entry's old value.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
/// use std::rc::Rc;
///
/// let key_one = Rc::new("a");
/// let key_two = Rc::new("a");
///
/// let mut map: HashMap<Rc<&str>, u32> = HashMap::new();
/// map.insert(key_one.clone(), 10);
///
/// assert_eq!(map[&key_one], 10);
/// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);
///
/// match map.raw_entry_mut().from_key(&key_one) {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(mut o) => {
/// let old_key = o.insert_key(key_two.clone());
/// assert!(Rc::ptr_eq(&old_key, &key_one));
/// }
/// }
/// assert_eq!(map[&key_two], 10);
/// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn insert_key(&mut self, key: K) -> K {
mem::replace(self.key_mut(), key)
}
/// Takes the value out of the entry, and returns it.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(o) => assert_eq!(o.remove(), 100),
/// }
/// assert_eq!(map.get(&"a"), None);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn remove(self) -> V {
self.remove_entry().1
}
/// Take the ownership of the key and value from the map.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
///
/// match map.raw_entry_mut().from_key(&"a") {
/// RawEntryMut::Vacant(_) => panic!(),
/// RawEntryMut::Occupied(o) => assert_eq!(o.remove_entry(), ("a", 100)),
/// }
/// assert_eq!(map.get(&"a"), None);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn remove_entry(self) -> (K, V) {
unsafe { self.table.remove(self.elem).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<F>(self, f: F) -> RawEntryMut<'a, K, V, S, A>
where
F: FnOnce(&K, V) -> Option<V>,
{
unsafe {
let still_occupied = self
.table
.replace_bucket_with(self.elem.clone(), |(key, value)| {
f(&key, value).map(|new_value| (key, new_value))
});
if still_occupied {
RawEntryMut::Occupied(self)
} else {
RawEntryMut::Vacant(RawVacantEntryMut {
table: self.table,
hash_builder: self.hash_builder,
})
}
}
}
}
impl<'a, K, V, S, A: Allocator> 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::<K, S>(self.hash_builder, &key);
self.insert_hashed_nocheck(hash, key, value)
}
/// Sets the value of the entry with the VacantEntry's key,
/// and returns a mutable reference to it.
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// fn compute_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
///
/// let mut map: HashMap<&str, u32> = [("a", 100), ("b", 200)].into();
/// let key = "c";
/// let hash = compute_hash(map.hasher(), &key);
///
/// match map.raw_entry_mut().from_key_hashed_nocheck(hash, &key) {
/// RawEntryMut::Occupied(_) => panic!(),
/// RawEntryMut::Vacant(v) => assert_eq!(
/// v.insert_hashed_nocheck(hash, key, 300),
/// (&mut "c", &mut 300)
/// ),
/// }
///
/// assert_eq!(map[&"c"], 300);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
#[allow(clippy::shadow_unrelated)]
pub fn insert_hashed_nocheck(self, hash: u64, key: K, value: V) -> (&'a mut K, &'a mut V)
where
K: Hash,
S: BuildHasher,
{
let &mut (ref mut k, ref mut v) = self.table.insert_entry(
hash,
(key, value),
make_hasher::<_, V, S>(self.hash_builder),
);
(k, v)
}
/// Set the value of an entry with a custom hasher function.
///
/// # Examples
///
/// ```
/// use core::hash::{BuildHasher, Hash};
/// use hashbrown::hash_map::{HashMap, RawEntryMut};
///
/// fn make_hasher<K, S>(hash_builder: &S) -> impl Fn(&K) -> u64 + '_
/// where
/// K: Hash + ?Sized,
/// S: BuildHasher,
/// {
/// move |key: &K| {
/// use core::hash::Hasher;
/// let mut state = hash_builder.build_hasher();
/// key.hash(&mut state);
/// state.finish()
/// }
/// }
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// let key = "a";
/// let hash_builder = map.hasher().clone();
/// let hash = make_hasher(&hash_builder)(&key);
///
/// match map.raw_entry_mut().from_hash(hash, |q| q == &key) {
/// RawEntryMut::Occupied(_) => panic!(),
/// RawEntryMut::Vacant(v) => assert_eq!(
/// v.insert_with_hasher(hash, key, 100, make_hasher(&hash_builder)),
/// (&mut "a", &mut 100)
/// ),
/// }
/// map.extend([("b", 200), ("c", 300), ("d", 400), ("e", 500), ("f", 600)]);
/// assert_eq!(map[&"a"], 100);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn insert_with_hasher<H>(
self,
hash: u64,
key: K,
value: V,
hasher: H,
) -> (&'a mut K, &'a mut V)
where
H: Fn(&K) -> u64,
{
let &mut (ref mut k, ref mut v) = self
.table
.insert_entry(hash, (key, value), |x| hasher(&x.0));
(k, v)
}
#[cfg_attr(feature = "inline-more", inline)]
fn insert_entry(self, key: K, value: V) -> RawOccupiedEntryMut<'a, K, V, S, A>
where
K: Hash,
S: BuildHasher,
{
let hash = make_hash::<K, S>(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<K, V, S, A: Allocator> Debug for RawEntryBuilderMut<'_, K, V, S, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("RawEntryBuilder").finish()
}
}
impl<K: Debug, V: Debug, S, A: Allocator> Debug for RawEntryMut<'_, K, V, S, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
RawEntryMut::Vacant(ref v) => f.debug_tuple("RawEntry").field(v).finish(),
RawEntryMut::Occupied(ref o) => f.debug_tuple("RawEntry").field(o).finish(),
}
}
}
impl<K: Debug, V: Debug, S, A: Allocator> Debug for RawOccupiedEntryMut<'_, K, V, S, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("RawOccupiedEntryMut")
.field("key", self.key())
.field("value", self.get())
.finish()
}
}
impl<K, V, S, A: Allocator> Debug for RawVacantEntryMut<'_, K, V, S, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("RawVacantEntryMut").finish()
}
}
impl<K, V, S, A: Allocator> 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<K: Debug, V: Debug, S, A: Allocator> 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<K>,
elem: Bucket<(K, V)>,
table: &'a mut HashMap<K, V, S, A>,
}
unsafe impl<K, V, S, A> Send for OccupiedEntry<'_, K, V, S, A>
where
K: Send,
V: Send,
S: Send,
A: Send + Allocator,
{
}
unsafe impl<K, V, S, A> Sync for OccupiedEntry<'_, K, V, S, A>
where
K: Sync,
V: Sync,
S: Sync,
A: Sync + Allocator,
{
}
impl<K: Debug, V: Debug, S, A: Allocator> 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<K, V, S, A>,
}
impl<K: Debug, V, S, A: Allocator> 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
///
/// # 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<String, i32> = HashMap::new();
///
/// match map.entry_ref("a") {
/// EntryRef::Occupied(_) => unreachable!(),
/// EntryRef::Vacant(_) => { }
/// }
/// ```
Vacant(VacantEntryRef<'a, 'b, K, Q, V, S, A>),
}
impl<K: Borrow<Q>, Q: ?Sized + Debug, V: Debug, S, A: Allocator> Debug
for EntryRef<'_, '_, K, Q, V, S, A>
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
EntryRef::Vacant(ref v) => f.debug_tuple("EntryRef").field(v).finish(),
EntryRef::Occupied(ref o) => f.debug_tuple("EntryRef").field(o).finish(),
}
}
}
enum KeyOrRef<'a, K, Q: ?Sized> {
Borrowed(&'a Q),
Owned(K),
}
impl<'a, K, Q: ?Sized> KeyOrRef<'a, K, Q> {
fn into_owned(self) -> K
where
K: From<&'a Q>,
{
match self {
Self::Borrowed(borrowed) => borrowed.into(),
Self::Owned(owned) => owned,
}
}
}
impl<'a, K: Borrow<Q>, Q: ?Sized> AsRef<Q> for KeyOrRef<'a, K, Q> {
fn as_ref(&self) -> &Q {
match self {
Self::Borrowed(borrowed) => borrowed,
Self::Owned(owned) => owned.borrow(),
}
}
}
/// A view into an occupied entry in a `HashMap`.
/// It is part of the [`EntryRef`] enum.
///
/// [`EntryRef`]: enum.EntryRef.html
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{EntryRef, HashMap, OccupiedEntryRef};
///
/// let mut map = HashMap::new();
/// map.extend([("a".to_owned(), 10), ("b".into(), 20), ("c".into(), 30)]);
///
/// let key = String::from("a");
/// let _entry_o: OccupiedEntryRef<_, _, _, _> = map.entry_ref(&key).insert(100);
/// assert_eq!(map.len(), 3);
///
/// // Existing key (insert and update)
/// match map.entry_ref("a") {
/// EntryRef::Vacant(_) => unreachable!(),
/// EntryRef::Occupied(mut view) => {
/// assert_eq!(view.get(), &100);
/// let v = view.get_mut();
/// *v *= 10;
/// assert_eq!(view.insert(1111), 1000);
/// }
/// }
///
/// assert_eq!(map["a"], 1111);
/// assert_eq!(map.len(), 3);
///
/// // Existing key (take)
/// match map.entry_ref("c") {
/// EntryRef::Vacant(_) => unreachable!(),
/// EntryRef::Occupied(view) => {
/// assert_eq!(view.remove_entry(), ("c".to_owned(), 30));
/// }
/// }
/// assert_eq!(map.get("c"), None);
/// assert_eq!(map.len(), 2);
/// ```
pub struct OccupiedEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator = Global> {
hash: u64,
key: Option<KeyOrRef<'b, K, Q>>,
elem: Bucket<(K, V)>,
table: &'a mut HashMap<K, V, S, A>,
}
unsafe impl<'a, 'b, K, Q, V, S, A> Send for OccupiedEntryRef<'a, 'b, K, Q, V, S, A>
where
K: Send,
Q: Sync + ?Sized,
V: Send,
S: Send,
A: Send + Allocator,
{
}
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<K: Borrow<Q>, 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::<String, i32>::new();
///
/// let entry_v: VacantEntryRef<_, _, _, _> = match map.entry_ref("a") {
/// EntryRef::Vacant(view) => view,
/// EntryRef::Occupied(_) => unreachable!(),
/// };
/// entry_v.insert(10);
/// assert!(map["a"] == 10 && map.len() == 1);
///
/// // Nonexistent key (insert and update)
/// match map.entry_ref("b") {
/// EntryRef::Occupied(_) => unreachable!(),
/// EntryRef::Vacant(view) => {
/// let value = view.insert(2);
/// assert_eq!(*value, 2);
/// *value = 20;
/// }
/// }
/// assert!(map["b"] == 20 && map.len() == 2);
/// ```
pub struct VacantEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator = Global> {
hash: u64,
key: KeyOrRef<'b, K, Q>,
table: &'a mut HashMap<K, V, S, A>,
}
impl<K: Borrow<Q>, Q: ?Sized + Debug, V, S, A: Allocator> 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<K: Debug, V: Debug, S, A: Allocator> 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<K, V, S, A> {
type Item = (&'a K, &'a V);
type IntoIter = Iter<'a, K, V>;
/// Creates an iterator over the entries of a `HashMap` in arbitrary order.
/// The iterator element type is `(&'a K, &'a V)`.
///
/// Return the same `Iter` struct as by the [`iter`] method on [`HashMap`].
///
/// [`iter`]: struct.HashMap.html#method.iter
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// let map_one: HashMap<_, _> = [(1, "a"), (2, "b"), (3, "c")].into();
/// let mut map_two = HashMap::new();
///
/// for (key, value) in &map_one {
/// println!("Key: {}, Value: {}", key, value);
/// map_two.insert_unique_unchecked(*key, *value);
/// }
///
/// assert_eq!(map_one, map_two);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
fn into_iter(self) -> Iter<'a, K, V> {
self.iter()
}
}
impl<'a, K, V, S, A: Allocator> IntoIterator for &'a mut HashMap<K, V, S, A> {
type Item = (&'a K, &'a mut V);
type IntoIter = IterMut<'a, K, V>;
/// Creates an iterator over the entries of a `HashMap` in arbitrary order
/// with mutable references to the values. The iterator element type is
/// `(&'a K, &'a mut V)`.
///
/// Return the same `IterMut` struct as by the [`iter_mut`] method on
/// [`HashMap`].
///
/// [`iter_mut`]: struct.HashMap.html#method.iter_mut
/// [`HashMap`]: struct.HashMap.html
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// let mut map: HashMap<_, _> = [("a", 1), ("b", 2), ("c", 3)].into();
///
/// for (key, value) in &mut map {
/// println!("Key: {}, Value: {}", key, value);
/// *value *= 2;
/// }
///
/// let mut vec = map.iter().collect::<Vec<_>>();
/// // The `Iter` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [(&"a", &2), (&"b", &4), (&"c", &6)]);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
fn into_iter(self) -> IterMut<'a, K, V> {
self.iter_mut()
}
}
impl<K, V, S, A: Allocator> IntoIterator for HashMap<K, V, S, A> {
type Item = (K, V);
type IntoIter = IntoIter<K, V, A>;
/// Creates a consuming iterator, that is, one that moves each key-value
/// pair out of the map in arbitrary order. The map cannot be used after
/// calling this.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let map: HashMap<_, _> = [("a", 1), ("b", 2), ("c", 3)].into();
///
/// // Not possible with .iter()
/// let mut vec: Vec<(&str, i32)> = map.into_iter().collect();
/// // The `IntoIter` iterator produces items in arbitrary order, so
/// // the items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [("a", 1), ("b", 2), ("c", 3)]);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
fn into_iter(self) -> IntoIter<K, V, A> {
IntoIter {
inner: self.table.into_iter(),
}
}
}
impl<'a, K, V> Iterator for Iter<'a, K, V> {
type Item = (&'a K, &'a V);
#[cfg_attr(feature = "inline-more", inline)]
fn next(&mut self) -> Option<(&'a K, &'a V)> {
// Avoid `Option::map` because it bloats LLVM IR.
match self.inner.next() {
Some(x) => unsafe {
let r = x.as_ref();
Some((&r.0, &r.1))
},
None => None,
}
}
#[cfg_attr(feature = "inline-more", inline)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[cfg_attr(feature = "inline-more", inline)]
fn fold<B, F>(self, init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, |acc, x| unsafe {
let (k, v) = x.as_ref();
f(acc, (k, v))
})
}
}
impl<K, V> ExactSizeIterator for Iter<'_, K, V> {
#[cfg_attr(feature = "inline-more", inline)]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V> FusedIterator for Iter<'_, K, V> {}
impl<'a, K, V> Iterator for IterMut<'a, K, V> {
type Item = (&'a K, &'a mut V);
#[cfg_attr(feature = "inline-more", inline)]
fn next(&mut self) -> Option<(&'a K, &'a mut V)> {
// Avoid `Option::map` because it bloats LLVM IR.
match self.inner.next() {
Some(x) => unsafe {
let r = x.as_mut();
Some((&r.0, &mut r.1))
},
None => None,
}
}
#[cfg_attr(feature = "inline-more", inline)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[cfg_attr(feature = "inline-more", inline)]
fn fold<B, F>(self, init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, |acc, x| unsafe {
let (k, v) = x.as_mut();
f(acc, (k, v))
})
}
}
impl<K, V> ExactSizeIterator for IterMut<'_, K, V> {
#[cfg_attr(feature = "inline-more", inline)]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V> FusedIterator for IterMut<'_, K, V> {}
impl<K, V> fmt::Debug for IterMut<'_, K, V>
where
K: fmt::Debug,
V: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.iter()).finish()
}
}
impl<K, V, A: Allocator> Iterator for IntoIter<K, V, A> {
type Item = (K, V);
#[cfg_attr(feature = "inline-more", inline)]
fn next(&mut self) -> Option<(K, V)> {
self.inner.next()
}
#[cfg_attr(feature = "inline-more", inline)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[cfg_attr(feature = "inline-more", inline)]
fn fold<B, F>(self, init: B, f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, f)
}
}
impl<K, V, A: Allocator> ExactSizeIterator for IntoIter<K, V, A> {
#[cfg_attr(feature = "inline-more", inline)]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V, A: Allocator> FusedIterator for IntoIter<K, V, A> {}
impl<K: Debug, V: Debug, A: Allocator> fmt::Debug for IntoIter<K, V, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.iter()).finish()
}
}
impl<'a, K, V> Iterator for Keys<'a, K, V> {
type Item = &'a K;
#[cfg_attr(feature = "inline-more", inline)]
fn next(&mut self) -> Option<&'a K> {
// Avoid `Option::map` because it bloats LLVM IR.
match self.inner.next() {
Some((k, _)) => Some(k),
None => None,
}
}
#[cfg_attr(feature = "inline-more", inline)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[cfg_attr(feature = "inline-more", inline)]
fn fold<B, F>(self, init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, |acc, (k, _)| f(acc, k))
}
}
impl<K, V> ExactSizeIterator for Keys<'_, K, V> {
#[cfg_attr(feature = "inline-more", inline)]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V> FusedIterator for Keys<'_, K, V> {}
impl<'a, K, V> Iterator for Values<'a, K, V> {
type Item = &'a V;
#[cfg_attr(feature = "inline-more", inline)]
fn next(&mut self) -> Option<&'a V> {
// Avoid `Option::map` because it bloats LLVM IR.
match self.inner.next() {
Some((_, v)) => Some(v),
None => None,
}
}
#[cfg_attr(feature = "inline-more", inline)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[cfg_attr(feature = "inline-more", inline)]
fn fold<B, F>(self, init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, |acc, (_, v)| f(acc, v))
}
}
impl<K, V> ExactSizeIterator for Values<'_, K, V> {
#[cfg_attr(feature = "inline-more", inline)]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V> FusedIterator for Values<'_, K, V> {}
impl<'a, K, V> Iterator for ValuesMut<'a, K, V> {
type Item = &'a mut V;
#[cfg_attr(feature = "inline-more", inline)]
fn next(&mut self) -> Option<&'a mut V> {
// Avoid `Option::map` because it bloats LLVM IR.
match self.inner.next() {
Some((_, v)) => Some(v),
None => None,
}
}
#[cfg_attr(feature = "inline-more", inline)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[cfg_attr(feature = "inline-more", inline)]
fn fold<B, F>(self, init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, |acc, (_, v)| f(acc, v))
}
}
impl<K, V> ExactSizeIterator for ValuesMut<'_, K, V> {
#[cfg_attr(feature = "inline-more", inline)]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V> FusedIterator for ValuesMut<'_, K, V> {}
impl<K, V: Debug> fmt::Debug for ValuesMut<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list()
.entries(self.inner.iter().map(|(_, val)| val))
.finish()
}
}
impl<'a, K, V, A: Allocator> Iterator for Drain<'a, K, V, A> {
type Item = (K, V);
#[cfg_attr(feature = "inline-more", inline)]
fn next(&mut self) -> Option<(K, V)> {
self.inner.next()
}
#[cfg_attr(feature = "inline-more", inline)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
#[cfg_attr(feature = "inline-more", inline)]
fn fold<B, F>(self, init: B, f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.inner.fold(init, f)
}
}
impl<K, V, A: Allocator> ExactSizeIterator for Drain<'_, K, V, A> {
#[cfg_attr(feature = "inline-more", inline)]
fn len(&self) -> usize {
self.inner.len()
}
}
impl<K, V, A: Allocator> FusedIterator for Drain<'_, K, V, A> {}
impl<K, V, A> fmt::Debug for Drain<'_, K, V, A>
where
K: fmt::Debug,
V: fmt::Debug,
A: Allocator,
{
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<F: FnOnce() -> V>(self, default: F) -> &'a mut V
where
K: Hash,
S: BuildHasher,
{
match self {
Entry::Occupied(entry) => entry.into_mut(),
Entry::Vacant(entry) => entry.insert(default()),
}
}
/// Ensures a value is in the entry by inserting, if empty, the result of the default function.
/// This method allows for generating key-derived values for insertion by providing the default
/// function a reference to the key that was moved during the `.entry(key)` method call.
///
/// The reference to the moved key is provided so that cloning or copying the key is
/// unnecessary, unlike with `.or_insert_with(|| ... )`.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, usize> = HashMap::new();
///
/// // nonexistent key
/// map.entry("poneyland").or_insert_with_key(|key| key.chars().count());
/// assert_eq!(map["poneyland"], 9);
///
/// // existing key
/// *map.entry("poneyland").or_insert_with_key(|key| key.chars().count() * 10) *= 2;
/// assert_eq!(map["poneyland"], 18);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut V
where
K: Hash,
S: BuildHasher,
{
match self {
Entry::Occupied(entry) => entry.into_mut(),
Entry::Vacant(entry) => {
let value = default(entry.key());
entry.insert(value)
}
}
}
/// Returns a reference to this entry's key.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.entry("poneyland").or_insert(3);
/// // existing key
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// // nonexistent key
/// assert_eq!(map.entry("horseland").key(), &"horseland");
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn key(&self) -> &K {
match *self {
Entry::Occupied(ref entry) => entry.key(),
Entry::Vacant(ref entry) => entry.key(),
}
}
/// Provides in-place mutable access to an occupied entry before any
/// potential inserts into the map.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// map.entry("poneyland")
/// .and_modify(|e| { *e += 1 })
/// .or_insert(42);
/// assert_eq!(map["poneyland"], 42);
///
/// map.entry("poneyland")
/// .and_modify(|e| { *e += 1 })
/// .or_insert(42);
/// assert_eq!(map["poneyland"], 43);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn and_modify<F>(self, f: F) -> Self
where
F: FnOnce(&mut V),
{
match self {
Entry::Occupied(mut entry) => {
f(entry.get_mut());
Entry::Occupied(entry)
}
Entry::Vacant(entry) => Entry::Vacant(entry),
}
}
/// Provides shared access to the key and owned access to the value of
/// an occupied entry and allows to replace or remove it based on the
/// value of the returned option.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// let entry = map
/// .entry("poneyland")
/// .and_replace_entry_with(|_k, _v| panic!());
///
/// match entry {
/// Entry::Vacant(e) => {
/// assert_eq!(e.key(), &"poneyland");
/// }
/// Entry::Occupied(_) => panic!(),
/// }
///
/// map.insert("poneyland", 42);
///
/// let entry = map
/// .entry("poneyland")
/// .and_replace_entry_with(|k, v| {
/// assert_eq!(k, &"poneyland");
/// assert_eq!(v, 42);
/// Some(v + 1)
/// });
///
/// match entry {
/// Entry::Occupied(e) => {
/// assert_eq!(e.key(), &"poneyland");
/// assert_eq!(e.get(), &43);
/// }
/// Entry::Vacant(_) => panic!(),
/// }
///
/// assert_eq!(map["poneyland"], 43);
///
/// let entry = map
/// .entry("poneyland")
/// .and_replace_entry_with(|_k, _v| None);
///
/// match entry {
/// Entry::Vacant(e) => assert_eq!(e.key(), &"poneyland"),
/// Entry::Occupied(_) => panic!(),
/// }
///
/// assert!(!map.contains_key("poneyland"));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn and_replace_entry_with<F>(self, f: F) -> Self
where
F: FnOnce(&K, V) -> Option<V>,
{
match self {
Entry::Occupied(entry) => entry.replace_entry_with(f),
Entry::Vacant(_) => self,
}
}
}
impl<'a, K, V: Default, S, A: Allocator> Entry<'a, K, V, S, A> {
/// Ensures a value is in the entry by inserting the default value if empty,
/// and returns a mutable reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<&str, Option<u32>> = HashMap::new();
///
/// // nonexistent key
/// map.entry("poneyland").or_default();
/// assert_eq!(map["poneyland"], None);
///
/// map.insert("horseland", Some(3));
///
/// // existing key
/// assert_eq!(map.entry("horseland").or_default(), &mut Some(3));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn or_default(self) -> &'a mut V
where
K: Hash,
S: BuildHasher,
{
match self {
Entry::Occupied(entry) => entry.into_mut(),
Entry::Vacant(entry) => entry.insert(Default::default()),
}
}
}
impl<'a, K, V, S, A: Allocator> 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<Rc<String>, u32> = HashMap::new();
/// let key_one = Rc::new("Stringthing".to_string());
/// let key_two = Rc::new("Stringthing".to_string());
///
/// map.insert(key_one.clone(), 15);
/// assert!(Rc::strong_count(&key_one) == 2 && Rc::strong_count(&key_two) == 1);
///
/// match map.entry(key_two.clone()) {
/// Entry::Occupied(entry) => {
/// let (old_key, old_value): (Rc<String>, u32) = entry.replace_entry(16);
/// assert!(Rc::ptr_eq(&key_one, &old_key) && old_value == 15);
/// }
/// Entry::Vacant(_) => panic!(),
/// }
///
/// assert!(Rc::strong_count(&key_one) == 1 && Rc::strong_count(&key_two) == 2);
/// assert_eq!(map[&"Stringthing".to_owned()], 16);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn replace_entry(self, value: V) -> (K, V) {
let entry = unsafe { self.elem.as_mut() };
let old_key = mem::replace(&mut entry.0, self.key.unwrap());
let old_value = mem::replace(&mut entry.1, value);
(old_key, old_value)
}
/// Replaces the key in the hash map with the key used to create this entry.
///
/// # Panics
///
/// Will panic if this OccupiedEntry was created through [`Entry::insert`].
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{Entry, HashMap};
/// use std::rc::Rc;
///
/// let mut map: HashMap<Rc<String>, usize> = HashMap::with_capacity(6);
/// let mut keys_one: Vec<Rc<String>> = Vec::with_capacity(6);
/// let mut keys_two: Vec<Rc<String>> = Vec::with_capacity(6);
///
/// for (value, key) in ["a", "b", "c", "d", "e", "f"].into_iter().enumerate() {
/// let rc_key = Rc::new(key.to_owned());
/// keys_one.push(rc_key.clone());
/// map.insert(rc_key.clone(), value);
/// keys_two.push(Rc::new(key.to_owned()));
/// }
///
/// assert!(
/// keys_one.iter().all(|key| Rc::strong_count(key) == 2)
/// && keys_two.iter().all(|key| Rc::strong_count(key) == 1)
/// );
///
/// reclaim_memory(&mut map, &keys_two);
///
/// assert!(
/// keys_one.iter().all(|key| Rc::strong_count(key) == 1)
/// && keys_two.iter().all(|key| Rc::strong_count(key) == 2)
/// );
///
/// fn reclaim_memory(map: &mut HashMap<Rc<String>, usize>, keys: &[Rc<String>]) {
/// for key in keys {
/// if let Entry::Occupied(entry) = map.entry(key.clone()) {
/// // Replaces the entry's key with our version of it in `keys`.
/// entry.replace_key();
/// }
/// }
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn replace_key(self) -> K {
let entry = unsafe { self.elem.as_mut() };
mem::replace(&mut entry.0, self.key.unwrap())
}
/// Provides shared access to the key and owned access to the value of
/// the entry and allows to replace or remove it based on the
/// value of the returned option.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.insert("poneyland", 42);
///
/// let entry = match map.entry("poneyland") {
/// Entry::Occupied(e) => {
/// e.replace_entry_with(|k, v| {
/// assert_eq!(k, &"poneyland");
/// assert_eq!(v, 42);
/// Some(v + 1)
/// })
/// }
/// Entry::Vacant(_) => panic!(),
/// };
///
/// match entry {
/// Entry::Occupied(e) => {
/// assert_eq!(e.key(), &"poneyland");
/// assert_eq!(e.get(), &43);
/// }
/// Entry::Vacant(_) => panic!(),
/// }
///
/// assert_eq!(map["poneyland"], 43);
///
/// let entry = match map.entry("poneyland") {
/// Entry::Occupied(e) => e.replace_entry_with(|_k, _v| None),
/// Entry::Vacant(_) => panic!(),
/// };
///
/// match entry {
/// Entry::Vacant(e) => {
/// assert_eq!(e.key(), &"poneyland");
/// }
/// Entry::Occupied(_) => panic!(),
/// }
///
/// assert!(!map.contains_key("poneyland"));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn replace_entry_with<F>(self, f: F) -> Entry<'a, K, V, S, A>
where
F: FnOnce(&K, V) -> Option<V>,
{
unsafe {
let mut spare_key = None;
self.table
.table
.replace_bucket_with(self.elem.clone(), |(key, value)| {
if let Some(new_value) = f(&key, value) {
Some((key, new_value))
} else {
spare_key = Some(key);
None
}
});
if let Some(key) = spare_key {
Entry::Vacant(VacantEntry {
hash: self.hash,
key,
table: self.table,
})
} else {
Entry::Occupied(self)
}
}
}
}
impl<'a, K, V, S, A: Allocator> 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<String, u32> = HashMap::new();
/// let entry = map.entry_ref("horseyland").insert(37);
///
/// assert_eq!(entry.key(), "horseyland");
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn insert(self, value: V) -> OccupiedEntryRef<'a, 'b, K, Q, V, S, A>
where
K: Hash + From<&'b Q>,
S: BuildHasher,
{
match self {
EntryRef::Occupied(mut entry) => {
entry.insert(value);
entry
}
EntryRef::Vacant(entry) => entry.insert_entry(value),
}
}
/// Ensures a value is in the entry by inserting the default if empty, and returns
/// a mutable reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
///
/// // nonexistent key
/// map.entry_ref("poneyland").or_insert(3);
/// assert_eq!(map["poneyland"], 3);
///
/// // existing key
/// *map.entry_ref("poneyland").or_insert(10) *= 2;
/// assert_eq!(map["poneyland"], 6);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn or_insert(self, default: V) -> &'a mut V
where
K: Hash + From<&'b Q>,
S: BuildHasher,
{
match self {
EntryRef::Occupied(entry) => entry.into_mut(),
EntryRef::Vacant(entry) => entry.insert(default),
}
}
/// Ensures a value is in the entry by inserting the result of the default function if empty,
/// and returns a mutable reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
///
/// // nonexistent key
/// map.entry_ref("poneyland").or_insert_with(|| 3);
/// assert_eq!(map["poneyland"], 3);
///
/// // existing key
/// *map.entry_ref("poneyland").or_insert_with(|| 10) *= 2;
/// assert_eq!(map["poneyland"], 6);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V
where
K: Hash + From<&'b Q>,
S: BuildHasher,
{
match self {
EntryRef::Occupied(entry) => entry.into_mut(),
EntryRef::Vacant(entry) => entry.insert(default()),
}
}
/// Ensures a value is in the entry by inserting, if empty, the result of the default function.
/// This method allows for generating key-derived values for insertion by providing the default
/// function an access to the borrower form of the key.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<String, usize> = HashMap::new();
///
/// // nonexistent key
/// map.entry_ref("poneyland").or_insert_with_key(|key| key.chars().count());
/// assert_eq!(map["poneyland"], 9);
///
/// // existing key
/// *map.entry_ref("poneyland").or_insert_with_key(|key| key.chars().count() * 10) *= 2;
/// assert_eq!(map["poneyland"], 18);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn or_insert_with_key<F: FnOnce(&Q) -> V>(self, default: F) -> &'a mut V
where
K: Hash + Borrow<Q> + From<&'b Q>,
S: BuildHasher,
{
match self {
EntryRef::Occupied(entry) => entry.into_mut(),
EntryRef::Vacant(entry) => {
let value = default(entry.key.as_ref());
entry.insert(value)
}
}
}
/// Returns a reference to this entry's key.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// map.entry_ref("poneyland").or_insert(3);
/// // existing key
/// assert_eq!(map.entry_ref("poneyland").key(), "poneyland");
/// // nonexistent key
/// assert_eq!(map.entry_ref("horseland").key(), "horseland");
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn key(&self) -> &Q
where
K: Borrow<Q>,
{
match *self {
EntryRef::Occupied(ref entry) => entry.key().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<String, u32> = HashMap::new();
///
/// map.entry_ref("poneyland")
/// .and_modify(|e| { *e += 1 })
/// .or_insert(42);
/// assert_eq!(map["poneyland"], 42);
///
/// map.entry_ref("poneyland")
/// .and_modify(|e| { *e += 1 })
/// .or_insert(42);
/// assert_eq!(map["poneyland"], 43);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn and_modify<F>(self, f: F) -> Self
where
F: FnOnce(&mut V),
{
match self {
EntryRef::Occupied(mut entry) => {
f(entry.get_mut());
EntryRef::Occupied(entry)
}
EntryRef::Vacant(entry) => EntryRef::Vacant(entry),
}
}
/// Provides shared access to the key and owned access to the value of
/// an occupied entry and allows to replace or remove it based on the
/// value of the returned option.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::EntryRef;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
///
/// let entry = map
/// .entry_ref("poneyland")
/// .and_replace_entry_with(|_k, _v| panic!());
///
/// match entry {
/// EntryRef::Vacant(e) => {
/// assert_eq!(e.key(), "poneyland");
/// }
/// EntryRef::Occupied(_) => panic!(),
/// }
///
/// map.insert("poneyland".to_string(), 42);
///
/// let entry = map
/// .entry_ref("poneyland")
/// .and_replace_entry_with(|k, v| {
/// assert_eq!(k, "poneyland");
/// assert_eq!(v, 42);
/// Some(v + 1)
/// });
///
/// match entry {
/// EntryRef::Occupied(e) => {
/// assert_eq!(e.key(), "poneyland");
/// assert_eq!(e.get(), &43);
/// }
/// EntryRef::Vacant(_) => panic!(),
/// }
///
/// assert_eq!(map["poneyland"], 43);
///
/// let entry = map
/// .entry_ref("poneyland")
/// .and_replace_entry_with(|_k, _v| None);
///
/// match entry {
/// EntryRef::Vacant(e) => assert_eq!(e.key(), "poneyland"),
/// EntryRef::Occupied(_) => panic!(),
/// }
///
/// assert!(!map.contains_key("poneyland"));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn and_replace_entry_with<F>(self, f: F) -> Self
where
F: FnOnce(&K, V) -> Option<V>,
{
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<String, Option<u32>> = HashMap::new();
///
/// // nonexistent key
/// map.entry_ref("poneyland").or_default();
/// assert_eq!(map["poneyland"], None);
///
/// map.insert("horseland".to_string(), Some(3));
///
/// // existing key
/// assert_eq!(map.entry_ref("horseland").or_default(), &mut Some(3));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn or_default(self) -> &'a mut V
where
K: Hash + From<&'b Q>,
S: BuildHasher,
{
match self {
EntryRef::Occupied(entry) => entry.into_mut(),
EntryRef::Vacant(entry) => entry.insert(Default::default()),
}
}
}
impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator> OccupiedEntryRef<'a, 'b, K, Q, V, S, A> {
/// Gets a reference to the key in the entry.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{EntryRef, HashMap};
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// map.entry_ref("poneyland").or_insert(12);
///
/// match map.entry_ref("poneyland") {
/// EntryRef::Vacant(_) => panic!(),
/// EntryRef::Occupied(entry) => assert_eq!(entry.key(), "poneyland"),
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn key(&self) -> &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<String, u32> = 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<String, u32> = HashMap::new();
/// map.entry_ref("poneyland").or_insert(12);
///
/// match map.entry_ref("poneyland") {
/// EntryRef::Vacant(_) => panic!(),
/// EntryRef::Occupied(entry) => assert_eq!(entry.get(), &12),
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn get(&self) -> &V {
unsafe { &self.elem.as_ref().1 }
}
/// Gets a mutable reference to the value in the entry.
///
/// If you need a reference to the `OccupiedEntryRef` which may outlive the
/// destruction of the `EntryRef` value, see [`into_mut`].
///
/// [`into_mut`]: #method.into_mut
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::EntryRef;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// map.entry_ref("poneyland").or_insert(12);
///
/// assert_eq!(map["poneyland"], 12);
/// if let EntryRef::Occupied(mut o) = map.entry_ref("poneyland") {
/// *o.get_mut() += 10;
/// assert_eq!(*o.get(), 22);
///
/// // We can use the same Entry multiple times.
/// *o.get_mut() += 2;
/// }
///
/// assert_eq!(map["poneyland"], 24);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn get_mut(&mut self) -> &mut V {
unsafe { &mut self.elem.as_mut().1 }
}
/// Converts the OccupiedEntryRef into a mutable reference to the value in the entry
/// with a lifetime bound to the map itself.
///
/// If you need multiple references to the `OccupiedEntryRef`, see [`get_mut`].
///
/// [`get_mut`]: #method.get_mut
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{EntryRef, HashMap};
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// map.entry_ref("poneyland").or_insert(12);
///
/// let value: &mut u32;
/// match map.entry_ref("poneyland") {
/// EntryRef::Occupied(entry) => value = entry.into_mut(),
/// EntryRef::Vacant(_) => panic!(),
/// }
/// *value += 10;
///
/// assert_eq!(map["poneyland"], 22);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn into_mut(self) -> &'a mut V {
unsafe { &mut self.elem.as_mut().1 }
}
/// Sets the value of the entry, and returns the entry's old value.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::EntryRef;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// map.entry_ref("poneyland").or_insert(12);
///
/// if let EntryRef::Occupied(mut o) = map.entry_ref("poneyland") {
/// assert_eq!(o.insert(15), 12);
/// }
///
/// assert_eq!(map["poneyland"], 15);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn insert(&mut self, value: V) -> V {
mem::replace(self.get_mut(), value)
}
/// Takes the value out of the entry, and returns it.
/// Keeps the allocated memory for reuse.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::EntryRef;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// // The map is empty
/// assert!(map.is_empty() && map.capacity() == 0);
///
/// map.entry_ref("poneyland").or_insert(12);
///
/// 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<Rc<str>, u32> = HashMap::new();
/// let key: Rc<str> = Rc::from("Stringthing");
///
/// map.insert(key.clone(), 15);
/// assert_eq!(Rc::strong_count(&key), 2);
///
/// match map.entry_ref("Stringthing") {
/// EntryRef::Occupied(entry) => {
/// let (old_key, old_value): (Rc<str>, u32) = entry.replace_entry(16);
/// assert!(Rc::ptr_eq(&key, &old_key) && old_value == 15);
/// }
/// EntryRef::Vacant(_) => panic!(),
/// }
///
/// assert_eq!(Rc::strong_count(&key), 1);
/// assert_eq!(map["Stringthing"], 16);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn replace_entry(self, value: V) -> (K, V)
where
K: From<&'b Q>,
{
let entry = unsafe { self.elem.as_mut() };
let old_key = mem::replace(&mut entry.0, self.key.unwrap().into_owned());
let old_value = mem::replace(&mut entry.1, value);
(old_key, old_value)
}
/// Replaces the key in the hash map with the key used to create this entry.
///
/// # Panics
///
/// Will panic if this OccupiedEntryRef was created through [`EntryRef::insert`].
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{EntryRef, HashMap};
/// use std::rc::Rc;
///
/// let mut map: HashMap<Rc<str>, usize> = HashMap::with_capacity(6);
/// let mut keys: Vec<Rc<str>> = Vec::with_capacity(6);
///
/// for (value, key) in ["a", "b", "c", "d", "e", "f"].into_iter().enumerate() {
/// let rc_key: Rc<str> = Rc::from(key);
/// keys.push(rc_key.clone());
/// map.insert(rc_key.clone(), value);
/// }
///
/// assert!(keys.iter().all(|key| Rc::strong_count(key) == 2));
///
/// // It doesn't matter that we kind of use a vector with the same keys,
/// // because all keys will be newly created from the references
/// reclaim_memory(&mut map, &keys);
///
/// assert!(keys.iter().all(|key| Rc::strong_count(key) == 1));
///
/// fn reclaim_memory(map: &mut HashMap<Rc<str>, usize>, keys: &[Rc<str>]) {
/// for key in keys {
/// if let EntryRef::Occupied(entry) = map.entry_ref(key.as_ref()) {
/// // Replaces the entry's key with our version of it in `keys`.
/// entry.replace_key();
/// }
/// }
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn replace_key(self) -> K
where
K: From<&'b Q>,
{
let entry = unsafe { self.elem.as_mut() };
mem::replace(&mut entry.0, self.key.unwrap().into_owned())
}
/// Provides shared access to the key and owned access to the value of
/// the entry and allows to replace or remove it based on the
/// value of the returned option.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::EntryRef;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// map.insert("poneyland".to_string(), 42);
///
/// let entry = match map.entry_ref("poneyland") {
/// EntryRef::Occupied(e) => {
/// e.replace_entry_with(|k, v| {
/// assert_eq!(k, "poneyland");
/// assert_eq!(v, 42);
/// Some(v + 1)
/// })
/// }
/// EntryRef::Vacant(_) => panic!(),
/// };
///
/// match entry {
/// EntryRef::Occupied(e) => {
/// assert_eq!(e.key(), "poneyland");
/// assert_eq!(e.get(), &43);
/// }
/// EntryRef::Vacant(_) => panic!(),
/// }
///
/// assert_eq!(map["poneyland"], 43);
///
/// let entry = match map.entry_ref("poneyland") {
/// EntryRef::Occupied(e) => e.replace_entry_with(|_k, _v| None),
/// EntryRef::Vacant(_) => panic!(),
/// };
///
/// match entry {
/// EntryRef::Vacant(e) => {
/// assert_eq!(e.key(), "poneyland");
/// }
/// EntryRef::Occupied(_) => panic!(),
/// }
///
/// assert!(!map.contains_key("poneyland"));
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn replace_entry_with<F>(self, f: F) -> EntryRef<'a, 'b, K, Q, V, S, A>
where
F: FnOnce(&K, V) -> Option<V>,
{
unsafe {
let mut spare_key = None;
self.table
.table
.replace_bucket_with(self.elem.clone(), |(key, value)| {
if let Some(new_value) = f(&key, value) {
Some((key, new_value))
} else {
spare_key = Some(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<String, u32> = HashMap::new();
/// let key: &str = "poneyland";
/// assert_eq!(map.entry_ref(key).key(), "poneyland");
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn key(&self) -> &Q
where
K: Borrow<Q>,
{
self.key.as_ref()
}
/// Take ownership of the key.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::{EntryRef, HashMap};
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// let key: &str = "poneyland";
///
/// match map.entry_ref(key) {
/// EntryRef::Occupied(_) => panic!(),
/// EntryRef::Vacant(v) => assert_eq!(v.into_key(), "poneyland".to_owned()),
/// }
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn into_key(self) -> K
where
K: From<&'b Q>,
{
self.key.into_owned()
}
/// Sets the value of the entry with the VacantEntryRef's key,
/// and returns a mutable reference to it.
///
/// # Examples
///
/// ```
/// use hashbrown::HashMap;
/// use hashbrown::hash_map::EntryRef;
///
/// let mut map: HashMap<String, u32> = HashMap::new();
/// let key: &str = "poneyland";
///
/// if let EntryRef::Vacant(o) = map.entry_ref(key) {
/// o.insert(37);
/// }
/// assert_eq!(map["poneyland"], 37);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
pub fn insert(self, value: V) -> &'a mut V
where
K: Hash + From<&'b Q>,
S: BuildHasher,
{
let table = &mut self.table.table;
let entry = table.insert_entry(
self.hash,
(self.key.into_owned(), value),
make_hasher::<_, 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<K, V, S, A> FromIterator<(K, V)> for HashMap<K, V, S, A>
where
K: Eq + Hash,
S: BuildHasher + Default,
A: Default + Allocator,
{
#[cfg_attr(feature = "inline-more", inline)]
fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> Self {
let iter = iter.into_iter();
let mut map =
Self::with_capacity_and_hasher_in(iter.size_hint().0, S::default(), A::default());
iter.for_each(|(k, v)| {
map.insert(k, v);
});
map
}
}
/// Inserts all new key-values from the iterator and replaces values with existing
/// keys with new values returned from the iterator.
impl<K, V, S, A> Extend<(K, V)> for HashMap<K, V, S, A>
where
K: Eq + Hash,
S: BuildHasher,
A: Allocator,
{
/// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`.
/// Replace values with existing keys with new values returned from the iterator.
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, 100);
///
/// let some_iter = [(1, 1), (2, 2)].into_iter();
/// map.extend(some_iter);
/// // Replace values with existing keys with new values returned from the iterator.
/// // So that the map.get(&1) doesn't return Some(&100).
/// assert_eq!(map.get(&1), Some(&1));
///
/// let some_vec: Vec<_> = vec![(3, 3), (4, 4)];
/// map.extend(some_vec);
///
/// let some_arr = [(5, 5), (6, 6)];
/// map.extend(some_arr);
/// let old_map_len = map.len();
///
/// // You can also extend from another HashMap
/// let mut new_map = HashMap::new();
/// new_map.extend(map);
/// assert_eq!(new_map.len(), old_map_len);
///
/// let mut vec: Vec<_> = new_map.into_iter().collect();
/// // The `IntoIter` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
fn extend<T: IntoIterator<Item = (K, V)>>(&mut self, iter: T) {
// Keys may be already present or show multiple times in the iterator.
// Reserve the entire hint lower bound if the map is empty.
// Otherwise reserve half the hint (rounded up), so the map
// will only resize twice in the worst case.
let iter = iter.into_iter();
let reserve = if self.is_empty() {
iter.size_hint().0
} else {
(iter.size_hint().0 + 1) / 2
};
self.reserve(reserve);
iter.for_each(move |(k, v)| {
self.insert(k, v);
});
}
#[inline]
#[cfg(feature = "nightly")]
fn extend_one(&mut self, (k, v): (K, V)) {
self.insert(k, v);
}
#[inline]
#[cfg(feature = "nightly")]
fn extend_reserve(&mut self, additional: usize) {
// Keys may be already present or show multiple times in the iterator.
// Reserve the entire hint lower bound if the map is empty.
// Otherwise reserve half the hint (rounded up), so the map
// will only resize twice in the worst case.
let reserve = if self.is_empty() {
additional
} else {
(additional + 1) / 2
};
self.reserve(reserve);
}
}
/// Inserts all new key-values from the iterator and replaces values with existing
/// keys with new values returned from the iterator.
impl<'a, K, V, S, A> Extend<(&'a K, &'a V)> for HashMap<K, V, S, A>
where
K: Eq + Hash + Copy,
V: Copy,
S: BuildHasher,
A: Allocator,
{
/// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`.
/// Replace values with existing keys with new values returned from the iterator.
/// The keys and values must implement [`Copy`] trait.
///
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, 100);
///
/// let arr = [(1, 1), (2, 2)];
/// let some_iter = arr.iter().map(|(k, v)| (k, v));
/// map.extend(some_iter);
/// // Replace values with existing keys with new values returned from the iterator.
/// // So that the map.get(&1) doesn't return Some(&100).
/// assert_eq!(map.get(&1), Some(&1));
///
/// let some_vec: Vec<_> = vec![(3, 3), (4, 4)];
/// map.extend(some_vec.iter().map(|(k, v)| (k, v)));
///
/// let some_arr = [(5, 5), (6, 6)];
/// map.extend(some_arr.iter().map(|(k, v)| (k, v)));
///
/// // You can also extend from another HashMap
/// let mut new_map = HashMap::new();
/// new_map.extend(&map);
/// assert_eq!(new_map, map);
///
/// let mut vec: Vec<_> = new_map.into_iter().collect();
/// // The `IntoIter` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
fn extend<T: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: T) {
self.extend(iter.into_iter().map(|(&key, &value)| (key, value)));
}
#[inline]
#[cfg(feature = "nightly")]
fn extend_one(&mut self, (k, v): (&'a K, &'a V)) {
self.insert(*k, *v);
}
#[inline]
#[cfg(feature = "nightly")]
fn extend_reserve(&mut self, additional: usize) {
Extend::<(K, V)>::extend_reserve(self, additional);
}
}
/// Inserts all new key-values from the iterator and replaces values with existing
/// keys with new values returned from the iterator.
impl<'a, K, V, S, A> Extend<&'a (K, V)> for HashMap<K, V, S, A>
where
K: Eq + Hash + Copy,
V: Copy,
S: BuildHasher,
A: Allocator,
{
/// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`.
/// Replace values with existing keys with new values returned from the iterator.
/// The keys and values must implement [`Copy`] trait.
///
///
/// # Examples
///
/// ```
/// use hashbrown::hash_map::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, 100);
///
/// let arr = [(1, 1), (2, 2)];
/// let some_iter = arr.iter();
/// map.extend(some_iter);
/// // Replace values with existing keys with new values returned from the iterator.
/// // So that the map.get(&1) doesn't return Some(&100).
/// assert_eq!(map.get(&1), Some(&1));
///
/// let some_vec: Vec<_> = vec![(3, 3), (4, 4)];
/// map.extend(&some_vec);
///
/// let some_arr = [(5, 5), (6, 6)];
/// map.extend(&some_arr);
///
/// let mut vec: Vec<_> = map.into_iter().collect();
/// // The `IntoIter` iterator produces items in arbitrary order, so the
/// // items must be sorted to test them against a sorted array.
/// vec.sort_unstable();
/// assert_eq!(vec, [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]);
/// ```
#[cfg_attr(feature = "inline-more", inline)]
fn extend<T: IntoIterator<Item = &'a (K, V)>>(&mut self, iter: T) {
self.extend(iter.into_iter().map(|&(key, value)| (key, value)));
}
#[inline]
#[cfg(feature = "nightly")]
fn extend_one(&mut self, &(k, v): &'a (K, V)) {
self.insert(k, v);
}
#[inline]
#[cfg(feature = "nightly")]
fn extend_reserve(&mut self, additional: usize) {
Extend::<(K, V)>::extend_reserve(self, additional);
}
}
#[allow(dead_code)]
fn assert_covariance() {
fn map_key<'new>(v: HashMap<&'static str, u8>) -> HashMap<&'new str, u8> {
v
}
fn map_val<'new>(v: HashMap<u8, &'static str>) -> HashMap<u8, &'new str> {
v
}
fn iter_key<'a, 'new>(v: Iter<'a, &'static str, u8>) -> Iter<'a, &'new str, u8> {
v
}
fn iter_val<'a, 'new>(v: Iter<'a, u8, &'static str>) -> Iter<'a, u8, &'new str> {
v
}
fn into_iter_key<'new, A: Allocator>(
v: IntoIter<&'static str, u8, A>,
) -> IntoIter<&'new str, u8, A> {
v
}
fn into_iter_val<'new, A: Allocator>(
v: IntoIter<u8, &'static str, A>,
) -> IntoIter<u8, &'new str, A> {
v
}
fn keys_key<'a, 'new>(v: Keys<'a, &'static str, u8>) -> Keys<'a, &'new str, u8> {
v
}
fn keys_val<'a, 'new>(v: Keys<'a, u8, &'static str>) -> Keys<'a, u8, &'new str> {
v
}
fn values_key<'a, 'new>(v: Values<'a, &'static str, u8>) -> Values<'a, &'new str, u8> {
v
}
fn values_val<'a, 'new>(v: Values<'a, u8, &'static str>) -> Values<'a, u8, &'new str> {
v
}
fn drain<'new>(
d: Drain<'static, &'static str, &'static str>,
) -> Drain<'new, &'new str, &'new str> {
d
}
}
#[cfg(test)]
mod test_map {
use super::DefaultHashBuilder;
use super::Entry::{Occupied, Vacant};
use super::EntryRef;
use super::{HashMap, RawEntryMut};
use 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<i32, i32>;
let m = HM::new();
assert_eq!(m.capacity(), 0);
let m = HM::default();
assert_eq!(m.capacity(), 0);
let m = HM::with_hasher(DefaultHashBuilder::default());
assert_eq!(m.capacity(), 0);
let m = HM::with_capacity(0);
assert_eq!(m.capacity(), 0);
let m = HM::with_capacity_and_hasher(0, DefaultHashBuilder::default());
assert_eq!(m.capacity(), 0);
let mut m = HM::new();
m.insert(1, 1);
m.insert(2, 2);
m.remove(&1);
m.remove(&2);
m.shrink_to_fit();
assert_eq!(m.capacity(), 0);
let mut m = HM::new();
m.reserve(0);
assert_eq!(m.capacity(), 0);
}
#[test]
fn test_create_capacity_zero() {
let mut m = HashMap::with_capacity(0);
assert!(m.insert(1, 1).is_none());
assert!(m.contains_key(&1));
assert!(!m.contains_key(&0));
}
#[test]
fn test_insert() {
let mut m = HashMap::new();
assert_eq!(m.len(), 0);
assert!(m.insert(1, 2).is_none());
assert_eq!(m.len(), 1);
assert!(m.insert(2, 4).is_none());
assert_eq!(m.len(), 2);
assert_eq!(*m.get(&1).unwrap(), 2);
assert_eq!(*m.get(&2).unwrap(), 4);
}
#[test]
fn test_clone() {
let mut m = HashMap::new();
assert_eq!(m.len(), 0);
assert!(m.insert(1, 2).is_none());
assert_eq!(m.len(), 1);
assert!(m.insert(2, 4).is_none());
assert_eq!(m.len(), 2);
#[allow(clippy::redundant_clone)]
let m2 = m.clone();
assert_eq!(*m2.get(&1).unwrap(), 2);
assert_eq!(*m2.get(&2).unwrap(), 4);
assert_eq!(m2.len(), 2);
}
#[test]
fn test_clone_from() {
let mut m = HashMap::new();
let mut m2 = HashMap::new();
assert_eq!(m.len(), 0);
assert!(m.insert(1, 2).is_none());
assert_eq!(m.len(), 1);
assert!(m.insert(2, 4).is_none());
assert_eq!(m.len(), 2);
m2.clone_from(&m);
assert_eq!(*m2.get(&1).unwrap(), 2);
assert_eq!(*m2.get(&2).unwrap(), 4);
assert_eq!(m2.len(), 2);
}
thread_local! { static DROP_VECTOR: RefCell<Vec<i32>> = const { 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<i32, bool> = HashMap::new();
assert_eq!(m.remove(&0), None);
}
#[test]
fn test_empty_entry() {
let mut m: HashMap<i32, bool> = HashMap::new();
match m.entry(0) {
Occupied(_) => panic!(),
Vacant(_) => {}
}
assert!(*m.entry(0).or_insert(true));
assert_eq!(m.len(), 1);
}
#[test]
fn test_empty_entry_ref() {
let mut m: HashMap<std::string::String, bool> = HashMap::new();
match m.entry_ref("poneyland") {
EntryRef::Occupied(_) => panic!(),
EntryRef::Vacant(_) => {}
}
assert!(*m.entry_ref("poneyland").or_insert(true));
assert_eq!(m.len(), 1);
}
#[test]
fn test_empty_iter() {
let mut m: HashMap<i32, bool> = HashMap::new();
assert_eq!(m.drain().next(), None);
assert_eq!(m.keys().next(), None);
assert_eq!(m.values().next(), None);
assert_eq!(m.values_mut().next(), None);
assert_eq!(m.iter().next(), None);
assert_eq!(m.iter_mut().next(), None);
assert_eq!(m.len(), 0);
assert!(m.is_empty());
assert_eq!(m.into_iter().next(), None);
}
#[test]
#[cfg_attr(miri, ignore)] // FIXME: takes too long
fn test_lots_of_insertions() {
let mut m = HashMap::new();
// Try this a few times to make sure we never screw up the hashmap's
// internal state.
for _ in 0..10 {
assert!(m.is_empty());
for i in 1..1001 {
assert!(m.insert(i, i).is_none());
for j in 1..=i {
let r = m.get(&j);
assert_eq!(r, Some(&j));
}
for j in i + 1..1001 {
let r = m.get(&j);
assert_eq!(r, None);
}
}
for i in 1001..2001 {
assert!(!m.contains_key(&i));
}
// remove forwards
for i in 1..1001 {
assert!(m.remove(&i).is_some());
for j in 1..=i {
assert!(!m.contains_key(&j));
}
for j in i + 1..1001 {
assert!(m.contains_key(&j));
}
}
for i in 1..1001 {
assert!(!m.contains_key(&i));
}
for i in 1..1001 {
assert!(m.insert(i, i).is_none());
}
// remove backwards
for i in (1..1001).rev() {
assert!(m.remove(&i).is_some());
for j in i..1001 {
assert!(!m.contains_key(&j));
}
for j in 1..i {
assert!(m.contains_key(&j));
}
}
}
}
#[test]
fn test_find_mut() {
let mut m = HashMap::new();
assert!(m.insert(1, 12).is_none());
assert!(m.insert(2, 8).is_none());
assert!(m.insert(5, 14).is_none());
let new = 100;
match m.get_mut(&5) {
None => panic!(),
Some(x) => *x = new,
}
assert_eq!(m.get(&5), Some(&new));
}
#[test]
fn test_insert_overwrite() {
let mut m = HashMap::new();
assert!(m.insert(1, 2).is_none());
assert_eq!(*m.get(&1).unwrap(), 2);
assert!(m.insert(1, 3).is_some());
assert_eq!(*m.get(&1).unwrap(), 3);
}
#[test]
fn test_insert_conflicts() {
let mut m = HashMap::with_capacity(4);
assert!(m.insert(1, 2).is_none());
assert!(m.insert(5, 3).is_none());
assert!(m.insert(9, 4).is_none());
assert_eq!(*m.get(&9).unwrap(), 4);
assert_eq!(*m.get(&5).unwrap(), 3);
assert_eq!(*m.get(&1).unwrap(), 2);
}
#[test]
fn test_conflict_remove() {
let mut m = HashMap::with_capacity(4);
assert!(m.insert(1, 2).is_none());
assert_eq!(*m.get(&1).unwrap(), 2);
assert!(m.insert(5, 3).is_none());
assert_eq!(*m.get(&1).unwrap(), 2);
assert_eq!(*m.get(&5).unwrap(), 3);
assert!(m.insert(9, 4).is_none());
assert_eq!(*m.get(&1).unwrap(), 2);
assert_eq!(*m.get(&5).unwrap(), 3);
assert_eq!(*m.get(&9).unwrap(), 4);
assert!(m.remove(&1).is_some());
assert_eq!(*m.get(&9).unwrap(), 4);
assert_eq!(*m.get(&5).unwrap(), 3);
}
#[test]
fn test_insert_unique_unchecked() {
let mut map = HashMap::new();
let (k1, v1) = map.insert_unique_unchecked(10, 11);
assert_eq!((&10, &mut 11), (k1, v1));
let (k2, v2) = map.insert_unique_unchecked(20, 21);
assert_eq!((&20, &mut 21), (k2, v2));
assert_eq!(Some(&11), map.get(&10));
assert_eq!(Some(&21), map.get(&20));
assert_eq!(None, map.get(&30));
}
#[test]
fn test_is_empty() {
let mut m = HashMap::with_capacity(4);
assert!(m.insert(1, 2).is_none());
assert!(!m.is_empty());
assert!(m.remove(&1).is_some());
assert!(m.is_empty());
}
#[test]
fn test_remove() {
let mut m = HashMap::new();
m.insert(1, 2);
assert_eq!(m.remove(&1), Some(2));
assert_eq!(m.remove(&1), None);
}
#[test]
fn test_remove_entry() {
let mut m = HashMap::new();
m.insert(1, 2);
assert_eq!(m.remove_entry(&1), Some((1, 2)));
assert_eq!(m.remove(&1), None);
}
#[test]
fn test_iterate() {
let mut m = HashMap::with_capacity(4);
for i in 0..32 {
assert!(m.insert(i, i * 2).is_none());
}
assert_eq!(m.len(), 32);
let mut observed: u32 = 0;
for (k, v) in &m {
assert_eq!(*v, *k * 2);
observed |= 1 << *k;
}
assert_eq!(observed, 0xFFFF_FFFF);
}
#[test]
fn test_keys() {
let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
let map: HashMap<_, _> = vec.into_iter().collect();
let keys: Vec<_> = map.keys().copied().collect();
assert_eq!(keys.len(), 3);
assert!(keys.contains(&1));
assert!(keys.contains(&2));
assert!(keys.contains(&3));
}
#[test]
fn test_values() {
let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
let map: HashMap<_, _> = vec.into_iter().collect();
let values: Vec<_> = map.values().copied().collect();
assert_eq!(values.len(), 3);
assert!(values.contains(&'a'));
assert!(values.contains(&'b'));
assert!(values.contains(&'c'));
}
#[test]
fn test_values_mut() {
let vec = vec![(1, 1), (2, 2), (3, 3)];
let mut map: HashMap<_, _> = vec.into_iter().collect();
for value in map.values_mut() {
*value *= 2;
}
let values: Vec<_> = map.values().copied().collect();
assert_eq!(values.len(), 3);
assert!(values.contains(&2));
assert!(values.contains(&4));
assert!(values.contains(&6));
}
#[test]
fn test_into_keys() {
let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
let map: HashMap<_, _> = vec.into_iter().collect();
let keys: Vec<_> = map.into_keys().collect();
assert_eq!(keys.len(), 3);
assert!(keys.contains(&1));
assert!(keys.contains(&2));
assert!(keys.contains(&3));
}
#[test]
fn test_into_values() {
let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
let map: HashMap<_, _> = vec.into_iter().collect();
let values: Vec<_> = map.into_values().collect();
assert_eq!(values.len(), 3);
assert!(values.contains(&'a'));
assert!(values.contains(&'b'));
assert!(values.contains(&'c'));
}
#[test]
fn test_find() {
let mut m = HashMap::new();
assert!(m.get(&1).is_none());
m.insert(1, 2);
match m.get(&1) {
None => panic!(),
Some(v) => assert_eq!(*v, 2),
}
}
#[test]
fn test_eq() {
let mut m1 = HashMap::new();
m1.insert(1, 2);
m1.insert(2, 3);
m1.insert(3, 4);
let mut m2 = HashMap::new();
m2.insert(1, 2);
m2.insert(2, 3);
assert!(m1 != m2);
m2.insert(3, 4);
assert_eq!(m1, m2);
}
#[test]
fn test_show() {
let mut map = HashMap::new();
let empty: HashMap<i32, i32> = HashMap::new();
map.insert(1, 2);
map.insert(3, 4);
let map_str = format!("{map:?}");
assert!(map_str == "{1: 2, 3: 4}" || map_str == "{3: 4, 1: 2}");
assert_eq!(format!("{empty:?}"), "{}");
}
#[test]
fn test_expand() {
let mut m = HashMap::new();
assert_eq!(m.len(), 0);
assert!(m.is_empty());
let mut i = 0;
let old_raw_cap = m.raw_capacity();
while old_raw_cap == m.raw_capacity() {
m.insert(i, i);
i += 1;
}
assert_eq!(m.len(), i);
assert!(!m.is_empty());
}
#[test]
fn test_behavior_resize_policy() {
let mut m = HashMap::new();
assert_eq!(m.len(), 0);
assert_eq!(m.raw_capacity(), 1);
assert!(m.is_empty());
m.insert(0, 0);
m.remove(&0);
assert!(m.is_empty());
let initial_raw_cap = m.raw_capacity();
m.reserve(initial_raw_cap);
let raw_cap = m.raw_capacity();
assert_eq!(raw_cap, initial_raw_cap * 2);
let mut i = 0;
for _ in 0..raw_cap * 3 / 4 {
m.insert(i, i);
i += 1;
}
// three quarters full
assert_eq!(m.len(), i);
assert_eq!(m.raw_capacity(), raw_cap);
for _ in 0..raw_cap / 4 {
m.insert(i, i);
i += 1;
}
// half full
let new_raw_cap = m.raw_capacity();
assert_eq!(new_raw_cap, raw_cap * 2);
for _ in 0..raw_cap / 2 - 1 {
i -= 1;
m.remove(&i);
assert_eq!(m.raw_capacity(), new_raw_cap);
}
// A little more than one quarter full.
m.shrink_to_fit();
assert_eq!(m.raw_capacity(), raw_cap);
// again, a little more than half full
for _ in 0..raw_cap / 2 {
i -= 1;
m.remove(&i);
}
m.shrink_to_fit();
assert_eq!(m.len(), i);
assert!(!m.is_empty());
assert_eq!(m.raw_capacity(), initial_raw_cap);
}
#[test]
fn test_reserve_shrink_to_fit() {
let mut m = HashMap::new();
m.insert(0, 0);
m.remove(&0);
assert!(m.capacity() >= m.len());
for i in 0..128 {
m.insert(i, i);
}
m.reserve(256);
let usable_cap = m.capacity();
for i in 128..(128 + 256) {
m.insert(i, i);
assert_eq!(m.capacity(), usable_cap);
}
for i in 100..(128 + 256) {
assert_eq!(m.remove(&i), Some(i));
}
m.shrink_to_fit();
assert_eq!(m.len(), 100);
assert!(!m.is_empty());
assert!(m.capacity() >= m.len());
for i in 0..100 {
assert_eq!(m.remove(&i), Some(i));
}
m.shrink_to_fit();
m.insert(0, 0);
assert_eq!(m.len(), 1);
assert!(m.capacity() >= m.len());
assert_eq!(m.remove(&0), Some(0));
}
#[test]
fn test_from_iter() {
let xs = [(1, 1), (2, 2), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let map: HashMap<_, _> = xs.iter().copied().collect();
for &(k, v) in &xs {
assert_eq!(map.get(&k), Some(&v));
}
assert_eq!(map.iter().len(), xs.len() - 1);
}
#[test]
fn test_size_hint() {
let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let map: HashMap<_, _> = xs.iter().copied().collect();
let mut iter = map.iter();
for _ in iter.by_ref().take(3) {}
assert_eq!(iter.size_hint(), (3, Some(3)));
}
#[test]
fn test_iter_len() {
let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let map: HashMap<_, _> = xs.iter().copied().collect();
let mut iter = map.iter();
for _ in iter.by_ref().take(3) {}
assert_eq!(iter.len(), 3);
}
#[test]
fn test_mut_size_hint() {
let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let mut map: HashMap<_, _> = xs.iter().copied().collect();
let mut iter = map.iter_mut();
for _ in iter.by_ref().take(3) {}
assert_eq!(iter.size_hint(), (3, Some(3)));
}
#[test]
fn test_iter_mut_len() {
let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let mut map: HashMap<_, _> = xs.iter().copied().collect();
let mut iter = map.iter_mut();
for _ in iter.by_ref().take(3) {}
assert_eq!(iter.len(), 3);
}
#[test]
fn test_index() {
let mut map = HashMap::new();
map.insert(1, 2);
map.insert(2, 1);
map.insert(3, 4);
assert_eq!(map[&2], 1);
}
#[test]
#[should_panic]
fn test_index_nonexistent() {
let mut map = HashMap::new();
map.insert(1, 2);
map.insert(2, 1);
map.insert(3, 4);
#[allow(clippy::no_effect)] // false positive lint
map[&4];
}
#[test]
fn test_entry() {
let xs = [(1, 10), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)];
let mut map: HashMap<_, _> = xs.iter().copied().collect();
// Existing key (insert)
match map.entry(1) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
assert_eq!(view.get(), &10);
assert_eq!(view.insert(100), 10);
}
}
assert_eq!(map.get(&1).unwrap(), &100);
assert_eq!(map.len(), 6);
// Existing key (update)
match map.entry(2) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
let v = view.get_mut();
let new_v = (*v) * 10;
*v = new_v;
}
}
assert_eq!(map.get(&2).unwrap(), &200);
assert_eq!(map.len(), 6);
// Existing key (take)
match map.entry(3) {
Vacant(_) => unreachable!(),
Occupied(view) => {
assert_eq!(view.remove(), 30);
}
}
assert_eq!(map.get(&3), None);
assert_eq!(map.len(), 5);
// Inexistent key (insert)
match map.entry(10) {
Occupied(_) => unreachable!(),
Vacant(view) => {
assert_eq!(*view.insert(1000), 1000);
}
}
assert_eq!(map.get(&10).unwrap(), &1000);
assert_eq!(map.len(), 6);
}
#[test]
fn test_entry_ref() {
let xs = [
("One".to_owned(), 10),
("Two".to_owned(), 20),
("Three".to_owned(), 30),
("Four".to_owned(), 40),
("Five".to_owned(), 50),
("Six".to_owned(), 60),
];
let mut map: HashMap<_, _> = xs.iter().cloned().collect();
// Existing key (insert)
match map.entry_ref("One") {
EntryRef::Vacant(_) => unreachable!(),
EntryRef::Occupied(mut view) => {
assert_eq!(view.get(), &10);
assert_eq!(view.insert(100), 10);
}
}
assert_eq!(map.get("One").unwrap(), &100);
assert_eq!(map.len(), 6);
// Existing key (update)
match map.entry_ref("Two") {
EntryRef::Vacant(_) => unreachable!(),
EntryRef::Occupied(mut view) => {
let v = view.get_mut();
let new_v = (*v) * 10;
*v = new_v;
}
}
assert_eq!(map.get("Two").unwrap(), &200);
assert_eq!(map.len(), 6);
// Existing key (take)
match map.entry_ref("Three") {
EntryRef::Vacant(_) => unreachable!(),
EntryRef::Occupied(view) => {
assert_eq!(view.remove(), 30);
}
}
assert_eq!(map.get("Three"), None);
assert_eq!(map.len(), 5);
// Inexistent key (insert)
match map.entry_ref("Ten") {
EntryRef::Occupied(_) => unreachable!(),
EntryRef::Vacant(view) => {
assert_eq!(*view.insert(1000), 1000);
}
}
assert_eq!(map.get("Ten").unwrap(), &1000);
assert_eq!(map.len(), 6);
}
#[test]
fn test_entry_take_doesnt_corrupt() {
#![allow(deprecated)] //rand
// Test for #19292
fn check(m: &HashMap<i32, ()>) {
for k in m.keys() {
assert!(m.contains_key(k), "{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<std::string::String, ()>) {
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<T: AddAssign<T> + Copy, const N: usize>(start: T, step: T) -> [(T, T); N] {
let mut outs: [(T, T); N] = [(start, start); N];
let mut element = step;
outs.iter_mut().skip(1).for_each(|(k, v)| {
*k += element;
*v += element;
element += step;
});
outs
}
let for_iter: Vec<_> = (0..100).map(|i| (i, i)).collect();
let iter = for_iter.iter();
let vec: Vec<_> = (100..200).map(|i| (i, i)).collect();
a.extend(iter);
a.extend(&vec);
a.extend(create_arr::<i32, 100>(200, 1));
assert_eq!(a.len(), 300);
for item in 0..300 {
assert_eq!(a[&item], item);
}
}
#[test]
fn test_capacity_not_less_than_len() {
let mut a = HashMap::new();
let mut item = 0;
for _ in 0..116 {
a.insert(item, 0);
item += 1;
}
assert!(a.capacity() > a.len());
let free = a.capacity() - a.len();
for _ in 0..free {
a.insert(item, 0);
item += 1;
}
assert_eq!(a.len(), a.capacity());
// Insert at capacity should cause allocation.
a.insert(item, 0);
assert!(a.capacity() > a.len());
}
#[test]
fn test_occupied_entry_key() {
let mut a = HashMap::new();
let key = "hello there";
let value = "value goes here";
assert!(a.is_empty());
a.insert(key, value);
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
match a.entry(key) {
Vacant(_) => panic!(),
Occupied(e) => assert_eq!(key, *e.key()),
}
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
}
#[test]
fn test_occupied_entry_ref_key() {
let mut a = HashMap::new();
let key = "hello there";
let value = "value goes here";
assert!(a.is_empty());
a.insert(key.to_owned(), value);
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
match a.entry_ref(key) {
EntryRef::Vacant(_) => panic!(),
EntryRef::Occupied(e) => assert_eq!(key, e.key()),
}
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
}
#[test]
fn test_vacant_entry_key() {
let mut a = HashMap::new();
let key = "hello there";
let value = "value goes here";
assert!(a.is_empty());
match a.entry(key) {
Occupied(_) => panic!(),
Vacant(e) => {
assert_eq!(key, *e.key());
e.insert(value);
}
}
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
}
#[test]
fn test_vacant_entry_ref_key() {
let mut a: HashMap<std::string::String, &str> = HashMap::new();
let key = "hello there";
let value = "value goes here";
assert!(a.is_empty());
match a.entry_ref(key) {
EntryRef::Occupied(_) => panic!(),
EntryRef::Vacant(e) => {
assert_eq!(key, e.key());
e.insert(value);
}
}
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
}
#[test]
fn test_occupied_entry_replace_entry_with() {
let mut a = HashMap::new();
let key = "a key";
let value = "an initial value";
let new_value = "a new value";
let entry = a.entry(key).insert(value).replace_entry_with(|k, v| {
assert_eq!(k, &key);
assert_eq!(v, value);
Some(new_value)
});
match entry {
Occupied(e) => {
assert_eq!(e.key(), &key);
assert_eq!(e.get(), &new_value);
}
Vacant(_) => panic!(),
}
assert_eq!(a[key], new_value);
assert_eq!(a.len(), 1);
let entry = match a.entry(key) {
Occupied(e) => e.replace_entry_with(|k, v| {
assert_eq!(k, &key);
assert_eq!(v, new_value);
None
}),
Vacant(_) => panic!(),
};
match entry {
Vacant(e) => assert_eq!(e.key(), &key),
Occupied(_) => panic!(),
}
assert!(!a.contains_key(key));
assert_eq!(a.len(), 0);
}
#[test]
fn test_occupied_entry_ref_replace_entry_with() {
let mut a: HashMap<std::string::String, &str> = HashMap::new();
let key = "a key";
let value = "an initial value";
let new_value = "a new value";
let entry = a.entry_ref(key).insert(value).replace_entry_with(|k, v| {
assert_eq!(k, key);
assert_eq!(v, value);
Some(new_value)
});
match entry {
EntryRef::Occupied(e) => {
assert_eq!(e.key(), key);
assert_eq!(e.get(), &new_value);
}
EntryRef::Vacant(_) => panic!(),
}
assert_eq!(a[key], new_value);
assert_eq!(a.len(), 1);
let entry = match a.entry_ref(key) {
EntryRef::Occupied(e) => e.replace_entry_with(|k, v| {
assert_eq!(k, key);
assert_eq!(v, new_value);
None
}),
EntryRef::Vacant(_) => panic!(),
};
match entry {
EntryRef::Vacant(e) => assert_eq!(e.key(), key),
EntryRef::Occupied(_) => panic!(),
}
assert!(!a.contains_key(key));
assert_eq!(a.len(), 0);
}
#[test]
fn test_entry_and_replace_entry_with() {
let mut a = HashMap::new();
let key = "a key";
let value = "an initial value";
let new_value = "a new value";
let entry = a.entry(key).and_replace_entry_with(|_, _| panic!());
match entry {
Vacant(e) => assert_eq!(e.key(), &key),
Occupied(_) => panic!(),
}
a.insert(key, value);
let entry = a.entry(key).and_replace_entry_with(|k, v| {
assert_eq!(k, &key);
assert_eq!(v, value);
Some(new_value)
});
match entry {
Occupied(e) => {
assert_eq!(e.key(), &key);
assert_eq!(e.get(), &new_value);
}
Vacant(_) => panic!(),
}
assert_eq!(a[key], new_value);
assert_eq!(a.len(), 1);
let entry = a.entry(key).and_replace_entry_with(|k, v| {
assert_eq!(k, &key);
assert_eq!(v, new_value);
None
});
match entry {
Vacant(e) => assert_eq!(e.key(), &key),
Occupied(_) => panic!(),
}
assert!(!a.contains_key(key));
assert_eq!(a.len(), 0);
}
#[test]
fn test_entry_ref_and_replace_entry_with() {
let mut a = HashMap::new();
let key = "a key";
let value = "an initial value";
let new_value = "a new value";
let entry = a.entry_ref(key).and_replace_entry_with(|_, _| panic!());
match entry {
EntryRef::Vacant(e) => assert_eq!(e.key(), key),
EntryRef::Occupied(_) => panic!(),
}
a.insert(key.to_owned(), value);
let entry = a.entry_ref(key).and_replace_entry_with(|k, v| {
assert_eq!(k, key);
assert_eq!(v, value);
Some(new_value)
});
match entry {
EntryRef::Occupied(e) => {
assert_eq!(e.key(), key);
assert_eq!(e.get(), &new_value);
}
EntryRef::Vacant(_) => panic!(),
}
assert_eq!(a[key], new_value);
assert_eq!(a.len(), 1);
let entry = a.entry_ref(key).and_replace_entry_with(|k, v| {
assert_eq!(k, key);
assert_eq!(v, new_value);
None
});
match entry {
EntryRef::Vacant(e) => assert_eq!(e.key(), key),
EntryRef::Occupied(_) => panic!(),
}
assert!(!a.contains_key(key));
assert_eq!(a.len(), 0);
}
#[test]
fn test_raw_occupied_entry_replace_entry_with() {
let mut a = HashMap::new();
let key = "a key";
let value = "an initial value";
let new_value = "a new value";
let entry = a
.raw_entry_mut()
.from_key(&key)
.insert(key, value)
.replace_entry_with(|k, v| {
assert_eq!(k, &key);
assert_eq!(v, value);
Some(new_value)
});
match entry {
RawEntryMut::Occupied(e) => {
assert_eq!(e.key(), &key);
assert_eq!(e.get(), &new_value);
}
RawEntryMut::Vacant(_) => panic!(),
}
assert_eq!(a[key], new_value);
assert_eq!(a.len(), 1);
let entry = match a.raw_entry_mut().from_key(&key) {
RawEntryMut::Occupied(e) => e.replace_entry_with(|k, v| {
assert_eq!(k, &key);
assert_eq!(v, new_value);
None
}),
RawEntryMut::Vacant(_) => panic!(),
};
match entry {
RawEntryMut::Vacant(_) => {}
RawEntryMut::Occupied(_) => panic!(),
}
assert!(!a.contains_key(key));
assert_eq!(a.len(), 0);
}
#[test]
fn test_raw_entry_and_replace_entry_with() {
let mut a = HashMap::new();
let key = "a key";
let value = "an initial value";
let new_value = "a new value";
let entry = a
.raw_entry_mut()
.from_key(&key)
.and_replace_entry_with(|_, _| panic!());
match entry {
RawEntryMut::Vacant(_) => {}
RawEntryMut::Occupied(_) => panic!(),
}
a.insert(key, value);
let entry = a
.raw_entry_mut()
.from_key(&key)
.and_replace_entry_with(|k, v| {
assert_eq!(k, &key);
assert_eq!(v, value);
Some(new_value)
});
match entry {
RawEntryMut::Occupied(e) => {
assert_eq!(e.key(), &key);
assert_eq!(e.get(), &new_value);
}
RawEntryMut::Vacant(_) => panic!(),
}
assert_eq!(a[key], new_value);
assert_eq!(a.len(), 1);
let entry = a
.raw_entry_mut()
.from_key(&key)
.and_replace_entry_with(|k, v| {
assert_eq!(k, &key);
assert_eq!(v, new_value);
None
});
match entry {
RawEntryMut::Vacant(_) => {}
RawEntryMut::Occupied(_) => panic!(),
}
assert!(!a.contains_key(key));
assert_eq!(a.len(), 0);
}
#[test]
fn test_replace_entry_with_doesnt_corrupt() {
#![allow(deprecated)] //rand
// Test for #19292
fn check(m: &HashMap<i32, ()>) {
for k in m.keys() {
assert!(m.contains_key(k), "{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<std::string::String, ()>) {
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<i32, i32> = (0..100).map(|x| (x, x * 10)).collect();
map.retain(|&k, _| k % 2 == 0);
assert_eq!(map.len(), 50);
assert_eq!(map[&2], 20);
assert_eq!(map[&4], 40);
assert_eq!(map[&6], 60);
}
#[test]
fn test_extract_if() {
{
let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x * 10)).collect();
let drained = map.extract_if(|&k, _| k % 2 == 0);
let mut out = drained.collect::<Vec<_>>();
out.sort_unstable();
assert_eq!(vec![(0, 0), (2, 20), (4, 40), (6, 60)], out);
assert_eq!(map.len(), 4);
}
{
let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x * 10)).collect();
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<u8, u8> = 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<u8, u8> = HashMap::new();
let _ = empty_bytes2.try_reserve(MAX_ISIZE / 5);
let mut empty_bytes3: HashMap<u8, u8> = HashMap::new();
let _ = empty_bytes3.try_reserve(MAX_ISIZE / 5);
let mut empty_bytes4: HashMap<u8, u8> = 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<i32, i32>, k: i32| -> u64 {
super::make_hash::<i32, _>(map.hasher(), &k)
};
// Existing key (insert)
match map.raw_entry_mut().from_key(&1) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
assert_eq!(view.get(), &10);
assert_eq!(view.insert(100), 10);
}
}
let hash1 = compute_hash(&map, 1);
assert_eq!(map.raw_entry().from_key(&1).unwrap(), (&1, &100));
assert_eq!(
map.raw_entry().from_hash(hash1, |k| *k == 1).unwrap(),
(&1, &100)
);
assert_eq!(
map.raw_entry().from_key_hashed_nocheck(hash1, &1).unwrap(),
(&1, &100)
);
assert_eq!(map.len(), 6);
// Existing key (update)
match map.raw_entry_mut().from_key(&2) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
let v = view.get_mut();
let new_v = (*v) * 10;
*v = new_v;
}
}
let hash2 = compute_hash(&map, 2);
assert_eq!(map.raw_entry().from_key(&2).unwrap(), (&2, &200));
assert_eq!(
map.raw_entry().from_hash(hash2, |k| *k == 2).unwrap(),
(&2, &200)
);
assert_eq!(
map.raw_entry().from_key_hashed_nocheck(hash2, &2).unwrap(),
(&2, &200)
);
assert_eq!(map.len(), 6);
// Existing key (take)
let hash3 = compute_hash(&map, 3);
match map.raw_entry_mut().from_key_hashed_nocheck(hash3, &3) {
Vacant(_) => unreachable!(),
Occupied(view) => {
assert_eq!(view.remove_entry(), (3, 30));
}
}
assert_eq!(map.raw_entry().from_key(&3), None);
assert_eq!(map.raw_entry().from_hash(hash3, |k| *k == 3), None);
assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash3, &3), None);
assert_eq!(map.len(), 5);
// Nonexistent key (insert)
match map.raw_entry_mut().from_key(&10) {
Occupied(_) => unreachable!(),
Vacant(view) => {
assert_eq!(view.insert(10, 1000), (&mut 10, &mut 1000));
}
}
assert_eq!(map.raw_entry().from_key(&10).unwrap(), (&10, &1000));
assert_eq!(map.len(), 6);
// Ensure all lookup methods produce equivalent results.
for k in 0..12 {
let hash = compute_hash(&map, k);
let v = map.get(&k).copied();
let kv = v.as_ref().map(|v| (&k, v));
assert_eq!(map.raw_entry().from_key(&k), kv);
assert_eq!(map.raw_entry().from_hash(hash, |q| *q == k), kv);
assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv);
match map.raw_entry_mut().from_key(&k) {
Occupied(o) => assert_eq!(Some(o.get_key_value()), kv),
Vacant(_) => assert_eq!(v, None),
}
match map.raw_entry_mut().from_key_hashed_nocheck(hash, &k) {
Occupied(o) => assert_eq!(Some(o.get_key_value()), kv),
Vacant(_) => assert_eq!(v, None),
}
match map.raw_entry_mut().from_hash(hash, |q| *q == k) {
Occupied(o) => assert_eq!(Some(o.get_key_value()), kv),
Vacant(_) => assert_eq!(v, None),
}
}
}
#[test]
fn test_key_without_hash_impl() {
#[derive(Debug)]
struct IntWrapper(u64);
let mut m: HashMap<IntWrapper, (), ()> = HashMap::default();
{
assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_none());
}
{
let vacant_entry = match m.raw_entry_mut().from_hash(0, |k| k.0 == 0) {
RawEntryMut::Occupied(..) => panic!("Found entry for key 0"),
RawEntryMut::Vacant(e) => e,
};
vacant_entry.insert_with_hasher(0, IntWrapper(0), (), |k| k.0);
}
{
assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_some());
assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_none());
assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none());
}
{
let vacant_entry = match m.raw_entry_mut().from_hash(1, |k| k.0 == 1) {
RawEntryMut::Occupied(..) => panic!("Found entry for key 1"),
RawEntryMut::Vacant(e) => e,
};
vacant_entry.insert_with_hasher(1, IntWrapper(1), (), |k| k.0);
}
{
assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_some());
assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_some());
assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none());
}
{
let occupied_entry = match m.raw_entry_mut().from_hash(0, |k| k.0 == 0) {
RawEntryMut::Occupied(e) => e,
RawEntryMut::Vacant(..) => panic!("Couldn't find entry for key 0"),
};
occupied_entry.remove();
}
assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_none());
assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_some());
assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none());
}
#[test]
#[cfg(feature = "raw")]
fn test_into_iter_refresh() {
#[cfg(miri)]
const N: usize = 32;
#[cfg(not(miri))]
const N: usize = 128;
let mut rng = rand::thread_rng();
for n in 0..N {
let mut map = HashMap::new();
for i in 0..n {
assert!(map.insert(i, 2 * i).is_none());
}
let hash_builder = map.hasher().clone();
let mut it = unsafe { map.table.iter() };
assert_eq!(it.len(), n);
let mut i = 0;
let mut left = n;
let mut removed = Vec::new();
loop {
// occasionally remove some elements
if i < n && rng.gen_bool(0.1) {
let hash_value = super::make_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<u32, std::string::String, MyHasher> =
HashMap::with_hasher(MyHasher);
let mut map = EMPTY_MAP;
map.insert(17, "seventeen".to_owned());
assert_eq!("seventeen", map[&17]);
}
#[test]
fn test_get_each_mut() {
let mut map = HashMap::new();
map.insert("foo".to_owned(), 0);
map.insert("bar".to_owned(), 10);
map.insert("baz".to_owned(), 20);
map.insert("qux".to_owned(), 30);
let xs = map.get_many_mut(["foo", "qux"]);
assert_eq!(xs, Some([&mut 0, &mut 30]));
let xs = map.get_many_mut(["foo", "dud"]);
assert_eq!(xs, None);
let xs = map.get_many_mut(["foo", "foo"]);
assert_eq!(xs, None);
let ys = map.get_many_key_value_mut(["bar", "baz"]);
assert_eq!(
ys,
Some([(&"bar".to_owned(), &mut 10), (&"baz".to_owned(), &mut 20),]),
);
let ys = map.get_many_key_value_mut(["bar", "dip"]);
assert_eq!(ys, None);
let ys = map.get_many_key_value_mut(["baz", "baz"]);
assert_eq!(ys, None);
}
#[test]
#[should_panic = "panic in drop"]
fn test_clone_from_double_drop() {
#[derive(Clone)]
struct CheckedDrop {
panic_in_drop: bool,
dropped: bool,
}
impl Drop for CheckedDrop {
fn drop(&mut self) {
if self.panic_in_drop {
self.dropped = true;
panic!("panic in drop");
}
if self.dropped {
panic!("double drop");
}
self.dropped = true;
}
}
const DISARMED: CheckedDrop = CheckedDrop {
panic_in_drop: false,
dropped: false,
};
const ARMED: CheckedDrop = CheckedDrop {
panic_in_drop: true,
dropped: false,
};
let mut map1 = HashMap::new();
map1.insert(1, DISARMED);
map1.insert(2, DISARMED);
map1.insert(3, DISARMED);
map1.insert(4, DISARMED);
let mut map2 = HashMap::new();
map2.insert(1, DISARMED);
map2.insert(2, ARMED);
map2.insert(3, DISARMED);
map2.insert(4, DISARMED);
map2.clone_from(&map1);
}
#[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<i32>,
}
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<AtomicI8>,
}
#[derive(Clone)]
struct MyAlloc {
_inner: Arc<MyAllocInner>,
}
impl MyAlloc {
fn new(drop_count: Arc<AtomicI8>) -> 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<NonNull<[u8]>, AllocError> {
let g = Global;
g.allocate(layout)
}
unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
let g = Global;
g.deallocate(ptr, layout)
}
}
#[test]
fn test_hashmap_into_iter_bug() {
let dropped: Arc<AtomicI8> = 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<T> {
panic_in_clone: bool,
panic_in_drop: bool,
dropped: bool,
data: T,
}
impl<T> CheckedCloneDrop<T> {
fn new(panic_in_clone: bool, panic_in_drop: bool, data: T) -> Self {
CheckedCloneDrop {
panic_in_clone,
panic_in_drop,
dropped: false,
data,
}
}
}
impl<T: Clone> Clone for CheckedCloneDrop<T> {
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<T> Drop for CheckedCloneDrop<T> {
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<I, T, A>(
iter: I,
mut fun: impl FnMut(u64) -> T,
alloc: A,
) -> Result<HashMap<u64, CheckedCloneDrop<T>, DefaultHashBuilder, A>, String>
where
I: Iterator<Item = (bool, bool)> + Clone + ExactSizeIterator,
A: Allocator,
T: PartialEq + core::fmt::Debug,
{
use crate::scopeguard::guard;
let mut map: HashMap<u64, CheckedCloneDrop<T>, _, 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::<T>() && 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<AtomicI8> = Arc::new(AtomicI8::new(2));
{
assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len());
let map: HashMap<u64, CheckedCloneDrop<Vec<u64>>, 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<AtomicI8>` and the memory of already cloned
// elements (Vec<i32> 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<AtomicI8> = Arc::new(AtomicI8::new(2));
{
assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len());
let map: HashMap<u64, CheckedCloneDrop<u64>, 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<AtomicI8> = 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<AtomicI8> = 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);
}
}