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+//! `IndexMap` is a hash table where the iteration order of the key-value
+//! pairs is independent of the hash values of the keys.
+
+mod core;
+
+pub use crate::mutable_keys::MutableKeys;
+
+#[cfg(feature = "rayon")]
+pub use crate::rayon::map as rayon;
+
+use crate::vec::{self, Vec};
+use ::core::cmp::Ordering;
+use ::core::fmt;
+use ::core::hash::{BuildHasher, Hash, Hasher};
+use ::core::iter::FusedIterator;
+use ::core::ops::{Index, IndexMut, RangeBounds};
+use ::core::slice::{Iter as SliceIter, IterMut as SliceIterMut};
+
+#[cfg(has_std)]
+use std::collections::hash_map::RandomState;
+
+use self::core::IndexMapCore;
+use crate::equivalent::Equivalent;
+use crate::util::third;
+use crate::{Bucket, Entries, HashValue};
+
+pub use self::core::{Entry, OccupiedEntry, VacantEntry};
+
+/// A hash table where the iteration order of the key-value pairs is independent
+/// of the hash values of the keys.
+///
+/// The interface is closely compatible with the standard `HashMap`, but also
+/// has additional features.
+///
+/// # Order
+///
+/// The key-value pairs have a consistent order that is determined by
+/// the sequence of insertion and removal calls on the map. The order does
+/// not depend on the keys or the hash function at all.
+///
+/// All iterators traverse the map in *the order*.
+///
+/// The insertion order is preserved, with **notable exceptions** like the
+/// `.remove()` or `.swap_remove()` methods. Methods such as `.sort_by()` of
+/// course result in a new order, depending on the sorting order.
+///
+/// # Indices
+///
+/// The key-value pairs are indexed in a compact range without holes in the
+/// range `0..self.len()`. For example, the method `.get_full` looks up the
+/// index for a key, and the method `.get_index` looks up the key-value pair by
+/// index.
+///
+/// # Examples
+///
+/// ```
+/// use indexmap::IndexMap;
+///
+/// // count the frequency of each letter in a sentence.
+/// let mut letters = IndexMap::new();
+/// for ch in "a short treatise on fungi".chars() {
+/// *letters.entry(ch).or_insert(0) += 1;
+/// }
+///
+/// assert_eq!(letters[&'s'], 2);
+/// assert_eq!(letters[&'t'], 3);
+/// assert_eq!(letters[&'u'], 1);
+/// assert_eq!(letters.get(&'y'), None);
+/// ```
+#[cfg(has_std)]
+pub struct IndexMap<K, V, S = RandomState> {
+ pub(crate) core: IndexMapCore<K, V>,
+ hash_builder: S,
+}
+#[cfg(not(has_std))]
+pub struct IndexMap<K, V, S> {
+ pub(crate) core: IndexMapCore<K, V>,
+ hash_builder: S,
+}
+
+impl<K, V, S> Clone for IndexMap<K, V, S>
+where
+ K: Clone,
+ V: Clone,
+ S: Clone,
+{
+ fn clone(&self) -> Self {
+ IndexMap {
+ core: self.core.clone(),
+ hash_builder: self.hash_builder.clone(),
+ }
+ }
+
+ fn clone_from(&mut self, other: &Self) {
+ self.core.clone_from(&other.core);
+ self.hash_builder.clone_from(&other.hash_builder);
+ }
+}
+
+impl<K, V, S> Entries for IndexMap<K, V, S> {
+ type Entry = Bucket<K, V>;
+
+ #[inline]
+ fn into_entries(self) -> Vec<Self::Entry> {
+ self.core.into_entries()
+ }
+
+ #[inline]
+ fn as_entries(&self) -> &[Self::Entry] {
+ self.core.as_entries()
+ }
+
+ #[inline]
+ fn as_entries_mut(&mut self) -> &mut [Self::Entry] {
+ self.core.as_entries_mut()
+ }
+
+ fn with_entries<F>(&mut self, f: F)
+ where
+ F: FnOnce(&mut [Self::Entry]),
+ {
+ self.core.with_entries(f);
+ }
+}
+
+impl<K, V, S> fmt::Debug for IndexMap<K, V, S>
+where
+ K: fmt::Debug,
+ V: fmt::Debug,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ if cfg!(not(feature = "test_debug")) {
+ f.debug_map().entries(self.iter()).finish()
+ } else {
+ // Let the inner `IndexMapCore` print all of its details
+ f.debug_struct("IndexMap")
+ .field("core", &self.core)
+ .finish()
+ }
+ }
+}
+
+#[cfg(has_std)]
+impl<K, V> IndexMap<K, V> {
+ /// Create a new map. (Does not allocate.)
+ #[inline]
+ pub fn new() -> Self {
+ Self::with_capacity(0)
+ }
+
+ /// Create a new map with capacity for `n` key-value pairs. (Does not
+ /// allocate if `n` is zero.)
+ ///
+ /// Computes in **O(n)** time.
+ #[inline]
+ pub fn with_capacity(n: usize) -> Self {
+ Self::with_capacity_and_hasher(n, <_>::default())
+ }
+}
+
+impl<K, V, S> IndexMap<K, V, S> {
+ /// Create a new map with capacity for `n` key-value pairs. (Does not
+ /// allocate if `n` is zero.)
+ ///
+ /// Computes in **O(n)** time.
+ #[inline]
+ pub fn with_capacity_and_hasher(n: usize, hash_builder: S) -> Self {
+ if n == 0 {
+ Self::with_hasher(hash_builder)
+ } else {
+ IndexMap {
+ core: IndexMapCore::with_capacity(n),
+ hash_builder,
+ }
+ }
+ }
+
+ /// Create a new map with `hash_builder`.
+ ///
+ /// This function is `const`, so it
+ /// can be called in `static` contexts.
+ pub const fn with_hasher(hash_builder: S) -> Self {
+ IndexMap {
+ core: IndexMapCore::new(),
+ hash_builder,
+ }
+ }
+
+ /// Computes in **O(1)** time.
+ pub fn capacity(&self) -> usize {
+ self.core.capacity()
+ }
+
+ /// Return a reference to the map's `BuildHasher`.
+ pub fn hasher(&self) -> &S {
+ &self.hash_builder
+ }
+
+ /// Return the number of key-value pairs in the map.
+ ///
+ /// Computes in **O(1)** time.
+ #[inline]
+ pub fn len(&self) -> usize {
+ self.core.len()
+ }
+
+ /// Returns true if the map contains no elements.
+ ///
+ /// Computes in **O(1)** time.
+ #[inline]
+ pub fn is_empty(&self) -> bool {
+ self.len() == 0
+ }
+
+ /// Return an iterator over the key-value pairs of the map, in their order
+ pub fn iter(&self) -> Iter<'_, K, V> {
+ Iter {
+ iter: self.as_entries().iter(),
+ }
+ }
+
+ /// Return an iterator over the key-value pairs of the map, in their order
+ pub fn iter_mut(&mut self) -> IterMut<'_, K, V> {
+ IterMut {
+ iter: self.as_entries_mut().iter_mut(),
+ }
+ }
+
+ /// Return an iterator over the keys of the map, in their order
+ pub fn keys(&self) -> Keys<'_, K, V> {
+ Keys {
+ iter: self.as_entries().iter(),
+ }
+ }
+
+ /// Return an owning iterator over the keys of the map, in their order
+ pub fn into_keys(self) -> IntoKeys<K, V> {
+ IntoKeys {
+ iter: self.into_entries().into_iter(),
+ }
+ }
+
+ /// Return an iterator over the values of the map, in their order
+ pub fn values(&self) -> Values<'_, K, V> {
+ Values {
+ iter: self.as_entries().iter(),
+ }
+ }
+
+ /// Return an iterator over mutable references to the values of the map,
+ /// in their order
+ pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> {
+ ValuesMut {
+ iter: self.as_entries_mut().iter_mut(),
+ }
+ }
+
+ /// Return an owning iterator over the values of the map, in their order
+ pub fn into_values(self) -> IntoValues<K, V> {
+ IntoValues {
+ iter: self.into_entries().into_iter(),
+ }
+ }
+
+ /// Remove all key-value pairs in the map, while preserving its capacity.
+ ///
+ /// Computes in **O(n)** time.
+ pub fn clear(&mut self) {
+ self.core.clear();
+ }
+
+ /// Shortens the map, keeping the first `len` elements and dropping the rest.
+ ///
+ /// If `len` is greater than the map's current length, this has no effect.
+ pub fn truncate(&mut self, len: usize) {
+ self.core.truncate(len);
+ }
+
+ /// Clears the `IndexMap` in the given index range, returning those
+ /// key-value pairs as a drain iterator.
+ ///
+ /// The range may be any type that implements `RangeBounds<usize>`,
+ /// including all of the `std::ops::Range*` types, or even a tuple pair of
+ /// `Bound` start and end values. To drain the map entirely, use `RangeFull`
+ /// like `map.drain(..)`.
+ ///
+ /// This shifts down all entries following the drained range to fill the
+ /// gap, and keeps the allocated memory for reuse.
+ ///
+ /// ***Panics*** if the starting point is greater than the end point or if
+ /// the end point is greater than the length of the map.
+ pub fn drain<R>(&mut self, range: R) -> Drain<'_, K, V>
+ where
+ R: RangeBounds<usize>,
+ {
+ Drain {
+ iter: self.core.drain(range),
+ }
+ }
+
+ /// Splits the collection into two at the given index.
+ ///
+ /// Returns a newly allocated map containing the elements in the range
+ /// `[at, len)`. After the call, the original map will be left containing
+ /// the elements `[0, at)` with its previous capacity unchanged.
+ ///
+ /// ***Panics*** if `at > len`.
+ pub fn split_off(&mut self, at: usize) -> Self
+ where
+ S: Clone,
+ {
+ Self {
+ core: self.core.split_off(at),
+ hash_builder: self.hash_builder.clone(),
+ }
+ }
+}
+
+impl<K, V, S> IndexMap<K, V, S>
+where
+ K: Hash + Eq,
+ S: BuildHasher,
+{
+ /// Reserve capacity for `additional` more key-value pairs.
+ ///
+ /// Computes in **O(n)** time.
+ pub fn reserve(&mut self, additional: usize) {
+ self.core.reserve(additional);
+ }
+
+ /// Shrink the capacity of the map as much as possible.
+ ///
+ /// Computes in **O(n)** time.
+ pub fn shrink_to_fit(&mut self) {
+ self.core.shrink_to(0);
+ }
+
+ /// Shrink the capacity of the map with a lower limit.
+ ///
+ /// Computes in **O(n)** time.
+ pub fn shrink_to(&mut self, min_capacity: usize) {
+ self.core.shrink_to(min_capacity);
+ }
+
+ fn hash<Q: ?Sized + Hash>(&self, key: &Q) -> HashValue {
+ let mut h = self.hash_builder.build_hasher();
+ key.hash(&mut h);
+ HashValue(h.finish() as usize)
+ }
+
+ /// Insert a key-value pair in the map.
+ ///
+ /// If an equivalent key already exists in the map: the key remains and
+ /// retains in its place in the order, its corresponding value is updated
+ /// with `value` and the older value is returned inside `Some(_)`.
+ ///
+ /// If no equivalent key existed in the map: the new key-value pair is
+ /// inserted, last in order, and `None` is returned.
+ ///
+ /// Computes in **O(1)** time (amortized average).
+ ///
+ /// See also [`entry`](#method.entry) if you you want to insert *or* modify
+ /// or if you need to get the index of the corresponding key-value pair.
+ pub fn insert(&mut self, key: K, value: V) -> Option<V> {
+ self.insert_full(key, value).1
+ }
+
+ /// Insert a key-value pair in the map, and get their index.
+ ///
+ /// If an equivalent key already exists in the map: the key remains and
+ /// retains in its place in the order, its corresponding value is updated
+ /// with `value` and the older value is returned inside `(index, Some(_))`.
+ ///
+ /// If no equivalent key existed in the map: the new key-value pair is
+ /// inserted, last in order, and `(index, None)` is returned.
+ ///
+ /// Computes in **O(1)** time (amortized average).
+ ///
+ /// See also [`entry`](#method.entry) if you you want to insert *or* modify
+ /// or if you need to get the index of the corresponding key-value pair.
+ pub fn insert_full(&mut self, key: K, value: V) -> (usize, Option<V>) {
+ let hash = self.hash(&key);
+ self.core.insert_full(hash, key, value)
+ }
+
+ /// Get the given key’s corresponding entry in the map for insertion and/or
+ /// in-place manipulation.
+ ///
+ /// Computes in **O(1)** time (amortized average).
+ pub fn entry(&mut self, key: K) -> Entry<'_, K, V> {
+ let hash = self.hash(&key);
+ self.core.entry(hash, key)
+ }
+
+ /// Return `true` if an equivalent to `key` exists in the map.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn contains_key<Q: ?Sized>(&self, key: &Q) -> bool
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ self.get_index_of(key).is_some()
+ }
+
+ /// Return a reference to the value stored for `key`, if it is present,
+ /// else `None`.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn get<Q: ?Sized>(&self, key: &Q) -> Option<&V>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if let Some(i) = self.get_index_of(key) {
+ let entry = &self.as_entries()[i];
+ Some(&entry.value)
+ } else {
+ None
+ }
+ }
+
+ /// Return references to the key-value pair stored for `key`,
+ /// if it is present, else `None`.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn get_key_value<Q: ?Sized>(&self, key: &Q) -> Option<(&K, &V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if let Some(i) = self.get_index_of(key) {
+ let entry = &self.as_entries()[i];
+ Some((&entry.key, &entry.value))
+ } else {
+ None
+ }
+ }
+
+ /// Return item index, key and value
+ pub fn get_full<Q: ?Sized>(&self, key: &Q) -> Option<(usize, &K, &V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if let Some(i) = self.get_index_of(key) {
+ let entry = &self.as_entries()[i];
+ Some((i, &entry.key, &entry.value))
+ } else {
+ None
+ }
+ }
+
+ /// Return item index, if it exists in the map
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn get_index_of<Q: ?Sized>(&self, key: &Q) -> Option<usize>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if self.is_empty() {
+ None
+ } else {
+ let hash = self.hash(key);
+ self.core.get_index_of(hash, key)
+ }
+ }
+
+ pub fn get_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<&mut V>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if let Some(i) = self.get_index_of(key) {
+ let entry = &mut self.as_entries_mut()[i];
+ Some(&mut entry.value)
+ } else {
+ None
+ }
+ }
+
+ pub fn get_full_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, &K, &mut V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if let Some(i) = self.get_index_of(key) {
+ let entry = &mut self.as_entries_mut()[i];
+ Some((i, &entry.key, &mut entry.value))
+ } else {
+ None
+ }
+ }
+
+ pub(crate) fn get_full_mut2_impl<Q: ?Sized>(
+ &mut self,
+ key: &Q,
+ ) -> Option<(usize, &mut K, &mut V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if let Some(i) = self.get_index_of(key) {
+ let entry = &mut self.as_entries_mut()[i];
+ Some((i, &mut entry.key, &mut entry.value))
+ } else {
+ None
+ }
+ }
+
+ /// Remove the key-value pair equivalent to `key` and return
+ /// its value.
+ ///
+ /// **NOTE:** This is equivalent to `.swap_remove(key)`, if you need to
+ /// preserve the order of the keys in the map, use `.shift_remove(key)`
+ /// instead.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ self.swap_remove(key)
+ }
+
+ /// Remove and return the key-value pair equivalent to `key`.
+ ///
+ /// **NOTE:** This is equivalent to `.swap_remove_entry(key)`, if you need to
+ /// preserve the order of the keys in the map, use `.shift_remove_entry(key)`
+ /// instead.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ self.swap_remove_entry(key)
+ }
+
+ /// Remove the key-value pair equivalent to `key` and return
+ /// its value.
+ ///
+ /// Like `Vec::swap_remove`, the pair is removed by swapping it with the
+ /// last element of the map and popping it off. **This perturbs
+ /// the position of what used to be the last element!**
+ ///
+ /// Return `None` if `key` is not in map.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn swap_remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ self.swap_remove_full(key).map(third)
+ }
+
+ /// Remove and return the key-value pair equivalent to `key`.
+ ///
+ /// Like `Vec::swap_remove`, the pair is removed by swapping it with the
+ /// last element of the map and popping it off. **This perturbs
+ /// the position of what used to be the last element!**
+ ///
+ /// Return `None` if `key` is not in map.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn swap_remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ match self.swap_remove_full(key) {
+ Some((_, key, value)) => Some((key, value)),
+ None => None,
+ }
+ }
+
+ /// Remove the key-value pair equivalent to `key` and return it and
+ /// the index it had.
+ ///
+ /// Like `Vec::swap_remove`, the pair is removed by swapping it with the
+ /// last element of the map and popping it off. **This perturbs
+ /// the position of what used to be the last element!**
+ ///
+ /// Return `None` if `key` is not in map.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn swap_remove_full<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, K, V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if self.is_empty() {
+ return None;
+ }
+ let hash = self.hash(key);
+ self.core.swap_remove_full(hash, key)
+ }
+
+ /// Remove the key-value pair equivalent to `key` and return
+ /// its value.
+ ///
+ /// Like `Vec::remove`, the pair is removed by shifting all of the
+ /// elements that follow it, preserving their relative order.
+ /// **This perturbs the index of all of those elements!**
+ ///
+ /// Return `None` if `key` is not in map.
+ ///
+ /// Computes in **O(n)** time (average).
+ pub fn shift_remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ self.shift_remove_full(key).map(third)
+ }
+
+ /// Remove and return the key-value pair equivalent to `key`.
+ ///
+ /// Like `Vec::remove`, the pair is removed by shifting all of the
+ /// elements that follow it, preserving their relative order.
+ /// **This perturbs the index of all of those elements!**
+ ///
+ /// Return `None` if `key` is not in map.
+ ///
+ /// Computes in **O(n)** time (average).
+ pub fn shift_remove_entry<Q: ?Sized>(&mut self, key: &Q) -> Option<(K, V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ match self.shift_remove_full(key) {
+ Some((_, key, value)) => Some((key, value)),
+ None => None,
+ }
+ }
+
+ /// Remove the key-value pair equivalent to `key` and return it and
+ /// the index it had.
+ ///
+ /// Like `Vec::remove`, the pair is removed by shifting all of the
+ /// elements that follow it, preserving their relative order.
+ /// **This perturbs the index of all of those elements!**
+ ///
+ /// Return `None` if `key` is not in map.
+ ///
+ /// Computes in **O(n)** time (average).
+ pub fn shift_remove_full<Q: ?Sized>(&mut self, key: &Q) -> Option<(usize, K, V)>
+ where
+ Q: Hash + Equivalent<K>,
+ {
+ if self.is_empty() {
+ return None;
+ }
+ let hash = self.hash(key);
+ self.core.shift_remove_full(hash, key)
+ }
+
+ /// Remove the last key-value pair
+ ///
+ /// This preserves the order of the remaining elements.
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn pop(&mut self) -> Option<(K, V)> {
+ self.core.pop()
+ }
+
+ /// Scan through each key-value pair in the map and keep those where the
+ /// closure `keep` returns `true`.
+ ///
+ /// The elements are visited in order, and remaining elements keep their
+ /// order.
+ ///
+ /// Computes in **O(n)** time (average).
+ pub fn retain<F>(&mut self, mut keep: F)
+ where
+ F: FnMut(&K, &mut V) -> bool,
+ {
+ self.core.retain_in_order(move |k, v| keep(k, v));
+ }
+
+ pub(crate) fn retain_mut<F>(&mut self, keep: F)
+ where
+ F: FnMut(&mut K, &mut V) -> bool,
+ {
+ self.core.retain_in_order(keep);
+ }
+
+ /// Sort the map’s key-value pairs by the default ordering of the keys.
+ ///
+ /// See [`sort_by`](Self::sort_by) for details.
+ pub fn sort_keys(&mut self)
+ where
+ K: Ord,
+ {
+ self.with_entries(move |entries| {
+ entries.sort_by(move |a, b| K::cmp(&a.key, &b.key));
+ });
+ }
+
+ /// Sort the map’s key-value pairs in place using the comparison
+ /// function `cmp`.
+ ///
+ /// The comparison function receives two key and value pairs to compare (you
+ /// can sort by keys or values or their combination as needed).
+ ///
+ /// Computes in **O(n log n + c)** time and **O(n)** space where *n* is
+ /// the length of the map and *c* the capacity. The sort is stable.
+ pub fn sort_by<F>(&mut self, mut cmp: F)
+ where
+ F: FnMut(&K, &V, &K, &V) -> Ordering,
+ {
+ self.with_entries(move |entries| {
+ entries.sort_by(move |a, b| cmp(&a.key, &a.value, &b.key, &b.value));
+ });
+ }
+
+ /// Sort the key-value pairs of the map and return a by-value iterator of
+ /// the key-value pairs with the result.
+ ///
+ /// The sort is stable.
+ pub fn sorted_by<F>(self, mut cmp: F) -> IntoIter<K, V>
+ where
+ F: FnMut(&K, &V, &K, &V) -> Ordering,
+ {
+ let mut entries = self.into_entries();
+ entries.sort_by(move |a, b| cmp(&a.key, &a.value, &b.key, &b.value));
+ IntoIter {
+ iter: entries.into_iter(),
+ }
+ }
+
+ /// Sort the map's key-value pairs by the default ordering of the keys, but
+ /// may not preserve the order of equal elements.
+ ///
+ /// See [`sort_unstable_by`](Self::sort_unstable_by) for details.
+ pub fn sort_unstable_keys(&mut self)
+ where
+ K: Ord,
+ {
+ self.with_entries(move |entries| {
+ entries.sort_unstable_by(move |a, b| K::cmp(&a.key, &b.key));
+ });
+ }
+
+ /// Sort the map's key-value pairs in place using the comparison function `cmp`, but
+ /// may not preserve the order of equal elements.
+ ///
+ /// The comparison function receives two key and value pairs to compare (you
+ /// can sort by keys or values or their combination as needed).
+ ///
+ /// Computes in **O(n log n + c)** time where *n* is
+ /// the length of the map and *c* is the capacity. The sort is unstable.
+ pub fn sort_unstable_by<F>(&mut self, mut cmp: F)
+ where
+ F: FnMut(&K, &V, &K, &V) -> Ordering,
+ {
+ self.with_entries(move |entries| {
+ entries.sort_unstable_by(move |a, b| cmp(&a.key, &a.value, &b.key, &b.value));
+ });
+ }
+
+ /// Sort the key-value pairs of the map and return a by-value iterator of
+ /// the key-value pairs with the result.
+ ///
+ /// The sort is unstable.
+ #[inline]
+ pub fn sorted_unstable_by<F>(self, mut cmp: F) -> IntoIter<K, V>
+ where
+ F: FnMut(&K, &V, &K, &V) -> Ordering,
+ {
+ let mut entries = self.into_entries();
+ entries.sort_unstable_by(move |a, b| cmp(&a.key, &a.value, &b.key, &b.value));
+ IntoIter {
+ iter: entries.into_iter(),
+ }
+ }
+
+ /// Reverses the order of the map’s key-value pairs in place.
+ ///
+ /// Computes in **O(n)** time and **O(1)** space.
+ pub fn reverse(&mut self) {
+ self.core.reverse()
+ }
+}
+
+impl<K, V, S> IndexMap<K, V, S> {
+ /// Get a key-value pair by index
+ ///
+ /// Valid indices are *0 <= index < self.len()*
+ ///
+ /// Computes in **O(1)** time.
+ pub fn get_index(&self, index: usize) -> Option<(&K, &V)> {
+ self.as_entries().get(index).map(Bucket::refs)
+ }
+
+ /// Get a key-value pair by index
+ ///
+ /// Valid indices are *0 <= index < self.len()*
+ ///
+ /// Computes in **O(1)** time.
+ pub fn get_index_mut(&mut self, index: usize) -> Option<(&mut K, &mut V)> {
+ self.as_entries_mut().get_mut(index).map(Bucket::muts)
+ }
+
+ /// Get the first key-value pair
+ ///
+ /// Computes in **O(1)** time.
+ pub fn first(&self) -> Option<(&K, &V)> {
+ self.as_entries().first().map(Bucket::refs)
+ }
+
+ /// Get the first key-value pair, with mutable access to the value
+ ///
+ /// Computes in **O(1)** time.
+ pub fn first_mut(&mut self) -> Option<(&K, &mut V)> {
+ self.as_entries_mut().first_mut().map(Bucket::ref_mut)
+ }
+
+ /// Get the last key-value pair
+ ///
+ /// Computes in **O(1)** time.
+ pub fn last(&self) -> Option<(&K, &V)> {
+ self.as_entries().last().map(Bucket::refs)
+ }
+
+ /// Get the last key-value pair, with mutable access to the value
+ ///
+ /// Computes in **O(1)** time.
+ pub fn last_mut(&mut self) -> Option<(&K, &mut V)> {
+ self.as_entries_mut().last_mut().map(Bucket::ref_mut)
+ }
+
+ /// Remove the key-value pair by index
+ ///
+ /// Valid indices are *0 <= index < self.len()*
+ ///
+ /// Like `Vec::swap_remove`, the pair is removed by swapping it with the
+ /// last element of the map and popping it off. **This perturbs
+ /// the position of what used to be the last element!**
+ ///
+ /// Computes in **O(1)** time (average).
+ pub fn swap_remove_index(&mut self, index: usize) -> Option<(K, V)> {
+ self.core.swap_remove_index(index)
+ }
+
+ /// Remove the key-value pair by index
+ ///
+ /// Valid indices are *0 <= index < self.len()*
+ ///
+ /// Like `Vec::remove`, the pair is removed by shifting all of the
+ /// elements that follow it, preserving their relative order.
+ /// **This perturbs the index of all of those elements!**
+ ///
+ /// Computes in **O(n)** time (average).
+ pub fn shift_remove_index(&mut self, index: usize) -> Option<(K, V)> {
+ self.core.shift_remove_index(index)
+ }
+
+ /// Moves the position of a key-value pair from one index to another
+ /// by shifting all other pairs in-between.
+ ///
+ /// * If `from < to`, the other pairs will shift down while the targeted pair moves up.
+ /// * If `from > to`, the other pairs will shift up while the targeted pair moves down.
+ ///
+ /// ***Panics*** if `from` or `to` are out of bounds.
+ ///
+ /// Computes in **O(n)** time (average).
+ pub fn move_index(&mut self, from: usize, to: usize) {
+ self.core.move_index(from, to)
+ }
+
+ /// Swaps the position of two key-value pairs in the map.
+ ///
+ /// ***Panics*** if `a` or `b` are out of bounds.
+ pub fn swap_indices(&mut self, a: usize, b: usize) {
+ self.core.swap_indices(a, b)
+ }
+}
+
+/// An iterator over the keys of a `IndexMap`.
+///
+/// This `struct` is created by the [`keys`] method on [`IndexMap`]. See its
+/// documentation for more.
+///
+/// [`keys`]: struct.IndexMap.html#method.keys
+/// [`IndexMap`]: struct.IndexMap.html
+pub struct Keys<'a, K, V> {
+ iter: SliceIter<'a, Bucket<K, V>>,
+}
+
+impl<'a, K, V> Iterator for Keys<'a, K, V> {
+ type Item = &'a K;
+
+ iterator_methods!(Bucket::key_ref);
+}
+
+impl<K, V> DoubleEndedIterator for Keys<'_, K, V> {
+ double_ended_iterator_methods!(Bucket::key_ref);
+}
+
+impl<K, V> ExactSizeIterator for Keys<'_, K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for Keys<'_, K, V> {}
+
+// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
+impl<K, V> Clone for Keys<'_, K, V> {
+ fn clone(&self) -> Self {
+ Keys {
+ iter: self.iter.clone(),
+ }
+ }
+}
+
+impl<K: fmt::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 owning iterator over the keys of a `IndexMap`.
+///
+/// This `struct` is created by the [`into_keys`] method on [`IndexMap`].
+/// See its documentation for more.
+///
+/// [`IndexMap`]: struct.IndexMap.html
+/// [`into_keys`]: struct.IndexMap.html#method.into_keys
+pub struct IntoKeys<K, V> {
+ iter: vec::IntoIter<Bucket<K, V>>,
+}
+
+impl<K, V> Iterator for IntoKeys<K, V> {
+ type Item = K;
+
+ iterator_methods!(Bucket::key);
+}
+
+impl<K, V> DoubleEndedIterator for IntoKeys<K, V> {
+ double_ended_iterator_methods!(Bucket::key);
+}
+
+impl<K, V> ExactSizeIterator for IntoKeys<K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for IntoKeys<K, V> {}
+
+impl<K: fmt::Debug, V> fmt::Debug for IntoKeys<K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let iter = self.iter.as_slice().iter().map(Bucket::key_ref);
+ f.debug_list().entries(iter).finish()
+ }
+}
+
+/// An iterator over the values of a `IndexMap`.
+///
+/// This `struct` is created by the [`values`] method on [`IndexMap`]. See its
+/// documentation for more.
+///
+/// [`values`]: struct.IndexMap.html#method.values
+/// [`IndexMap`]: struct.IndexMap.html
+pub struct Values<'a, K, V> {
+ iter: SliceIter<'a, Bucket<K, V>>,
+}
+
+impl<'a, K, V> Iterator for Values<'a, K, V> {
+ type Item = &'a V;
+
+ iterator_methods!(Bucket::value_ref);
+}
+
+impl<K, V> DoubleEndedIterator for Values<'_, K, V> {
+ double_ended_iterator_methods!(Bucket::value_ref);
+}
+
+impl<K, V> ExactSizeIterator for Values<'_, K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for Values<'_, K, V> {}
+
+// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
+impl<K, V> Clone for Values<'_, K, V> {
+ fn clone(&self) -> Self {
+ Values {
+ iter: self.iter.clone(),
+ }
+ }
+}
+
+impl<K, V: fmt::Debug> fmt::Debug for Values<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+/// A mutable iterator over the values of a `IndexMap`.
+///
+/// This `struct` is created by the [`values_mut`] method on [`IndexMap`]. See its
+/// documentation for more.
+///
+/// [`values_mut`]: struct.IndexMap.html#method.values_mut
+/// [`IndexMap`]: struct.IndexMap.html
+pub struct ValuesMut<'a, K, V> {
+ iter: SliceIterMut<'a, Bucket<K, V>>,
+}
+
+impl<'a, K, V> Iterator for ValuesMut<'a, K, V> {
+ type Item = &'a mut V;
+
+ iterator_methods!(Bucket::value_mut);
+}
+
+impl<K, V> DoubleEndedIterator for ValuesMut<'_, K, V> {
+ double_ended_iterator_methods!(Bucket::value_mut);
+}
+
+impl<K, V> ExactSizeIterator for ValuesMut<'_, K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for ValuesMut<'_, K, V> {}
+
+impl<K, V: fmt::Debug> fmt::Debug for ValuesMut<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let iter = self.iter.as_slice().iter().map(Bucket::value_ref);
+ f.debug_list().entries(iter).finish()
+ }
+}
+
+/// An owning iterator over the values of a `IndexMap`.
+///
+/// This `struct` is created by the [`into_values`] method on [`IndexMap`].
+/// See its documentation for more.
+///
+/// [`IndexMap`]: struct.IndexMap.html
+/// [`into_values`]: struct.IndexMap.html#method.into_values
+pub struct IntoValues<K, V> {
+ iter: vec::IntoIter<Bucket<K, V>>,
+}
+
+impl<K, V> Iterator for IntoValues<K, V> {
+ type Item = V;
+
+ iterator_methods!(Bucket::value);
+}
+
+impl<K, V> DoubleEndedIterator for IntoValues<K, V> {
+ double_ended_iterator_methods!(Bucket::value);
+}
+
+impl<K, V> ExactSizeIterator for IntoValues<K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for IntoValues<K, V> {}
+
+impl<K, V: fmt::Debug> fmt::Debug for IntoValues<K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let iter = self.iter.as_slice().iter().map(Bucket::value_ref);
+ f.debug_list().entries(iter).finish()
+ }
+}
+
+/// An iterator over the entries of a `IndexMap`.
+///
+/// This `struct` is created by the [`iter`] method on [`IndexMap`]. See its
+/// documentation for more.
+///
+/// [`iter`]: struct.IndexMap.html#method.iter
+/// [`IndexMap`]: struct.IndexMap.html
+pub struct Iter<'a, K, V> {
+ iter: SliceIter<'a, Bucket<K, V>>,
+}
+
+impl<'a, K, V> Iterator for Iter<'a, K, V> {
+ type Item = (&'a K, &'a V);
+
+ iterator_methods!(Bucket::refs);
+}
+
+impl<K, V> DoubleEndedIterator for Iter<'_, K, V> {
+ double_ended_iterator_methods!(Bucket::refs);
+}
+
+impl<K, V> ExactSizeIterator for Iter<'_, K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for Iter<'_, K, V> {}
+
+// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
+impl<K, V> Clone for Iter<'_, K, V> {
+ fn clone(&self) -> Self {
+ Iter {
+ iter: self.iter.clone(),
+ }
+ }
+}
+
+impl<K: fmt::Debug, V: fmt::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 `IndexMap`.
+///
+/// This `struct` is created by the [`iter_mut`] method on [`IndexMap`]. See its
+/// documentation for more.
+///
+/// [`iter_mut`]: struct.IndexMap.html#method.iter_mut
+/// [`IndexMap`]: struct.IndexMap.html
+pub struct IterMut<'a, K, V> {
+ iter: SliceIterMut<'a, Bucket<K, V>>,
+}
+
+impl<'a, K, V> Iterator for IterMut<'a, K, V> {
+ type Item = (&'a K, &'a mut V);
+
+ iterator_methods!(Bucket::ref_mut);
+}
+
+impl<K, V> DoubleEndedIterator for IterMut<'_, K, V> {
+ double_ended_iterator_methods!(Bucket::ref_mut);
+}
+
+impl<K, V> ExactSizeIterator for IterMut<'_, K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for IterMut<'_, K, V> {}
+
+impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for IterMut<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let iter = self.iter.as_slice().iter().map(Bucket::refs);
+ f.debug_list().entries(iter).finish()
+ }
+}
+
+/// An owning iterator over the entries of a `IndexMap`.
+///
+/// This `struct` is created by the [`into_iter`] method on [`IndexMap`]
+/// (provided by the `IntoIterator` trait). See its documentation for more.
+///
+/// [`into_iter`]: struct.IndexMap.html#method.into_iter
+/// [`IndexMap`]: struct.IndexMap.html
+pub struct IntoIter<K, V> {
+ iter: vec::IntoIter<Bucket<K, V>>,
+}
+
+impl<K, V> Iterator for IntoIter<K, V> {
+ type Item = (K, V);
+
+ iterator_methods!(Bucket::key_value);
+}
+
+impl<K, V> DoubleEndedIterator for IntoIter<K, V> {
+ double_ended_iterator_methods!(Bucket::key_value);
+}
+
+impl<K, V> ExactSizeIterator for IntoIter<K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for IntoIter<K, V> {}
+
+impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for IntoIter<K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let iter = self.iter.as_slice().iter().map(Bucket::refs);
+ f.debug_list().entries(iter).finish()
+ }
+}
+
+/// A draining iterator over the entries of a `IndexMap`.
+///
+/// This `struct` is created by the [`drain`] method on [`IndexMap`]. See its
+/// documentation for more.
+///
+/// [`drain`]: struct.IndexMap.html#method.drain
+/// [`IndexMap`]: struct.IndexMap.html
+pub struct Drain<'a, K, V> {
+ pub(crate) iter: vec::Drain<'a, Bucket<K, V>>,
+}
+
+impl<K, V> Iterator for Drain<'_, K, V> {
+ type Item = (K, V);
+
+ iterator_methods!(Bucket::key_value);
+}
+
+impl<K, V> DoubleEndedIterator for Drain<'_, K, V> {
+ double_ended_iterator_methods!(Bucket::key_value);
+}
+
+impl<K, V> ExactSizeIterator for Drain<'_, K, V> {
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+
+impl<K, V> FusedIterator for Drain<'_, K, V> {}
+
+impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for Drain<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let iter = self.iter.as_slice().iter().map(Bucket::refs);
+ f.debug_list().entries(iter).finish()
+ }
+}
+
+impl<'a, K, V, S> IntoIterator for &'a IndexMap<K, V, S> {
+ type Item = (&'a K, &'a V);
+ type IntoIter = Iter<'a, K, V>;
+ fn into_iter(self) -> Self::IntoIter {
+ self.iter()
+ }
+}
+
+impl<'a, K, V, S> IntoIterator for &'a mut IndexMap<K, V, S> {
+ type Item = (&'a K, &'a mut V);
+ type IntoIter = IterMut<'a, K, V>;
+ fn into_iter(self) -> Self::IntoIter {
+ self.iter_mut()
+ }
+}
+
+impl<K, V, S> IntoIterator for IndexMap<K, V, S> {
+ type Item = (K, V);
+ type IntoIter = IntoIter<K, V>;
+ fn into_iter(self) -> Self::IntoIter {
+ IntoIter {
+ iter: self.into_entries().into_iter(),
+ }
+ }
+}
+
+/// Access `IndexMap` values corresponding to a key.
+///
+/// # Examples
+///
+/// ```
+/// use indexmap::IndexMap;
+///
+/// let mut map = IndexMap::new();
+/// for word in "Lorem ipsum dolor sit amet".split_whitespace() {
+/// map.insert(word.to_lowercase(), word.to_uppercase());
+/// }
+/// assert_eq!(map["lorem"], "LOREM");
+/// assert_eq!(map["ipsum"], "IPSUM");
+/// ```
+///
+/// ```should_panic
+/// use indexmap::IndexMap;
+///
+/// let mut map = IndexMap::new();
+/// map.insert("foo", 1);
+/// println!("{:?}", map["bar"]); // panics!
+/// ```
+impl<K, V, Q: ?Sized, S> Index<&Q> for IndexMap<K, V, S>
+where
+ Q: Hash + Equivalent<K>,
+ K: Hash + Eq,
+ S: BuildHasher,
+{
+ type Output = V;
+
+ /// Returns a reference to the value corresponding to the supplied `key`.
+ ///
+ /// ***Panics*** if `key` is not present in the map.
+ fn index(&self, key: &Q) -> &V {
+ self.get(key).expect("IndexMap: key not found")
+ }
+}
+
+/// Access `IndexMap` values corresponding to a key.
+///
+/// Mutable indexing allows changing / updating values of key-value
+/// pairs that are already present.
+///
+/// You can **not** insert new pairs with index syntax, use `.insert()`.
+///
+/// # Examples
+///
+/// ```
+/// use indexmap::IndexMap;
+///
+/// let mut map = IndexMap::new();
+/// for word in "Lorem ipsum dolor sit amet".split_whitespace() {
+/// map.insert(word.to_lowercase(), word.to_string());
+/// }
+/// let lorem = &mut map["lorem"];
+/// assert_eq!(lorem, "Lorem");
+/// lorem.retain(char::is_lowercase);
+/// assert_eq!(map["lorem"], "orem");
+/// ```
+///
+/// ```should_panic
+/// use indexmap::IndexMap;
+///
+/// let mut map = IndexMap::new();
+/// map.insert("foo", 1);
+/// map["bar"] = 1; // panics!
+/// ```
+impl<K, V, Q: ?Sized, S> IndexMut<&Q> for IndexMap<K, V, S>
+where
+ Q: Hash + Equivalent<K>,
+ K: Hash + Eq,
+ S: BuildHasher,
+{
+ /// Returns a mutable reference to the value corresponding to the supplied `key`.
+ ///
+ /// ***Panics*** if `key` is not present in the map.
+ fn index_mut(&mut self, key: &Q) -> &mut V {
+ self.get_mut(key).expect("IndexMap: key not found")
+ }
+}
+
+/// Access `IndexMap` values at indexed positions.
+///
+/// # Examples
+///
+/// ```
+/// use indexmap::IndexMap;
+///
+/// let mut map = IndexMap::new();
+/// for word in "Lorem ipsum dolor sit amet".split_whitespace() {
+/// map.insert(word.to_lowercase(), word.to_uppercase());
+/// }
+/// assert_eq!(map[0], "LOREM");
+/// assert_eq!(map[1], "IPSUM");
+/// map.reverse();
+/// assert_eq!(map[0], "AMET");
+/// assert_eq!(map[1], "SIT");
+/// map.sort_keys();
+/// assert_eq!(map[0], "AMET");
+/// assert_eq!(map[1], "DOLOR");
+/// ```
+///
+/// ```should_panic
+/// use indexmap::IndexMap;
+///
+/// let mut map = IndexMap::new();
+/// map.insert("foo", 1);
+/// println!("{:?}", map[10]); // panics!
+/// ```
+impl<K, V, S> Index<usize> for IndexMap<K, V, S> {
+ type Output = V;
+
+ /// Returns a reference to the value at the supplied `index`.
+ ///
+ /// ***Panics*** if `index` is out of bounds.
+ fn index(&self, index: usize) -> &V {
+ self.get_index(index)
+ .expect("IndexMap: index out of bounds")
+ .1
+ }
+}
+
+/// Access `IndexMap` values at indexed positions.
+///
+/// Mutable indexing allows changing / updating indexed values
+/// that are already present.
+///
+/// You can **not** insert new values with index syntax, use `.insert()`.
+///
+/// # Examples
+///
+/// ```
+/// use indexmap::IndexMap;
+///
+/// let mut map = IndexMap::new();
+/// for word in "Lorem ipsum dolor sit amet".split_whitespace() {
+/// map.insert(word.to_lowercase(), word.to_string());
+/// }
+/// let lorem = &mut map[0];
+/// assert_eq!(lorem, "Lorem");
+/// lorem.retain(char::is_lowercase);
+/// assert_eq!(map["lorem"], "orem");
+/// ```
+///
+/// ```should_panic
+/// use indexmap::IndexMap;
+///
+/// let mut map = IndexMap::new();
+/// map.insert("foo", 1);
+/// map[10] = 1; // panics!
+/// ```
+impl<K, V, S> IndexMut<usize> for IndexMap<K, V, S> {
+ /// Returns a mutable reference to the value at the supplied `index`.
+ ///
+ /// ***Panics*** if `index` is out of bounds.
+ fn index_mut(&mut self, index: usize) -> &mut V {
+ self.get_index_mut(index)
+ .expect("IndexMap: index out of bounds")
+ .1
+ }
+}
+
+impl<K, V, S> FromIterator<(K, V)> for IndexMap<K, V, S>
+where
+ K: Hash + Eq,
+ S: BuildHasher + Default,
+{
+ /// Create an `IndexMap` from the sequence of key-value pairs in the
+ /// iterable.
+ ///
+ /// `from_iter` uses the same logic as `extend`. See
+ /// [`extend`](#method.extend) for more details.
+ fn from_iter<I: IntoIterator<Item = (K, V)>>(iterable: I) -> Self {
+ let iter = iterable.into_iter();
+ let (low, _) = iter.size_hint();
+ let mut map = Self::with_capacity_and_hasher(low, <_>::default());
+ map.extend(iter);
+ map
+ }
+}
+
+#[cfg(has_std)]
+impl<K, V, const N: usize> From<[(K, V); N]> for IndexMap<K, V, RandomState>
+where
+ K: Hash + Eq,
+{
+ /// # Examples
+ ///
+ /// ```
+ /// use indexmap::IndexMap;
+ ///
+ /// let map1 = IndexMap::from([(1, 2), (3, 4)]);
+ /// let map2: IndexMap<_, _> = [(1, 2), (3, 4)].into();
+ /// assert_eq!(map1, map2);
+ /// ```
+ fn from(arr: [(K, V); N]) -> Self {
+ Self::from_iter(arr)
+ }
+}
+
+impl<K, V, S> Extend<(K, V)> for IndexMap<K, V, S>
+where
+ K: Hash + Eq,
+ S: BuildHasher,
+{
+ /// Extend the map with all key-value pairs in the iterable.
+ ///
+ /// This is equivalent to calling [`insert`](#method.insert) for each of
+ /// them in order, which means that for keys that already existed
+ /// in the map, their value is updated but it keeps the existing order.
+ ///
+ /// New keys are inserted in the order they appear in the sequence. If
+ /// equivalents of a key occur more than once, the last corresponding value
+ /// prevails.
+ fn extend<I: IntoIterator<Item = (K, V)>>(&mut self, iterable: I) {
+ // (Note: this is a copy of `std`/`hashbrown`'s reservation logic.)
+ // 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 = iterable.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);
+ });
+ }
+}
+
+impl<'a, K, V, S> Extend<(&'a K, &'a V)> for IndexMap<K, V, S>
+where
+ K: Hash + Eq + Copy,
+ V: Copy,
+ S: BuildHasher,
+{
+ /// Extend the map with all key-value pairs in the iterable.
+ ///
+ /// See the first extend method for more details.
+ fn extend<I: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iterable: I) {
+ self.extend(iterable.into_iter().map(|(&key, &value)| (key, value)));
+ }
+}
+
+impl<K, V, S> Default for IndexMap<K, V, S>
+where
+ S: Default,
+{
+ /// Return an empty `IndexMap`
+ fn default() -> Self {
+ Self::with_capacity_and_hasher(0, S::default())
+ }
+}
+
+impl<K, V1, S1, V2, S2> PartialEq<IndexMap<K, V2, S2>> for IndexMap<K, V1, S1>
+where
+ K: Hash + Eq,
+ V1: PartialEq<V2>,
+ S1: BuildHasher,
+ S2: BuildHasher,
+{
+ fn eq(&self, other: &IndexMap<K, V2, S2>) -> 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> Eq for IndexMap<K, V, S>
+where
+ K: Eq + Hash,
+ V: Eq,
+ S: BuildHasher,
+{
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use std::string::String;
+
+ #[test]
+ fn it_works() {
+ let mut map = IndexMap::new();
+ assert_eq!(map.is_empty(), true);
+ map.insert(1, ());
+ map.insert(1, ());
+ assert_eq!(map.len(), 1);
+ assert!(map.get(&1).is_some());
+ assert_eq!(map.is_empty(), false);
+ }
+
+ #[test]
+ fn new() {
+ let map = IndexMap::<String, String>::new();
+ println!("{:?}", map);
+ assert_eq!(map.capacity(), 0);
+ assert_eq!(map.len(), 0);
+ assert_eq!(map.is_empty(), true);
+ }
+
+ #[test]
+ fn insert() {
+ let insert = [0, 4, 2, 12, 8, 7, 11, 5];
+ let not_present = [1, 3, 6, 9, 10];
+ let mut map = IndexMap::with_capacity(insert.len());
+
+ for (i, &elt) in insert.iter().enumerate() {
+ assert_eq!(map.len(), i);
+ map.insert(elt, elt);
+ assert_eq!(map.len(), i + 1);
+ assert_eq!(map.get(&elt), Some(&elt));
+ assert_eq!(map[&elt], elt);
+ }
+ println!("{:?}", map);
+
+ for &elt in &not_present {
+ assert!(map.get(&elt).is_none());
+ }
+ }
+
+ #[test]
+ fn insert_full() {
+ let insert = vec![9, 2, 7, 1, 4, 6, 13];
+ let present = vec![1, 6, 2];
+ let mut map = IndexMap::with_capacity(insert.len());
+
+ for (i, &elt) in insert.iter().enumerate() {
+ assert_eq!(map.len(), i);
+ let (index, existing) = map.insert_full(elt, elt);
+ assert_eq!(existing, None);
+ assert_eq!(Some(index), map.get_full(&elt).map(|x| x.0));
+ assert_eq!(map.len(), i + 1);
+ }
+
+ let len = map.len();
+ for &elt in &present {
+ let (index, existing) = map.insert_full(elt, elt);
+ assert_eq!(existing, Some(elt));
+ assert_eq!(Some(index), map.get_full(&elt).map(|x| x.0));
+ assert_eq!(map.len(), len);
+ }
+ }
+
+ #[test]
+ fn insert_2() {
+ let mut map = IndexMap::with_capacity(16);
+
+ let mut keys = vec![];
+ keys.extend(0..16);
+ keys.extend(if cfg!(miri) { 32..64 } else { 128..267 });
+
+ for &i in &keys {
+ let old_map = map.clone();
+ map.insert(i, ());
+ for key in old_map.keys() {
+ if map.get(key).is_none() {
+ println!("old_map: {:?}", old_map);
+ println!("map: {:?}", map);
+ panic!("did not find {} in map", key);
+ }
+ }
+ }
+
+ for &i in &keys {
+ assert!(map.get(&i).is_some(), "did not find {}", i);
+ }
+ }
+
+ #[test]
+ fn insert_order() {
+ let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
+ let mut map = IndexMap::new();
+
+ for &elt in &insert {
+ map.insert(elt, ());
+ }
+
+ assert_eq!(map.keys().count(), map.len());
+ assert_eq!(map.keys().count(), insert.len());
+ for (a, b) in insert.iter().zip(map.keys()) {
+ assert_eq!(a, b);
+ }
+ for (i, k) in (0..insert.len()).zip(map.keys()) {
+ assert_eq!(map.get_index(i).unwrap().0, k);
+ }
+ }
+
+ #[test]
+ fn grow() {
+ let insert = [0, 4, 2, 12, 8, 7, 11];
+ let not_present = [1, 3, 6, 9, 10];
+ let mut map = IndexMap::with_capacity(insert.len());
+
+ for (i, &elt) in insert.iter().enumerate() {
+ assert_eq!(map.len(), i);
+ map.insert(elt, elt);
+ assert_eq!(map.len(), i + 1);
+ assert_eq!(map.get(&elt), Some(&elt));
+ assert_eq!(map[&elt], elt);
+ }
+
+ println!("{:?}", map);
+ for &elt in &insert {
+ map.insert(elt * 10, elt);
+ }
+ for &elt in &insert {
+ map.insert(elt * 100, elt);
+ }
+ for (i, &elt) in insert.iter().cycle().enumerate().take(100) {
+ map.insert(elt * 100 + i as i32, elt);
+ }
+ println!("{:?}", map);
+ for &elt in &not_present {
+ assert!(map.get(&elt).is_none());
+ }
+ }
+
+ #[test]
+ fn reserve() {
+ let mut map = IndexMap::<usize, usize>::new();
+ assert_eq!(map.capacity(), 0);
+ map.reserve(100);
+ let capacity = map.capacity();
+ assert!(capacity >= 100);
+ for i in 0..capacity {
+ assert_eq!(map.len(), i);
+ map.insert(i, i * i);
+ assert_eq!(map.len(), i + 1);
+ assert_eq!(map.capacity(), capacity);
+ assert_eq!(map.get(&i), Some(&(i * i)));
+ }
+ map.insert(capacity, std::usize::MAX);
+ assert_eq!(map.len(), capacity + 1);
+ assert!(map.capacity() > capacity);
+ assert_eq!(map.get(&capacity), Some(&std::usize::MAX));
+ }
+
+ #[test]
+ fn shrink_to_fit() {
+ let mut map = IndexMap::<usize, usize>::new();
+ assert_eq!(map.capacity(), 0);
+ for i in 0..100 {
+ assert_eq!(map.len(), i);
+ map.insert(i, i * i);
+ assert_eq!(map.len(), i + 1);
+ assert!(map.capacity() >= i + 1);
+ assert_eq!(map.get(&i), Some(&(i * i)));
+ map.shrink_to_fit();
+ assert_eq!(map.len(), i + 1);
+ assert_eq!(map.capacity(), i + 1);
+ assert_eq!(map.get(&i), Some(&(i * i)));
+ }
+ }
+
+ #[test]
+ fn remove() {
+ let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
+ let mut map = IndexMap::new();
+
+ for &elt in &insert {
+ map.insert(elt, elt);
+ }
+
+ assert_eq!(map.keys().count(), map.len());
+ assert_eq!(map.keys().count(), insert.len());
+ for (a, b) in insert.iter().zip(map.keys()) {
+ assert_eq!(a, b);
+ }
+
+ let remove_fail = [99, 77];
+ let remove = [4, 12, 8, 7];
+
+ for &key in &remove_fail {
+ assert!(map.swap_remove_full(&key).is_none());
+ }
+ println!("{:?}", map);
+ for &key in &remove {
+ //println!("{:?}", map);
+ let index = map.get_full(&key).unwrap().0;
+ assert_eq!(map.swap_remove_full(&key), Some((index, key, key)));
+ }
+ println!("{:?}", map);
+
+ for key in &insert {
+ assert_eq!(map.get(key).is_some(), !remove.contains(key));
+ }
+ assert_eq!(map.len(), insert.len() - remove.len());
+ assert_eq!(map.keys().count(), insert.len() - remove.len());
+ }
+
+ #[test]
+ fn remove_to_empty() {
+ let mut map = indexmap! { 0 => 0, 4 => 4, 5 => 5 };
+ map.swap_remove(&5).unwrap();
+ map.swap_remove(&4).unwrap();
+ map.swap_remove(&0).unwrap();
+ assert!(map.is_empty());
+ }
+
+ #[test]
+ fn swap_remove_index() {
+ let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
+ let mut map = IndexMap::new();
+
+ for &elt in &insert {
+ map.insert(elt, elt * 2);
+ }
+
+ let mut vector = insert.to_vec();
+ let remove_sequence = &[3, 3, 10, 4, 5, 4, 3, 0, 1];
+
+ // check that the same swap remove sequence on vec and map
+ // have the same result.
+ for &rm in remove_sequence {
+ let out_vec = vector.swap_remove(rm);
+ let (out_map, _) = map.swap_remove_index(rm).unwrap();
+ assert_eq!(out_vec, out_map);
+ }
+ assert_eq!(vector.len(), map.len());
+ for (a, b) in vector.iter().zip(map.keys()) {
+ assert_eq!(a, b);
+ }
+ }
+
+ #[test]
+ fn partial_eq_and_eq() {
+ let mut map_a = IndexMap::new();
+ map_a.insert(1, "1");
+ map_a.insert(2, "2");
+ let mut map_b = map_a.clone();
+ assert_eq!(map_a, map_b);
+ map_b.swap_remove(&1);
+ assert_ne!(map_a, map_b);
+
+ let map_c: IndexMap<_, String> = map_b.into_iter().map(|(k, v)| (k, v.into())).collect();
+ assert_ne!(map_a, map_c);
+ assert_ne!(map_c, map_a);
+ }
+
+ #[test]
+ fn extend() {
+ let mut map = IndexMap::new();
+ map.extend(vec![(&1, &2), (&3, &4)]);
+ map.extend(vec![(5, 6)]);
+ assert_eq!(
+ map.into_iter().collect::<Vec<_>>(),
+ vec![(1, 2), (3, 4), (5, 6)]
+ );
+ }
+
+ #[test]
+ fn entry() {
+ let mut map = IndexMap::new();
+
+ map.insert(1, "1");
+ map.insert(2, "2");
+ {
+ let e = map.entry(3);
+ assert_eq!(e.index(), 2);
+ let e = e.or_insert("3");
+ assert_eq!(e, &"3");
+ }
+
+ let e = map.entry(2);
+ assert_eq!(e.index(), 1);
+ assert_eq!(e.key(), &2);
+ match e {
+ Entry::Occupied(ref e) => assert_eq!(e.get(), &"2"),
+ Entry::Vacant(_) => panic!(),
+ }
+ assert_eq!(e.or_insert("4"), &"2");
+ }
+
+ #[test]
+ fn entry_and_modify() {
+ let mut map = IndexMap::new();
+
+ map.insert(1, "1");
+ map.entry(1).and_modify(|x| *x = "2");
+ assert_eq!(Some(&"2"), map.get(&1));
+
+ map.entry(2).and_modify(|x| *x = "doesn't exist");
+ assert_eq!(None, map.get(&2));
+ }
+
+ #[test]
+ fn entry_or_default() {
+ let mut map = IndexMap::new();
+
+ #[derive(Debug, PartialEq)]
+ enum TestEnum {
+ DefaultValue,
+ NonDefaultValue,
+ }
+
+ impl Default for TestEnum {
+ fn default() -> Self {
+ TestEnum::DefaultValue
+ }
+ }
+
+ map.insert(1, TestEnum::NonDefaultValue);
+ assert_eq!(&mut TestEnum::NonDefaultValue, map.entry(1).or_default());
+
+ assert_eq!(&mut TestEnum::DefaultValue, map.entry(2).or_default());
+ }
+
+ #[test]
+ fn occupied_entry_key() {
+ // These keys match hash and equality, but their addresses are distinct.
+ let (k1, k2) = (&mut 1, &mut 1);
+ let k1_ptr = k1 as *const i32;
+ let k2_ptr = k2 as *const i32;
+ assert_ne!(k1_ptr, k2_ptr);
+
+ let mut map = IndexMap::new();
+ map.insert(k1, "value");
+ match map.entry(k2) {
+ Entry::Occupied(ref e) => {
+ // `OccupiedEntry::key` should reference the key in the map,
+ // not the key that was used to find the entry.
+ let ptr = *e.key() as *const i32;
+ assert_eq!(ptr, k1_ptr);
+ assert_ne!(ptr, k2_ptr);
+ }
+ Entry::Vacant(_) => panic!(),
+ }
+ }
+
+ #[test]
+ fn keys() {
+ let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
+ let map: IndexMap<_, _> = 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 into_keys() {
+ let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
+ let map: IndexMap<_, _> = vec.into_iter().collect();
+ let keys: Vec<i32> = map.into_keys().collect();
+ assert_eq!(keys.len(), 3);
+ assert!(keys.contains(&1));
+ assert!(keys.contains(&2));
+ assert!(keys.contains(&3));
+ }
+
+ #[test]
+ fn values() {
+ let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
+ let map: IndexMap<_, _> = 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 values_mut() {
+ let vec = vec![(1, 1), (2, 2), (3, 3)];
+ let mut map: IndexMap<_, _> = 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 into_values() {
+ let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
+ let map: IndexMap<_, _> = vec.into_iter().collect();
+ let values: Vec<char> = map.into_values().collect();
+ assert_eq!(values.len(), 3);
+ assert!(values.contains(&'a'));
+ assert!(values.contains(&'b'));
+ assert!(values.contains(&'c'));
+ }
+
+ #[test]
+ #[cfg(has_std)]
+ fn from_array() {
+ let map = IndexMap::from([(1, 2), (3, 4)]);
+ let mut expected = IndexMap::new();
+ expected.insert(1, 2);
+ expected.insert(3, 4);
+
+ assert_eq!(map, expected)
+ }
+}