Type Alias SupportMap

pub type SupportMap<A> = BTreeMap<A, Support<A>>;

Linkage from a winner to their Support.

This is more helpful than a normal Supports as it allows faster error checking.

Aliased Type

struct SupportMap<A> { /* private fields */ }

Implementations

impl<K, V> BTreeMap<K, V>

pub const fn new() -> BTreeMap<K, V>

Makes a new, empty BTreeMap.

Does not allocate anything on its own.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();

// entries can now be inserted into the empty map
map.insert(1, "a");

impl<K, V, A> BTreeMap<K, V, A>

where A: Allocator + Clone,

pub fn iter(&self) -> Iter<'_, K, V>

Gets an iterator over the entries of the map, sorted by key.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(3, "c");
map.insert(2, "b");
map.insert(1, "a");

for (key, value) in map.iter() {
    println!("{key}: {value}");
}

let (first_key, first_value) = map.iter().next().unwrap();
assert_eq!((*first_key, *first_value), (1, "a"));

pub fn iter_mut(&mut self) -> IterMut<'_, K, V>

Gets a mutable iterator over the entries of the map, sorted by key.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::from([
   ("a", 1),
   ("b", 2),
   ("c", 3),
]);

// add 10 to the value if the key isn't "a"
for (key, value) in map.iter_mut() {
    if key != &"a" {
        *value += 10;
    }
}

pub fn keys(&self) -> Keys<'_, K, V>

Gets an iterator over the keys of the map, in sorted order.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(2, "b");
a.insert(1, "a");

let keys: Vec<_> = a.keys().cloned().collect();
assert_eq!(keys, [1, 2]);

pub fn values(&self) -> Values<'_, K, V>

Gets an iterator over the values of the map, in order by key.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, "hello");
a.insert(2, "goodbye");

let values: Vec<&str> = a.values().cloned().collect();
assert_eq!(values, ["hello", "goodbye"]);

pub fn values_mut(&mut self) -> ValuesMut<'_, K, V>

Gets a mutable iterator over the values of the map, in order by key.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, String::from("hello"));
a.insert(2, String::from("goodbye"));

for value in a.values_mut() {
    value.push_str("!");
}

let values: Vec<String> = a.values().cloned().collect();
assert_eq!(values, [String::from("hello!"),
                    String::from("goodbye!")]);

pub fn len(&self) -> usize

Returns the number of elements in the map.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
assert_eq!(a.len(), 0);
a.insert(1, "a");
assert_eq!(a.len(), 1);

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
assert!(a.is_empty());
a.insert(1, "a");
assert!(!a.is_empty());

pub fn lower_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

🔬This is a nightly-only experimental API. (btree_cursors)

Returns a Cursor pointing at the gap before the smallest key greater than the given bound.

Passing Bound::Included(x) will return a cursor pointing to the gap before the smallest key greater than or equal to x.

Passing Bound::Excluded(x) will return a cursor pointing to the gap before the smallest key greater than x.

Passing Bound::Unbounded will return a cursor pointing to the gap before the smallest key in the map.

Examples

#![feature(btree_cursors)]

use std::collections::BTreeMap;
use std::ops::Bound;

let map = BTreeMap::from([
    (1, "a"),
    (2, "b"),
    (3, "c"),
    (4, "d"),
]);

let cursor = map.lower_bound(Bound::Included(&2));
assert_eq!(cursor.peek_prev(), Some((&1, &"a")));
assert_eq!(cursor.peek_next(), Some((&2, &"b")));

let cursor = map.lower_bound(Bound::Excluded(&2));
assert_eq!(cursor.peek_prev(), Some((&2, &"b")));
assert_eq!(cursor.peek_next(), Some((&3, &"c")));

let cursor = map.lower_bound(Bound::Unbounded);
assert_eq!(cursor.peek_prev(), None);
assert_eq!(cursor.peek_next(), Some((&1, &"a")));

pub fn lower_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

🔬This is a nightly-only experimental API. (btree_cursors)

Returns a CursorMut pointing at the gap before the smallest key greater than the given bound.

Passing Bound::Included(x) will return a cursor pointing to the gap before the smallest key greater than or equal to x.

Passing Bound::Excluded(x) will return a cursor pointing to the gap before the smallest key greater than x.

Passing Bound::Unbounded will return a cursor pointing to the gap before the smallest key in the map.

Examples

#![feature(btree_cursors)]

use std::collections::BTreeMap;
use std::ops::Bound;

let mut map = BTreeMap::from([
    (1, "a"),
    (2, "b"),
    (3, "c"),
    (4, "d"),
]);

let mut cursor = map.lower_bound_mut(Bound::Included(&2));
assert_eq!(cursor.peek_prev(), Some((&1, &mut "a")));
assert_eq!(cursor.peek_next(), Some((&2, &mut "b")));

let mut cursor = map.lower_bound_mut(Bound::Excluded(&2));
assert_eq!(cursor.peek_prev(), Some((&2, &mut "b")));
assert_eq!(cursor.peek_next(), Some((&3, &mut "c")));

let mut cursor = map.lower_bound_mut(Bound::Unbounded);
assert_eq!(cursor.peek_prev(), None);
assert_eq!(cursor.peek_next(), Some((&1, &mut "a")));

pub fn upper_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

🔬This is a nightly-only experimental API. (btree_cursors)

Returns a Cursor pointing at the gap after the greatest key smaller than the given bound.

Passing Bound::Included(x) will return a cursor pointing to the gap after the greatest key smaller than or equal to x.

Passing Bound::Excluded(x) will return a cursor pointing to the gap after the greatest key smaller than x.

Passing Bound::Unbounded will return a cursor pointing to the gap after the greatest key in the map.

Examples

#![feature(btree_cursors)]

use std::collections::BTreeMap;
use std::ops::Bound;

let map = BTreeMap::from([
    (1, "a"),
    (2, "b"),
    (3, "c"),
    (4, "d"),
]);

let cursor = map.upper_bound(Bound::Included(&3));
assert_eq!(cursor.peek_prev(), Some((&3, &"c")));
assert_eq!(cursor.peek_next(), Some((&4, &"d")));

let cursor = map.upper_bound(Bound::Excluded(&3));
assert_eq!(cursor.peek_prev(), Some((&2, &"b")));
assert_eq!(cursor.peek_next(), Some((&3, &"c")));

let cursor = map.upper_bound(Bound::Unbounded);
assert_eq!(cursor.peek_prev(), Some((&4, &"d")));
assert_eq!(cursor.peek_next(), None);

pub fn upper_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

🔬This is a nightly-only experimental API. (btree_cursors)

Returns a CursorMut pointing at the gap after the greatest key smaller than the given bound.

Passing Bound::Included(x) will return a cursor pointing to the gap after the greatest key smaller than or equal to x.

Passing Bound::Excluded(x) will return a cursor pointing to the gap after the greatest key smaller than x.

Passing Bound::Unbounded will return a cursor pointing to the gap after the greatest key in the map.

Examples

#![feature(btree_cursors)]

use std::collections::BTreeMap;
use std::ops::Bound;

let mut map = BTreeMap::from([
    (1, "a"),
    (2, "b"),
    (3, "c"),
    (4, "d"),
]);

let mut cursor = map.upper_bound_mut(Bound::Included(&3));
assert_eq!(cursor.peek_prev(), Some((&3, &mut "c")));
assert_eq!(cursor.peek_next(), Some((&4, &mut "d")));

let mut cursor = map.upper_bound_mut(Bound::Excluded(&3));
assert_eq!(cursor.peek_prev(), Some((&2, &mut "b")));
assert_eq!(cursor.peek_next(), Some((&3, &mut "c")));

let mut cursor = map.upper_bound_mut(Bound::Unbounded);
assert_eq!(cursor.peek_prev(), Some((&4, &mut "d")));
assert_eq!(cursor.peek_next(), None);

impl<K, V, A> BTreeMap<K, V, A>

where A: Allocator + Clone,

pub fn clear(&mut self)

Clears the map, removing all elements.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.clear();
assert!(a.is_empty());

pub const fn new_in(alloc: A) -> BTreeMap<K, V, A>

🔬This is a nightly-only experimental API. (btreemap_alloc)

Makes a new empty BTreeMap with a reasonable choice for B.

Examples

use std::collections::BTreeMap;
use std::alloc::Global;

let mut map = BTreeMap::new_in(Global);

// entries can now be inserted into the empty map
map.insert(1, "a");

impl<K, V, A> BTreeMap<K, V, A>

where A: Allocator + Clone,

pub fn get<Q>(&self, key: &Q) -> Option<&V>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Returns a reference to the value corresponding to the key.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.get(&1), Some(&"a"));
assert_eq!(map.get(&2), None);

pub fn get_key_value<Q>(&self, k: &Q) -> Option<(&K, &V)>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Returns the key-value pair corresponding to the supplied key. This is potentially useful:

• for key types where non-identical keys can be considered equal;
• for getting the &K stored key value from a borrowed &Q lookup key; or
• for getting a reference to a key with the same lifetime as the collection.

The supplied key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use std::cmp::Ordering;
use std::collections::BTreeMap;

#[derive(Clone, Copy, Debug)]
struct S {
    id: u32,
    name: &'static str, // ignored by equality and ordering operations
}

impl PartialEq for S {
    fn eq(&self, other: &S) -> bool {
        self.id == other.id
    }
}

impl Eq for S {}

impl PartialOrd for S {
    fn partial_cmp(&self, other: &S) -> Option<Ordering> {
        self.id.partial_cmp(&other.id)
    }
}

impl Ord for S {
    fn cmp(&self, other: &S) -> Ordering {
        self.id.cmp(&other.id)
    }
}

let j_a = S { id: 1, name: "Jessica" };
let j_b = S { id: 1, name: "Jess" };
let p = S { id: 2, name: "Paul" };
assert_eq!(j_a, j_b);

let mut map = BTreeMap::new();
map.insert(j_a, "Paris");
assert_eq!(map.get_key_value(&j_a), Some((&j_a, &"Paris")));
assert_eq!(map.get_key_value(&j_b), Some((&j_a, &"Paris"))); // the notable case
assert_eq!(map.get_key_value(&p), None);

pub fn first_key_value(&self) -> Option<(&K, &V)>

where K: Ord,

Returns the first key-value pair in the map. The key in this pair is the minimum key in the map.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
assert_eq!(map.first_key_value(), None);
map.insert(1, "b");
map.insert(2, "a");
assert_eq!(map.first_key_value(), Some((&1, &"b")));

pub fn first_entry(&mut self) -> Option<OccupiedEntry<'_, K, V, A>>

where K: Ord,

Returns the first entry in the map for in-place manipulation. The key of this entry is the minimum key in the map.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
map.insert(2, "b");
if let Some(mut entry) = map.first_entry() {
    if *entry.key() > 0 {
        entry.insert("first");
    }
}
assert_eq!(*map.get(&1).unwrap(), "first");
assert_eq!(*map.get(&2).unwrap(), "b");

pub fn pop_first(&mut self) -> Option<(K, V)>

where K: Ord,

Removes and returns the first element in the map. The key of this element is the minimum key that was in the map.

Examples

Draining elements in ascending order, while keeping a usable map each iteration.

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
map.insert(2, "b");
while let Some((key, _val)) = map.pop_first() {
    assert!(map.iter().all(|(k, _v)| *k > key));
}
assert!(map.is_empty());

pub fn last_key_value(&self) -> Option<(&K, &V)>

where K: Ord,

Returns the last key-value pair in the map. The key in this pair is the maximum key in the map.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "b");
map.insert(2, "a");
assert_eq!(map.last_key_value(), Some((&2, &"a")));

pub fn last_entry(&mut self) -> Option<OccupiedEntry<'_, K, V, A>>

where K: Ord,

Returns the last entry in the map for in-place manipulation. The key of this entry is the maximum key in the map.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
map.insert(2, "b");
if let Some(mut entry) = map.last_entry() {
    if *entry.key() > 0 {
        entry.insert("last");
    }
}
assert_eq!(*map.get(&1).unwrap(), "a");
assert_eq!(*map.get(&2).unwrap(), "last");

pub fn pop_last(&mut self) -> Option<(K, V)>

where K: Ord,

Removes and returns the last element in the map. The key of this element is the maximum key that was in the map.

Examples

Draining elements in descending order, while keeping a usable map each iteration.

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
map.insert(2, "b");
while let Some((key, _val)) = map.pop_last() {
    assert!(map.iter().all(|(k, _v)| *k < key));
}
assert!(map.is_empty());

pub fn contains_key<Q>(&self, key: &Q) -> bool

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

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 the ordering on the borrowed form must match the ordering on the key type.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.contains_key(&1), true);
assert_eq!(map.contains_key(&2), false);

pub fn get_mut<Q>(&mut self, key: &Q) -> Option<&mut V>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

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 the ordering on the borrowed form must match the ordering on the key type.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
if let Some(x) = map.get_mut(&1) {
    *x = "b";
}
assert_eq!(map[&1], "b");

pub fn insert(&mut self, key: K, value: V) -> Option<V>

where K: Ord,

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 module-level documentation for more.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::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");

pub fn try_insert( &mut self, key: K, value: V, ) -> Result<&mut V, OccupiedError<'_, K, V, A>>

where K: Ord,

🔬This is a nightly-only experimental API. (map_try_insert)

Tries to insert a key-value pair into the map, and returns a mutable reference to the value in the entry.

If the map already had this key present, nothing is updated, and an error containing the occupied entry and the value is returned.

Examples

#![feature(map_try_insert)]

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
assert_eq!(map.try_insert(37, "a").unwrap(), &"a");

let err = map.try_insert(37, "b").unwrap_err();
assert_eq!(err.entry.key(), &37);
assert_eq!(err.entry.get(), &"a");
assert_eq!(err.value, "b");

pub fn remove<Q>(&mut self, key: &Q) -> Option<V>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Removes a key from the map, returning the value at the key if the key was previously in the map.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.remove(&1), Some("a"));
assert_eq!(map.remove(&1), None);

pub fn remove_entry<Q>(&mut self, key: &Q) -> Option<(K, V)>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Removes a key from the map, returning the stored key and value if the key was previously in the map.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.remove_entry(&1), Some((1, "a")));
assert_eq!(map.remove_entry(&1), None);

pub fn retain<F>(&mut self, f: F)

where K: Ord, F: FnMut(&K, &mut V) -> bool,

Retains only the elements specified by the predicate.

In other words, remove all pairs (k, v) for which f(&k, &mut v) returns false. The elements are visited in ascending key order.

Examples

use std::collections::BTreeMap;

let mut map: BTreeMap<i32, i32> = (0..8).map(|x| (x, x*10)).collect();
// Keep only the elements with even-numbered keys.
map.retain(|&k, _| k % 2 == 0);
assert!(map.into_iter().eq(vec![(0, 0), (2, 20), (4, 40), (6, 60)]));

pub fn append(&mut self, other: &mut BTreeMap<K, V, A>)

where K: Ord, A: Clone,

Moves all elements from other into self, leaving other empty.

If a key from other is already present in self, the respective value from self will be overwritten with the respective value from other.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c"); // Note: Key (3) also present in b.

let mut b = BTreeMap::new();
b.insert(3, "d"); // Note: Key (3) also present in a.
b.insert(4, "e");
b.insert(5, "f");

a.append(&mut b);

assert_eq!(a.len(), 5);
assert_eq!(b.len(), 0);

assert_eq!(a[&1], "a");
assert_eq!(a[&2], "b");
assert_eq!(a[&3], "d"); // Note: "c" has been overwritten.
assert_eq!(a[&4], "e");
assert_eq!(a[&5], "f");

pub fn range<T, R>(&self, range: R) -> Range<'_, K, V>

where T: Ord + ?Sized, K: Borrow<T> + Ord, R: RangeBounds<T>,

Constructs a double-ended iterator over a sub-range of elements in the map. The simplest way is to use the range syntax min..max, thus range(min..max) will yield elements from min (inclusive) to max (exclusive). The range may also be entered as (Bound<T>, Bound<T>), so for example range((Excluded(4), Included(10))) will yield a left-exclusive, right-inclusive range from 4 to 10.

Panics

Panics if range start > end. Panics if range start == end and both bounds are Excluded.

Examples

use std::collections::BTreeMap;
use std::ops::Bound::Included;

let mut map = BTreeMap::new();
map.insert(3, "a");
map.insert(5, "b");
map.insert(8, "c");
for (&key, &value) in map.range((Included(&4), Included(&8))) {
    println!("{key}: {value}");
}
assert_eq!(Some((&5, &"b")), map.range(4..).next());

pub fn range_mut<T, R>(&mut self, range: R) -> RangeMut<'_, K, V>

where T: Ord + ?Sized, K: Borrow<T> + Ord, R: RangeBounds<T>,

Constructs a mutable double-ended iterator over a sub-range of elements in the map. The simplest way is to use the range syntax min..max, thus range(min..max) will yield elements from min (inclusive) to max (exclusive). The range may also be entered as (Bound<T>, Bound<T>), so for example range((Excluded(4), Included(10))) will yield a left-exclusive, right-inclusive range from 4 to 10.

Panics

Panics if range start > end. Panics if range start == end and both bounds are Excluded.

Examples

use std::collections::BTreeMap;

let mut map: BTreeMap<&str, i32> =
    [("Alice", 0), ("Bob", 0), ("Carol", 0), ("Cheryl", 0)].into();
for (_, balance) in map.range_mut("B".."Cheryl") {
    *balance += 100;
}
for (name, balance) in &map {
    println!("{name} => {balance}");
}

pub fn entry(&mut self, key: K) -> Entry<'_, K, V, A>

where K: Ord,

Gets the given key’s corresponding entry in the map for in-place manipulation.

Examples

use std::collections::BTreeMap;

let mut count: BTreeMap<&str, usize> = BTreeMap::new();

// count the number of occurrences of letters in the vec
for x in ["a", "b", "a", "c", "a", "b"] {
    count.entry(x).and_modify(|curr| *curr += 1).or_insert(1);
}

assert_eq!(count["a"], 3);
assert_eq!(count["b"], 2);
assert_eq!(count["c"], 1);

pub fn split_off<Q>(&mut self, key: &Q) -> BTreeMap<K, V, A>

where Q: Ord + ?Sized, K: Borrow<Q> + Ord, A: Clone,

Splits the collection into two at the given key. Returns everything after the given key, including the key.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(17, "d");
a.insert(41, "e");

let b = a.split_off(&3);

assert_eq!(a.len(), 2);
assert_eq!(b.len(), 3);

assert_eq!(a[&1], "a");
assert_eq!(a[&2], "b");

assert_eq!(b[&3], "c");
assert_eq!(b[&17], "d");
assert_eq!(b[&41], "e");

pub fn extract_if<F>(&mut self, pred: F) -> ExtractIf<'_, K, V, F, A>

where K: Ord, F: FnMut(&K, &mut V) -> bool,

🔬This is a nightly-only experimental API. (btree_extract_if)

Creates an iterator that visits all elements (key-value pairs) in ascending key order and uses a closure to determine if an element should be removed. If the closure returns true, the element is removed from the map and yielded. If the closure returns false, or panics, the element remains in the map and will not be yielded.

The iterator also lets you mutate the value of each element in the 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.

Examples

Splitting a map into even and odd keys, reusing the original map:

#![feature(btree_extract_if)]
use std::collections::BTreeMap;

let mut map: BTreeMap<i32, i32> = (0..8).map(|x| (x, x)).collect();
let evens: BTreeMap<_, _> = map.extract_if(|k, _v| k % 2 == 0).collect();
let odds = map;
assert_eq!(evens.keys().copied().collect::<Vec<_>>(), [0, 2, 4, 6]);
assert_eq!(odds.keys().copied().collect::<Vec<_>>(), [1, 3, 5, 7]);

pub fn into_keys(self) -> IntoKeys<K, V, A>

Creates a consuming iterator visiting all the keys, in sorted order. The map cannot be used after calling this. The iterator element type is K.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(2, "b");
a.insert(1, "a");

let keys: Vec<i32> = a.into_keys().collect();
assert_eq!(keys, [1, 2]);

pub fn into_values(self) -> IntoValues<K, V, A>

Creates a consuming iterator visiting all the values, in order by key. The map cannot be used after calling this. The iterator element type is V.

Examples

use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, "hello");
a.insert(2, "goodbye");

let values: Vec<&str> = a.into_values().collect();
assert_eq!(values, ["hello", "goodbye"]);

Trait Implementations

impl<K, V> AggregatePublicKey for BTreeMap<K, V>

where K: Borrow<PublicKey> + Ord,

fn weighting(&self, choice: &PublicKey) -> Option<Scalar>

👎Deprecated since 0.11.0: This module will be replaced in the future

Return delinearization weighting for one of many public keys being aggregated.

fn public_key(&self) -> PublicKey

👎Deprecated since 0.11.0: This module will be replaced in the future

Returns aggregated public key.

impl<'a, K, V> Arbitrary<'a> for BTreeMap<K, V>

where K: Arbitrary<'a> + Ord, V: Arbitrary<'a>,

fn arbitrary(u: &mut Unstructured<'a>) -> Result<BTreeMap<K, V>, Error>

Generate an arbitrary value of Self from the given unstructured data.

fn arbitrary_take_rest(u: Unstructured<'a>) -> Result<BTreeMap<K, V>, Error>

Generate an arbitrary value of Self from the entirety of the given unstructured data.

fn size_hint(_depth: usize) -> (usize, Option<usize>)

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself.

impl<K, V> CanonicalDeserialize for BTreeMap<K, V>

where K: Ord + CanonicalDeserialize, V: CanonicalDeserialize,

fn deserialize_with_mode<R>( reader: R, compress: Compress, validate: Validate, ) -> Result<BTreeMap<K, V>, SerializationError>

where R: Read,

Deserializes a BTreeMap from len(map) || key 1 || value 1 || ... || key n || value n.

fn deserialize_compressed<R>(reader: R) -> Result<Self, SerializationError>

where R: Read,

fn deserialize_compressed_unchecked<R>( reader: R, ) -> Result<Self, SerializationError>

where R: Read,

fn deserialize_uncompressed<R>(reader: R) -> Result<Self, SerializationError>

where R: Read,

fn deserialize_uncompressed_unchecked<R>( reader: R, ) -> Result<Self, SerializationError>

where R: Read,

impl<K, V> CanonicalDeserialize for BTreeMap<K, V>

where K: Ord + CanonicalDeserialize, V: CanonicalDeserialize,

fn deserialize_with_mode<R>( reader: R, compress: Compress, validate: Validate, ) -> Result<BTreeMap<K, V>, SerializationError>

where R: Read,

Deserializes a BTreeMap from len(map) || key 1 || value 1 || ... || key n || value n.

fn deserialize_compressed<R>(reader: R) -> Result<Self, SerializationError>

where R: Read,

fn deserialize_compressed_unchecked<R>( reader: R, ) -> Result<Self, SerializationError>

where R: Read,

fn deserialize_uncompressed<R>(reader: R) -> Result<Self, SerializationError>

where R: Read,

fn deserialize_uncompressed_unchecked<R>( reader: R, ) -> Result<Self, SerializationError>

where R: Read,

impl<K, V> CanonicalSerialize for BTreeMap<K, V>

where K: CanonicalSerialize, V: CanonicalSerialize,

fn serialize_with_mode<W>( &self, writer: W, compress: Compress, ) -> Result<(), SerializationError>

where W: Write,

Serializes a BTreeMap as len(map) || key 1 || value 1 || ... || key n || value n.

fn serialized_size(&self, compress: Compress) -> usize

fn serialize_compressed<W>(&self, writer: W) -> Result<(), SerializationError>

where W: Write,

fn compressed_size(&self) -> usize

fn serialize_uncompressed<W>(&self, writer: W) -> Result<(), SerializationError>

where W: Write,

fn uncompressed_size(&self) -> usize

impl<K, V> CanonicalSerialize for BTreeMap<K, V>

where K: CanonicalSerialize, V: CanonicalSerialize,

fn serialize_with_mode<W>( &self, writer: W, compress: Compress, ) -> Result<(), SerializationError>

where W: Write,

Serializes a BTreeMap as len(map) || key 1 || value 1 || ... || key n || value n.

fn serialized_size(&self, compress: Compress) -> usize

fn serialize_compressed<W>(&self, writer: W) -> Result<(), SerializationError>

where W: Write,

fn compressed_size(&self) -> usize

fn serialize_uncompressed<W>(&self, writer: W) -> Result<(), SerializationError>

where W: Write,

fn uncompressed_size(&self) -> usize

impl<K, V, A> Clone for BTreeMap<K, V, A>

where K: Clone, V: Clone, A: Allocator + Clone,

fn clone(&self) -> BTreeMap<K, V, A>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<K, V, A> Debug for BTreeMap<K, V, A>

where K: Debug, V: Debug, A: Allocator + Clone,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<K, V> Decode for BTreeMap<K, V>

where K: Decode + Ord, V: Decode,

fn decode<I>(input: &mut I) -> Result<BTreeMap<K, V>, Error>

where I: Input,

Attempt to deserialise the value from input.

fn decode_into<I>( input: &mut I, dst: &mut MaybeUninit<Self>, ) -> Result<DecodeFinished, Error>

where I: Input,

Attempt to deserialize the value from input into a pre-allocated piece of memory.

fn skip<I>(input: &mut I) -> Result<(), Error>

where I: Input,

Attempt to skip the encoded value from input.

fn encoded_fixed_size() -> Option<usize>

Returns the fixed encoded size of the type.

impl<K, V> DecodeLength for BTreeMap<K, V>

fn len(self_encoded: &[u8]) -> Result<usize, Error>

Return the number of elements in self_encoded.

impl<K, V> Default for BTreeMap<K, V>

fn default() -> BTreeMap<K, V>

Creates an empty BTreeMap.

impl<'de, K, V> Deserialize<'de> for BTreeMap<K, V>

where K: Deserialize<'de> + Ord, V: Deserialize<'de>,

fn deserialize<D>( deserializer: D, ) -> Result<BTreeMap<K, V>, <D as Deserializer<'de>>::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<K, V, A> Drop for BTreeMap<K, V, A>

where A: Allocator + Clone,

fn drop(&mut self)

Executes the destructor for this type.

impl<K, V> Encode for BTreeMap<K, V>

where K: Encode, V: Encode,

fn size_hint(&self) -> usize

If possible give a hint of expected size of the encoding.

fn encode_to<W>(&self, dest: &mut W)

where W: Output + ?Sized,

Convert self to a slice and append it to the destination.

fn encode(&self) -> Vec<u8>

Convert self to an owned vector.

fn using_encoded<R, F>(&self, f: F) -> R

where F: FnOnce(&[u8]) -> R,

Convert self to a slice and then invoke the given closure with it.

fn encoded_size(&self) -> usize

Calculates the encoded size.

impl<'a, K, V, A> Extend<(&'a K, &'a V)> for BTreeMap<K, V, A>

where K: Ord + Copy, V: Copy, A: Allocator + Clone,

fn extend<I>(&mut self, iter: I)

where I: IntoIterator<Item = (&'a K, &'a V)>,

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, _: (&'a K, &'a V))

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<K, V, A> Extend<(K, V)> for BTreeMap<K, V, A>

where K: Ord, A: Allocator + Clone,

fn extend<T>(&mut self, iter: T)

where T: IntoIterator<Item = (K, V)>,

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, _: (K, V))

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<K, V, const N: usize> From<[(K, V); N]> for BTreeMap<K, V>

where K: Ord,

fn from(arr: [(K, V); N]) -> BTreeMap<K, V>

Converts a [(K, V); N] into a BTreeMap<(K, V)>.

use std::collections::BTreeMap;

let map1 = BTreeMap::from([(1, 2), (3, 4)]);
let map2: BTreeMap<_, _> = [(1, 2), (3, 4)].into();
assert_eq!(map1, map2);

impl<K, V, S> From<BoundedBTreeMap<K, V, S>> for BTreeMap<K, V>

where K: Ord,

fn from(map: BoundedBTreeMap<K, V, S>) -> BTreeMap<K, V>

Converts to this type from the input type.

impl<K, V> FromFallibleIterator<(K, V)> for BTreeMap<K, V>

where K: Ord,

fn from_fallible_iter<I>( it: I, ) -> Result<BTreeMap<K, V>, <I as IntoFallibleIterator>::Error>

where I: IntoFallibleIterator<Item = (K, V)>,

Creates a value from a fallible iterator.

impl<K, V> FromIterator<(K, V)> for BTreeMap<K, V>

where K: Ord,

fn from_iter<T>(iter: T) -> BTreeMap<K, V>

where T: IntoIterator<Item = (K, V)>,

Creates a value from an iterator.

impl<K, V> FromParallelIterator<(K, V)> for BTreeMap<K, V>

where K: Ord + Send, V: Send,

Collects (key, value) pairs from a parallel iterator into a btreemap. If multiple pairs correspond to the same key, then the ones produced earlier in the parallel iterator will be overwritten, just as with a sequential iterator.

fn from_par_iter<I>(par_iter: I) -> BTreeMap<K, V>

where I: IntoParallelIterator<Item = (K, V)>,

Creates an instance of the collection from the parallel iterator par_iter.

impl<K, V, A> Hash for BTreeMap<K, V, A>

where K: Hash, V: Hash, A: Allocator + Clone,

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<K, Q, V, A> Index<&Q> for BTreeMap<K, V, A>

where A: Allocator + Clone, K: Borrow<Q> + Ord, Q: Ord + ?Sized,

fn index(&self, key: &Q) -> &V

Returns a reference to the value corresponding to the supplied key.

Panics

Panics if the key is not present in the BTreeMap.

type Output = V

The returned type after indexing.

impl<'de, K, V, E> IntoDeserializer<'de, E> for BTreeMap<K, V>

where K: IntoDeserializer<'de, E> + Eq + Ord, V: IntoDeserializer<'de, E>, E: Error,

type Deserializer = MapDeserializer<'de, <BTreeMap<K, V> as IntoIterator>::IntoIter, E>

The type of the deserializer being converted into.

fn into_deserializer( self, ) -> <BTreeMap<K, V> as IntoDeserializer<'de, E>>::Deserializer

Convert this value into a deserializer.

impl<K, V, A> IntoIterator for BTreeMap<K, V, A>

where A: Allocator + Clone,

fn into_iter(self) -> IntoIter<K, V, A>

Gets an owning iterator over the entries of the map, sorted by key.

type Item = (K, V)

The type of the elements being iterated over.

type IntoIter = IntoIter<K, V, A>

Which kind of iterator are we turning this into?

impl<K, V> IntoParallelIterator for BTreeMap<K, V>

where K: Ord + Send, V: Send,

type Item = <BTreeMap<K, V> as IntoIterator>::Item

The type of item that the parallel iterator will produce.

type Iter = IntoIter<K, V>

The parallel iterator type that will be created.

fn into_par_iter(self) -> <BTreeMap<K, V> as IntoParallelIterator>::Iter

Converts self into a parallel iterator.

impl<K, V> JsonSchema for BTreeMap<K, V>

where V: JsonSchema,

fn is_referenceable() -> bool

Whether JSON Schemas generated for this type should be re-used where possible using the $ref keyword.

fn schema_name() -> String

The name of the generated JSON Schema.

fn json_schema(gen: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

impl<K, V, A> Ord for BTreeMap<K, V, A>

where K: Ord, V: Ord, A: Allocator + Clone,

fn cmp(&self, other: &BTreeMap<K, V, A>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<'a, K, V> ParallelExtend<(&'a K, &'a V)> for BTreeMap<K, V>

where K: 'a + Copy + Ord + Send + Sync, V: 'a + Copy + Send + Sync,

Extends a B-tree map with copied items from a parallel iterator.

fn par_extend<I>(&mut self, par_iter: I)

where I: IntoParallelIterator<Item = (&'a K, &'a V)>,

Extends an instance of the collection with the elements drawn from the parallel iterator par_iter.

impl<K, V> ParallelExtend<(K, V)> for BTreeMap<K, V>

where K: Ord + Send, V: Send,

Extends a B-tree map with items from a parallel iterator.

fn par_extend<I>(&mut self, par_iter: I)

where I: IntoParallelIterator<Item = (K, V)>,

Extends an instance of the collection with the elements drawn from the parallel iterator par_iter.

impl<K, V, A> PartialEq for BTreeMap<K, V, A>

where K: PartialEq, V: PartialEq, A: Allocator + Clone,

fn eq(&self, other: &BTreeMap<K, V, A>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<K, V, A> PartialOrd for BTreeMap<K, V, A>

where K: PartialOrd, V: PartialOrd, A: Allocator + Clone,

fn partial_cmp(&self, other: &BTreeMap<K, V, A>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<K, V> Serialize for BTreeMap<K, V>

where K: Serialize, V: Serialize,

fn serialize<S>( &self, serializer: S, ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, V> Source for BTreeMap<K, V>

where K: ToKey + Borrow<str> + Ord, V: ToValue,

fn visit<'kvs>( &'kvs self, visitor: &mut dyn VisitSource<'kvs>, ) -> Result<(), Error>

Visit key-values.

fn get(&self, key: Key<'_>) -> Option<Value<'_>>

Get the value for a given key.

fn count(&self) -> usize

Count the number of key-values that can be visited.

impl<K, V> TypeInfo for BTreeMap<K, V>

where K: TypeInfo + 'static, V: TypeInfo + 'static,

type Identity = BTreeMap<K, V>

The type identifying for which type info is provided.

fn type_info() -> Type

Returns the static type identifier for Self.

impl<K, V> Valid for BTreeMap<K, V>

where K: Valid, V: Valid,

fn check(&self) -> Result<(), SerializationError>

fn batch_check<'a>( batch: impl Iterator<Item = &'a BTreeMap<K, V>>, ) -> Result<(), SerializationError>

where BTreeMap<K, V>: 'a,

impl<K, V> Valid for BTreeMap<K, V>

where K: Valid, V: Valid,

fn check(&self) -> Result<(), SerializationError>

fn batch_check<'a>( batch: impl Iterator<Item = &'a BTreeMap<K, V>>, ) -> Result<(), SerializationError>

where BTreeMap<K, V>: 'a,

impl<K, V> DecodeWithMemTracking for BTreeMap<K, V>

where K: DecodeWithMemTracking, V: DecodeWithMemTracking, BTreeMap<K, V>: Decode,

impl<K, LikeK, V, LikeV> EncodeLike<&[(LikeK, LikeV)]> for BTreeMap<K, V>

where K: EncodeLike<LikeK>, LikeK: Encode, V: EncodeLike<LikeV>, LikeV: Encode,

impl<K, LikeK, V, LikeV> EncodeLike<BTreeMap<LikeK, LikeV>> for BTreeMap<K, V>

where K: EncodeLike<LikeK>, LikeK: Encode, V: EncodeLike<LikeV>, LikeV: Encode,

impl<K, V, A> Eq for BTreeMap<K, V, A>

where K: Eq, V: Eq, A: Allocator + Clone,

impl<K, V, A> UnwindSafe for BTreeMap<K, V, A>

where A: Allocator + Clone + UnwindSafe, K: RefUnwindSafe, V: RefUnwindSafe,