ruma::events::receipt

Type Alias UserReceipts

Source
pub type UserReceipts = BTreeMap<OwnedUserId, Receipt>;
Available on crate feature events only.
Expand description

A mapping of user ID to receipt.

The user ID is the entity who sent this receipt.

Aliased Type§

struct UserReceipts { /* private fields */ }

Implementations

Source§

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

1.0.0 (const: 1.66.0) · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
Source§

impl<K, V, A> BTreeMap<K, V, A>
where A: Allocator + Clone,

1.0.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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"));
1.0.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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;
    }
}
1.0.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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]);
1.0.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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"]);
1.10.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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!")]);
1.0.0 (const: unstable) · Source

pub fn len(&self) -> usize

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
1.0.0 (const: unstable) · Source

pub fn is_empty(&self) -> bool

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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());
Source

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)
Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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")));
Source

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)
Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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")));
Source

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)
Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
Source

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)
Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
Source§

impl<K, V, A> BTreeMap<K, V, A>
where A: Allocator + Clone,

1.0.0 · Source

pub fn clear(&mut self)

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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());
Source

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

🔬This is a nightly-only experimental API. (btreemap_alloc)
Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
Source§

impl<K, V, A> BTreeMap<K, V, A>
where A: Allocator + Clone,

1.0.0 · Source

pub fn get<Q>(&self, key: &Q) -> Option<&V>
where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
1.40.0 · Source

pub fn get_key_value<Q>(&self, k: &Q) -> Option<(&K, &V)>
where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
1.66.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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")));
1.66.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
1.66.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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());
1.66.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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")));
1.66.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
1.66.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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());
1.0.0 · Source

pub fn contains_key<Q>(&self, key: &Q) -> bool
where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
1.0.0 · Source

pub fn get_mut<Q>(&mut self, key: &Q) -> Option<&mut V>
where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
1.0.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
Source

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)
Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
1.0.0 · Source

pub fn remove<Q>(&mut self, key: &Q) -> Option<V>
where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
1.45.0 · Source

pub fn remove_entry<Q>(&mut self, key: &Q) -> Option<(K, V)>
where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
1.53.0 · Source

pub fn retain<F>(&mut self, f: F)
where K: Ord, F: FnMut(&K, &mut V) -> bool,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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)]));
1.11.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
1.17.0 · Source

pub fn range<T, R>(&self, range: R) -> Range<'_, K, V>
where T: Ord + ?Sized, K: Borrow<T> + Ord, R: RangeBounds<T>,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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());
1.17.0 · Source

pub fn range_mut<T, R>(&mut self, range: R) -> RangeMut<'_, K, V>
where T: Ord + ?Sized, K: Borrow<T> + Ord, R: RangeBounds<T>,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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}");
}
1.0.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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);
1.11.0 · Source

pub fn split_off<Q>(&mut self, key: &Q) -> BTreeMap<K, V, A>
where Q: Ord + ?Sized, K: Borrow<Q> + Ord, A: Clone,

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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");
Source

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)
Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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]);
1.54.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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]);
1.54.0 · Source

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

Available on (crate features client-api-c or client-api-s) and (crate features client or server) and crate feature api only.

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

1.0.0 · Source§

impl<K, V, A> Clone for BTreeMap<K, V, A>
where K: Clone, V: Clone, A: Allocator + Clone,

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

Returns a copy of the value. Read more
1.0.0 · Source§

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

Performs copy-assignment from source. Read more
1.0.0 · Source§

impl<K, V, A> Debug for BTreeMap<K, V, A>
where K: Debug, V: Debug, A: Allocator + Clone,

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

Formats the value using the given formatter. Read more
1.0.0 · Source§

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

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

Creates an empty BTreeMap.

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

Available on crate features std or alloc only.
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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. Read more
1.7.0 · Source§

impl<K, V, A> Drop for BTreeMap<K, V, A>
where A: Allocator + Clone,

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fn drop(&mut self)

Executes the destructor for this type. Read more
1.2.0 · Source§

impl<'a, K, V, A> Extend<(&'a K, &'a V)> for BTreeMap<K, V, A>
where K: Ord + Copy, V: Copy, A: Allocator + Clone,

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fn extend<I>(&mut self, iter: I)
where I: IntoIterator<Item = (&'a K, &'a V)>,

Extends a collection with the contents of an iterator. Read more
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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.
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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. Read more
1.0.0 · Source§

impl<K, V, A> Extend<(K, V)> for BTreeMap<K, V, A>
where K: Ord, A: Allocator + Clone,

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fn extend<T>(&mut self, iter: T)
where T: IntoIterator<Item = (K, V)>,

Extends a collection with the contents of an iterator. Read more
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fn extend_one(&mut self, _: (K, V))

🔬This is a nightly-only experimental API. (extend_one)
Extends a collection with exactly one element.
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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. Read more
1.56.0 · Source§

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

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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);
1.0.0 · Source§

impl<K, V> FromIterator<(K, V)> for BTreeMap<K, V>
where K: Ord,

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fn from_iter<T>(iter: T) -> BTreeMap<K, V>
where T: IntoIterator<Item = (K, V)>,

Creates a value from an iterator. Read more
1.0.0 · Source§

impl<K, V, A> Hash for BTreeMap<K, V, A>
where K: Hash, V: Hash, A: Allocator + Clone,

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

Feeds this value into the given Hasher. Read more
1.3.0 · Source§

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

Feeds a slice of this type into the given Hasher. Read more
1.0.0 · Source§

impl<K, Q, V, A> Index<&Q> for BTreeMap<K, V, A>
where A: Allocator + Clone, K: Borrow<Q> + Ord, Q: Ord + ?Sized,

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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.

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type Output = V

The returned type after indexing.
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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,

Available on crate features std or alloc only.
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type Deserializer = MapDeserializer<'de, <BTreeMap<K, V> as IntoIterator>::IntoIter, E>

The type of the deserializer being converted into.
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fn into_deserializer( self, ) -> <BTreeMap<K, V> as IntoDeserializer<'de, E>>::Deserializer

Convert this value into a deserializer.
1.0.0 · Source§

impl<K, V, A> IntoIterator for BTreeMap<K, V, A>
where A: Allocator + Clone,

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

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

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type Item = (K, V)

The type of the elements being iterated over.
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type IntoIter = IntoIter<K, V, A>

Which kind of iterator are we turning this into?
1.0.0 · Source§

impl<K, V, A> Ord for BTreeMap<K, V, A>
where K: Ord, V: Ord, A: Allocator + Clone,

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

This method returns an Ordering between self and other. Read more
1.21.0 · Source§

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

Compares and returns the maximum of two values. Read more
1.21.0 · Source§

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

Compares and returns the minimum of two values. Read more
1.50.0 · Source§

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

Restrict a value to a certain interval. Read more
1.0.0 · Source§

impl<K, V, A> PartialEq for BTreeMap<K, V, A>
where K: PartialEq, V: PartialEq, A: Allocator + Clone,

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

Tests for self and other values to be equal, and is used by ==.
1.0.0 · Source§

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

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

impl<K, V, A> PartialOrd for BTreeMap<K, V, A>
where K: PartialOrd, V: PartialOrd, A: Allocator + Clone,

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

This method returns an ordering between self and other values if one exists. Read more
1.0.0 · Source§

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

Tests less than (for self and other) and is used by the < operator. Read more
1.0.0 · Source§

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

Tests less than or equal to (for self and other) and is used by the <= operator. Read more
1.0.0 · Source§

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

Tests greater than (for self and other) and is used by the > operator. Read more
1.0.0 · Source§

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

Tests greater than or equal to (for self and other) and is used by the >= operator. Read more
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impl<K, V> Serialize for BTreeMap<K, V>
where K: Serialize, V: Serialize,

Available on crate features std or alloc only.
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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. Read more
1.0.0 · Source§

impl<K, V, A> Eq for BTreeMap<K, V, A>
where K: Eq, V: Eq, A: Allocator + Clone,

1.64.0 · Source§

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