Struct MultikeyBTreeMap

pub struct MultikeyBTreeMap<K1, K2, V> {
    main: BTreeMap<K1, (K2, V)>,
    alt: BTreeMap<K2, K1>,
}

A BTreeMap that supports 2 types of keys per value. All the usual restrictions and warnings for std::collections::BTreeMap also apply to this struct. Additionally, there is a 1:1 relationship between the 2 key types. In other words, for each K1 in the map, there is exactly one K2 in the map and vice versa.

Fields

main: BTreeMap<K1, (K2, V)>

alt: BTreeMap<K2, K1>

Implementations

impl<K1, K2, V> MultikeyBTreeMap<K1, K2, V>

where K1: Clone + Ord, K2: Clone + Ord,

pub fn new() -> Self

Create a new empty MultikeyBTreeMap.

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

where K1: Borrow<Q>, Q: Ord + ?Sized,

Returns a reference to the value corresponding to the key.

The key may be any borrowed form of K1``, but the ordering on the borrowed form must match the ordering on K1`.

pub fn get_alt<Q2>(&self, key: &Q2) -> Option<&V>

where K2: Borrow<Q2>, Q2: Ord + ?Sized,

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

The key may be any borrowed form of the K2``, but the ordering on the borrowed form must match the ordering on K2`.

Note that this method performs 2 lookups: one to get the main key and another to get the value associated with that key. For best performance callers should prefer the get method over this method whenever possible as get only needs to perform one lookup.

pub fn insert(&mut self, k1: K1, k2: K2, v: V) -> Option<V>

Inserts a new entry into the map with the given keys and value.

Returns None if the map did not have an entry with k1 or k2 present. If exactly one key was present, then the value associated with that key is updated, the other key is removed, and the old value is returned. If both keys were present then the value associated with the main key is updated, the value associated with the alternate key is removed, and the old value associated with the main key is returned.

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

where K1: Borrow<Q>, Q: Ord + ?Sized,

Remove a key from the map, returning the value associated with that key if it was previously in the map.

The key may be any borrowed form of K1``, but the ordering on the borrowed form must match the ordering on K1`.

pub fn clear(&mut self)

Clears the map, removing all values.

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

where F: Fn(&V),

Calls a closure on each value in the map.

Trait Implementations

impl<K1, K2, V> Default for MultikeyBTreeMap<K1, K2, V>

fn default() -> Self

Returns the “default value” for a type.