Trait KeyedCollection 

pub trait KeyedCollection: Collection<Item = (Self::Key, Self::Value)> {
    type Key: Eq + Hash;
    type Value;
    type Entry<'a>
       where Self: 'a;

    // Required methods
    fn contains_key(&self, key: &Self::Key) -> bool;
    fn get(&self, key: &Self::Key) -> Option<&Self::Value>;
    fn get_mut(&mut self, key: &Self::Key) -> Option<&mut Self::Value>;
    fn iter(&self) -> impl Iterator<Item = (&Self::Key, &Self::Value)>;
    fn iter_mut(
        &mut self,
    ) -> impl Iterator<Item = (&Self::Key, &mut Self::Value)>;
    fn values_mut(&mut self) -> impl Iterator<Item = &mut Self::Value>;
    fn insert(
        &mut self,
        key: Self::Key,
        value: Self::Value,
    ) -> Option<Self::Value>;
    fn remove(&mut self, key: &Self::Key) -> Option<Self::Value>;
    fn entry(&mut self, key: Self::Key) -> Self::Entry<'_>;
    fn retain(&mut self, f: impl FnMut(&Self::Key, &mut Self::Value) -> bool);
}

Trait implemented by key-value maps which need to support collection confinement.

Required Associated Types

type Key: Eq + Hash

Key type for the collection.

type Value

Value type for the collection.

type Entry<'a> where Self: 'a

Required Methods

fn contains_key(&self, key: &Self::Key) -> bool

Checks whether a given key is contained in the collection.

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

Gets a value of the collection.

fn get_mut(&mut self, key: &Self::Key) -> Option<&mut Self::Value>

Gets a mutable value of the collection.

fn iter(&self) -> impl Iterator<Item = (&Self::Key, &Self::Value)>

Returns iterator over keys and values.

fn iter_mut(&mut self) -> impl Iterator<Item = (&Self::Key, &mut Self::Value)>

Returns iterator over keys and mutable values.

fn values_mut(&mut self) -> impl Iterator<Item = &mut Self::Value>

Constructs iterator over mutable values.

fn insert(&mut self, key: Self::Key, value: Self::Value) -> Option<Self::Value>

Inserts a new value under a key. Returns previous value if a value under the key was already present in the collection.

fn remove(&mut self, key: &Self::Key) -> Option<Self::Value>

Removes a value stored under a given key, returning an owned value if it was in the collection.

fn entry(&mut self, key: Self::Key) -> Self::Entry<'_>

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

fn retain(&mut self, f: impl FnMut(&Self::Key, &mut Self::Value) -> 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 unsorted (and unspecified) order.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<K: Eq + Hash, V> KeyedCollection for HashMap<K, V>

Available on crate feature std only.

type Key = K

type Value = V

type Entry<'a> = Entry<'a, K, V> where K: 'a, V: 'a

fn contains_key(&self, key: &Self::Key) -> bool

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

fn get_mut(&mut self, key: &Self::Key) -> Option<&mut Self::Value>

fn iter(&self) -> impl Iterator<Item = (&Self::Key, &Self::Value)>

fn iter_mut(&mut self) -> impl Iterator<Item = (&Self::Key, &mut Self::Value)>

fn values_mut(&mut self) -> impl Iterator<Item = &mut Self::Value>

fn insert(&mut self, key: Self::Key, value: Self::Value) -> Option<Self::Value>

fn remove(&mut self, key: &Self::Key) -> Option<Self::Value>

fn entry(&mut self, key: Self::Key) -> Self::Entry<'_>

fn retain(&mut self, f: impl FnMut(&K, &mut V) -> bool)

impl<K: Ord + Hash, V> KeyedCollection for BTreeMap<K, V>

type Key = K

type Value = V

type Entry<'a> = Entry<'a, K, V> where K: 'a, V: 'a

fn contains_key(&self, key: &Self::Key) -> bool

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

fn get_mut(&mut self, key: &Self::Key) -> Option<&mut Self::Value>

fn iter(&self) -> impl Iterator<Item = (&Self::Key, &Self::Value)>

fn iter_mut(&mut self) -> impl Iterator<Item = (&Self::Key, &mut Self::Value)>

fn values_mut(&mut self) -> impl Iterator<Item = &mut Self::Value>

fn insert(&mut self, key: Self::Key, value: Self::Value) -> Option<Self::Value>

fn remove(&mut self, key: &Self::Key) -> Option<Self::Value>

fn entry(&mut self, key: Self::Key) -> Self::Entry<'_>

fn retain(&mut self, f: impl FnMut(&K, &mut V) -> bool)

Implementors