Trait Collection

pub trait Collection {
    type Entry;
    type Val;

    // Required method
    fn entry_to_val(e: Self::Entry) -> Self::Val;
}

Represents a collection by defining the types of entries and values it handles.

This trait abstracts the nature of collections in data structures, facilitating the handling of contained entries and values, especially in scenarios where the structure of the collection allows for complex relationships, such as HashMaps. It not only identifies what constitutes an entry and a value in the context of the collection but also provides utility for converting between these two, which is critical in operations involving entry manipulation and value retrieval.

Required Associated Types

type Entry

The type of entries that can be added to the collection. This type can differ from Val in collections like HashMap, where an entry might represent a key-value pair, and Val could represent just the value or the key.

type Val

The type of values stored in the collection. This might be distinct from Entry in complex collections. For example, in a HashMap, while Entry might be a ( key, value ) tuple, Val might only be the value part.

Required Methods

fn entry_to_val(e: Self::Entry) -> Self::Val

Converts an entry to its corresponding value within the collection. This function is essential for abstracting the collection’s internal representation from the values it manipulates.

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<E> Collection for BinaryHeap<E>

type Entry = E

type Val = E

fn entry_to_val( e: <BinaryHeap<E> as Collection>::Entry, ) -> <BinaryHeap<E> as Collection>::Val

impl<E> Collection for BTreeSet<E>

type Entry = E

type Val = E

fn entry_to_val( e: <BTreeSet<E> as Collection>::Entry, ) -> <BTreeSet<E> as Collection>::Val

impl<E> Collection for LinkedList<E>

type Entry = E

type Val = E

fn entry_to_val( e: <LinkedList<E> as Collection>::Entry, ) -> <LinkedList<E> as Collection>::Val

impl<E> Collection for VecDeque<E>

type Entry = E

type Val = E

fn entry_to_val( e: <VecDeque<E> as Collection>::Entry, ) -> <VecDeque<E> as Collection>::Val

impl<E> Collection for Vec<E>

type Entry = E

type Val = E

fn entry_to_val(e: <Vec<E> as Collection>::Entry) -> <Vec<E> as Collection>::Val

impl<K> Collection for HashSet<K>

where K: Eq + Hash,

type Entry = K

type Val = K

fn entry_to_val( e: <HashSet<K> as Collection>::Entry, ) -> <HashSet<K> as Collection>::Val

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

where K: Ord,

type Entry = (K, V)

type Val = V

fn entry_to_val( e: <BTreeMap<K, V> as Collection>::Entry, ) -> <BTreeMap<K, V> as Collection>::Val

impl<K, V> Collection for HashMap<K, V>

where K: Eq + Hash,

type Entry = (K, V)

type Val = V

fn entry_to_val( e: <HashMap<K, V> as Collection>::Entry, ) -> <HashMap<K, V> as Collection>::Val

Implementors