Trait Collection 

pub trait Collection {
    type Item;

    // Required method
    fn len(&self) -> usize;

    // Provided methods
    fn is_empty(&self) -> bool { ... }
    fn is_nonempty(&self) -> bool { ... }
}

A trait for collections of items.

Required Associated Types

type Item

Required Methods

fn len(&self) -> usize

Returns the number of items in the collection.

Provided Methods

fn is_empty(&self) -> bool

Checks whether the collection is empty.

fn is_nonempty(&self) -> bool

Checks whether the collection is nonempty.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

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

where K: Ord,

type Item = (K, V)

fn len(&self) -> usize

fn is_empty(&self) -> bool

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

where K: Eq + Hash,

Available on crate feature std only.

type Item = (K, V)

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T, const N: usize> Collection for [T; N]

type Item = T

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T> Collection for BTreeSet<T>

where T: Ord,

type Item = T

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T> Collection for BinaryHeap<T>

where T: Ord,

type Item = T

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T> Collection for HashSet<T>

where T: Eq + Hash,

Available on crate feature std only.

type Item = T

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T> Collection for LinkedList<T>

type Item = T

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T> Collection for Vec<T>

type Item = T

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T> Collection for VecDeque<T>

type Item = T

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T> Collection for [T]

type Item = T

fn len(&self) -> usize

fn is_empty(&self) -> bool

Implementors