Trait Empty 

pub trait Empty {
    // Required method
    fn is_empty(&self) -> bool;
}

A trait for describing whether a collection is empty, i.e., its length is zero.

Checking whether a collection is empty should take a constant amount of time and space.

Required Methods

fn is_empty(&self) -> bool

Returns whether the collection is empty.

Examples

use len_trait::Empty;

fn check_empty<C: ?Sized + Empty>(collection: &C) {
    assert!(collection.is_empty());
}

check_empty("");
check_empty(&[1, 2, 3][..0]);
check_empty(&"".to_string());

Implementations on Foreign Types

impl Empty for str

fn is_empty(&self) -> bool

impl Empty for CString

fn is_empty(&self) -> bool

impl Empty for String

fn is_empty(&self) -> bool

impl Empty for CStr

fn is_empty(&self) -> bool

impl Empty for OsStr

fn is_empty(&self) -> bool

impl Empty for OsString

fn is_empty(&self) -> bool

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

fn is_empty(&self) -> bool

impl<K: Ord, V> Empty for BTreeMap<K, V>

fn is_empty(&self) -> bool

impl<T> Empty for [T]

fn is_empty(&self) -> bool

impl<T> Empty for LinkedList<T>

fn is_empty(&self) -> bool

impl<T> Empty for VecDeque<T>

fn is_empty(&self) -> bool

impl<T> Empty for Vec<T>

fn is_empty(&self) -> bool

impl<T: Eq + Hash> Empty for HashSet<T>

fn is_empty(&self) -> bool

impl<T: Ord> Empty for BinaryHeap<T>

fn is_empty(&self) -> bool

impl<T: Ord> Empty for BTreeSet<T>

fn is_empty(&self) -> bool

impl<T: ?Sized + Empty> Empty for Box<T>

fn is_empty(&self) -> bool

impl<T: ?Sized + Empty> Empty for Rc<T>

fn is_empty(&self) -> bool

impl<T: ?Sized + Empty> Empty for Arc<T>

fn is_empty(&self) -> bool

Implementors