Trait Len 

pub trait Len {
    // Required method
    fn len(&self) -> usize;

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

Abstraction over payload containers stored in a TopicMatcherNode, used to detect when a node’s payload has become empty and can be pruned.

Required Methods

fn len(&self) -> usize

Number of elements currently held.

Provided Methods

fn is_empty(&self) -> bool

Returns true when the container holds no elements.

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> Len for HashMap<K, V>

fn len(&self) -> usize

fn is_empty(&self) -> bool

impl<T> Len for HashSet<T>

fn len(&self) -> usize

fn is_empty(&self) -> bool

Implementors