Trait ContainerLen 

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

A trait to let you see how many values the container is holding.

Required Methods

fn len(&self) -> usize

Returns the number of elements in the container.

Dyn Compatibility

This trait is dyn compatible.

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

Implementations on Foreign Types

impl<I, O, S> ContainerLen for HashMap<I, O, S>

where I: Eq + Hash, S: BuildHasher,

fn len(&self) -> usize

impl<I, O> ContainerLen for BTreeMap<I, O>

where I: Ord,

fn len(&self) -> usize

Implementors