Trait MapCollection 

pub trait MapCollection {
    type Key;
    type Value;
    type Iter<'a>: Iterator<Item = (&'a Self::Key, &'a Self::Value)> + 'a
       where Self: 'a;

    // Required methods
    fn iter(&self) -> Self::Iter<'_>;
    fn len(&self) -> usize;

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

MapCollection

Explicit iteration contract for map wrapper types. Keeps generic map code on one stable boundary even when concrete wrapper types opt into direct container ergonomics.

Required Associated Types

type Key

type Value

type Iter<'a>: Iterator<Item = (&'a Self::Key, &'a Self::Value)> + 'a where Self: 'a

Iterator over the map’s key/value pairs, tied to the borrow of self.

Required Methods

fn iter(&self) -> Self::Iter<'_>

Returns an iterator over the map’s key/value pairs.

fn len(&self) -> usize

Returns the number of entries in the map.

Provided Methods

fn is_empty(&self) -> bool

Returns true if the map contains no entries.

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.

Implementors