Trait KeyedRef 

pub trait KeyedRef: Keyed {
    type KeyRef<'a>: Clone + Deref<Target = Self::Key>
       where Self: 'a;

    // Required method
    fn upcast_key_ref<'short, 'long: 'short>(
        r: Self::KeyRef<'long>,
    ) -> Self::KeyRef<'short>
       where Self: 'long;
}

Abstract keyed collection whose key can be referenced.

Required Associated Types

type KeyRef<'a>: Clone + Deref<Target = Self::Key> where Self: 'a

Type of references to keys of the collection.

Required Methods

fn upcast_key_ref<'short, 'long: 'short>( r: Self::KeyRef<'long>, ) -> Self::KeyRef<'short>

where Self: 'long,

Changes a key reference into a shorter lived reference.

See the CollectionRef::upcast_item_ref function for more information. You can use the covariant_key_ref! macro to automatically implement this function.

Dyn Compatibility

This trait is not dyn compatible.

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

Implementations on Foreign Types

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

type KeyRef<'a> = &'a K where Self: 'a

fn upcast_key_ref<'short, 'long: 'short>( r: Self::KeyRef<'long>, ) -> Self::KeyRef<'short>

where Self: 'long,

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

type KeyRef<'a> = &'a K where Self: 'a

fn upcast_key_ref<'short, 'long: 'short>( r: Self::KeyRef<'long>, ) -> Self::KeyRef<'short>

where Self: 'long,

Implementors