Trait IdOrdItem 

pub trait IdOrdItem {
    type Key<'a>: Ord
       where Self: 'a;

    // Required methods
    fn key(&self) -> Self::Key<'_>;
    fn upcast_key<'short, 'long: 'short>(
        long: Self::Key<'long>,
    ) -> Self::Key<'short>;
}

An element stored in an IdOrdMap.

This trait is used to define the key type for the map.

Examples

use iddqd::{IdOrdItem, IdOrdMap, id_upcast};

// Define a struct with a key.
#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
struct MyItem {
    id: String,
    value: u32,
}

// Implement IdOrdItem for the struct.
impl IdOrdItem for MyItem {
    // Keys can borrow from the item.
    type Key<'a> = &'a str;

    fn key(&self) -> Self::Key<'_> {
        &self.id
    }

    id_upcast!();
}

// Create an IdOrdMap and insert items.
let mut map = IdOrdMap::new();
map.insert_unique(MyItem { id: "foo".to_string(), value: 42 }).unwrap();
map.insert_unique(MyItem { id: "bar".to_string(), value: 20 }).unwrap();

Required Associated Types

type Key<'a>: Ord where Self: 'a

The key type.

Required Methods

fn key(&self) -> Self::Key<'_>

Retrieves the key.

fn upcast_key<'short, 'long: 'short>( long: Self::Key<'long>, ) -> Self::Key<'short>

Upcasts the key to a shorter lifetime, in effect asserting that the lifetime 'a on IdOrdItem::Key is covariant.

Typically implemented via the id_upcast macro.

Dyn Compatibility

This trait is not dyn compatible.

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

Implementations on Foreign Types

impl<'b, T: 'b + ?Sized + IdOrdItem> IdOrdItem for &'b T

type Key<'a> = <T as IdOrdItem>::Key<'a> where Self: 'a

fn key(&self) -> Self::Key<'_>

fn upcast_key<'short, 'long: 'short>( long: Self::Key<'long>, ) -> Self::Key<'short>

where Self: 'long,

impl<'b, T: 'b + ?Sized + IdOrdItem> IdOrdItem for &'b mut T

type Key<'a> = <T as IdOrdItem>::Key<'a> where Self: 'a

fn key(&self) -> Self::Key<'_>

fn upcast_key<'short, 'long: 'short>( long: Self::Key<'long>, ) -> Self::Key<'short>

where Self: 'long,

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

type Key<'a> = <T as IdOrdItem>::Key<'a> where Self: 'a

fn key(&self) -> Self::Key<'_>

fn upcast_key<'short, 'long: 'short>( long: Self::Key<'long>, ) -> Self::Key<'short>

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

type Key<'a> = <T as IdOrdItem>::Key<'a> where Self: 'a

fn key(&self) -> Self::Key<'_>

fn upcast_key<'short, 'long: 'short>( long: Self::Key<'long>, ) -> Self::Key<'short>

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

type Key<'a> = <T as IdOrdItem>::Key<'a> where Self: 'a

fn key(&self) -> Self::Key<'_>

fn upcast_key<'short, 'long: 'short>( long: Self::Key<'long>, ) -> Self::Key<'short>

Implementors