Crate automap[−][src]
A simple pattern to implement maps where the value type also contains the key type.
Implementations for HashMap
and BTreeMap
from std::collections
are provided.
use std::collections::HashMap; use automap::{AutoHashMap, AutoMapped}; // Let's say we want a `Person` to be keyed by their `name` in a HashMap #[derive(Debug, Clone, Hash, PartialEq, Eq)] struct Person { name: String, age: u16, } // We can specify how to derive the key from the value // As long as the Key type meets the bounds for a normal HashMap key, we // can use this value in an AutoHashMap. // (Similarly for BTreeMap.) impl AutoMapped for Person { type Key = String; fn key(&self) -> &Self::Key { &self.name } } // Then, we can simply use an `AutoHashMap` to insert values directly. let mut map = AutoHashMap::new(); let michelle = Person { name: "Michelle".into(), age: 37 }; map.insert(michelle.clone()); // You can access all other normal HashMap methods directly: assert_eq!(map.get("Michelle".into()), Some(&michelle)); assert_eq!(map.remove("Michelle".into()), Some(michelle)); // We can also go From and Into a normal HashMap easily. let inner: HashMap<_, _> = map.into(); let map: AutoHashMap<_> = inner.into();
Structs
AutoBTreeMap | A map whose values also contain their keys |
AutoHashMap | A map whose values also contain their keys |
Traits
AutoBTreeMapKey | The constraints on an AutoBTreeMap key |
AutoHashMapKey | The constraints on an AutoHashMap key |
AutoMapped | Trait that describes how to extract a key out of a value |