blob: d72b2ef3a202ceb71e9d8866aafcb893869baaa9 [file] [log] [blame]
use std::borrow::Borrow;
/// Key equivalence trait.
/// This trait allows hash table lookup to be customized.
/// It has one blanket implementation that uses the regular `Borrow` solution,
/// just like `HashMap` and `BTreeMap` do, so that you can pass `&str` to lookup
/// into a map with `String` keys and so on.
/// # Contract
/// The implementor **must** hash like `K`, if it is hashable.
pub trait Equivalent<K: ?Sized> {
/// Compare self to `key` and return `true` if they are equal.
fn equivalent(&self, key: &K) -> bool;
impl<Q: ?Sized, K: ?Sized> Equivalent<K> for Q
where Q: Eq,
K: Borrow<Q>,
fn equivalent(&self, key: &K) -> bool {
*self == *key.borrow()