use core::cmp::Ordering;
use core::hash::{Hash, Hasher};
pub trait Key {
type Output;
fn key(&self) -> Self::Output;
}
#[derive(Clone, Copy, Debug, Default)]
pub struct Keyed<T>(pub T);
impl<T: Key> From<T> for Keyed<T> {
fn from(value: T) -> Self {
Self(value)
}
}
impl<T: Key> PartialEq for Keyed<T>
where
T::Output: PartialEq,
{
fn eq(&self, other: &Self) -> bool {
self.0.key().eq(&other.0.key())
}
#[allow(clippy::partialeq_ne_impl)]
fn ne(&self, other: &Self) -> bool {
self.0.key().ne(&other.0.key())
}
}
impl<T: Key> Eq for Keyed<T> where T::Output: Eq {}
impl<T: Key> PartialOrd for Keyed<T>
where
T::Output: PartialOrd,
{
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
self.0.key().partial_cmp(&other.0.key())
}
fn lt(&self, other: &Self) -> bool {
self.0.key().lt(&other.0.key())
}
fn le(&self, other: &Self) -> bool {
self.0.key().le(&other.0.key())
}
fn gt(&self, other: &Self) -> bool {
self.0.key().gt(&other.0.key())
}
fn ge(&self, other: &Self) -> bool {
self.0.key().ge(&other.0.key())
}
}
impl<T: Key> Ord for Keyed<T>
where
T::Output: Ord,
{
fn cmp(&self, other: &Self) -> Ordering {
self.0.key().cmp(&other.0.key())
}
}
impl<T: Key> Hash for Keyed<T>
where
T::Output: Hash,
{
fn hash<H: Hasher>(&self, state: &mut H) {
self.0.key().hash(state)
}
}
#[cfg(test)]
mod tests {
use super::super::tests::{self, KeyValuePair};
use super::{Key, Keyed};
impl<K: Clone, V> Key for KeyValuePair<K, V> {
type Output = K;
fn key(&self) -> Self::Output {
self.key.clone()
}
}
#[test]
fn test_partial_eq() {
tests::test_partial_eq(Keyed);
}
#[test]
fn test_eq() {
tests::test_eq(Keyed);
}
#[test]
fn test_partial_ord() {
tests::test_partial_ord(Keyed);
}
#[test]
fn test_ord() {
tests::test_ord(Keyed);
}
#[test]
fn test_hash() {
tests::test_hash(Keyed);
}
}