extract_map 0.1.1

A HashMap for memory efficent storage of value types which contain their own keys.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54

use std::{borrow::Borrow, hash::Hash, marker::PhantomData};

use crate::ExtractKey;

pub(crate) struct ValueWrapper<K, V>(pub V, pub PhantomData<K>);

impl<K, V: std::fmt::Debug> std::fmt::Debug for ValueWrapper<K, V> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        std::fmt::Debug::fmt(&self.0, f)
    }
}

impl<K, V> Borrow<K> for ValueWrapper<K, V>
where
    K: Hash + Eq,
    V: ExtractKey<K>,
{
    fn borrow(&self) -> &K {
        self.0.extract_key()
    }
}

impl<K, V> Hash for ValueWrapper<K, V>
where
    K: Hash + Eq,
    V: ExtractKey<K>,
{
    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
        self.0.extract_key().hash(state);
    }
}

impl<K, V> PartialEq for ValueWrapper<K, V>
where
    K: Hash + Eq,
    V: ExtractKey<K>,
{
    fn eq(&self, other: &Self) -> bool {
        self.0.extract_key() == other.0.extract_key()
    }
}

impl<K, V> Eq for ValueWrapper<K, V>
where
    K: Hash + Eq,
    V: ExtractKey<K>,
{
}

impl<K, V: Clone> Clone for ValueWrapper<K, V> {
    fn clone(&self) -> Self {
        Self(self.0.clone(), PhantomData)
    }
}