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
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70

use std::ops::{Range, Index, IndexMut};
use std::iter::Map;
use std::marker::PhantomData;
use super::Id;

pub type Ids<K> = Map<Range<usize>, fn(usize) -> Id<K>>;

#[derive(Debug)]
#[derive(Serialize, Deserialize)]
pub struct IdVec<K, V=K> {
    items: Vec<V>,
    marker: PhantomData<K>,
}

impl<K, V> IdVec<K, V> {
    pub fn new() -> Self {
        Self::default()
    }

    pub fn push(&mut self, item: V) -> Id<K> {
        self.items.push(item);
        Id::from(self.len() - 1)
    }

    pub fn len(&self) -> usize {
        self.items.len()
    }
    
    pub fn ids(&self) -> Ids<K> {
        (0 .. self.len()).map(Id::from)
    }
}

impl<K, V> Index<Id<K>> for IdVec<K, V> {
    type Output = V;

    fn index(&self, id: Id<K>) -> &Self::Output {
        &self.items[Into::<usize>::into(id)]
    }
}

impl<K, V> IndexMut<Id<K>> for IdVec<K, V> {
    fn index_mut(&mut self, id: Id<K>) -> &mut Self::Output {
        &mut self.items[Into::<usize>::into(id)]
    }
}

impl<K, V> Default for IdVec<K, V> {
    fn default() -> Self {
        Self { 
            items: Default::default(),
            marker: PhantomData::default(),
        }
    }
}

impl<K, V> From<Vec<V>> for IdVec<K, V> {
    fn from(items: Vec<V>) -> Self {
        Self { 
            items,
            marker: PhantomData::default(),
        }
    }
}

impl<K, V> Into<Vec<V>> for IdVec<K, V> {
    fn into(self) -> Vec<V> {
        self.items
    }
}