zed_util/
arc_cow.rs

1use std::{
2    borrow::Cow,
3    cmp::Ordering,
4    fmt::{self, Debug},
5    hash::{Hash, Hasher},
6    sync::Arc,
7};
8
9pub enum ArcCow<'a, T: ?Sized> {
10    Borrowed(&'a T),
11    Owned(Arc<T>),
12}
13
14impl<T: ?Sized + PartialEq> PartialEq for ArcCow<'_, T> {
15    fn eq(&self, other: &Self) -> bool {
16        let a = self.as_ref();
17        let b = other.as_ref();
18        a == b
19    }
20}
21
22impl<T: ?Sized + PartialOrd> PartialOrd for ArcCow<'_, T> {
23    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
24        self.as_ref().partial_cmp(other.as_ref())
25    }
26}
27
28impl<T: ?Sized + Ord> Ord for ArcCow<'_, T> {
29    fn cmp(&self, other: &Self) -> Ordering {
30        self.as_ref().cmp(other.as_ref())
31    }
32}
33
34impl<T: ?Sized + Eq> Eq for ArcCow<'_, T> {}
35
36impl<T: ?Sized + Hash> Hash for ArcCow<'_, T> {
37    fn hash<H: Hasher>(&self, state: &mut H) {
38        match self {
39            Self::Borrowed(borrowed) => Hash::hash(borrowed, state),
40            Self::Owned(owned) => Hash::hash(&**owned, state),
41        }
42    }
43}
44
45impl<T: ?Sized> Clone for ArcCow<'_, T> {
46    fn clone(&self) -> Self {
47        match self {
48            Self::Borrowed(borrowed) => Self::Borrowed(borrowed),
49            Self::Owned(owned) => Self::Owned(owned.clone()),
50        }
51    }
52}
53
54impl<'a, T: ?Sized> From<&'a T> for ArcCow<'a, T> {
55    fn from(s: &'a T) -> Self {
56        Self::Borrowed(s)
57    }
58}
59
60impl<T: ?Sized> From<Arc<T>> for ArcCow<'_, T> {
61    fn from(s: Arc<T>) -> Self {
62        Self::Owned(s)
63    }
64}
65
66impl<T: ?Sized> From<&'_ Arc<T>> for ArcCow<'_, T> {
67    fn from(s: &'_ Arc<T>) -> Self {
68        Self::Owned(s.clone())
69    }
70}
71
72impl From<String> for ArcCow<'_, str> {
73    fn from(value: String) -> Self {
74        Self::Owned(value.into())
75    }
76}
77
78impl From<&String> for ArcCow<'_, str> {
79    fn from(value: &String) -> Self {
80        Self::Owned(value.clone().into())
81    }
82}
83
84impl<'a> From<Cow<'a, str>> for ArcCow<'a, str> {
85    fn from(value: Cow<'a, str>) -> Self {
86        match value {
87            Cow::Borrowed(borrowed) => Self::Borrowed(borrowed),
88            Cow::Owned(owned) => Self::Owned(owned.into()),
89        }
90    }
91}
92
93impl<T> From<Vec<T>> for ArcCow<'_, [T]> {
94    fn from(vec: Vec<T>) -> Self {
95        ArcCow::Owned(Arc::from(vec))
96    }
97}
98
99impl<'a> From<&'a str> for ArcCow<'a, [u8]> {
100    fn from(s: &'a str) -> Self {
101        ArcCow::Borrowed(s.as_bytes())
102    }
103}
104
105impl<T: ?Sized + ToOwned> std::borrow::Borrow<T> for ArcCow<'_, T> {
106    fn borrow(&self) -> &T {
107        match self {
108            ArcCow::Borrowed(borrowed) => borrowed,
109            ArcCow::Owned(owned) => owned.as_ref(),
110        }
111    }
112}
113
114impl<T: ?Sized> std::ops::Deref for ArcCow<'_, T> {
115    type Target = T;
116
117    fn deref(&self) -> &Self::Target {
118        match self {
119            ArcCow::Borrowed(s) => s,
120            ArcCow::Owned(s) => s.as_ref(),
121        }
122    }
123}
124
125impl<T: ?Sized> AsRef<T> for ArcCow<'_, T> {
126    fn as_ref(&self) -> &T {
127        match self {
128            ArcCow::Borrowed(borrowed) => borrowed,
129            ArcCow::Owned(owned) => owned.as_ref(),
130        }
131    }
132}
133
134impl<T: ?Sized + Debug> Debug for ArcCow<'_, T> {
135    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
136        match self {
137            ArcCow::Borrowed(borrowed) => Debug::fmt(borrowed, f),
138            ArcCow::Owned(owned) => Debug::fmt(&**owned, f),
139        }
140    }
141}
zed_util/arc_cow.rs

zed_util/
arc_cow.rs
