flex_alloc/vec/
cow.rs

1use super::Vec;
2use crate::alloc::{AllocateIn, Allocator, AllocatorDefault};
3use crate::borrow::{Cow, ToOwnedIn};
4use crate::error::StorageError;
5
6impl<T: Clone, A: Allocator> ToOwnedIn<A> for [T] {
7    type Owned = Vec<T, A>;
8
9    fn try_to_owned_in<I>(&self, alloc_in: I) -> Result<Self::Owned, StorageError>
10    where
11        I: AllocateIn<Alloc = A>,
12    {
13        Vec::try_from_slice_in(self, alloc_in)
14    }
15}
16
17impl<'a, T: Clone, A: Allocator, const N: usize> From<&'a [T; N]> for Cow<'a, [T], A> {
18    fn from(s: &'a [T; N]) -> Cow<'a, [T], A> {
19        Cow::Borrowed(s.as_slice())
20    }
21}
22
23impl<'a, T: Clone, A: Allocator, const N: usize> From<&'a mut [T; N]> for Cow<'a, [T], A> {
24    fn from(s: &'a mut [T; N]) -> Cow<'a, [T], A> {
25        Cow::Borrowed(s.as_slice())
26    }
27}
28
29impl<'a, T: Clone, A: Allocator> From<Vec<T, A>> for Cow<'a, [T], A> {
30    fn from(vec: Vec<T, A>) -> Cow<'a, [T], A> {
31        Cow::Owned(vec)
32    }
33}
34
35impl<'a, T: Clone, A: Allocator> From<&'a Vec<T, A>> for Cow<'a, [T], A> {
36    fn from(vec: &'a Vec<T, A>) -> Cow<'a, [T], A> {
37        Cow::Borrowed(vec.as_slice())
38    }
39}
40
41impl<'a, T: Clone, A: AllocatorDefault> FromIterator<T> for Cow<'a, [T], A> {
42    fn from_iter<I: IntoIterator<Item = T>>(it: I) -> Cow<'a, [T], A> {
43        Cow::Owned(Vec::from_iter(it))
44    }
45}
46
47#[cfg(test)]
48mod tests {
49    #[cfg(feature = "alloc")]
50    use crate::alloc::Global;
51
52    #[cfg(feature = "alloc")]
53    use const_default::ConstDefault;
54
55    #[cfg(feature = "alloc")]
56    use super::*;
57
58    #[cfg(feature = "alloc")]
59    #[test]
60    fn cow_borrow_vec() {
61        let mut b = Cow::<[u32], Global>::default();
62        assert!(b.is_owned());
63        b.to_mut().push(1);
64        assert_eq!(b.into_owned(), &[1]);
65
66        let b = Cow::<[u32], Global>::from(&[1, 2, 3]);
67        assert!(b.is_borrowed());
68        assert_eq!(b.into_owned(), &[1, 2, 3]);
69    }
70
71    #[cfg(feature = "alloc")]
72    #[test]
73    fn const_default_cow() {
74        let c = Cow::<[u32], Global>::DEFAULT;
75        assert_eq!(c.as_ref(), &[]);
76    }
77}
flex_alloc/vec/cow.rs

flex_alloc/vec/
cow.rs
