der/
referenced.rs

Help
1//! A module for working with referenced data.
2
3/// A trait for borrowing data from an owned struct
4pub trait OwnedToRef {
5    /// The resulting type referencing back to Self
6    type Borrowed<'a>
7    where
8        Self: 'a;
9
10    /// Creates a new object referencing back to the self for storage
11    fn owned_to_ref(&self) -> Self::Borrowed<'_>;
12}
13
14/// A trait for cloning a referenced structure and getting owned objects
15///
16/// This is the pendant to [`OwnedToRef`]
17pub trait RefToOwned<'a> {
18    /// The resulting type after obtaining ownership.
19    type Owned: OwnedToRef<Borrowed<'a> = Self>
20    where
21        Self: 'a;
22
23    /// Creates a new object taking ownership of the data
24    fn ref_to_owned(&self) -> Self::Owned;
25}
26
27impl<T> OwnedToRef for Option<T>
28where
29    T: OwnedToRef,
30{
31    type Borrowed<'a> = Option<T::Borrowed<'a>> where T: 'a;
32
33    fn owned_to_ref(&self) -> Self::Borrowed<'_> {
34        self.as_ref().map(|o| o.owned_to_ref())
35    }
36}
37
38impl<'a, T> RefToOwned<'a> for Option<T>
39where
40    T: RefToOwned<'a> + 'a,
41    T::Owned: OwnedToRef,
42{
43    type Owned = Option<T::Owned>;
44    fn ref_to_owned(&self) -> Self::Owned {
45        self.as_ref().map(|o| o.ref_to_owned())
46    }
47}
48
49#[cfg(feature = "alloc")]
50mod allocating {
51    use super::{OwnedToRef, RefToOwned};
52    use alloc::boxed::Box;
53
54    impl<'a> RefToOwned<'a> for &'a [u8] {
55        type Owned = Box<[u8]>;
56
57        fn ref_to_owned(&self) -> Self::Owned {
58            Box::from(*self)
59        }
60    }
61
62    impl OwnedToRef for Box<[u8]> {
63        type Borrowed<'a> = &'a [u8];
64
65        fn owned_to_ref(&self) -> Self::Borrowed<'_> {
66            self.as_ref()
67        }
68    }
69}
der/referenced.rs

der/
referenced.rs
