[PATCH 1/4] rust: alloc: implement `Borrow` and `BorrowMut` for `Vec`

[Alexandre Courbot <acourbot@nvidia.com>]

Implement these two common traits, which allow generic types to store
either an owned value or a reference to it.

The implementation leverages `as_slice` and `as_mut_slice`.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 rust/kernel/alloc/kvec.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs
index 1a0dd852a468ccda6ea1b521bc1e7dbc8d7fc79c..45f813f69fe0f338a83c577752dd3ba1b3b2003f 100644
--- a/rust/kernel/alloc/kvec.rs
+++ b/rust/kernel/alloc/kvec.rs
@@ -8,6 +8,7 @@
     AllocError, Allocator, Box, Flags,
 };
 use core::{
+    borrow::{Borrow, BorrowMut},
     fmt,
     marker::PhantomData,
     mem::{ManuallyDrop, MaybeUninit},
@@ -890,6 +891,24 @@ fn deref_mut(&mut self) -> &mut [T] {
     }
 }
 
+impl<T, A> Borrow<[T]> for Vec<T, A>
+where
+    A: Allocator,
+{
+    fn borrow(&self) -> &[T] {
+        self.as_slice()
+    }
+}
+
+impl<T, A> BorrowMut<[T]> for Vec<T, A>
+where
+    A: Allocator,
+{
+    fn borrow_mut(&mut self) -> &mut [T] {
+        self.as_mut_slice()
+    }
+}
+
 impl<T: Eq, A> Eq for Vec<T, A> where A: Allocator {}
 
 impl<T, I: SliceIndex<[T]>, A> Index<I> for Vec<T, A>

-- 
2.49.0