impl `From<&[T; N]>` for `Cow<[T]>`

1 files changed, 13 insertions, 0 deletions

diff --git a/library/alloc/src/vec/cow.rs b/library/alloc/src/vec/cow.rs
index 2c799605b7b..7d2462ee32e 100644
--- a/library/alloc/src/vec/cow.rs
+++ b/library/alloc/src/vec/cow.rs
@@ -15,6 +15,19 @@ impl<'a, T: Clone> From<&'a [T]> for Cow<'a, [T]> {
     }
 }
 
+#[unstable(feature = "cow_from_array_ref", issue = "none")]
+impl<'a, T: Clone, const N: usize> From<&'a [T; N]> for Cow<'a, [T]> {
+    /// Creates a [`Borrowed`] variant of [`Cow`]
+    /// from a reference to an array.
+    ///
+    /// This conversion does not allocate or clone the data.
+    ///
+    /// [`Borrowed`]: crate::borrow::Cow::Borrowed
+    fn from(s: &'a [T; N]) -> Cow<'a, [T]> {
+        Cow::Borrowed(s as &[_])
+    }
+}
+
 #[stable(feature = "cow_from_vec", since = "1.8.0")]
 impl<'a, T: Clone> From<Vec<T>> for Cow<'a, [T]> {
     /// Creates an [`Owned`] variant of [`Cow`]