From 72b411fd89675a38613d347b31481cd8e8a59bb7 Mon Sep 17 00:00:00 2001
From: rhysd <lin90162@yahoo.co.jp>
Date: Sat, 20 Nov 2021 21:40:41 +0900
Subject: [PATCH] Implement `TryFrom<&'_ mut [T]>` for `[T; N]`

---
 library/core/src/array/mod.rs | 12 ++++++++++++
 library/core/tests/array.rs   | 13 ++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/library/core/src/array/mod.rs b/library/core/src/array/mod.rs
index 09bb4519170da..eadf6fd9a4f89 100644
--- a/library/core/src/array/mod.rs
+++ b/library/core/src/array/mod.rs
@@ -176,6 +176,18 @@ where
     }
 }
 
+#[stable(feature = "try_from_mut_slice_to_array", since = "1.57.0")]
+impl<T, const N: usize> TryFrom<&mut [T]> for [T; N]
+where
+    T: Copy,
+{
+    type Error = TryFromSliceError;
+
+    fn try_from(slice: &mut [T]) -> Result<[T; N], TryFromSliceError> {
+        <Self>::try_from(slice.as_ref())
+    }
+}
+
 #[stable(feature = "try_from", since = "1.34.0")]
 impl<'a, T, const N: usize> TryFrom<&'a [T]> for &'a [T; N] {
     type Error = TryFromSliceError;
diff --git a/library/core/tests/array.rs b/library/core/tests/array.rs
index 7dc071b74235d..1f53cdf200a59 100644
--- a/library/core/tests/array.rs
+++ b/library/core/tests/array.rs
@@ -28,11 +28,22 @@ fn array_try_from() {
         ($($N:expr)+) => {
             $({
                 type Array = [u8; $N];
-                let array: Array = [0; $N];
+                let mut array: Array = [0; $N];
                 let slice: &[u8] = &array[..];
 
                 let result = <&Array>::try_from(slice);
                 assert_eq!(&array, result.unwrap());
+
+                let result = <Array>::try_from(slice);
+                assert_eq!(&array, &result.unwrap());
+
+                let mut_slice: &mut [u8] = &mut array[..];
+                let result = <&mut Array>::try_from(mut_slice);
+                assert_eq!(&[0; $N], result.unwrap());
+
+                let mut_slice: &mut [u8] = &mut array[..];
+                let result = <Array>::try_from(mut_slice);
+                assert_eq!(&array, &result.unwrap());
             })+
         }
     }