hybrid-array: use From for Array<->[T; N] reference conversions (#1026)

...instead of `AsRef`/`AsMut`, which allows inference to work for those
traits.

Notably `[T; N]` doesn't impl `AsRef`/`AsMut` for itself, only for
slices, so this is more consistent.

Author: tarcieri

hybrid-array/src/lib.rs

@@ -212,17 +212,6 @@ where
     }
 }
 
-impl<T, U, const N: usize> AsRef<[T; N]> for Array<T, U>
-where
-    Self: ArrayOps<T, N>,
-    U: ArraySize,
-{
-    #[inline]
-    fn as_ref(&self) -> &[T; N] {
-        self.as_core_array()
-    }
-}
-
 impl<T, U> AsMut<[T]> for Array<T, U>
 where
     U: ArraySize,
@@ -233,17 +222,6 @@ where
     }
 }
 
-impl<T, U, const N: usize> AsMut<[T; N]> for Array<T, U>
-where
-    Self: ArrayOps<T, N>,
-    U: ArraySize,
-{
-    #[inline]
-    fn as_mut(&mut self) -> &mut [T; N] {
-        self.as_mut_core_array()
-    }
-}
-
 impl<T, U> Borrow<[T]> for Array<T, U>
 where
     U: ArraySize,
@@ -386,6 +364,17 @@ where
     }
 }
 
+impl<'a, T, U, const N: usize> From<&'a Array<T, U>> for &'a [T; N]
+where
+    Array<T, U>: ArrayOps<T, N>,
+    U: ArraySize,
+{
+    #[inline]
+    fn from(array_ref: &'a Array<T, U>) -> &'a [T; N] {
+        array_ref.as_core_array()
+    }
+}
+
 impl<'a, T, U, const N: usize> From<&'a mut [T; N]> for &'a mut Array<T, U>
 where
     Array<T, U>: ArrayOps<T, N>,
@@ -397,6 +386,17 @@ where
     }
 }
 
+impl<'a, T, U, const N: usize> From<&'a mut Array<T, U>> for &'a mut [T; N]
+where
+    Array<T, U>: ArrayOps<T, N>,
+    U: ArraySize,
+{
+    #[inline]
+    fn from(array_ref: &'a mut Array<T, U>) -> &'a mut [T; N] {
+        array_ref.as_mut_core_array()
+    }
+}
+
 impl<T, U> Hash for Array<T, U>
 where
     T: Hash,