add Hash to ArrayVec and TinyVec

src/arrayvec.rs

@@ -918,24 +918,15 @@ where
   }
 }
 
-/*
-
-I think, in retrospect, this is useless?
-
-The `&mut [A::Item]` should coerce to `&[A::Item]` and use the above impl.
-I'll leave it here for now though since we already had it written out..
-
-impl<A: Array> PartialEq<&mut [A::Item]> for ArrayVec<A>
+impl<A: Array> Hash for ArrayVec<A>
 where
-  A::Item: PartialEq,
+  A::Item: Hash,
 {
   #[inline]
-  #[must_use]
-  fn eq(&self, other: &&mut [A::Item]) -> bool {
-    self.deref() == *other
+  fn hash<H: Hasher>(&self, state: &mut H) {
+    self.as_slice().hash(state)
   }
 }
-*/
 
 // //
 // Formatting impls

src/lib.rs

@@ -66,6 +66,7 @@ use core::{
     Binary, Debug, Display, Formatter, LowerExp, LowerHex, Octal, Pointer,
     UpperExp, UpperHex,
   },
+  hash::{Hash, Hasher},
   iter::{Extend, FromIterator, IntoIterator, Iterator},
   mem::{needs_drop, replace},
   ops::{Deref, DerefMut, Index, IndexMut, RangeBounds},

src/tinyvec.rs

@@ -792,24 +792,15 @@ where
   }
 }
 
-/*
-
-I think, in retrospect, this is useless?
-
-The `&mut [A::Item]` should coerce to `&[A::Item]` and use the above impl.
-I'll leave it here for now though since we already had it written out..
-
-impl<A: Array> PartialEq<&mut [A::Item]> for TinyVec<A>
+impl<A: Array> Hash for TinyVec<A>
 where
-  A::Item: PartialEq,
+  A::Item: Hash,
 {
   #[inline]
-  #[must_use]
-  fn eq(&self, other: &&mut [A::Item]) -> bool {
-    self.deref() == *other
+  fn hash<H: Hasher>(&self, state: &mut H) {
+    self.as_slice().hash(state)
   }
 }
-*/
 
 // //
 // Formatting impls