diff --git a/Sources/BasicContainers/RigidArray/RigidArray+Container.swift b/Sources/BasicContainers/RigidArray/RigidArray+Container.swift
index 1dfa411e2..9cc46ed17 100644
--- a/Sources/BasicContainers/RigidArray/RigidArray+Container.swift
+++ b/Sources/BasicContainers/RigidArray/RigidArray+Container.swift
@@ -303,7 +303,7 @@ extension RigidArray where Element: ~Copyable {
   ///    This optimization may be removed in future versions; do not rely on it.
   ///
   /// - Parameter index: A valid index of the array. On return, `index` is
-  ///    set to `limit` if
+  ///    set to the resulting position.
   /// - Parameter n: The distance to offset `index`.
   ///    On return, `n` is set to zero if the operation succeeded without
   ///    hitting the limit; otherwise, `n` reflects the number of steps that
diff --git a/Sources/BasicContainers/RigidArray/RigidArray+Descriptions.swift b/Sources/BasicContainers/RigidArray/RigidArray+Descriptions.swift
index 73a829132..5043d4cd2 100644
--- a/Sources/BasicContainers/RigidArray/RigidArray+Descriptions.swift
+++ b/Sources/BasicContainers/RigidArray/RigidArray+Descriptions.swift
@@ -13,20 +13,35 @@
 
 #if compiler(>=6.2)
 
+// FIXME: Add this when/if SE-0499 gets implemented.
+//#if compiler(>=6.x)
+//@available(SwiftStdlib 5.0, *)
+//extension RigidArray: CustomStringConvertible where Element: ~Copyable {
+//}
+//#endif
+
 @available(SwiftStdlib 5.0, *)
-extension RigidArray /*: CustomStringConvertible */ where Element: ~Copyable {
+extension RigidArray where Element: ~Copyable {
   public var description: String {
     /// FIXME: Print the item descriptions when available.
     "<\(count) items>"
   }
 }
 
+// FIXME: Add this when/if SE-0499 gets implemented.
+//#if compiler(>=6.5)
+//@available(SwiftStdlib 5.0, *)
+//extension RigidArray: CustomDebugStringConvertible where Element: ~Copyable {
+//}
+//#endif
+
 @available(SwiftStdlib 5.0, *)
-extension RigidArray /*: CustomDebugStringConvertible */ where Element: ~Copyable {
+extension RigidArray where Element: ~Copyable {
   public var debugDescription: String {
     /// FIXME: Print the item descriptions when available.
     "<\(count) items>"
   }
 }
 
+
 #endif
diff --git a/Sources/BasicContainers/RigidArray/RigidArray+Equatable.swift b/Sources/BasicContainers/RigidArray/RigidArray+Equatable.swift
index 2a2a37ede..b0cc93164 100644
--- a/Sources/BasicContainers/RigidArray/RigidArray+Equatable.swift
+++ b/Sources/BasicContainers/RigidArray/RigidArray+Equatable.swift
@@ -18,14 +18,25 @@ import InternalCollectionsUtilities
 #endif
 
 @available(SwiftStdlib 5.0, *)
-extension RigidArray /*: Equatable */ where Element: Equatable /* & ~Copyable */ {
+extension RigidArray where Element: ~Copyable {
   public func isTriviallyIdentical(to other: borrowing Self) -> Bool {
     self._storage._isIdentical(to: other._storage)
     && self._count == other._count
   }
 }
 
-
+#if compiler(>=6.4) && COLLECTIONS_UNSTABLE_CONTAINERS_PREVIEW
+@available(SwiftStdlib 5.0, *)
+extension RigidArray: Equatable where Element: Equatable & ~Copyable {
+  @inlinable
+  public static func ==(
+    left: borrowing Self,
+    right: borrowing Self
+  ) -> Bool {
+    left.span._elementsEqual(to: right.span)
+  }
+}
+#else
 @available(SwiftStdlib 5.0, *)
 extension RigidArray /*: Equatable */ where Element: Equatable /* & ~Copyable */ {
   @inlinable
@@ -36,5 +47,6 @@ extension RigidArray /*: Equatable */ where Element: Equatable /* & ~Copyable */
     left.span._elementsEqual(to: right.span)
   }
 }
+#endif
 
 #endif
diff --git a/Sources/BasicContainers/UniqueArray/UniqueArray+Container.swift b/Sources/BasicContainers/UniqueArray/UniqueArray+Container.swift
index 2917ee85a..defd02cd6 100644
--- a/Sources/BasicContainers/UniqueArray/UniqueArray+Container.swift
+++ b/Sources/BasicContainers/UniqueArray/UniqueArray+Container.swift
@@ -264,7 +264,7 @@ extension UniqueArray where Element: ~Copyable {
   ///    This optimization may be removed in future versions; do not rely on it.
   ///
   /// - Parameter index: A valid index of the array. On return, `index` is
-  ///    set to `limit` if
+  ///    set to the resulting position.
   /// - Parameter n: The distance to offset `index`.
   ///    On return, `n` is set to zero if the operation succeeded without
   ///    hitting the limit; otherwise, `n` reflects the number of steps that
diff --git a/Sources/BasicContainers/UniqueArray/UniqueArray+Equatable.swift b/Sources/BasicContainers/UniqueArray/UniqueArray+Equatable.swift
index 8b10c1e1b..722c14187 100644
--- a/Sources/BasicContainers/UniqueArray/UniqueArray+Equatable.swift
+++ b/Sources/BasicContainers/UniqueArray/UniqueArray+Equatable.swift
@@ -18,7 +18,26 @@ import InternalCollectionsUtilities
 #endif
 
 @available(SwiftStdlib 5.0, *)
-extension UniqueArray /*: Equatable */ where Element: Equatable /* & ~Copyable */ {
+extension UniqueArray where Element: ~Copyable {
+  public func isTriviallyIdentical(to other: borrowing Self) -> Bool {
+    self._storage.isTriviallyIdentical(to: other._storage)
+  }
+}
+
+#if compiler(>=6.4) && COLLECTIONS_UNSTABLE_CONTAINERS_PREVIEW
+@available(SwiftStdlib 5.0, *)
+extension UniqueArray: Equatable where Element: Equatable & ~Copyable {
+  @inlinable
+  public static func ==(
+    left: borrowing Self,
+    right: borrowing Self
+  ) -> Bool {
+    left.span._elementsEqual(to: right.span)
+  }
+}
+#else
+@available(SwiftStdlib 5.0, *)
+extension UniqueArray where Element: Equatable {
   @inlinable
   public static func ==(
     left: borrowing Self,
@@ -27,5 +46,6 @@ extension UniqueArray /*: Equatable */ where Element: Equatable /* & ~Copyable *
     left.span._elementsEqual(to: right.span)
   }
 }
+#endif
 
 #endif
diff --git a/Sources/BasicContainers/UniqueArray/UniqueArray+Insertions.swift b/Sources/BasicContainers/UniqueArray/UniqueArray+Insertions.swift
index a86ed57b0..7e8c2f7d8 100644
--- a/Sources/BasicContainers/UniqueArray/UniqueArray+Insertions.swift
+++ b/Sources/BasicContainers/UniqueArray/UniqueArray+Insertions.swift
@@ -281,7 +281,7 @@ extension UniqueArray where Element: ~Copyable {
 
 @available(SwiftStdlib 5.0, *)
 extension UniqueArray {
-  /// Copyies the elements of a fully initialized buffer pointer into this
+  /// Copies the elements of a fully initialized buffer pointer into this
   /// array at the specified position.
   ///
   /// The new elements are inserted before the element currently at the
@@ -311,7 +311,7 @@ extension UniqueArray {
     unsafe _storage.insert(copying: newElements, at: index)
   }
 
-  /// Copyies the elements of a fully initialized buffer pointer into this
+  /// Copies the elements of a fully initialized buffer pointer into this
   /// array at the specified position.
   ///
   /// The new elements are inserted before the element currently at the
diff --git a/Sources/InternalCollectionsUtilities/Span+Extras.swift b/Sources/InternalCollectionsUtilities/Span+Extras.swift
index 3abfd8b6d..e23582ef4 100644
--- a/Sources/InternalCollectionsUtilities/Span+Extras.swift
+++ b/Sources/InternalCollectionsUtilities/Span+Extras.swift
@@ -38,6 +38,26 @@ extension Span where Element: ~Copyable {
   }
 }
 
+#if compiler(>=6.4) && COLLECTIONS_UNSTABLE_CONTAINERS_PREVIEW
+@available(SwiftStdlib 5.0, *)
+extension Span where Element: Equatable & ~Copyable {
+  @_alwaysEmitIntoClient
+  package func _elementsEqual(to other: borrowing Self) -> Bool {
+    return self.withUnsafeBufferPointer { a in
+      other.withUnsafeBufferPointer { b in
+        guard a.count == b.count else { return false }
+        guard a.baseAddress != b.baseAddress else { return true }
+        var i = 0
+        while i < self.count {
+          guard a[i] == b[i] else { return false }
+          i &+= 1
+        }
+        return true
+      }
+    }
+  }
+}
+#else
 @available(SwiftStdlib 5.0, *)
 extension Span where Element: Equatable /* & ~Copyable */ {
   @_alwaysEmitIntoClient
@@ -56,6 +76,7 @@ extension Span where Element: Equatable /* & ~Copyable */ {
     }
   }
 }
+#endif
 
 @available(SwiftStdlib 5.0, *)
 extension Span where Element: Hashable /* & ~Copyable */ {