How to check two `Array` instances for identity equality in constant time?

Using Swift
49

If we are willing to accept the possibility of padding bytes giving us a false negative, it is trivially easy to write a function that checks two values of the same type for identicality—identicalness?

extension Equatable {
  @inlinable /* @backDeployed etc */
  public func isKnownIdentical(to other: Self) -> Bool {
    withUnsafeBytes(of: self) { lhs in
      withUnsafeBytes(of: other) { rhs in
        lhs.elementsEqual(rhs) // or just memcmp
      }
    }
  }
}

Have we definitely ruled out the utility of that option in this thread? It would be at least as correct as a default implementation that always returned false.

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