atrick6

Yes, it removes exclusivity checks and bounds checks.

From the doc comments:

  /// Accesses the `Pointee` instance referenced by `self`.
  ///
  /// - Precondition: Either the pointee has been initialized with an
  ///   instance of type `Pointee`, or `pointee` is being assigned to
  ///   and `Pointee` is a trivial type.
  public var pointee: Pointee

So, `a.pointee = 42` is fine since we all know that `Int` is a trivial type.