/// traversal couldn't start, `*undeleted_files` must be set to 0 and
  /// `*undeleted_dirs` must be set to 1.
  ///
  /// TODO(b/139060984): After all filesystems are converted, consider
  /// invariant about `*undeleted_files` and `*undeleted_dirs`.
  ///
  /// Plugins:
  ///   * Must set `status` to `TF_OK` if directory was deleted.
  ///   * Must set `status` to `TF_NOT_FOUND` if `path` doesn't exist.

	if s == "CFType" {
		return true
	}
	if c.getTypeIDs[s] {
		return true
	}
	if i := strings.Index(s, "Mutable"); i >= 0 && c.getTypeIDs[s[:i]+s[i+7:]] {
		// Mutable and immutable variants share a type ID.
		return true
	}
	return false
}

// Comment from Darwin's CFInternal.h
/*
// Tagged pointer support
// Low-bit set means tagged object, next 3 bits (currently)