   ) where R.Bound == Index {
     let range = range.relative(to: self)
     _ns.enumerateLinguisticTags(
-      in: _toNSRange(range),
+      in: _toRelativeNSRange(range),
       scheme: tagScheme._ephemeralString,
       options: opts,
       orthography: orthography != nil ? orthography! : nil

  @available(swift, deprecated: 4.0,
    message: "Please use String slicing subscript.")
  public func substring(with aRange: Range<Index>) -> String {
    return _ns.substring(with: _toNSRange(aRange))
  }
}


      _ns.rangeOfCharacter(
        from: aSet,
        options: mask,
        range: _toRelativeNSRange(
          aRange ?? startIndex..<endIndex
        )
      )
