getLineStart(_:end:contentsEnd:for:)

Returns by reference the beginning of the first line and the end of the last line touched by the given range.

func getLineStart(_ start: UnsafeMutablePointer<Self.Index>, end: UnsafeMutablePointer<Self.Index>, contentsEnd: UnsafeMutablePointer<Self.Index>, for range: some RangeExpression<String.Index>)