diff -r 7ba63bd216af -r c268def0784b src/Pure/ROOT.scala
--- a/src/Pure/ROOT.scala	Fri Jun 23 13:51:23 2023 +0200
+++ b/src/Pure/ROOT.scala	Fri Jun 23 14:43:15 2023 +0200
@@ -13,6 +13,8 @@
     Library.using(a)(f)
   def using_option[A <: AutoCloseable, B](opt: Option[A])(f: A => B): Option[B] =
     Library.using_option(opt)(f)
+  def using_optional[A <: AutoCloseable, B](opt: Option[A])(f: Option[A] => B): B =
+    Library.using_optional(opt)(f)
 
   val space_explode = Library.space_explode _
   val split_lines = Library.split_lines _