Using

This method is similar to apply, except the parameter type is changed from a generic R to the SAM type ScopeExitHandler, which allows for function literal expressions in Scala 2.12+ or Scala 2.11 with -Xexperimental compiler option.

The following function will perform n *= 2 after n += 20:

        import scala.concurrent.Future
        import com.thoughtworks.dsl.keywords.Using.scopeExit
        import com.thoughtworks.dsl.bangnotation._
        var n = 1
        def multiplicationAfterAddition = *[Future] {
          !scopeExit { () =>
            n *= 2
          }
          n += 20
        }

    Therefore, the final value of `n` should be `(1 + 20) * 2 = 42`.

        multiplicationAfterAddition.map { _ =>
          n should be(42)
        }