gistfile1.txt

$ ~/scala/scala-2.13.10/bin/scala -opt:local
Welcome to Scala 2.13.10 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_131).
Type in expressions for evaluation. Or try :help.

scala> case class Box[A](value: A) extends AnyVal
class Box

scala> class C { def foo = Box(42).value }
class C

scala> :javap C
[...]
  public int foo();
    descriptor: ()I
    flags: ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
         0: bipush        42
         2: ireturn