scala> :power Power mode enabled. :phase is at typer. import scala.tools.nsc._, intp.global._, definitions._ Try :help or completions for vals._ and power._ scala> val u = rootMirror.universe u: $r.intp.global.type = scala> import u._, scala.reflect.internal.Flags import u._ import scala.reflect.internal.Flags scala> class C defined class C scala> val sym = u.typeOf[C].typeSymbol sym: u.Symbol = class C scala> sym.isContravariant res0: Boolean = false scala> sym setFlag Flags.INCONSTRUCTOR res1: sym.type = class C scala> sym.isClassLocalToConstructor res2: Boolean = true scala> sym.isContravariant // was true res3: Boolean = false scala> :quit