Scala: typeTag for an abstract type?

Question

I want to do something like the following:

trait Sim {
    type Probe
    var probe: Probe

    def reflectProbe() {
      // works: 
      val tt_int = scala.reflect.runtime.universe.typeTag[Int]
      // does not work (No TypeTag available for Sim.this.Probe):
      val tt_probe = scala.reflect.runtime.universe.typeTag[Probe]
    }
}

class WorldProbe

class World extends Sim {
  type Probe = WorldProbe
  var probe: Probe = new WorldProbe
}

I want to write a reflection method in trait sim that reflects the probe class of trait sim, defined as an abstract type Probe. How can I make typetag information for the abstract type available?

Thanks!

Answer 1

对于抽象类型，可以使用WeakTypeTags ：

val tt_probe = scala.reflect.runtime.universe.weakTypeTag[Probe]