How to create an instance of type T at runtime with TypeTags

Question

Here below is how to create a new instance of type T at runtime with Manifest:

trait MyTrait
class MyClass1(val name: String) extends MyTrait
cl         


        

Answer 1

Eventually here is the implementation that actually works - please just assume this answer comes from som-snytt:

import scala.reflect.runtime._
import scala.reflect.runtime.universe._

class Test[T <: MyTrait : TypeTag] {

  def createInstance(args: AnyRef*)(ctor: Int = 0): T = {
    val tt = typeTag[T]

    currentMirror.reflectClass(tt.tpe.typeSymbol.asClass).reflectConstructor(
      tt.tpe.members.filter(m =>
        m.isMethod && m.asMethod.isConstructor
      ).iterator.toSeq(ctor).asMethod
    )(args: _*).asInstanceOf[T]
  }   
}

I hope that helps.