restrict creation of of objects to a factory in swift 4

I have a family of classes in swift 4.2 and I want to restrict the creation of those instances only to the factory class, in C++ I can enforce this by declaring the constructors as private and add the friend keyword to the factory method like this:

class A{
 friend factoryClass::createInstance(int type);
  private A();
}

class subA: private A{
  friend factoryClass::createInstance(int type);
  private subA() : A(){
  }
}

class factoryClass{
    static A* createInstance(int type){
      switch(type){
      case 0:
         return new A();
      case 1:
      default:
         return new subA();
      }
    }
}

Is it possible to do this in swift 4.2? I'm pretty a new on this.