How to mix-in a trait to instance?

Question

Given a trait MyTrait:

trait MyTrait {
  def doSomething = println(\"boo\")
}

it can be mixed into a class with extends<

Answer 1

What about an implicit class? It seems easier to me compared to the way in the other answers with a final inner class and a "mixin"-function.

trait MyTrait {

    def traitFunction = println("trait function executed")

}

class MyClass {

    /**
     * This inner class must be in scope wherever an instance of MyClass
     * should be used as an instance of MyTrait. Depending on where you place
     * and use the implicit class you must import it into scope with
     * "import mypackacke.MyImplictClassLocation" or
     * "import mypackage.MyImplicitClassLocation._" or no import at all if
     * the implicit class is already in scope.
     * 
     * Depending on the visibility and location of use this implicit class an
     * be placed inside the trait to mixin, inside the instances class,
     * inside the instances class' companion object or somewhere where you
     * use or call the class' instance with as the trait. Probably the
     * implicit class can even reside inside a package object. It also can be
     * declared private to reduce visibility. It all depends on the structure
     * of your API.
     */
    implicit class MyImplicitClass(instance: MyClass) extends MyTrait

    /**
     * Usage
     */
    new MyClass().traitFunction

}