Using self-type (Scala)

	package types
	object SelfTypeDemo {
	/**
	* using the self-type we declare that any BigTimeSpender also must be a Millionaire
	*/
	trait BigTimeSpender {
	self: Millionaire =>
	def wasteMoney: Unit = println("I can waste money on champagne")
	}
	trait Millionaire
	//class RichEmployee extends BigTimeSpender
	/**
	* This does not compile and gives following error:
	* illegal inheritance; self-type types.SelfTypeDemo.RichEmployee
	* does not conform to types.SelfTypeDemo.BigTimeSpender's selftype
	* types.SelfTypeDemo.BigTimeSpender with types.SelfTypeDemo.Millionaire
	*/
	//we have to mixin Millionaire
	class RichEmployee extends BigTimeSpender with Millionaire
	//but the order in which the traits are mixed in does not matter for this particular case
	class OtherRichEmployee extends Millionaire with BigTimeSpender
	def main(args: Array[String]): Unit = {
	val employee1 = new RichEmployee
	employee1.wasteMoney
	val employee2 = new OtherRichEmployee
	employee2.wasteMoney
	//we can also create a similar type in runtime
	val employee3 = new Object with BigTimeSpender with Millionaire
	employee3.wasteMoney
	}
	}

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