If you do the second one as ``` data class Id private constr kotlinlang #getting-started

If you do the second one as ``` data class Id priv...

Ruckus

12/18/2016, 1:30 PM

If you do the second one as

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data class Id private constructor(val value: String) {
   companion object {
       operator fun invoke(value: String) = Id(value.toLowerCase)
   }
}

you don't need to define the extra function.