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package scala
package reflect
package internal
package util
import scala.language.implicitConversions
import TriState._
/** A simple true/false/unknown value, for those days when
* true and false don't quite partition the space.
*/
final class TriState private (val value: Int) extends AnyVal {
def isKnown = this != Unknown
def booleanValue = this match {
case True => true
case False => false
case _ => sys.error("Not a Boolean value")
}
}
object TriState {
implicit def booleanToTriState(b: Boolean): TriState = if (b) True else False
val Unknown = new TriState(-1)
val False = new TriState(0)
val True = new TriState(1)
}
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