gistfile1.scala

trait ExpressionTrueness[T] {
        def myElse(then: => T)
}

class ExpressionTruth[T](obj: T) extends ExpressionTrueness[T] {
        def myElse(then: => T) = obj
}

class ExpressionFalsity[T] extends ExpressionTrueness[T]() {
        def myElse(then: => T) = then
}

def myIf[T](cond: Boolean)(then: => T) : ExpressionTrueness[T] = {
        if (cond) {
                new ExpressionTruth[T](then)
        }
        else {
                new ExpressionFalsity[T]()
        }
}

myIf (1 > 2)  { println("true") } myElse { println("false") }

myIf (1 < 2)  { println("true") } myElse { println("false") }