class IncDec() {
fun inc() : IncDec = this
fun dec() : IncDec = this
}
fun testIncDec() {
var x = IncDec()
x++
++x
x--
--x
x = x++
x = x--
x = ++x
x = --x
}
class WrongIncDec() {
fun inc() : Int = 1
fun dec() : Int = 1
}
fun testWrongIncDec() {
var x = WrongIncDec()
x++
++x
x--
--x
}
class UnitIncDec() {
fun inc() : Unit {}
fun dec() : Unit {}
}
fun testUnitIncDec() {
var x = UnitIncDec()
x++
++x
x--
--x
x = x++
x = x--
x = ++x
x = --x
}