blob: c3fe0e1625f543b9e532f327d5451605409f66a8 (
plain) (
tree)
|
|
object approximateUnion {
trait C[+T]
trait D
trait E
trait X[-T]
{
trait A extends C[A] with D
trait B extends C[B] with D
val coin = true
val x = if (coin) new A else new B
val y = Some(if (coin) new A else new B)
val xtest: C[A | B] & D = x
val ytest: Some[C[A | B] & D] = y
}
{
trait A extends C[X[A]] with D
trait B extends C[X[B]] with D with E
val coin = true
val x = if (coin) new A else new B
val y = Some(if (coin) new A else new B)
val xtest: C[X[A & B]] & D = x
val ytest: Some[C[X[A & B]] & D] = y
}
}
object approximateUnion2 {
trait C[T]
trait D
trait E
trait X[-T]
{
trait A extends C[A] with D
trait B extends C[B] with D
val coin = true
val x = if (coin) new A else new B
val y = Some(if (coin) new A else new B)
val xtest: C[_ >: A & B <: A | B] & D = x
val ytest: Some[C[_ >: A & B <: A | B] & D] = y
}
{
trait A extends C[X[A]] with D
trait B extends C[X[B]] with D with E
val coin = true
val x = if (coin) new A else new B
val y = Some(if (coin) new A else new B)
val xtest: C[_ >: X[A | B] <: X[A & B]] & D = x
val ytest: Some[C[_ >: X[A | B] <: X[A & B]]] = y
}
}
object approximateUnion3 {
trait C[-T]
trait D
trait E
trait X[-T]
{
trait A extends C[A] with D
trait B extends C[B] with D
val coin = true
val x = if (coin) new A else new B
val y = Some(if (coin) new A else new B)
val xtest: C[A & B] & D = x
val ytest: Some[C[A & B] & D] = y
}
{
trait A extends C[X[A]] with D
trait B extends C[X[B]] with D with E
val coin = true
val x = if (coin) new A else new B
val y = Some(if (coin) new A else new B)
val xtest: C[X[A | B]] & D = x
val ytest2: Some[C[X[A | B]] & D] = y
}
}
|