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object LeftOrRight {
def unapply[A](value: Either[A, A]): Option[A] = value match {
case scala.Left(x) => Some(x)
case scala.Right(x) => Some(x)
}
}
object NativelyTwo {
def unapply[A](value: Either[A, A]): Option[(A, A)] = value match {
case scala.Left(x) => Some(x -> x)
case scala.Right(x) => Some(x -> x)
}
}
class E {
def f1 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case LeftOrRight(a) => a } // warn
def f2 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case LeftOrRight((a, b)) => a } // no warn
def f3 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case LeftOrRight((a, b, c)) => a } // fail
}
class B {
def f1[A](x: A) = (Left(x): Either[A, A]) match { case LeftOrRight(a) => a } // no warn
def f2[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case LeftOrRight(a) => a } // warn
def f3[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case LeftOrRight((a, b)) => a } // no warn
def f4[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case LeftOrRight((a, b, c)) => a } // fail
}
class C {
def f1 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case NativelyTwo(a) => a } // warn
def f2 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case NativelyTwo((a, b)) => a } // no warn
def f3 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case NativelyTwo((a, b, c)) => a } // fail
}
class D {
def f1[A](x: A) = (Left(x): Either[A, A]) match { case NativelyTwo(a) => a } // warn
def f2[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case NativelyTwo(a) => a } // warn
def f3[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case NativelyTwo((a, b)) => a } // no warn
def f4[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case NativelyTwo((a, b, c)) => a } // fail
}
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