t12240.check

newSource1.scala:40: warning: unreachable code
    case ElidableIsEmpty(x) => x
                               ^
[[syntax trees at end of                    patmat]] // newSource1.scala
package <empty> {
  object SideEffectingIsEmpty extends scala.AnyRef {
    def <init>(): SideEffectingIsEmpty.type = {
      SideEffectingIsEmpty.super.<init>();
      ()
    };
    def unapply(i: Int): SideEffectingIsEmpty.type = this;
    def isEmpty: false = {
      scala.Predef.println("confirm isEmpty method doesn\'t get elided");
      false
    };
    private[this] val get: Int = 7;
    <stable> <accessor> def get: Int = SideEffectingIsEmpty.this.get
  };
  object ElidableIsEmpty extends scala.AnyRef {
    def <init>(): ElidableIsEmpty.type = {
      ElidableIsEmpty.super.<init>();
      ()
    };
    def unapply(i: Int): ElidableIsEmpty.type = this;
    private[this] val isEmpty: false = false;
    <stable> <accessor> def isEmpty: false = ElidableIsEmpty.this.isEmpty;
    private[this] val get: Int = 8;
    <stable> <accessor> def get: Int = ElidableIsEmpty.this.get
  };
  object SideEffectingIsEmptySeq extends scala.AnyRef {
    def <init>(): SideEffectingIsEmptySeq.type = {
      SideEffectingIsEmptySeq.super.<init>();
      ()
    };
    def unapplySeq(i: Int): SideEffectingIsEmptySeq.type = this;
    private[this] val length: Int = 3;
    <stable> <accessor> def length: Int = SideEffectingIsEmptySeq.this.length;
    private[this] val get: SideEffectingIsEmptySeq.type = this;
    <stable> <accessor> def get: SideEffectingIsEmptySeq.type = SideEffectingIsEmptySeq.this.get;
    private[this] val toSeq: List[String] = scala.`package`.List.apply[String]("Got", "Some", "List");
    <stable> <accessor> def toSeq: List[String] = SideEffectingIsEmptySeq.this.toSeq;
    def apply(i: Int): String = SideEffectingIsEmptySeq.this.toSeq.apply(i);
    def isEmpty: false = {
      scala.Predef.println("confirm seq isEmpty method doesn\'t get elided");
      false
    }
  };
  object ElidableIsEmptySeq extends scala.AnyRef {
    def <init>(): ElidableIsEmptySeq.type = {
      ElidableIsEmptySeq.super.<init>();
      ()
    };
    def unapplySeq(i: Int): ElidableIsEmptySeq.type = this;
    private[this] val length: Int = 3;
    <stable> <accessor> def length: Int = ElidableIsEmptySeq.this.length;
    private[this] val get: ElidableIsEmptySeq.type = this;
    <stable> <accessor> def get: ElidableIsEmptySeq.type = ElidableIsEmptySeq.this.get;
    private[this] val toSeq: List[String] = scala.`package`.List.apply[String]("Got", "Some", "List");
    <stable> <accessor> def toSeq: List[String] = ElidableIsEmptySeq.this.toSeq;
    def apply(i: Int): String = ElidableIsEmptySeq.this.toSeq.apply(i);
    private[this] val isEmpty: false = false;
    <stable> <accessor> def isEmpty: false = ElidableIsEmptySeq.this.isEmpty
  };
  object UseIt extends scala.AnyRef {
    def <init>(): UseIt.type = {
      UseIt.super.<init>();
      ()
    };
    def main(args: Array[String]): Int = {
      case <synthetic> val x1: Int = args.length;
      case8(){
        <synthetic> val o10: SideEffectingIsEmpty.type = SideEffectingIsEmpty.unapply(x1);
        if (o10.isEmpty.unary_!)
          {
            val x: Int = o10.get;
            matchEnd7(x)
          }
        else
          case9()
      };
      case9(){
        <synthetic> val o12: ElidableIsEmpty.type = ElidableIsEmpty.unapply(x1);
        if (o12.isEmpty.unary_!)
          {
            val x: Int = o12.get;
            matchEnd7(x)
          }
        else
          case11()
      };
      case11(){
        <synthetic> val o14: SideEffectingIsEmptySeq.type = SideEffectingIsEmptySeq.unapplySeq(x1);
        if (o14.isEmpty.unary_!)
          {
            val s: Seq[String] = o14.get.toSeq;
            matchEnd7(s.length)
          }
        else
          case13()
      };
      case13(){
        <synthetic> val o16: ElidableIsEmptySeq.type = ElidableIsEmptySeq.unapplySeq(x1);
        if (o16.isEmpty.unary_!)
          {
            val s: Seq[String] = o16.get.toSeq;
            matchEnd7(s.length)
          }
        else
          case15()
      };
      case15(){
        matchEnd7(throw new MatchError(x1))
      };
      matchEnd7(x: Int){
        x
      }
    }
  }
}

[[syntax trees at end of               posterasure]] // newSource1.scala
package <empty> {
  object SideEffectingIsEmpty extends Object {
    def <init>(): SideEffectingIsEmpty.type = {
      SideEffectingIsEmpty.super.<init>();
      ()
    };
    def unapply(i: Int): SideEffectingIsEmpty.type = this;
    def isEmpty(): Boolean = {
      scala.Predef.println("confirm isEmpty method doesn\'t get elided");
      false
    };
    private[this] val get: Int = 7;
    <stable> <accessor> def get(): Int = SideEffectingIsEmpty.this.get
  };
  object ElidableIsEmpty extends Object {
    def <init>(): ElidableIsEmpty.type = {
      ElidableIsEmpty.super.<init>();
      ()
    };
    def unapply(i: Int): ElidableIsEmpty.type = this;
    private[this] val isEmpty: Boolean = false;
    <stable> <accessor> def isEmpty(): Boolean = ElidableIsEmpty.this.isEmpty;
    private[this] val get: Int = 8;
    <stable> <accessor> def get(): Int = ElidableIsEmpty.this.get
  };
  object SideEffectingIsEmptySeq extends Object {
    def <init>(): SideEffectingIsEmptySeq.type = {
      SideEffectingIsEmptySeq.super.<init>();
      ()
    };
    def unapplySeq(i: Int): SideEffectingIsEmptySeq.type = this;
    private[this] val length: Int = 3;
    <stable> <accessor> def length(): Int = SideEffectingIsEmptySeq.this.length;
    private[this] val get: SideEffectingIsEmptySeq.type = this;
    <stable> <accessor> def get(): SideEffectingIsEmptySeq.type = SideEffectingIsEmptySeq.this.get;
    private[this] val toSeq: List = scala.`package`.List().apply(scala.runtime.ScalaRunTime.wrapRefArray(Array[String]{"Got", "Some", "List"}.$asInstanceOf[Array[Object]]())).$asInstanceOf[List]();
    <stable> <accessor> def toSeq(): List = SideEffectingIsEmptySeq.this.toSeq;
    def apply(i: Int): String = SideEffectingIsEmptySeq.this.toSeq().apply(i).$asInstanceOf[String]();
    def isEmpty(): Boolean = {
      scala.Predef.println("confirm seq isEmpty method doesn\'t get elided");
      false
    }
  };
  object ElidableIsEmptySeq extends Object {
    def <init>(): ElidableIsEmptySeq.type = {
      ElidableIsEmptySeq.super.<init>();
      ()
    };
    def unapplySeq(i: Int): ElidableIsEmptySeq.type = this;
    private[this] val length: Int = 3;
    <stable> <accessor> def length(): Int = ElidableIsEmptySeq.this.length;
    private[this] val get: ElidableIsEmptySeq.type = this;
    <stable> <accessor> def get(): ElidableIsEmptySeq.type = ElidableIsEmptySeq.this.get;
    private[this] val toSeq: List = scala.`package`.List().apply(scala.runtime.ScalaRunTime.wrapRefArray(Array[String]{"Got", "Some", "List"}.$asInstanceOf[Array[Object]]())).$asInstanceOf[List]();
    <stable> <accessor> def toSeq(): List = ElidableIsEmptySeq.this.toSeq;
    def apply(i: Int): String = ElidableIsEmptySeq.this.toSeq().apply(i).$asInstanceOf[String]();
    private[this] val isEmpty: Boolean = false;
    <stable> <accessor> def isEmpty(): Boolean = ElidableIsEmptySeq.this.isEmpty
  };
  object UseIt extends Object {
    def <init>(): UseIt.type = {
      UseIt.super.<init>();
      ()
    };
    def main(args: Array[String]): Int = {
      case <synthetic> val x1: Int = args.length();
      case8(){
        <synthetic> val o10: SideEffectingIsEmpty.type = SideEffectingIsEmpty.unapply(x1);
        if (o10.isEmpty().unary_!())
          {
            val x: Int = o10.get();
            matchEnd7(x)
          }
        else
          case9()
      };
      case9(){
        <synthetic> val o12: ElidableIsEmpty.type = ElidableIsEmpty.unapply(x1);
        if (o12.isEmpty().unary_!())
          {
            val x: Int = o12.get();
            matchEnd7(x)
          }
        else
          case11()
      };
      case11(){
        <synthetic> val o14: SideEffectingIsEmptySeq.type = SideEffectingIsEmptySeq.unapplySeq(x1);
        if (o14.isEmpty().unary_!())
          {
            val s: Seq = o14.get().toSeq();
            matchEnd7(s.length())
          }
        else
          case13()
      };
      case13(){
        <synthetic> val o16: ElidableIsEmptySeq.type = ElidableIsEmptySeq.unapplySeq(x1);
        if (o16.isEmpty().unary_!())
          {
            val s: Seq = o16.get().toSeq();
            matchEnd7(s.length())
          }
        else
          case15()
      };
      case15(){
        matchEnd7(throw new MatchError(scala.Int.box(x1)))
      };
      matchEnd7(x: Int){
        x
      }
    }
  }
}