Merge pull request #4693 from scala/revert-3791-ticket/8346

Revert "SI-8346 Rebuild invariant sets in #toSet, avoiding CCE"

5 files changed, 6 insertions, 64 deletions

diff --git a/src/library/scala/collection/immutable/HashSet.scala b/src/library/scala/collection/immutable/HashSet.scala
index f548eac88d..6851ab6bc7 100644
--- a/src/library/scala/collection/immutable/HashSet.scala
+++ b/src/library/scala/collection/immutable/HashSet.scala
@@ -162,13 +162,6 @@ class HashSet[A] extends AbstractSet[A]
   def - (e: A): HashSet[A] =
     nullToEmpty(removed0(e, computeHash(e), 0))
 
-  /** Returns this $coll as an immutable set.
-   *  
-   *  A new set will not be built; lazy collections will stay lazy.
-   */
-  @deprecatedOverriding("Immutable sets should do nothing on toSet but return themselves cast as a Set.", "2.11.0")
-  override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
-
   override def filter(p: A => Boolean) = {
     val buffer = new Array[HashSet[A]](bufferSize(size))
     nullToEmpty(filter0(p, false, 0, buffer, 0))
diff --git a/src/library/scala/collection/immutable/ListSet.scala b/src/library/scala/collection/immutable/ListSet.scala
index a6e6fba0a5..2e17677359 100644
--- a/src/library/scala/collection/immutable/ListSet.scala
+++ b/src/library/scala/collection/immutable/ListSet.scala
@@ -138,13 +138,6 @@ class ListSet[A] extends AbstractSet[A]
 
   override def stringPrefix = "ListSet"
 
-  /** Returns this $coll as an immutable set.
-   *  
-   *  A new set will not be built; lazy collections will stay lazy.
-   */
-  @deprecatedOverriding("Immutable sets should do nothing on toSet but return themselves cast as a Set.", "2.11.0")
-  override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
-
   /** Represents an entry in the `ListSet`.
    */
   protected class Node(override val head: A) extends ListSet[A] with Serializable {
diff --git a/src/library/scala/collection/immutable/Set.scala b/src/library/scala/collection/immutable/Set.scala
index 7725ad9ee3..0fbf7942d4 100644
--- a/src/library/scala/collection/immutable/Set.scala
+++ b/src/library/scala/collection/immutable/Set.scala
@@ -35,7 +35,12 @@ trait Set[A] extends Iterable[A]
   override def companion: GenericCompanion[Set] = Set
   
   
-  override def toSet[B >: A]: Set[B] = to[({type l[a] = immutable.Set[B]})#l] // for bincompat; remove in dev
+  /** Returns this $coll as an immutable map.
+   *  
+   *  A new map will not be built; lazy collections will stay lazy.
+   */
+  @deprecatedOverriding("Immutable sets should do nothing on toSet but return themselves cast as a Set.", "2.11.0")
+  override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
   
   override def seq: Set[A] = this
   protected override def parCombiner = ParSet.newCombiner[A] // if `immutable.SetLike` gets introduced, please move this there!
@@ -57,7 +62,6 @@ object Set extends ImmutableSetFactory[Set] {
     def - (elem: Any): Set[Any] = this
     def iterator: Iterator[Any] = Iterator.empty
     override def foreach[U](f: Any =>  U): Unit = {}
-    override def toSet[B >: Any]: Set[B] = this.asInstanceOf[Set[B]]
   }
   private[collection] def emptyInstance: Set[Any] = EmptySet
 
@@ -88,8 +92,6 @@ object Set extends ImmutableSetFactory[Set] {
       if (f(elem1)) Some(elem1)
       else None
     }
-    @deprecatedOverriding("Immutable sets should do nothing on toSet but return themselves cast as a Set.", "2.11.0")
-    override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
   }
 
   /** An optimized representation for immutable sets of size 2 */
@@ -121,8 +123,6 @@ object Set extends ImmutableSetFactory[Set] {
       else if (f(elem2)) Some(elem2)
       else None
     }
-    @deprecatedOverriding("Immutable sets should do nothing on toSet but return themselves cast as a Set.", "2.11.0")
-    override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
   }
 
   /** An optimized representation for immutable sets of size 3 */
@@ -156,8 +156,6 @@ object Set extends ImmutableSetFactory[Set] {
       else if (f(elem3)) Some(elem3)
       else None
     }
-    @deprecatedOverriding("Immutable sets should do nothing on toSet but return themselves cast as a Set.", "2.11.0")
-    override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
   }
 
   /** An optimized representation for immutable sets of size 4 */
@@ -193,8 +191,6 @@ object Set extends ImmutableSetFactory[Set] {
       else if (f(elem4)) Some(elem4)
       else None
     }
-    @deprecatedOverriding("Immutable sets should do nothing on toSet but return themselves cast as a Set.", "2.11.0")
-    override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
   }
 }
 
diff --git a/test/files/run/t8346.check b/test/files/run/t8346.check
deleted file mode 100644
index 1ba5c31abe..0000000000
--- a/test/files/run/t8346.check
+++ /dev/null
@@ -1,6 +0,0 @@
-BitSet: List(invariant, invariant, invariant, invariant)
-HashSet: List(covariant (true), covariant (true), covariant (true), covariant (true))
-ListSet: List(covariant (true), covariant (true), covariant (true), covariant (true))
-SortedSet: List(invariant, invariant, invariant, invariant)
-TreeSet: List(invariant, invariant, invariant, invariant)
-ValueSet: invariant
diff --git a/test/files/run/t8346.scala b/test/files/run/t8346.scala
deleted file mode 100644
index 5f3df84174..0000000000
--- a/test/files/run/t8346.scala
+++ /dev/null
@@ -1,34 +0,0 @@
-object Test extends App {
-  import reflect.ClassTag
-
-  object SomeEnum extends Enumeration {
-    val one, two, three, four = Value
-  }
-
-  def sctor[A <: Set[Int]](f: Int => A)(implicit A: ClassTag[A])
-      : (String, Int => Set[Int]) =
-    (A.runtimeClass.getSimpleName, f)
-
-  val inits: Seq[(String, Int => Set[Int])] = {
-    import collection.immutable.{Seq => _, _}
-    Seq(sctor(BitSet(_)),
-        sctor(HashSet(_)),
-        sctor(ListSet(_)),
-        sctor(SortedSet(_)),
-        sctor(TreeSet(_)))
-  }
-
-  def sVarInfo[A](sa: Set[A]): String = {
-    val saa = sa.toSet[Any]
-    if (sa eq saa) s"""covariant (${(saa + "hi") contains "hi"})"""
-    else "invariant"
-  }
-
-  inits foreach {case (name, singleton) =>
-    print(s"${name}: ")
-    val one = singleton(1)
-    println(Seq(2,3,4).scanLeft(one)(_ + _) map sVarInfo toList)
-  }
-
-  println(s"ValueSet: ${sVarInfo(SomeEnum.values)}")
-}