Make Factory capture checked

Author: odersky

tests/pos-special/stdlib/collection/Factory.scala

@@ -400,7 +400,7 @@ trait IterableOps[+A, +CC[_], +C] extends Any with IterableOnce[A] with Iterable
       if (i != headSize)
         fail
     }
-    iterableFactory.from(bs.map(_.result()))
+    iterableFactory.from(bs.map(_.result())).asInstanceOf // !!! needed for cc
   }
 
   def filter(pred: A => Boolean): C^{this, pred} = fromSpecific(new View.Filter(this, pred, isFlipped = false))
@@ -902,10 +902,10 @@ object IterableOps {
     protected def filtered: Iterable[A]^{this} =
       new View.Filter(self, p, isFlipped = false)
 
-    def map[B](f: A => B): CC[B]^{this} =
+    def map[B](f: A => B): CC[B]^{this, f} =
       self.iterableFactory.from(new View.Map(filtered, f))
 
-    def flatMap[B](f: A => IterableOnce[B]): CC[B]^{this} =
+    def flatMap[B](f: A => IterableOnce[B]): CC[B]^{this, f} =
       self.iterableFactory.from(new View.FlatMap(filtered, f))
 
     def foreach[U](f: A => U): Unit = filtered.foreach(f)

tests/pos-special/stdlib/collection/Iterable.scala

@@ -82,6 +82,8 @@ trait SeqOps[+A, +CC[_], +C] extends Any with SeqViewOps[A, CC, C] { self =>
 
   override def view: SeqView[A] = new SeqView.Id[A](this)
 
+  def iterableFactory: FreeSeqFactory[CC]
+
   /** Get the element at the specified index. This operation is provided for convenience in `Seq`. It should
     * not be assumed to be efficient unless you have an `IndexedSeq`. */
   @throws[IndexOutOfBoundsException]

tests/pos-special/stdlib/collection/Seq.scala

@@ -32,7 +32,7 @@ trait Iterable[+A] extends collection.Iterable[A]
 
 @SerialVersionUID(3L)
 object Iterable extends IterableFactory.Delegate[Iterable](List) {
-  override def from[E](it: IterableOnce[E]): Iterable[E] = it match {
+  override def from[E](it: IterableOnce[E]^): Iterable[E]^{it} = it match {
     case iterable: Iterable[E] => iterable
     case _ => super.from(it)
   }

tests/pos-special/stdlib/collection/immutable/Iterable.scala

@@ -526,7 +526,7 @@ class ArrayDeque[sealed A] protected (
 @SerialVersionUID(3L)
 object ArrayDeque extends StrictOptimizedSeqFactory[ArrayDeque] {
 
-  def from[sealed B](coll: collection.IterableOnce[B]): ArrayDeque[B] = {
+  def from[sealed B](coll: collection.IterableOnce[B]^): ArrayDeque[B] = {
     val s = coll.knownSize
     if (s >= 0) {
       val array = alloc(s)

tests/pos-special/stdlib/collection/mutable/ArrayDeque.scala

@@ -110,7 +110,7 @@ object ArraySeq extends StrictOptimizedClassTagSeqFactory[ArraySeq] { self =>
   private[this] val EmptyArraySeq  = new ofRef[AnyRef](new Array[AnyRef](0))
   def empty[T : ClassTag]: ArraySeq[T] = EmptyArraySeq.asInstanceOf[ArraySeq[T]]
 
-  def from[sealed A : ClassTag](it: scala.collection.IterableOnce[A]): ArraySeq[A] = make(Array.from[A](it))
+  def from[sealed A : ClassTag](it: scala.collection.IterableOnce[A]^): ArraySeq[A] = make(Array.from[A](it))
 
   def newBuilder[sealed A : ClassTag]: Builder[A, ArraySeq[A]] = ArrayBuilder.make[A].mapResult(make)
 

tests/pos-special/stdlib/collection/mutable/ArraySeq.scala

@@ -130,7 +130,7 @@ class Queue[sealed A] protected (array: Array[AnyRef], start: Int, end: Int)
 @SerialVersionUID(3L)
 object Queue extends StrictOptimizedSeqFactory[Queue] {
 
-  def from[sealed A](source: IterableOnce[A]): Queue[A] = empty ++= source
+  def from[sealed A](source: IterableOnce[A]^): Queue[A] = empty ++= source
 
   def empty[sealed A]: Queue[A] = new Queue
 

tests/pos-special/stdlib/collection/mutable/Queue.scala

@@ -135,7 +135,7 @@ class Stack[sealed A] protected (array: Array[AnyRef], start: Int, end: Int)
 @SerialVersionUID(3L)
 object Stack extends StrictOptimizedSeqFactory[Stack] {
 
-  def from[sealed A](source: IterableOnce[A]): Stack[A] = empty ++= source
+  def from[sealed A](source: IterableOnce[A]^): Stack[A] = empty ++= source
 
   def empty[sealed A]: Stack[A] = new Stack