scala> val b = strawman.collection.immutable.BitSet(1)
b: strawman.collection.immutable.BitSet = BitSet.BitSet1(1)
scala> b.collect{ case x => x }
^
error: ambiguous reference to overloaded definition,
both method collect in trait StrictOptimizedIterableOps of type [B](pf: PartialFunction[Int,B])strawman.collection.immutable.Set[B]
and method collect in trait SortedSetOps of type [B](pf: PartialFunction[Int,B])(implicit evidence$6: Ordering[B])strawman.collection.immutable.SortedSet[B]
match argument types (PartialFunction[Int,Int])