Deprecated the @serializable annotation, introd...

Deprecated the @serializable annotation, introduce a new trait
"scala.Serializable" which has to be extended instead (cross-platform).

Known issues:
 - Companion objects of serializable classes (including case classes) are automatically made serializable. However, they don't extend "Serializable" statically because of the known difficulty (should be done before typing, but hard).
 - Writing "case class C() extends Serializable" gives "error: trait Serializable is inherited twice"
 - Functions are serializable, but don't extend Serializable dynamically (could be fixed by making FunctionN Serializable - shouldn't we?)

Note that @SerialVersionUID continues to be an annotation; it generates
a static field, which is not possible otherwise in scala.

Review by dragos, extempore.

Question to dragos: in JavaPlatform.isMaybeBoxed, why is there a test
for "JavaSerializableClass"? Is that correct?

1 files changed, 2 insertions, 1 deletions

diff --git a/src/library/scala/collection/mutable/ListBuffer.scala b/src/library/scala/collection/mutable/ListBuffer.scala
index 55629fe523..3c58ecb6df 100644
--- a/src/library/scala/collection/mutable/ListBuffer.scala
+++ b/src/library/scala/collection/mutable/ListBuffer.scala
@@ -38,13 +38,14 @@ import immutable.{List, Nil, ::}
  *  @define mayNotTerminateInf
  *  @define willNotTerminateInf
  */
-@serializable @SerialVersionUID(3419063961353022661L)
+@SerialVersionUID(3419063961353022661L)
 final class ListBuffer[A]
       extends Buffer[A]
          with GenericTraversableTemplate[A, ListBuffer]
          with BufferLike[A, ListBuffer[A]]
          with Builder[A, List[A]]
          with SeqForwarder[A]
+         with Serializable
 {
   override def companion: GenericCompanion[ListBuffer] = ListBuffer