Explicit SerialVersionUID for all ClassTags / Manifests

Looking at the class hierarchy around ClassTag and Manifest, the only
class that had a serialVersionUID is AnyValManifest, where the hierarchy
is something like:

trait ClassTag                      // extends Serializable
|- class GenericClassTag
|- trait Manifest
   |- class ClassTypeManifest
   |- class SingletonTypeManifest
   |- ...
   |- abstract class AnyValManifest // has SerialVersionUID
      |- class DoubleManifest
      |- ...

Note that AnyValManifest is an abstract class, so the SerialVersionUID
annotation does not help there.

This commit adds explicit SerialVersionUID annotations to (hopefully)
all subclasses of ClassTag, to make sure they are stable under
compatible changes (such as changing -Xmixin-force-forwarders).

1 files changed, 1 insertions, 0 deletions

diff --git a/src/library/scala/reflect/ClassTag.scala b/src/library/scala/reflect/ClassTag.scala
index eb3aeeecfc..30ceadceeb 100644
--- a/src/library/scala/reflect/ClassTag.scala
+++ b/src/library/scala/reflect/ClassTag.scala
@@ -119,6 +119,7 @@ object ClassTag {
   val Nothing : ClassTag[scala.Nothing]    = Manifest.Nothing
   val Null    : ClassTag[scala.Null]       = Manifest.Null
 
+  @SerialVersionUID(1L)
   private class GenericClassTag[T](val runtimeClass: jClass[_]) extends ClassTag[T]
 
   def apply[T](runtimeClass1: jClass[_]): ClassTag[T] =