More fun with -Xmigration.

to BufferLike (++ and similar now create a new collection.)

Removed MapLikeBase.  Annotated all the methods in mutable.{ Map, Set }
which mutated in-place in 2.7 to note that they create new
collections, and implemented same.

At this point the only +/- like method which mutates in place which I am
aware of is BufferLike.+ (see source comment for my observations.)

Also tweaked some collections return types as necessitated by these
changes, such as mutable.Set.clone() now returning "This" rather than
mutable.Set[A].

References #3089, closes #3179. Review by odersky.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/library/scala/collection/immutable/MapProxy.scala b/src/library/scala/collection/immutable/MapProxy.scala
index 84775c9a82..371af042e7 100644
--- a/src/library/scala/collection/immutable/MapProxy.scala
+++ b/src/library/scala/collection/immutable/MapProxy.scala
@@ -37,6 +37,7 @@ trait MapProxy[A, +B] extends Map[A, B] with MapProxyLike[A, B, Map[A, B]]
   override def + [B1 >: B](kv: (A, B1)): Map[A, B1] = newProxy(self + kv)
   override def + [B1 >: B](elem1: (A, B1), elem2: (A, B1), elems: (A, B1) *) =
     newProxy(self.+(elem1, elem2, elems: _*))
+
   override def -(key: A) = newProxy(self - key)
 
   override def filterKeys(p: A => Boolean) = self.filterKeys(p)