separated mutable and immutable maps

1 files changed, 8 insertions, 8 deletions

diff --git a/src/library/scala/collection/mutable/MapProxy.scala b/src/library/scala/collection/mutable/MapProxy.scala
index a215702f19..eda46ac702 100644
--- a/src/library/scala/collection/mutable/MapProxy.scala
+++ b/src/library/scala/collection/mutable/MapProxy.scala
@@ -30,18 +30,18 @@ trait MapProxy[A, B] extends Map[A, B] with collection.MapProxy[A, B] {
   def self: Map[A, B]
 
   override def update(key: A, value: B): Unit = self.update(key, value)
-  override def += (kv: (A, B)) = self += kv
-  override def += (kv1: (A, B), kv2: (A, B), kvs: (A, B)*) = self.+=(kv1, kv2, kvs: _*)
-  override def ++= (kvs: Iterable[(A, B)]) = self ++= kvs
-  override def ++= (kvs: Iterator[(A, B)]) = self ++= kvs
+  override def += (kv: (A, B)): this.type = { self += kv; this }
+  override def += (kv1: (A, B), kv2: (A, B), kvs: (A, B)*): this.type = { self.+=(kv1, kv2, kvs: _*); this }
+  override def ++= (kvs: Iterable[(A, B)]): this.type = { self ++= kvs; this }
+  override def ++= (kvs: Iterator[(A, B)]): this.type = { self ++= kvs; this }
   override def + (kv: (A, B)): Map[A, B] = self + kv
   override def + (kv1: (A, B), kv2: (A, B), kvs: (A, B)*): Map[A, B] = self.+(kv1, kv2, kvs: _*)
   override def ++ (kvs: Iterable[(A, B)]): Map[A, B] = self ++ kvs
   override def ++ (kvs: Iterator[(A, B)]): Map[A, B] = self ++ kvs
-  override def -= (key: A) = self -= key
-  override def -= (key1: A, key2: A, keys: A*) = self.-=(key1, key2, keys: _*)
-  override def --= (keys: Iterable[A]) = self --= keys
-  override def --= (keys: Iterator[A]) = self --= keys
+  override def -= (key: A): this.type = { self -= key; this }
+  override def -= (key1: A, key2: A, keys: A*): this.type = { self.-=(key1, key2, keys: _*); this }
+  override def --= (keys: Iterable[A]): this.type = { self --= keys; this }
+  override def --= (keys: Iterator[A]): this.type = { self --= keys; this }
   override def - (key: A): Map[A, B] = self - key
   override def - (key1: A, key2: A, keys: A*): Map[A, B] = self.-(key1, key2, keys: _*)
   override def -- (keys: Iterable[A]): Map[A, B] = self -- keys