Merge pull request #9083 from lrytz/smallCleanups

[nomerge] small cleanups
scala · Jun 25, 2020 · cbe6ade · cbe6ade
2 parents d332b43 + 5ba248e
commit cbe6ade
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Showing 2 changed files with 8 additions and 5 deletions.
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -1292,7 +1292,7 @@ abstract class RefChecks extends Transform {
                 |it should have been processed and eliminated during expansion of an enclosing macro."""
           // The getOrElse part should never happen, it's just here as a backstop.
           val msg = sym.compileTimeOnlyMessage getOrElse defaultMsg
-          reporter.error(pos, sym.compileTimeOnlyMessage getOrElse defaultMsg)
+          reporter.error(pos, msg)
         }
       }
     }

diff --git a/src/library/scala/collection/immutable/HashMap.scala b/src/library/scala/collection/immutable/HashMap.scala
@@ -187,7 +187,7 @@ sealed class HashMap[A, +B] extends AbstractMap[A, B]
             this.merge0(thatHash, 0, concatMerger[A, B])
           case that =>
             var result: HashMap[A, B] = this
-            that.asInstanceOf[GenTraversableOnce[(A, B)]] foreach { case kv: (_, _) => result = result + kv }
+            that.asInstanceOf[GenTraversableOnce[(A, B)]].foreach(result += _)
             result
         }
         castToThat(result)
@@ -212,9 +212,9 @@ sealed class HashMap[A, +B] extends AbstractMap[A, B]
       val merger = HashMap.concatMerger[A, B].invert
       val result: HashMap[A, B] = that match {
         case thatHash: HashMap[A, B] =>
-          this.merge0(thatHash, 0, HashMap.concatMerger[A, B].invert)
+          this.merge0(thatHash, 0, merger)
 
-        case that:HasForeachEntry[A, B] =>
+        case that: HasForeachEntry[A, B] =>
           object adder extends Function2[A, B, Unit] {
             var result: HashMap[A, B] = HashMap.this
             override def apply(key: A, value: B): Unit = {
@@ -231,12 +231,15 @@ sealed class HashMap[A, +B] extends AbstractMap[A, B]
               result = result.updated0(key, computeHash(key), 0, kv._2, kv, merger)
             }
           }
-          that.asInstanceOf[scala.Traversable[(A,B)]] foreach adder
+          that.asInstanceOf[GenTraversableOnce[(A,B)]] foreach adder
           adder.result
       }
       castToThat(result)
     }
   }
+
+  // These methods exist to encapsulate the `.asInstanceOf[That]` in a slightly safer way -- only suitable values can
+  // be cast and the type of the `CanBuildFrom` guides type inference.
   private[this] def castToThat[C, That](m: HashMap[A, B])(implicit bf: CanBuildFrom[HashMap[A, B], C, That]): That = {
     m.asInstanceOf[That]
   }