Merge pull request #249 from fdietze/fix-mutable-priority-queue

Add implicit: genericOrderedCompanionToCBF

Author: julienrf

compat/src/main/scala-2.11/scala/collection/compat/package.scala

@@ -12,10 +12,15 @@
 
 package scala.collection
 
-import scala.collection.generic.IsTraversableLike
+import scala.collection.generic.{CanBuildFrom, GenericOrderedCompanion, IsTraversableLike}
 import scala.{collection => c}
 
 package object compat extends compat.PackageShared {
+  implicit def genericOrderedCompanionToCBF[A, CC[X] <: Traversable[X]](
+      fact: GenericOrderedCompanion[CC])(
+      implicit ordering: Ordering[A]): CanBuildFrom[Any, A, CC[A]] =
+    CompatImpl.simpleCBF(fact.newBuilder[A])
+
   implicit def toTraversableLikeExtensionMethods[Repr](self: Repr)(
       implicit traversable: IsTraversableLike[Repr])
     : TraversableLikeExtensionMethods[traversable.A, Repr] =

compat/src/main/scala-2.12/scala/collection/compat/package.scala

@@ -12,7 +12,7 @@
 
 package scala.collection
 
-import scala.collection.generic.IsTraversableLike
+import scala.collection.generic.{CanBuildFrom, GenericOrderedCompanion, IsTraversableLike}
 import scala.{collection => c}
 import scala.collection.{mutable => m}
 
@@ -27,6 +27,11 @@ package object compat extends compat.PackageShared {
       build(m.SortedMap.newBuilder[K, V], source)
   }
 
+  implicit def genericOrderedCompanionToCBF[A, CC[X] <: Traversable[X]](
+      fact: GenericOrderedCompanion[CC])(
+      implicit ordering: Ordering[A]): CanBuildFrom[Any, A, CC[A]] =
+    CompatImpl.simpleCBF(fact.newBuilder[A])
+
   implicit def toTraversableLikeExtensionMethods[Repr](self: Repr)(
       implicit traversable: IsTraversableLike[Repr])
     : TraversableLikeExtensionMethods[traversable.A, Repr] =

compat/src/test/scala/test/scala/collection/CollectionTest.scala

@@ -17,6 +17,7 @@ import org.junit.Test
 
 import scala.collection.compat._
 import scala.collection.immutable.BitSet
+import scala.collection.mutable.PriorityQueue
 import scala.collection.LinearSeq
 
 class CollectionTest {
@@ -35,6 +36,10 @@ class CollectionTest {
     val bT: BitSet = b
     assertEquals(BitSet(1, 2, 3), b)
 
+    val c          = xs.to(PriorityQueue)
+    val cT: PriorityQueue[Int]  = c
+    assert(PriorityQueue(1, 2, 3) sameElements c)
+
     val ys = List(1 -> "a", 2 -> "b")
     val m  = ys.to(Map)
     // Not possible - `to` returns a Col[A] so this is only typed as an Iterable[(Int, String)]