scala.collection.generic.MutableSortedSetFactory.scala Maven / Gradle / Ivy
/*
* Scala (https://www.scala-lang.org)
*
* Copyright EPFL and Lightbend, Inc.
*
* Licensed under Apache License 2.0
* (http://www.apache.org/licenses/LICENSE-2.0).
*
* See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
package scala
package collection
package generic
import scala.collection.mutable.{ Builder, GrowingBuilder }
import scala.language.higherKinds
/**
* @define Coll `mutable.SortedSet`
* @define coll mutable sorted set
*
* @author Lucien Pereira
*
*/
abstract class MutableSortedSetFactory[CC[A] <: mutable.SortedSet[A] with SortedSetLike[A, CC[A]] with mutable.Set[A] with mutable.SetLike[A, CC[A]]] extends SortedSetFactory[CC] {
/**
* mutable.SetBuilder uses '+' which is not a primitive for anything extending mutable.SetLike,
* this causes serious performance issues since each time 'elems = elems + x'
* is evaluated elems is cloned (which is O(n)).
*
* Fortunately GrowingBuilder comes to rescue.
*
*/
override def newBuilder[A](implicit ord: Ordering[A]): Builder[A, CC[A]] = new GrowingBuilder[A, CC[A]](empty)
}