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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala
package collection
package immutable
import generic._
import mutable.Builder
/** A trait for traversable collections that are guaranteed immutable.
* $traversableInfo
* @define mutability immutable
*
* @define usesMutableState
*
* Note: Despite being an immutable collection, the implementation uses mutable state internally during
* construction. These state changes are invisible in single-threaded code but can lead to race conditions
* in some multi-threaded scenarios. The state of a new collection instance may not have been "published"
* (in the sense of the Java Memory Model specification), so that an unsynchronized non-volatile read from
* another thread may observe the object in an invalid state (see
* [[https://issues.scala-lang.org/browse/SI-7838 SI-7838]] for details). Note that such a read is not
* guaranteed to ''ever'' see the written object at all, and should therefore not be used, regardless
* of this issue. The easiest workaround is to exchange values between threads through a volatile var.
*/
trait Traversable[+A] extends scala.collection.Traversable[A]
// with GenTraversable[A]
with GenericTraversableTemplate[A, Traversable]
with TraversableLike[A, Traversable[A]]
with Immutable {
override def companion: GenericCompanion[Traversable] = Traversable
override def seq: Traversable[A] = this
}
/** $factoryInfo
* The current default implementation of a $Coll is a `List`.
* @define coll immutable traversable collection
* @define Coll `immutable.Traversable`
*/
object Traversable extends TraversableFactory[Traversable] {
implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, Traversable[A]] = ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]]
def newBuilder[A]: Builder[A, Traversable[A]] = new mutable.ListBuffer
}
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