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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.collection
package generic
import mutable.{Builder, MapBuilder}
import scala.language.higherKinds
/** A template for companion objects of `Map` and subclasses thereof.
*
* @define coll map
* @define Coll `Map`
* @define factoryInfo
* This object provides a set of operations needed to create `$Coll` values.
* @author Martin Odersky
* @version 2.8
* @since 2.8
* @define canBuildFromInfo
* The standard `CanBuildFrom` instance for `$Coll` objects.
* @see CanBuildFrom
* @define mapCanBuildFromInfo
* The standard `CanBuildFrom` instance for `$Coll` objects.
* The created value is an instance of class `MapCanBuildFrom`.
* @see CanBuildFrom
* @see GenericCanBuildFrom
*/
abstract class GenMapFactory[CC[A, B] <: GenMap[A, B] with GenMapLike[A, B, CC[A, B]]] {
/** The type constructor of the collection that can be built by this factory */
type Coll = CC[_, _]
/** An empty $Coll */
def empty[A, B]: CC[A, B]
/** A collection of type $Coll that contains given key/value bindings.
* @param elems the key/value pairs that make up the $coll
* @tparam A the type of the keys
* @tparam B the type of the associated values
* @return a new $coll consisting key/value pairs given by `elems`.
*/
def apply[A, B](elems: (A, B)*): CC[A, B] = (newBuilder[A, B] ++= elems).result
/** The default builder for $Coll objects.
* @tparam A the type of the keys
* @tparam B the type of the associated values
*/
def newBuilder[A, B]: Builder[(A, B), CC[A, B]] = new MapBuilder[A, B, CC[A, B]](empty[A, B])
/** The standard `CanBuildFrom` class for maps.
*/
class MapCanBuildFrom[A, B] extends CanBuildFrom[Coll, (A, B), CC[A, B]] {
def apply(from: Coll) = newBuilder[A, B]
def apply() = newBuilder
}
}
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