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Standard library for the Scala Programming Language
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.collection
package generic
import mutable.Builder
import scala.annotation.implicitNotFound
/** A base trait for builder factories.
*
* @tparam From the type of the underlying collection that requests
* a builder to be created.
* @tparam Elem the element type of the collection to be created.
* @tparam To the type of the collection to be created.
*
* @see [[scala.collection.mutable.Builder]]
* @author Martin Odersky
* @author Adriaan Moors
* @since 2.8
*/
@implicitNotFound(msg = "Cannot construct a collection of type ${To} with elements of type ${Elem} based on a collection of type ${From}.")
trait CanBuildFrom[-From, -Elem, +To] {
/** Creates a new builder on request of a collection.
* @param from the collection requesting the builder to be created.
* @return a builder for collections of type `To` with element type `Elem`.
* The collections framework usually arranges things so
* that the created builder will build the same kind of collection
* as `from`.
*/
def apply(from: From): Builder[Elem, To]
/** Creates a new builder from scratch.
*
* @return a builder for collections of type `To` with element type `Elem`.
* @see scala.collection.breakOut
*/
def apply(): Builder[Elem, To]
}