scala.Equals.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
/** An interface containing operations for equality.
* The only method not already present in class `AnyRef` is `canEqual`.
*/
trait Equals extends Any {
/** A method that should be called from every well-designed equals method
* that is open to be overridden in a subclass. See
* [[http://www.artima.com/pins1ed/object-equality.html Programming in Scala,
* Chapter 28]] for discussion and design.
*
* @param that the value being probed for possible equality
* @return true if this instance can possibly equal `that`, otherwise false
*/
def canEqual(that: Any): Boolean
/** The universal equality method defined in `AnyRef`.
*/
def equals(that: Any): Boolean
}