tag:blogger.com,1999:blog-5089773352404981635.post7463794881081527980..comments2023-10-04T08:15:13.812-07:00Comments on Daily scala: In- and Co- variance of type parametersAnonymoushttp://www.blogger.com/profile/07600430363435495915noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-5089773352404981635.post-10589653811844922010-08-31T12:56:38.444-07:002010-08-31T12:56:38.444-07:00While A in List is defined to be covariant, A in S...While A in List is defined to be covariant, A in Set is invariant: List[+A], Set[A]. Why is following still legal:<br /><br />case class C(i:Int)<br />case class D(j:Int) extends C(j)<br />val s = collection.mutable.Set(C(1))<br />s += D(2) // covariant?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5089773352404981635.post-43994661040285526252010-03-26T12:53:41.073-07:002010-03-26T12:53:41.073-07:00doh. I must have been sleepingdoh. I must have been sleepingAnonymoushttps://www.blogger.com/profile/07600430363435495915noreply@blogger.comtag:blogger.com,1999:blog-5089773352404981635.post-90675838142463787032010-03-26T06:05:49.948-07:002010-03-26T06:05:49.948-07:00I must admit I’ve never heard of “intravariance”.I must admit I’ve never heard of “intravariance”.Anonymousnoreply@blogger.com