accessing the class in which a trait is mixed in

You can try using "this.type":

trait SimpleTrait {
def foo: this.type = { println(this); this }
}

On Sat, Oct 2, 2010 at 10:48 AM, gabriele renzi wrote:
> Hi everyone,
>
> I've been looking around for a while but I am not sure if the answers
> I found are still up to date for scala 2.8: is it possible write a
> method m() in a trait T whose return type is the class in which the
> trait was mixed?
>
> E.g. in pseudo scala
>
> trait SillyTrait {
>  def printAndReturn: Self = { println(this); this }
> }
>
> or
>
> trait SillyTrait { self: UnboundT <: SillyTrait =>
>  def printAndReturn: UnboundT = ....
> }
>
>
> As far as I understand I have to write this as
>
> trait SillyTrait[Klass] {
>  def printAndReturn: Klass = {...}
> }
>
>
> because even by using self type annotations I am unable to use an
> unbound type parameter.
>
> Am I missing something, and this is already possible in some other way?
> Or, is this implicit access to the enclosing type something that is
> inherently impossible in the scala type system,
> or just something that is considered unnecessary since it can be
> solved by using a type parameter for the trait?
>
> Thanks in advance.
>
>
> --
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>