CODEWITHSUNDEEP
scalatypes
St.Antario
St.Antario

Reputation: 27455

Generic type argument

I have the following trait:

trait F{
   type T
}

and

trait C[T]{
   def getF: F{ type T = //I want the outer T}
}

Is there a way to refer to the generic type argument without introducing helper type variable and renaming the type parameter?

Upvotes: 1

Views: 47

Answers (2)

Dima
Dima

Reputation: 40510

If you weren't so inclined to call all types T, you could just do 

trait C[Foo] {
  def getF: F { type T = Foo }
}

Upvotes: 1

Mikaël Mayer
Mikaël Mayer

Reputation: 10710

It seems like in Dotty you can do so (see http://dotty.epfl.ch/docs/internals/higher-kinded-v2.html) :

trait C[type T]{ self =>
   def getF: F{ type T = self.T }
}

Otherwise for the current scala version I don't know if it is feasible to do better than introducing an helper type variable:

trait C[T]{
   type A = T
   def getF: F{ type T = A }
}

Upvotes: 2

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