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POUsing generic case classes in Scala
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copied!<p>I wonder whether using generics for Scala case classes can save some boilerplate code.</p> <p>Let's save I have the following class hieararchy to emulate a "variant" type that boxes a set of types and allows unboxing them using pattern matching:</p> <pre><code>sealed abstract class Box; case class DoubleBox(v: Double) extends Box; case class StringBox(v: String) extends Box; case class BooleanBox(v: Boolean) extends Box; def typeName(b: Box) = b match { case DoubleBox(v) => "Double" case StringBox(v) => "String" case BooleanBox(v) => "Boolean" case _ => "Unknown" } </code></pre> <p>There may be places in the code where it would be more convenient to deal with the leaf case classes if they were generics. Something like:</p> <pre><code>sealed abstract class Box; case class TypedBox[T](v: T) extends Box; def typeName2(b: Box) = b match { case TypedBox[Double](v) => "Double" case TypedBox[String](v) => "String" case TypedBox[Boolean](v) => "Boolean" case _ => "Unknown" } </code></pre> <p>But this doesn't compile. As far as I understand this syntax is not really recognized as valid Scala syntax.</p> <p>Is it possible to make what I want working or it's a bad idea and I just don't get something?</p> <p><strong>EDIT:</strong> Vinicius answered my question, but looking at the answer I have another question. Is it possible to hint the compiler somehow that only certain list of types can be used to parameters TypedBox? I want that to make sure the compiler can still do exhaustiveness check of TypedBox usage/matching.</p>

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