Allow Refined types on case classes used by Doobie

doobie-refined-meta-composite.scala

// Credit to  Kevin Horlick @beefyhalo fir the Meta implementation 
// See https://gitter.im/tpolecat/doobie/archives/2015/12/22
// It wasn't straightforward to find the answer, my Google-foo is weak, so I hope
// this helps people looking for this answer

// allows generation of doobie Meta objects from Refined types
  implicit def refinedMeta[T: Meta, P, F[_, _]](implicit tt: TypeTag[F[T, P]],
                                                ct: ClassTag[F[T, P]],
                                                validate: Validate[T, P],
                                                refType: RefType[F]): Meta[F[T, P]] =
    Meta[T].xmap(refType.refine[P](_) match {
      case Left(err) => throw InvalidObjectMapping(ct.runtimeClass, ct.getClass)
      case Right(t)  => t
    }, refType.unwrap)

  // allows generation of doobie Composite objects from Refined types
  implicit def refinedComposite[T: Composite, P, F[_, _]](implicit tt: TypeTag[F[T, P]],
                                                          ct: ClassTag[F[T, P]],
                                                          validate: Validate[T, P],
                                                          refType: RefType[F]): Composite[F[T, P]] =
    Composite[T].imap(refType.refine[P](_) match {
      case Left(err) => throw InvalidObjectMapping(ct.runtimeClass, ct.getClass)
      case Right(t)  => t
    })(refType.unwrap)

FYI we plan to have a doobie-refined module for 0.4.2

That's great! Thanks a lot!