Convert (small enough) case classes to and from tuples using shapeless ...

tuplegeneric.scala

import shapeless._
import ops.hlist.Tupler

trait TupleGeneric[C <: Product] extends Serializable {
  type Repr <: Product

  def to(t : C) : Repr

  def from(r : Repr) : C
}

object TupleGeneric {
  type Aux[C <: Product, R] = TupleGeneric[C] { type Repr = R }

  def apply[C <: Product](implicit tgc: TupleGeneric[C]): Aux[C, tgc.Repr] = tgc

  implicit def mkTG[C <: Product, L <: HList, R <: Product]
    (implicit cGen: Generic.Aux[C, L], tup: Tupler.Aux[L, R], tGen: Generic.Aux[R, L]): Aux[C, R] =
      new TupleGeneric[C] {
        type Repr = R

        def to(t : C) : Repr = cGen.to(t).tupled

        def from(r : Repr) : C = cGen.from(tGen.to(r))
      }
}

/// Repl session ...
scala> case class Person(name: String, age: Int)
defined class Person

scala> val gen = TupleGeneric[Person]
gen: TupleGeneric[Person]{type Repr = (String, Int)} = TupleGeneric$$anon$3@40fa23ce

scala> val mary = Person("Mary", 37)
mary: Person = Person(Mary,37)

scala> gen.to(mary)
res0: gen.Repr = (Mary,37)

scala> res0._1
res1: String = Mary

scala> res0._2
res2: Int = 37

scala> gen.from(("Fred", 23))
res3: Person = Person(Fred,23)