gistfile1.scala

trait ModelService[T] {
  
  val selectAll = Queryable[T] // Compiler error : No TypeTag for T, plus issues with "evidences"
  val selectById = (id:Int) => selectAll.filter(_.id == id)
  
  def all: Try[Option[Vector[T]]]
  def get (id:Int): Try[Option[T]]
  def add (obj: T): Try[Option[Int]]
  def update (id:Int, obj:T): Try[Option[Int]]
  def delete (id:Int):Try[Option[Int]]
  
}