FullExample.scala

val complex = ComplexElement(
  value = List(
    StringElement(value = "first element"),
    StringElement(value = "second element")
  )
)

import shapeless._

sealed trait DefaultValidation extends Poly1 {
  implicit def default[T] = at[T](x => true)
}
object validates extends DefaultValidation {
  implicit def caseValidated[A](implicit v: ValidatorTypeClass[A]) = at[A](x => v.validate(x))
}

object combine extends Poly2 {
  implicit def caseValidation = at[Boolean, Boolean] (_ && _)
}

sealed trait ValidatorTypeClass[A] {
  def validate(a: A): Boolean
}
object ValidatorTypeClass {
  def validateElement[A](a: A)(implicit v: ValidatorTypeClass[A]) = v.validate(a)

  implicit def stringElementValidator = new ValidatorTypeClass[String] {
    override def validate(a: String): Boolean = true //validation logic for strings
  }
  implicit def numberElementValidator = new ValidatorTypeClass[Double] {
    override def validate(a: Double): Boolean = true //validation logic for numbers
  }
  implicit def booleanElementValidator = new ValidatorTypeClass[Boolean] {
    override def validate(a: Boolean): Boolean = true //validation logic for booleans
  }
  implicit def complexElementValidator = new ValidatorTypeClass[ComplexElement] {
    override def validate(a: ComplexElement): Boolean = true
  }
}

everything(validates)(combine)(complex)