scala – 我的方法和Predef中的conforms之间隐含模糊的问题

error: ambiguous implicit values:
both method hParseNil in object HApplyOps of type => (com.mystuff.bigdata.commons.collections.hlist.HNil) => com.mystuff.bigdata.commons.collections.hlist.HNil
and method conforms in object Predef of type [A]<:<[A,A]
match expected type (com.mystuff.bigdata.commons.collections.hlist.HNil) => com.amadesa.bigdata.commons.collections.hlist.HNil
val l = hparse[HNil,HNil](HNil)

有人可以解释为什么会发生这种情况,以及它是否可以解决？

sealed trait HList

final case class HCons[H,T <: HList](head: H,tail: T) extends HList {
  def :+:[T](v: T) = HCons(v,this)
}

sealed class HNil extends HList {
  def :+:[T](v: T) = HCons(v,this)
}

object HNil extends HNil

// aliases for building HList types and for pattern matching
object HList {
  type :+:[H,T <: HList] = HCons[H,T]
  val :+: = HCons

}

object HApplyOps
{
  import HList.:+:



  implicit def hParseNil: HNil => HNil = _ => HNil

  implicit def hParseCons[InH,OutH,TIn <:HList,TOut<:HList](implicit parse:InH=>OutH,parseTail:TIn=>TOut): (InH :+: TIn) => (OutH :+: TOut) =
    in => HCons(parse(in.head),parseTail(in.tail))

  def hparse[In <: HList,Out <: HList](in:In)(implicit parse: In => Out):Out = in

}


object PG {

  import HList._


  def main(args: Array[String]) {

    import HApplyOps._

    val l = hparse[HNil,HNil](HNil)

  }
}