Implicit parameter resolution for higher kinded types

Question

Consider the following code:

object foo {

    trait Bar[Q[_]]

    implicit object OptionBar extends Bar[Option]

    def test[T, C[_]](c: C[T])(implicit ba         


        

Answer 1

That's because Some(42) is a more specific type than Option[Int]. It is a Some[Int]. See alternative coding below:

object foo {

    trait Bar[Q[_]]

    implicit object OptionBar extends Bar[Option]

    def test[T, C[_]](c: C[T])(implicit bar: Bar[C]) = ()

    def main(args: Array[String]) {
      test(Option(42))
    }
}