Adding a fluent API to a tagless interpreter via implicit function types

Fluent.scala

object Fluent {

  trait Foo[C[_]] {
    def meth1[T]() : C[T]
  }

  trait ConcreteC[T]

  class Lib[ElemT]{

    type Context[C[_], Alg[C] <: Foo[C], Elem] = implicit Alg[C] => C[Elem]

    def a : Context[ConcreteC, Foo[ConcreteC], ElemT] = implicitly[Foo[ConcreteC]]

    def meth1() : Context[Foo[ConcreteC], ElemT] = a.meth1()
  }
}