new FunctionK[F, IO] {
  override def apply[A](fa: F[A]): IO[A] = fa.toIO
}

Effect.toIOK

def doSomeAction[F[_]: cats.effect.Effect]: F[Unit] = ???

def main() = {
  doSomeAction[SomeContext].toIO.unsafeRunSync()
//                         ^~~~~~~~~~~~~~~~~~~~~
//                         warning: EffectがIOに即時変換されて副作用が発火されています
}

import scala.collection.immutable.Vector
Vector(1, 2, 3) ++ Vector(4)

import scala.collection.immutable.Vector
Vector(1, 2, 3) +: 4

import scala.collection.immutable.HashSet
HashSet(1, 2, 3) ++ Vector(4)

import scala.collection.immutable.HashSet
HashSet(1, 2, 3) + 4