4.6.Writer

/**
  * Writer
  */

import cats.syntax.writer._

val b = 123.writer(Vector("msg1", "msg2", "msg3"))

b.value
//cats.Id[Int] = 123

b.written
//cats.Id[scala.collection.immutable.Vector[String]] = Vector(msg1, msg2, msg3)

val (log, result) = b.run