tuples.kt

fun main(args: Array<String>) {
  println("a" to "b")
  println("a" to "b" tre "c")
  println("a" to "b" tre "c" fo "d")
  println("a" to "b" tre "c" fo "d" fi "e")
  println("a" to "b" tre "c" fo "d" fi "e" sik "f")
  println("a" to "b" tre "c" fo "d" fi "e" sik "f" seva "g")
}

infix fun <A, B, C> Pair<A, B>.tre(c: C) = Triple(first, second, c)
infix fun <A, B, C, D> Triple<A, B, C>.fo(d: D) = Quad(first, second, third, d)
infix fun <A, B, C, D, E> Quad<A, B, C, D>.fi(e: E) = Jackson(a, b, c, d, e)
infix fun <A, B, C, D, E, F> Jackson<A, B, C, D, E>.sik(f: F) = Rainbow(a, b, c, d, e, f)
infix fun <A, B, C, D, E, F, G> Rainbow<A, B, C, D, E, F>.seva(g: G) = Lucky(a, b, c, d, e, f, g)

data class Quad<out A, out B, out C, out D>(
  val a: A,
  val b: B,
  val c: C,
  val d: D
)

data class Jackson<out A, out B, out C, out D, out E>(
  val a: A,
  val b: B,
  val c: C,
  val d: D,
  val e: E
)

data class Rainbow<out A, out B, out C, out D, out E, out F>(
  val a: A,
  val b: B,
  val c: C,
  val d: D,
  val e: E,
  val f: F
)

data class Lucky<out A, out B, out C, out D, out E, out F, out G>(
  val a: A,
  val b: B,
  val c: C,
  val d: D,
  val e: E,
  val f: F,
  val g: G
)

What about suggestion to Kotlin lang? ;-)

Yes officer, this gist right here.

I regret only that I cannot happily react to the above comment by @ZacSweers

Clearly this needs:

data class Crazy<out A, out B, out C, out D, out E, out F, out G, out H>(
  val a: A,
  val b: B,
  val c: C,
  val d: D,
  val e: E,
  val f: F,
  val g: G,
  val h: H
)