class In<in T> {
  ~In.f:T->Unit~fun f(t : T) : Unit {}
  ~In.f:Int->Int~fun f(t : Int) : Int {}
  ~In.f1~fun f1(t : T) : Unit {}
}

class Out<out T> {
  ~Out.f~fun f() : T {}
  ~Out.f(a)~fun f(a : Int) : Int {a}
}

class Inv<T> {
  ~Inv.f~fun f(t : T) : T {t}
  ~Inv.inf~fun inf(t : T) : Unit {}
  ~Inv.outf~fun outf() : T {}
}

fun testInOut() {
  new In<String>().`In.f:T->Unit`f("1");
  (return : In<in String>).`In.f:T->Unit`f("1");
  (return : In<out String>).`!`f("1")
  (return : In<*>).`!`f("1");

  new In<String>().`In.f:Int->Int`f(1);
  (return : In<in String>).`In.f:Int->Int`f(1);
  (return : In<out String>).`In.f:Int->Int`f(1)
  (return : In<out String>).`!`f1(1)
  (return : In<*>).`In.f:Int->Int`f(1);

  new Out<Int>().`Out.f(a)`f(1)
  (return : Out<out Int>).`Out.f(a)`f(1)
  (return : Out<in Int>).`Out.f(a)`f(1)
  (return : Out<*>).`Out.f(a)`f(1)

  new Out<Int>().`Out.f`f()
  (return : Out<out Int>).`Out.f`f()
  (return : Out<in Int>).`Out.f`f()
  (return : Out<*>).`Out.f`f()

  new Inv<Int>().`Inv.f`f(1)
  (return : Inv<in Int>).`Inv.f`f(1)
  (return : Inv<out Int>).`!`f(1)
  (return : Inv<*>).`!`f(1)

  new Inv<Int>().`Inv.inf`inf(1)
  (return : Inv<in Int>).`Inv.inf`inf(1)
  (return : Inv<out Int>).`!`inf(1)
  (return : Inv<*>).`!`inf(1)

  new Inv<Int>().`Inv.outf`outf()
  ((return : Inv<in Int>).`Inv.outf`outf())`:std::Any`
  (return : Inv<out Int>).`Inv.outf`outf()
  (return : Inv<*>).`Inv.outf`outf()

  new Inv<Int>().`Inv.outf`outf(1)
}