typename T11, typename T12>
struct Types12 {
  typedef T1 Head;
  typedef Types11<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12> Tail;
};

template <typename T1, typename T2, typename T3, typename T4, typename T5,
    typename T6, typename T7, typename T8, typename T9, typename T10,
    typename T11, typename T12, typename T13>
struct Types13 {
  typedef T1 Head;

    typename T11, typename T12>
struct Types12 {
  typedef T1 Head;
  typedef Types11<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12> Tail;
};

template <typename T1, typename T2, typename T3, typename T4, typename T5,
    typename T6, typename T7, typename T8, typename T9, typename T10,
    typename T11, typename T12, typename T13>
struct Types13 {
  typedef T1 Head;

    typename T11, typename T12>
internal::ValueArray12<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11,
    T12> Values(T1 v1, T2 v2, T3 v3, T4 v4, T5 v5, T6 v6, T7 v7, T8 v8, T9 v9,
    T10 v10, T11 v11, T12 v12) {
  return internal::ValueArray12<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11,
      T12>(v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12);
}

    typename T11, typename T12>
internal::ValueArray12<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11,
    T12> Values(T1 v1, T2 v2, T3 v3, T4 v4, T5 v5, T6 v6, T7 v7, T8 v8, T9 v9,
    T10 v10, T11 v11, T12 v12) {
  return internal::ValueArray12<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11,
      T12>(v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12);
}

type T9 T3

type T10 struct {
	x struct {
		y ***struct {
			z *struct {
				Next *T11
			}
		}
	}
}

type T11 T10

type T12 struct {
	F1 *T15
	F2 *T13
	F3 *T16
}

type T13 T14
type T14 T15
type T15 T16
type T16 T17
type T17 T12

// issue 1672
type T18 *[10]T19
type T19 T18

func main() {
	_ = &T1{&T2{}}
	_ = &T2{&T2{}}
	_ = &T3{&T4{}}
	_ = &T4{&T4{}}

	P2 *T10
)

func (T11) m() {}

type T11 /* ERROR "invalid recursive type: T11 refers to itself" */ struct{ T11 }

type T12 /* ERROR "invalid recursive type: T12 refers to itself" */ struct{ T12 }

func (*T12) m() {}

type (
	P3 *T13
	T13 /* ERROR "invalid recursive type" */ T13
)

// test cases for issue 18643

// Check that overlong unions don't bog down type checking.
// Disallow them for now.

package p

type t int

type (
	t00 t; t01 t; t02 t; t03 t; t04 t; t05 t; t06 t; t07 t; t08 t; t09 t
	t10 t; t11 t; t12 t; t13 t; t14 t; t15 t; t16 t; t17 t; t18 t; t19 t
	t20 t; t21 t; t22 t; t23 t; t24 t; t25 t; t26 t; t27 t; t28 t; t29 t
	t30 t; t31 t; t32 t; t33 t; t34 t; t35 t; t36 t; t37 t; t38 t; t39 t
	t40 t; t41 t; t42 t; t43 t; t44 t; t45 t; t46

	T8  struct{}
	T9  struct {
		a    int
		b, c float32
		d    []string `go:"tag"`
	}
	T10 struct {
		T8
		T9
		_ *T10
	}
	T11 map[int]string
	T12 any
	T13 interface {
		m1()
		m2(int) float32
	}
	T14 interface {
		T12
		T13
		m3(x ...struct{}) []T9
	}
	T15 func()
	T16 func(int)
	T17 func(x int)
	T18 func() float32
	T19 func() (x float32)
	T20 func(...any)

  const T10 v10_;
  const T11 v11_;
  const T12 v12_;
};

template <typename T1, typename T2, typename T3, typename T4, typename T5,
    typename T6, typename T7, typename T8, typename T9, typename T10,
    typename T11, typename T12, typename T13>
class ValueArray13 {
 public:
  ValueArray13(T1 v1, T2 v2, T3 v3, T4 v4, T5 v5, T6 v6, T7 v7, T8 v8, T9 v9,
      T10 v10, T11 v11, T12 v12, T13 v13) : v1_(v1), v2_(v2), v3_(v3), v4_(v4),

        //           (see TODO in validtype.go).
        // T10 interface { T9; T9 }
        // T11 interface { T10; T10 }
        // T12 interface { T11; T11 }
        // T13 interface { T12; T12 }
        // T14 interface { T13; T13 }
        // T15 interface { T14; T14 }
        // T16 interface { T15; T15 }
        // T17 interface { T16; T16 }
        // T18 interface { T17; T17 }