t.Error("expected compatibility error")
	}
}

// Mutually recursive slices of structs caused problems.
type Bug3 struct {
	Num      int
	Children []*Bug3
}

func TestGobPtrSlices(t *testing.T) {
	in := []*Bug3{
		{1, nil},
		{2, nil},
	}
	b := new(bytes.Buffer)
	err := NewEncoder(b).Encode(&in)
	if err != nil {
		t.Fatal("encode:", err)
	}

	var out []*Bug3