package typeapply import (	"testing") type Targ struct {} type List struct {	Next *List	Targ *Targ} type Other struct {	Targ *Targ} type Big struct {	A *Targ	B [2]*Targ	C []*Targ	D map[int]*Targ	E map[*Targ]int	F map[*Targ]*Targ	G ***Targ	H interface{}	I *List	J List	// no instances:	K chan *Targ	L func(*Targ) *Targ} func newBig() (big *Big, n int) {	T := func() *Targ {		n++		return &Targ{}	}	pppt := func() ***Targ {		pt := new(*Targ)		*pt = T()		ppt := new(**Targ)		*ppt = pt		return ppt	}	big = &Big{		A: T(),		B: [2]*Targ{T(), T()},		C: []*Targ{T(), T()},		D: map[int]*Targ{1: T(), 2: T()},		E: map[*Targ]int{T(): 1, T(): 2},		F: map[*Targ]*Targ{T(): T(), T(): T()},		G: pppt(),		H: Other{T()},		I: &List{&List{nil, T()}, T()},		J: List{&List{nil, T()}, T()},		K: make(chan *Targ),		L: func(*Targ) *Targ { return nil },	}	return} func TestBig(t *testing.T) {	b, n := newBig()	i := 0	m := make(map[*Targ]bool)	Do(func(targ *Targ) {		i++		if m[targ] {			t.Error("target reached twice")		}	}, b)	if i != n {		t.Errorf("wrong instance count; expected %d; got %d", n, i)	}}