t.Logf("%p", a)

	a[0][0][0][0][0][0][0][0][0][0] = new(int)
	*a[0][0][0][0][0][0][0][0][0][0] = 13
	runtime.GC()
	if *a[0][0][0][0][0][0][0][0][0][0] != 13 {
		t.Fail()
	}
}

func TestGcMapIndirection(t *testing.T) {
	defer debug.SetGCPercent(debug.SetGCPercent(1))
	runtime.GC()
	type T struct {
		a [256]int
	}
	m := make(map[T]T)
	for i := 0; i < 2000; i++ {
		var a T
		a.a[0] = i
		m[a] = T{}