}
	y, ok := m[0]
	if ok {
		t.Errorf("map value should be missing")
	}
	if y != (T{}) {
		t.Errorf("map value not zero")
	}
}

type empty struct {
}

func TestEmptyKeyAndValue(t *testing.T) {
	a := make(map[int]empty, 4)
	b := make(map[empty]int, 4)
	c := make(map[empty]empty, 4)
	a[0] = empty{}
	b[empty{}] = 0
	b[empty{}] = 1
	c[empty{}] = empty{}

	if len(a) != 1 {