1struct Foo;
2
3struct Bar {
4  const Foo& f;
5  unsigned m;
6};
7
8struct Baz {
9  Foo& f;
10  unsigned m;
11};
12
13struct Tar {
14  const Foo&& f;
15  unsigned m;
16};
17
18struct Taz {
19  Foo&& f;
20  unsigned m;
21};
22