https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117280
--- Comment #1 from Jiang An <de34 at live dot cn> ---
I've realize that the original example seems invalid because the temporary
object shouldn't be usable in constant evaluations (as it's of a volatile type
due to reference binding).
But this one (accidently?) has the same effects.
```
struct S { const int& ref; };
constexpr int n = 42;
constexpr volatile S s{n};
static_assert(s.ref == 42, "");
```
