https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89705
--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Another testcase with an lvalue reference:
struct W { operator const volatile int(); };
const int& i = W();
But I think all those testcases are invalid, because [dcl.init.ref] says: If T1
is reference-related to T2, cv1 shall be the same cv-qualification as, or
greater cv-qualification than, cv2.
