[Bug c++/128116] New: Accepts Invalid: `template struct S { static constexpr void(& foo)(void) = nullptr; };`

[songb432 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128116

            Bug ID: 128116
           Summary: Accepts Invalid: `template <class> struct S { static
                    constexpr void(& foo)(void) = nullptr; };`
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: songb432 at gmail dot com
  Target Milestone: ---

``template <class> struct S { static constexpr void(& foo)(void) = nullptr;
};``

This shouldn't compile. But GCC 5~16 and GCC trunk compiles, and GCC 4.9.4
doesn't. Link: https://godbolt.org/z/zf8zb5z7o