[Bug c++/98360] New: sizeof in template difference between g++/icc and clang++

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98360

            Bug ID: 98360
           Summary: sizeof in template difference between g++/icc and
                    clang++
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
                CC: dcb314 at hotmail dot com, jakub at gcc dot gnu.org,
                    marxin at gcc dot gnu.org, nathan at gcc dot gnu.org
        Depends on: 98340
  Target Milestone: ---

+++ This bug was initially created as a clone of Bug #98340 +++

template <typename T>
struct delete_ptr_hash
{
};

template <typename T>
struct hash_table
{
};

template <typename T>
struct uintset
{
  T values[1];
  struct traits : delete_ptr_hash <uintset>
  {
  };
  struct hash : hash_table <traits>
  {
    int foo ();
  };
  hash h;
};

template <typename T>
int
uintset<T>::hash::foo ()
{
  return sizeof (uintset::values);
}

uintset<int> s;
int x = s.h.foo ();

As stated in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98340#c2
the above has been rejected by g++ before
r0-99643-g2defb926479247a61fe0fffbcf95597722a94c40 and by icc 13 and is
rejected by all clang++ versions I've tried (but each compiler different
diagnostic), while it is accepted by g++ 4.6+ and icc 16+.

Is this an accepts-invalid bug in g++ or ice-on-invalid in clang++?


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98340
[Bug 98340] gcc trunk build with clang failure, part 2