[Bug c++/93989] [c++20] Error initializing trivial types in constexpr constructor

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93989

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-03-02
     Ever confirmed|0                           |1

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
With -mavx2 the first error is indeed the quoted one (but not the last).  The
non-header part can be reduced to the following (you need to add #includes
still), it produces exactly and only the quoted two errors.

using C = char;
static constexpr C c = 'a';
using traits = std::char_traits<C>;

using __gnu_test::constexpr_allocator;

consteval void test01()
{
  typedef constexpr_allocator<C> alloc_type;
  typedef std::basic_string<C, traits, alloc_type> test_type;
  constexpr alloc_type a1(1);
  constexpr test_type v1(a1);
}
int main()
{
  test01();
  return 0;
}