[Bug c++/105233] Incorrect "alignment not an integer constant" error in alignas with template parameter dependent argument

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105233

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2022-04-12
             Status|UNCONFIRMED                 |NEW

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Slightly more reduced:

template <typename _Tp>
constexpr _Tp
foo (_Tp __x) noexcept
{
  if (!__builtin_is_constant_evaluated ())
    {
      ;
    }
  return 4 * __alignof (int);
}

template <typename T>
struct A { T a, b, c; };

template <typename T>
struct alignas (foo (sizeof (A<T>))) B { A<T> d; };

B<int> e;

And we reject this since __builtin_is_constant_evaluated has been in
r9-2311-ge408261123697a82b5965c700fa2465999f0fd62 .