[Bug c++/118626] C++20 std::variant causes a segmentation fault

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118626

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|needs-reduction             |

--- Comment #6 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Reduced (but invalid):

```
template <long> struct _Nth_type;
template <typename, typename> long __accepted_index = 0;
template <typename> struct variant {
  template <typename _Tp>
  static constexpr long __accepted_index2 = __accepted_index<_Tp, variant>;
  template <long _Np> using __to_type = _Nth_type<_Np>;
  template <typename _Tp>
  using __accepted_type = __to_type<__accepted_index2<_Tp>>;
  template <typename _Tp, typename = __accepted_type<_Tp>> variant();
};
template <typename> struct Node;
template <typename R> using Tree = variant<Node<R>>;
auto tree = Tree {};
```