[Bug c++/82514] [8 Regression] ICE: in operator[], at vec.h:749

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82514

--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Smaller testcase from PR83727:

namespace a {
template <typename b, int c> b *begin(b (&)[c]);
}
class d {
public:
  d(const char *);
};
struct e {
  int f;
  d docstring;
  void (*func)(int &, int);
};
namespace a {
template <typename h, typename g> h i(h, h, g) { return 0; }
}
using a::begin;
template <typename j, typename k>
auto i(j &&container, k l) -> decltype(begin(container)) {
  return a::i(container, container, l);
}
enum { m };
template <int> void n(int &, int) {
  [] {
    struct p {
    } o[]{{}};
    i(o, p{});
  };
}
e cmds{'i', "", n<m>};