[Bug c++/83481] ICE in const-ref structured bindings.

["asolokha at gmx dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83481

Arseny Solokha <asolokha at gmx dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |asolokha at gmx dot com

--- Comment #2 from Arseny Solokha <asolokha at gmx dot com> ---
The fix seems to be backported to gcc 7 branch in r255730.

Reduced testcase:

typedef int b;
namespace a {
template <typename = void> struct c;
template <typename> class d;
} // namespace a
namespace ac {
template <typename, typename, typename = a::c<>> class e;
template <typename ad, typename g> struct h {
  ad ae;
  g f;
};
template <typename i, typename ad, typename j, typename, typename, typename k>
class ag {
public:
  using ah = k;
  ah operator*();
  i operator++();
  template <typename l, typename ai, typename aj, typename n>
  bool operator!=(ag<l, ad, j, ai, aj, n>);
};
template <typename ad, typename j, typename> class ak {
public:
  class m;
  using q = h<ad, j>;
  using o = ag<b, ad, j, b, q, q>;
  using r = ag<m, ad, j, m, q, q &>;
  class ab : public o {};
  class m : public r {};
  ab end();
  m begin();
};
template <typename ad, typename j, typename p> class e : ak<ad, j, p> {
  using al = ak<ad, j, p>;

public:
  using al::begin;
  using al::end;
};
} // namespace ac
using s = b;
using am = class {};
struct ao;
struct ap;
using aq = a::d<ap>;
namespace {
class ar {
  void as(const ao &, const aq &) { for (auto & [ a, av ] : at) {} }
  ac::e<am, s> at;
};
} // namespace