[Bug c++/63356] Compilation failure where clang does not have problems

[fiesh at zefix dot tv]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63356

--- Comment #9 from fiesh at zefix dot tv ---
Ever so little simplified:

struct A {};

template <typename _B1>
struct B : _B1 {};

template <typename _Tp>
_Tp declval();

template <typename _From, typename _To>
struct C {
  template <typename _From1, typename _To1,
            typename = decltype(_To1(declval<_From1>()))>
  static A __test(int);
  typedef decltype(__test<_From, _To>(0)) type;
};

template <typename _From, typename _To>
struct I : C<_From, _To>::type {};

template <int>
struct D {};

template <class _T1, class>
struct F {
  _T1 first;
  template <class _U1, class _U2,
            class = typename D<B<I<_U1, _T1>>::value>::type>
  F(F<_U1, _U2>);
  template <class _U2>
  F(_T1 p1, _U2)
      : first(p1) {}
};

class G;

class H {
 public:
  void push_back(F<F<F<G, G>, int>, int *>);
};

class G {
 public:
  template <typename PointType>
  G(PointType);
  H processEvent__counts_from_scanline;
  void processEvent_() {
    processEvent__counts_from_scanline.push_back(
        F<F<F<G, G>, int>, int *>(F<F<G, G>, int>(F<G, G>(0, 0), 0), 0));
  }
};