[Bug c++/87652] inner class template of outer class template can't access friend's protected data member

[haining.cpp at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87652

--- Comment #1 from Ryan R Haining <haining.cpp at gmail dot com> ---
ugh, very sorry, I copied the version with private: instead of protected. The
example program should be:

template <typename>
struct Outer {
  template <typename>
  class Inner {
    template <typename>
    friend class Inner; // All Inners should be friends

   public:
     template <typename T>
     void use_other_x(const Inner<T>& other) const {
       (void)other.x;
     }
   protected: // no error if private instead
     int x;
  };
};

int main() {
  Outer<int>::Inner<void> i1;
  Outer<int>::Inner<char> i2;
  i1.use_other_x(i2);
}