[Bug c++/86473] New: a problem in member lookup?

[zhonghao at pku dot org.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86473

            Bug ID: 86473
           Summary: a problem in member lookup?
           Product: gcc
           Version: 8.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhonghao at pku dot org.cn
  Target Milestone: ---

The code is as follows:

namespace PR5820 {
struct Base {};
struct D1 : public Base {};
struct D2 : public Base {};

struct Derived : public D1, public D2 {
 void Inner() {
 }
};
}

template<typename T>
struct BaseT {
 int Member;
};

template<typename T> struct Derived1T : BaseT<T> { };
template<typename T> struct Derived2T : BaseT<T> { };

template<typename T>
struct DerivedT : public Derived1T<T>, public Derived2T<T> {
 void Inner();
};

template<typename T>
void Test(DerivedT<T> d) {
 d.template Derived2T<T>::Member = 17;
}

template void Test(DerivedT<int>);

-------------------------------------

g++ rejects the code:

code0.cpp: In function 'void Test(DerivedT<T>)':
code0.cpp:27:25: error: expected ';' before '::' token
  d.template Derived2T<T>::Member = 17;
                         ^~
                         ;
code0.cpp: In instantiation of 'void Test(DerivedT<T>) [with T = int]':
code0.cpp:30:33:   required from here
code0.cpp:27:13: error: 'Derived2T' is not a member template function
  d.template Derived2T<T>::Member = 17;
  ~~~~~~~~~~~^~~~~~~~~~~~

This code looks legal for me. Clang++ accepts the code.