[Bug c++/86185] New: gcc does not reject the ill-formed code

[zhonghao at pku dot org.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86185

            Bug ID: 86185
           Summary: gcc does not reject the ill-formed code
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhonghao at pku dot org.cn
  Target Milestone: ---

gcc++ does not produce any errors when it compiles the following code:

template<typename T>
void f() {
  auto i = T(), j = 0;
}

int main() {
  f<long>();
  f<int>();
}

The code comes from a bug report of clang:
https://bugs.llvm.org/show_bug.cgi?id=9276

Johannes Schaub analyzed why clang shall reject the code. 
Shall gcc also reject the code?