[Bug c++/114974] New: CTAD: gcc rejects some valid code

[hokein.wu at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114974

            Bug ID: 114974
           Summary: CTAD: gcc rejects some valid code
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hokein.wu at gmail dot com
  Target Milestone: ---

gcc trunk rejects the following valid CTAD code:

```
template<typename T1>
struct A1 {
  template<typename T2>
  struct A2 { T2 t; };
};

template <typename K>
void s(K k) {
  A1<int>::A2 a(2);
}

void s() {
  s<double>(1.0);
}
```

https://godbolt.org/z/7bxEbhP47

It looks like in this case gcc fails? to generate the aggregate deduction
guide.