https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120775
--- Comment #14 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Indeed, I found more ICEs:
```
using info = decltype (^^int);
void fn (info) {}
```
which results in
internal compiler error: in adjust_one_expanded_partition_var, at
cfgexpand.cc:1898
and is actually not so easy to fix. It should be rejected. But e.g., our own
std::meta::exception::what() is also of consteval-only type and not an
immediate function and it cannot be escalated and we shouldn't error on it.
Then there's
```
template<typename T>
int fn (T) { return 4; }
const int a = fn (^^int);
```
internal compiler error: in gimplify_expr, at gimplify.cc:21216
