[Bug c++/99809] ICE: sorry, unimplemented: unexpected AST of kind nontype_argument_pack

[hewillk at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99809

--- Comment #3 from 康桓瑋 <hewillk at gmail dot com> ---
More reduced:

template <typename, typename>
concept C = true;

void f(auto... args) {
  [](C<decltype(args)> auto) {};
}

int main() { f(); }