[Bug c++/106221] lamba inside a decltype in a using statement does not always work

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106221

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Even more reduced (you don't need the namespace after all):
using T = decltype([](){});

template<typename Opts>
using foo = T;

using bar = foo<int>;