[Bug c++/78894] [7 Regression] [c++17] ICE for std::list template deduction from std:: initializer_list

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78894

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Yes, I think Jakub's reduced example is valid, and should deduce C<int>.

But I think the original example is invalid, the initializer-list constructor
can be deduced.