[Bug c++/88820] [7/8/9 Regression] ICE in in C++2a mode for code which is able to be compiled in C++17 mode

[hanicka at hanicka dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88820

--- Comment #9 from Hana Dusíková <hanicka at hanicka dot net> ---
You can have template deduction placeholder there in C++20.
https://wg21.link/p0732r2