https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98164
Marek Polacek <mpolacek at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 Status|UNCONFIRMED |NEW CC| |mpolacek at gcc dot gnu.org Last reconfirmed| |2020-12-07 --- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Confirmed. Doesn't need the include: struct s {}; template <auto> struct r {}; #ifdef FIX constexpr auto P = r <s {}> {}; #endif constexpr auto S = s {}; constexpr auto R = r <S> {}; void g () { using t = decltype (R); };