https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86883
vopl at bk dot ru changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |vopl at bk dot ru --- Comment #3 from vopl at bk dot ru --- Probably caused by the same $ cat test.cpp template<typename... T> struct Outer { template<T... Values0> struct Inner { static bool Member; }; }; template<typename... T> template<T... Values> bool Outer<T...>::Inner<Values...>::Member; $ g++-10.2.0 test.cpp test.cpp:12:34: error: expansion pattern ‘Values0’ contains no parameter packs 12 | bool Outer<T...>::Inner<Values...>::Member; | ^ test.cpp:12:6: error: too many template-parameter-lists 12 | bool Outer<T...>::Inner<Values...>::Member; | ^~~~~~~~~~~