https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100079
Jason Merrill <jason at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Known to work| |11.0 Summary|[9/10/11 Regression] |[9/10 Regression] Non-type |Non-type template |template parameter, itself |parameter, itself a nested |a nested template, rejected |template, rejected with |with internal error |internal error | Keywords|ice-on-invalid-code |ice-on-valid-code --- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> --- Fixed for GCC 11. I'm reluctant to backport this, since it significantly changes the mangling of C++20 class NTTPs, but am open to it if desired by C++20 users.