https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79308
--- Comment #6 from bjhend <bjh...@sags-per-mail.de> --- (In reply to Volker Reichelt from comment #5) > IMHO the testcase is invalid (e.g. clang rejects it). > But by changing the line > struct Element<int>::WriteOutput<InnerType> > into > struct Element<int>::WriteOutput > it can be turned into a valid testcase. Yes, you're right. It's the generic definition of the inner template so the additional <InnerType> shouldn't be there. Thanks for correcting this. > There are several similar testcases, so I opened a new PR 89744 for this. Thanks.