https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110824
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Denis Yaroshevskiy from comment #4) > Appreciate it. > > I'm still going to support gcc11 for the forseable future. Is there some > easy way you see I can confirm that this is this issue? > So that I don't create more duplicates? In this case, the pattern is simple is there a trailing return type and does it use decltype with a template function and is that template function defined (and in that scope or outer scope) then this will be a dup of that issue. (it is only valid C++20 rather than being valid C++17 too). Hope that helps. Also note C++20 support in GCC is still being fixed in many areas too so using GCC 11 which came out less than 4 months after C++20 was ratification and published is definitely going to be an issue.
