https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103448
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- >something collapses the tuple of tuples into a single tuple. The workaround is >to replace the std::tuple() constructor Yes it is called the copy (or move) constructor :).