https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56785
--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Marc Glisse from comment #1) > I assume (needs to be checked) this is related to the issue, reported > elsewhere, that makes the size of > std::tuple<std::tuple<std::tuple<std::tuple<>>>> grow linearly with the > nesting depth. That's PR51653. With the attached patch that occupies a single byte, for any depth.