Now that we have ruled out the presence of users of the nullary, default-initializing overload, we can replace the overload set with a variadic template. This allows nullary calls again, but the objects returned are now value-constructed instead of default constructed. As a drive-by, mark the function [[nodiscard]] (discarding the return value is a memory leak) and use q20::construct_at() instead of raw placement new. Change-Id: Ic4f842b9a05ab7e9b86ec9b2dee843ab276b6a00 Reviewed-by: Ulf Hermann <ulf.hermann@qt.io> Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>