https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65856
--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- I forgot to add "with -Wall -Wextra". gcc needs explicit -Woverloaded-virtual.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65856
--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- I forgot to add "with -Wall -Wextra". gcc needs explicit -Woverloaded-virtual.