types::none_type symmetric_difference_update(types::set<T> &set, U const &other) { set.symmetric_difference_update(other); return {}; }
void symmetric_difference_update(types::set<T> &set, U const &other) { set.symmetric_difference_update(other); }
types::none_type symmetric_difference_update(types::set<T> &set, U const &other) { set.symmetric_difference_update(other); return {}; }
void symmetric_difference_update(types::set<T> &set, U const &other) { set.symmetric_difference_update(other); }