auto iter_end = subscriber_vec_.end();

auto iter = std::remove(subscriber_vec_.begin(), iter_end, subscriber);

if (iter == iter_end) {

subscriber_vec_.push_back(subscriber);

}

{

auto iter_end = subscriber_vec_.end();

auto iter = std::remove(subscriber_vec_.begin(), iter_end, subscriber);

subscriber_vec_.erase(iter, iter_end);

}

{

auto iter_end = tmp_vec_.end();

auto iter = std::remove(tmp_vec_.begin(), iter_end, subscriber);

tmp_vec_.erase(iter, iter_end);

}

auto tmp_vec_ = subscriber_vec_;

while (!tmp_vec_.empty()) {

auto top_subscriber = tmp_vec_.back();

if (top_subscriber->onEvent(event))

break;

tmp_vec_.pop_back();

}

tmp_vec_.clear();