{

std::lock_guard<std::mutex> lk(mutex);

task_queue.push_back(std::move(task));

}

condition_variable.notify_one();

if (worker_threads.empty()) {

return;

}

{

std::lock_guard<std::mutex> lk(mutex);

is_shutting_down = true;

}

for (int i = 0; i < thread_count(); i++) {

condition_variable.notify_one();

}

for (auto& thread : worker_threads) {

if (thread.joinable()) {

thread.join();

}

}

worker_threads.clear();

is_shutting_down = false;

while (true) {

std::function<void()> task;

{

std::unique_lock<std::mutex> lk(mutex);

condition_variable.wait(lk, [this]() { return is_shutting_down || !task_queue.empty(); });

if (is_shutting_down) {

return;

}

task = std::move(task_queue.front());

task_queue.pop_front();

}

task();

}

if (worker_pool) {

return worker_pool->thread_count();

}

else {

return 0;

}

if (worker_pool) {

return worker_pool->size();

}

else {

return 0;

}

if (worker_pool) {

worker_pool->clear();

}

if (worker_pool) {

auto future = dispatch([](){});

future.wait();

}

clear();

if (worker_pool) {

delete worker_pool;

worker_pool = nullptr;

}