std::thread 五：打包任务（packaged_task）

#include <iostream>
#include <thread>
#include <mutex>
#include <list>
#include <future>
using namespace std;

int myThread(int num)
{
    cout << "myThread() start thread id =" << this_thread::get_id() << endl;
    cout << "num is " << num << endl;
    std::chrono::microseconds s(5000);
    std::this_thread::sleep_for(s);
    cout << "myThread() end thread id =" << this_thread::get_id() << endl;
    return 5;
}

int main()
{
    cout << "main run thread id =" << std::this_thread::get_id() << endl;
    /* packaged_task 包装函数，执行线程，可以拿到线程的返回值，不知道工作中应用场景在哪，但是学都学了，得记下来 */
    // 创建一个打包任务，把任务包装起来
    std::packaged_task<int(int)> mypt(myThread);
    std::thread t(std::ref(mypt), 121212);
    t.join();
    std::future<int> res = mypt.get_future();
    cout << res.get() << endl;
    cout << "main end" << endl;
    return 0;
}