c++ std::thread with class operator

thread_operator.cpp

// Reference : https://snowdeer.github.io/c++/2017/08/18/cpp11-thread-example/
// 함수 객체를 이용하는 방법 #2

#include <iostream>
#include <thread>
#include <chrono>

class A
{
    private:
        bool running;
        uint32_t counter;
    public:
        A() : running(false), counter(0) {};
        void operator() ();
        void stop() { running = false; };
};

void A::operator() ()
{
    running = true;
    while (running) {
        ++counter;
        std::cout << "running count : " << counter << std::endl;
        std::this_thread::sleep_for(std::chrono::seconds(1));
    }
    std::cout << "End of thread" << std::endl;
}

int32_t main(int32_t argc, char* argv[])
{
    A a;
    auto t = std::thread(a);
    std::this_thread::sleep_for(std::chrono::seconds(3));
    a.stop();
    t.join();
    return 0;
}

use std::ref