cpp_threads.cpp

#include <iostream>
#include <thread>
#include <functional>

int main(int argc, char *argv[]) {

    int x = 1;

    std::cout << "[1] x is " << x << std::endl;

    std::function<void()> f = [&](){
        x = 2;
        std::cout << "[3] x is " << x << std::endl;
    };

    std::thread t1(f);

    std::cout << "[2] x is " << x << std::endl;

    t1.join();

    std::cout << "[4] x is " << x << std::endl;

    return 0;
}