#include <thread>
#include <iostream>

volatile int counter=0;

void incr(const int count=200000)
{
    for(int i=0;i<count;i++)
        counter++;
}

int main()
{
    std::thread m(incr,200000);
    incr(200000);
    std::cout << "Expects 400000, get "<< counter <<std::endl;
    return 0;
}