future_expertiment.cpp

#include <iostream>
#include <vector>
#include <math.h>
#include <unordered_map>
#include <string>
#include <fstream>
#include <stack>
#include <unordered_set>
#include <queue>
#include <stack>
#include <limits>
#include <thread>
#include <set>
#include <array>
#include <future>
using namespace std;

int sum(vector<int>::iterator begin, vector<int>::iterator end, int count) {
  int sum = 0;

  while (begin != end) {
    sum += *begin;

    begin++;
  }

  return sum;
}

int main() {
  vector<int> numbers = { 1,2,3,4,5,6 };

  std::promise<int> sumPromise;
  std::future<int> sumFuture = sumPromise.get_future();

  auto job = std::thread([&] {
    int val = sum(numbers.begin(), numbers.end(), numbers.size());
    sumPromise.set_value(val);
  });
  
  int sumata = sumFuture.get();

  job.join();

  cout << sumata << endl;
}