#include <hpx/hpx.hpp>
#include <hpx/dataflow.hpp>
#include <hpx/parallel/executors/thread_pool_executors.hpp>

#include <iostream>

using hpx::threads::executors::local_priority_queue_executor;
using hpx::shared_future;
using hpx::dataflow;
using hpx::async;
using hpx::util::unwrapping;


int add(int a, int b) {
    return a+b;
}

int hpx_main()
{
    {
        local_priority_queue_executor exec;

        shared_future<int> f1 = async(exec, add, 2, 3);
        shared_future<int> f2 = async(exec, add, 4, 5);
        shared_future<int> f3 = dataflow(exec, unwrapping(add), f1, f2);

        std::cout << f3.get() << std::endl;
    }

    return hpx::finalize();
}

int main(int argc, char ** argv)
{
    return hpx::init(argc, argv);
}