gistfile1.txt

#include <hpx/hpx_main.hpp>
#include <hpx/include/parallel_executors.hpp>

struct test_async_executor
{
    typedef hpx::parallel::execution::parallel_execution_tag execution_category;

    template <typename F, typename ... Ts>
    static hpx::future<typename hpx::util::invoke_result<F, Ts...>::type>
    async_execute(F && f, Ts &&... ts)
    {
        return hpx::async(hpx::launch::async, std::forward<F>(f),
            std::forward<Ts>(ts)...);
    }
};

namespace hpx { namespace parallel { namespace execution
{
    template <>
    struct is_two_way_executor<test_async_executor>
      : std::true_type
    {};
}}}

int main()
{
    test_async_executor exec;
    hpx::future<void> f = hpx::make_ready_future();
    f.then(exec,
        [](hpx::future<void> && f)
        {
        });

    return 0;
}