std::async throw error of std::result_of on compile

This code provide imitation of async memory swaping, but call of std::async give me compile errors from std::result_of. What I do wrong?

std::async(std::launch::async, &Memory::CreateProc, std::ref(this),
           used_by_proc * pcount);

for (auto elem : elems) {
  std::async(std::launch::async, &Proc::Swap, std::ref(elem->proccess));
}

http://ift.tt/2ieQ9rE errors