Function set_executor

extern/boost/boost/thread/future.hpp:2345–2354

#ifdef BOOST_THREAD_PROVIDES_EXECUTORS
        void set_executor(executor_ptr_type aex)
        {
          lazy_init();
          if (future_.get()==0)
          {
              boost::throw_exception(promise_moved());
          }
          boost::lock_guard<boost::mutex> lk(future_->mutex);
          future_->set_executor_policy(aex, lk);
        }
#endif
        // Result retrieval
        BOOST_THREAD_FUTURE<R> get_future()