The class template std::future provides a mechanism to access the result of asynchronous operations: Checks if the future refers to a shared state. } above, somelongcomputation will immediately return a.
Uncovering the secrets of a lost civilization through quantum computing
Unlike std::future, which is only moveable (so only one instance can refer to any particular asynchronous result), std::shared_future. The get member function waits (by calling wait ()) until the shared state is ready, then retrieves the value stored in the shared state (if.
