std::future_status

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Thread support library

Threads
thread (C++11)
hardware_destructive_interference_sizehardware_constructive_interference_size (C++17)(C++17)
this_thread namespace
get_id (C++11) yield (C++11)	sleep_for (C++11) sleep_until (C++11)
Mutual exclusion
mutex (C++11) recursive_mutex (C++11) shared_mutex (C++17)	timed_mutex (C++11) recursive_timed_mutex (C++11) shared_timed_mutex (C++14)
Generic lock management
lock_guard (C++11) scoped_lock (C++17) unique_lock (C++11) shared_lock (C++14) defer_lock_ttry_to_lock_tadopt_lock_t (C++11)(C++11)(C++11)	lock (C++11) try_lock (C++11) defer_locktry_to_lockadopt_lock (C++11)(C++11)(C++11) once_flag (C++11) call_once (C++11)
Condition variables
condition_variable (C++11)
condition_variable_any (C++11)
notify_all_at_thread_exit (C++11)
cv_status (C++11)
Futures
promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11)	launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

Defined in header <future>
enum class future_status { ready, timeout, deferred };		(since C++11)

Specifies state of a future as returned by wait_for and wait_until functions of std::future and std::shared_future.

Constant	Explanation
deferred	the shared state contains a deferred function, so the result will be computed only when explicitly requested
ready	the shared state is ready
timeout	the shared state did not become ready before specified timeout duration has passed

See also

wait_for	waits for the result, returns if it is not available for the specified timeout duration (public member function of std::future)
wait_for	waits for the result, returns if it is not available for the specified timeout duration (public member function of std::shared_future)
wait_until	waits for the result, returns if it is not available until specified time point has been reached (public member function of std::future)
wait_until	waits for the result, returns if it is not available until specified time point has been reached (public member function of std::shared_future)