std::experimental::future

Defined in header `<experimental/future>`
template< class T > class future;	(1)	(concurrency TS)
template< class T > class future<T&>;	(2)	(concurrency TS)
template<> class future<void>;	(3)	(concurrency TS)

The class template std::experimental::future extends std::future with the following operations:

an unwrapping constructor from future<future<T>>;
a member function is_ready to query whether the associated shared state is ready; and
a member function then to attach a continuation to the future.

However, there is no interoperation between std::experimental::future and std::future.

(constructor)	construct a `future` object (public member function)
is_ready	checks if the shared state is ready (public member function)
then	attaches a continuation to a future (public member function)
operator=	moves the future object (public member function)

Members identical to std::future

Note that share() returns a std::experimental::shared_future<T>. The behavior is otherwise identical.

(destructor)	destructs the future object (public member function of `std::future<T>`)
share	transfers the shared state from `*this` to a `shared_future` and returns it (public member function of `std::future<T>`)
Getting the result
get	returns the result (public member function of `std::future<T>`)
State
valid	checks if the future has a shared state (public member function of `std::future<T>`)
wait	waits for the result to become available (public member function of `std::future<T>`)
wait_for	waits for the result, returns if it is not available for the specified timeout duration (public member function of `std::future<T>`)
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<T>`)

Compiler support
Freestanding and hosted
Language
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Metaprogramming library (C++11)
Diagnostics library
General utilities library
Strings library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Numerics library
Localizations library
Input/output library
Filesystem library (C++17)
Regular expressions library (C++11)
Concurrency support library (C++11)
Technical specifications
Symbols index
External libraries

Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals TS v2)
Library fundamentals 3 (library fundamentals TS v3)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Extensions for concurrency 2 (concurrency TS v2)
Concepts (concepts TS)
Ranges (ranges TS)
Reflection (reflection TS)
Mathematical special functions (special functions TR)

std::future extensions
experimental::future
experimental::shared_future
experimental::when_all
experimental::when_any
experimental::make_ready_future
experimental::make_exceptional_future
Latches and barriers
experimental::latch
experimental::barrier
experimental::flex_barrier
Atomic smart pointers
experimental::atomic_shared_ptr
experimental::atomic_weak_ptr