NAME¶

std::experimental::shared_future::shared_future - std::experimental::shared_future::shared_future

Synopsis¶

shared_future() noexcept; (1)
shared_future(std::experimental::shared_future<T>&& f) noexcept; (2)
shared_future(const std::experimental::shared_future<T>& f); (3)
shared_future(std::experimental::future<std::experimental::shared_future<T>> && (4)
other) noexcept;
shared_future(std::experimental::future<T>&& f) noexcept; (5)

1) Default constructor. Constructs an empty shared_future object that does not refer
to a shared state.
2) Constructs a shared_future object, transferring the shared state held by f, if
any. After construction, f.valid() is false.
3) Constructs a shared future that refers to the same shared state as f, if any.
4) Unwrapping constructor. Constructs a shared_future object from the shared state
referred to by other, if any. If other.valid() == false prior to this call, the
constructed shared_future object is empty. Otherwise, the resulting shared_future
object becomes ready when one of the following happens:

* other and other.get() are both ready. The value or exception from other.get() is
stored in the shared state associated with the resulting shared_future object.
* other is ready, but other.get() is invalid. An exception of type
std::future_error with an error condition of std::future_errc::broken_promise is
stored in the shared state associated with the resulting shared_future object.

After this constructor returns, valid() is equal to the value of other.valid() prior
to this call, and other.valid() == false.
5) Constructs a shared_future object, transferring the shared state held by f, if
any. After construction, f.valid() is false.

Parameters¶

f - another future object to initialize with
other - A std::experimental::future object to unwrap

Example¶

This section is incomplete
Reason: no example

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2697 Concurrency TS behavior of unwrapping constructor is constructs an empty
unclear with an invalid future future

See also¶

constructor constructs the future object
(public member function of std::shared_future<T>)