std::experimental::shared_future<T>:: shared_future

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 .