std::future::future

From cppreference.com
future();
(1) (since C++11)
future( future&& other );
(2) (since C++11)

Constructs a future object.

1) Default constructor. Constructs the future with no shared state.
2) Move constructor. Constructs the future with the shared state of other using move semantics. other has valid, but undefined state afterwards.

[edit] Parameters

other - another future to acquire the shared state from

[edit] Exceptions

1-2)
noexcept specification:  
noexcept
  (since C++11)