std::future::future

(1) default constructor

Constructs an empty future: The object has no shared state, and thus is not valid, but it can be move-assigned another future value.

(2) copy constructor [deleted]

future objects cannot be copied (see shared_future for a copyable future class).

(3) move constructor

The constructed object acquires the shared state of x (if any).
x is left with no shared state (it is no longer valid).

Parameters

x

Another future object of the same type (with the same template parameter, T).

Example

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

// future::future #include <iostream> // std::cout #include <future> // std::async, std::future int get_value() { return 10; } int main () { std::future<int> foo; // default-constructed std::future<int> bar = std::async (get_value); // move-constructed int x = bar.get(); std::cout << "value: " << x << '\n'; return 0; }

 value: 10 

Data races

Exception safety

See also

future::operator=

Move-assign future (public member function)

future::get

Get value (public member function)