std::shared_future::valid - cppreference.com (original) (raw)

| bool valid() const noexcept; | | (since C++11) | | ---------------------------- | | ------------- |

Checks if the future refers to a shared state.

This is the case only for futures that were not default-constructed or moved from. Unlike std::future, std::shared_future's shared state is not invalidated when get() is called.

The behavior is undefined if any member function other than the destructor, the copy-assignment operator, the move-assignment operator, or valid is called on a shared_future that does not refer to shared state (although implementations are encouraged to throw std::future_error indicating no_state in this case). It is valid to move or copy from a shared_future object for which valid() is false.

[edit] Parameters

(none)

[edit] Return value

true if *this refers to a shared state, otherwise false.

[edit] Example

[edit] See also

| | waits for the result to become available (public member function) [edit] | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |