std::future::valid

 

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std::future

future::future

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future::share

Getting the result

future::get

State

future::valid

future::wait

future::wait_for

future::wait_until

 

bool valid() const;		(since C++11)

Checks if the future refers to a shared state. This is the case only for futures returned by std::promise::get_future(), std::packaged_task::get_future() or std::async() until the first time get()or share() is called.

Parameters

(none)

Return value

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

Exceptions

noexcept specification:  

noexcept

  (since C++11)

See also

wait	waits for the result to become available (public member function)