std::packaged_task<R(Args...)>::operator()
void operator()( ArgTypes... args ); |
(since C++11) |
Calls the stored task with args as the arguments. The return value of the task or any exceptions thrown are stored in the shared state. The shared state is made ready and any threads waiting for this are unblocked.
Parameters
| args | - | the parameters to pass on invocation of the stored task |
Return value
(none).
Exceptions
std::future_error on the following error conditions:
- The stored task has already been invoked. The error category is set to
promise_already_satisfied. -
*thishas no shared state. The error category is set tono_state.
Example
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2142 | C++11 | A successful call to operator() synchronizes with a call to anymember function of a std::future or std::shared_future thatshare their shared state with *this. |
No additional synchronization guarantees other than what's already provided by shared state. |
See also
| executes the function ensuring that the result is ready only once the current thread exits (public member function) |
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