promise::set_value Method
Atomically stores a value as the result of this promise object and sets the associated asynchronous state to ready.
void promise::set_value(const Ty& Val);
void promise::set_value(Ty&& Val);
void promise<Ty&>::set_value(Ty& Val);
void promise<void>::set_value();
Parameters
- Val
The value to be stored as the result.
Remarks
If the promise object has no associated asynchronous state, this method throws a future_error that has an error code of no_state.
If set_exception, set_exception_at_thread_exit, set_value, or set_value_at_thread_exit has already been called for a promise object that has the same associated asynchronous state, this method throws a future_error that has an error code of promise_already_satisfied.
As a result of this method, any threads that are blocked on the associated asynchronous state become unblocked.
The first method also throws any exception that is thrown when Val is copied into the associated asynchronous state. In this situation, the associated asynchronous state is not set to ready.
The second method also throws any exception that is thrown when Val is moved into the associated asynchronous state. In this situation, the associated asynchronous state is not set to ready.
For the partial specialization promise<Ty&>, the stored value is in effect a reference to Val.
For the specialization promise<void>, no stored value exists.
Requirements
Header: future
Namespace: std