promise::get_future Method
Returns a future object that has the same associated asynchronous state as this promise.
future<Ty> get_future();
Remarks
If the promise object is empty, this method throws a future_error that has an error_code of no_state.
If this method has already been called for a promise object that has the same associated asynchronous state, the method throws a future_error that has an error_code of future_already_retrieved.
Requirements
Header: future
Namespace: std