std::promise::get_future(3)

NAME
std::promise::get_future - std::promise::get_future

Synopsis
   std::future<R> get_future(); (since C++11)
   Returns a future object associated with the same shared state as *this.
   An exception is thrown if *this has no shared state or get_future has already been
   called. To get multiple "pop" ends of the promise-future communication channel, use
   std::future::share.
   Calls to this function do not introduce data races with calls to set_value,
   set_exception, set_value_at_thread_exit, or set_exception_at_thread_exit (therefore
   they need not synchronize with each other).

Parameters
   (none)

Return value
   A future referring to the shared state of *this.

Exceptions
   std::future_error on the following conditions:
     * *this has no shared state. The error code is set to no_state.
     * get_future() has already been called on a promise with the same shared state as
       *this. The error code is set to future_already_retrieved.