The class template std::future provides a mechanism to access the result of asynchronous operations: An asynchronous operation (created via std::async, std::packaged_task, or std::promise) can provide a std::future object to the creator of that asynchronous operation. The creator of the asynchronous operation can then use a variety of methods to query, wait for, or extract a value from the std ... Unlike std::future, which is only moveable (so only one instance can refer to any particular asynchronous result), std::shared_future is copyable and multiple shared future objects may refer to the same shared state.
Access to the same shared state from multiple threads is safe if each thread does it through its own copy of a shared_future object. Checks if the future refers to a shared state. This is the case only for futures that were not default-constructed or moved from (i.e. returned by std::promise::get_future (), std::packaged_task::get_future () or std::async ()) until the first time get () or share () is called.
future cellular phones, The behavior is undefined if any member function other than the destructor, the move-assignment operator, or valid is ... Future<String> someLongComputation() async { ... } above, someLongComputation will immediately return a future, and after some time, said future will resolve with a string. What the await keyword does is wait until the future has returned a value and then returns said value, basically turning an asynchronous computation into a synchronous one, of course this would negate the whole point of ... Specifies state of a future as returned by wait_for and wait_until functions of std::future and std::shared_future.
future cellular phones, Constants If the future is the result of a call to std::async that used lazy evaluation, this function returns immediately without waiting. This function may block for longer than timeout_duration due to scheduling or resource contention delays. The standard recommends that a steady clock is used to measure the duration. wait_until waits for a result to become available. It blocks until specified timeout_time has been reached or the result becomes available, whichever comes first. The return value indicates why wait_until returned.
If the future is the result of a call to async that used lazy evaluation, this function returns immediately without waiting. The behavior is undefined if valid () is false before ... Considerations When future grants are defined on the same object type for a database and a schema in the same database, the schema-level grants take precedence over the database level grants, and the database level grants are ignored. This behavior applies to privileges on future objects granted to one role or different roles.
