std::future - cppreference.com
2024年3月12日 · future. 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 ...
What is __future__ in Python used for and how/when to use it, and …
2016年3月2日 · The future statement is intended to ease migration to future versions of Python that introduce incompatible changes to the language. It allows use of the new features on a per-module basis before the release in which the feature becomes standard. If you actually want to import the __future__ module, just do.
std::shared_future - cppreference.com
2023年10月23日 · shared_future. The class template std::shared_future provides a mechanism to access the result of asynchronous operations, similar to std::future, except that multiple threads are allowed to wait for the same shared state. Unlike std::future, which is only moveable (so only one instance can refer to any particular asynchronous result), std ...
std::future<T>::get - cppreference.com
2024年2月22日 · std::future<void> specialization. void get(); (3) (since C++11) The get member function waits (by calling wait ()) until the shared state is ready, then retrieves the value stored in the shared state (if any). Right after calling this function, valid () is false. If valid () is false before the call to this function, the behavior is undefined.
std::future<T>::wait - cppreference.com
2021年8月27日 · future::valid. future::wait. future::wait_for. future::wait_until. void wait() const; (since C++11) Blocks until the result becomes available. valid() == true after the call. The behavior is undefined if valid() == false before the call to this function.
std::future<T>:: wait_for - Reference
2021年8月27日 · std::future<T>:: wait_for. wait_for. Waits for the result to become available. Blocks until specified timeout_duration has elapsed or the result becomes available, whichever comes first. The return value identifies the state of the result. If the future is the result of a call to std::async that used lazy evaluation, this function returns ...
std::future<T>::valid - cppreference.com
2021年8月27日 · valid. 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. The behavior is undefined if any member function other than ...
std::promise - cppreference.com
2023年10月23日 · 1) Base template. 2) Non-void specialization, used to communicate objects between threads. 3) void specialization, used to communicate stateless events. The class template std::promise provides a facility to store a value or an exception that is later acquired asynchronously via a std::future object created by the std::promise object.
flutter - What is a Future and how do I use it? - Stack Overflow
2020年7月21日 · A Future<T> is something that in the future will give you a T. Lets try a different explanation: A future represents the result of an asynchronous operation, and can have two states: uncompleted or completed. Most likely, as you aren't doing this just for fun, you actually need the results of that Future<T> to progress in your application. You ...
std::async - cppreference.com
2024年10月28日 · Lazy evaluation is performed: . The first call to a non-timed wait function on the std::future that std::async returned to the caller will evaluate INVOKE (std:: move (g), std:: move (xyz)) in the thread that called the waiting function (which does not have to be the thread that originally called std::async), where