Mar 12, 2024 · 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,.
Feb 22, 2024 · 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..
Dec 28, 2021 · In summary: std::future is an object used in multithreaded programming to receive data or an exception from a different thread; it is one end of a single-use, one-way communication.
Aug 2, 2020 · 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 the call to this.
Nov 27, 2023 · future (const future &) = delete; ~future (); future & operator =(const future &) = delete; future & operator =(future &&) noexcept; shared_future <R> share () noexcept; // retrieving the value.
Aug 27, 2021 · Blocks until the result becomes available. valid() == true after the call. The behavior is undefined if valid() == false before the call to this function.
Oct 23, 2023 · 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.
Oct 23, 2023 · The promise is the "push" end of the promise-future communication channel: the operation that stores a value in the shared state synchronizes-with (as defined in std::memory_order).
Mar 6, 2020 · impl<F> Future for Box<F> where F: Unpin + Future + ?Sized, Boxed futures only implement the Future trait when the future inside the Box implements Unpin. Since your function.
Oct 28, 2024 · The function template std::async runs the function f asynchronously (potentially in a separate thread which might be a part of a thread pool) and returns a std::future that will eventually.
