The Future: C++23

Concurrency in C++20

It is difficult to make predictions, especially about the future (Niels Bohr).

Executors

An executor consists of a set of rules about where, when and how to run a callable unit. They are the basic building block to execute and specify if callables should run on an arbitrary thread, a thread pool, or even single threaded without concurrency. The extended futures, the extensions for networking N4734 depend on them but also the parallel algorithms of the STL, and the new concurrency features in C++20/23 such as latches and barriers, coroutines, transactional memory, and task blocks eventually use them.

Extended futures

Tasks called promises and futures, introduced in C++11, have a lot to offer, but they also have a drawback: tasks are not composable into powerful workflows. That limitation does not hold for the extended futures in C++20/23. Therefore, an extended future becomes ready, when its predecessor (then) becomes ready...