Introduction to std::async

This lesson gives an introduction to std::async which is used in C++ for multithreading.

std::async behaves like an asynchronous function call. This function call takes a callable together with its arguments. std::async is a variadic template and can, therefore, take an arbitrary number of arguments. The call to std::async returns a future object fut. That’s your handle for getting the result via fut.get().

std::async should be your first choice

The C++ runtime decides if std::async is executed in a separate thread. The decision of the C++ runtime may depend on the number of CPU cores available, the utilization of your system, or the size of your work package. By using std::async, you only specify the task that should run; the C++ runtime automatically manages the creation and also the lifetime of the thread.

Optionally, you can specify a start policy for std::async.

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