Introduction to std::packaged_task

std::packaged_task pack is a wrapper for a callable, which allows it to be invoked asynchronously. By calling pack.get_future(), we get the associated future. Invoking the call operator on pack (pack()) executes the std::packaged_task and, therefore, executes the callable.

Dealing with std::packaged_task usually consists of four steps:

I. Wrap our work: