...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Inform the thread pool that it has some outstanding work to do.
void on_work_started() const;
This function is used to inform the thread pool that some work has begun.
This ensures that the thread pool's join()
function will not
return while the work is underway.