...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Run the io_service's event processing loop to execute at most one handler.
std::size_t run_one();
The run_one() function blocks until one handler has been dispatched, or until the io_service has been stopped.
The number of handlers that were executed.
Thrown on failure.