>Let us consider following execution sequence:
>1. "io_service" destructor calls "io_service::service::shutdown_service";
>2. documentation of "io_service::service::shutdown_service" says that it
>should destroy all user defined handler objects.
>Is it true that user defined handler objects may access to (e.g. post a
>handler) that "io_service" being destroyed and therefore has not exist
>Could You please also clarify me what does "user defined handler object"