Finally, to wait at most until a specified time limit, use
:cpp:func:`s4u::Activity::wait_until() <simgrid::s4u::Activity::wait_until>`.
-.. todo::
-
- wait_for and wait_until are currently not implemented for Exec and Io activities.
-
Every kind of activity can be asynchronous:
- :ref:`s4u::CommPtr <API_s4u_Comm>` are created with