33 Execution control library [exec]

33.9 Senders [exec.snd]

33.9.11 Sender factories [exec.factories]

33.9.11.1 execution​::​schedule [exec.schedule]

schedule obtains a schedule sender ([exec.async.ops]) from a scheduler.
The name schedule denotes a customization point object.
For a subexpression sch, the expression schedule(sch) is expression-equivalent to sch.schedule().
Mandates: The type of sch.schedule() satisfies sender.
If the expression get_completion_scheduler<set_value_t>(get_env(sch.schedule())) == sch is ill-formed or evaluates to false, the behavior of calling schedule(sch) is undefined.