### execution::schedule

A customisation point that is used to obtain a sender from a scheduler.

    constexpr unspecified schedule = unspecified;

The name `execution::schedule` denotes a customisation point object. For some subexpression `s`, let `S` be a type such that `decltype((s))` is `S`. The expression `execution::schedule(s)` is expression-equivalent to:

- `s.schedule()`, if that expression is valid and its type models `sender`.
- Otherwise, `schedule(s)`, if that expression is valid and its type models `sender` with overload resolution performed in a context that includes the declaration `void schedule();` and that does not include a declaration of `execution::schedule`.
- Otherwise, `S` if `S` satisfies `executor`.
- Otherwise, `execution::schedule(s)` is ill-formed.

##### Requirements

Header: `asio/execution/schedule.hpp`

Convenience header: `asio/execution.hpp`