pollable

Make a nonblocking attempt to complete the I/O operation.

Returns true if the given async item is “ready” for its associated I/O action, false otherwise.

If an object is ready, the I/O action is guaranteed to complete without blocking.

Valid object handles includes bodies and pending requests. See the async-io.pollable definition for more details, including what I/O actions are associated with each handle type.

Create a new trivial pollable which reports being immediately ready.