#### io_context::restart

Restart the `io_context` in preparation for a subsequent `run()` invocation.

    void restart();

This function must be called prior to any second or later set of invocations of the `run()`, `run_one()`, `poll()` or `poll_one()` functions when a previous invocation of these functions returned due to the `io_context` being stopped or running out of work. After a call to `restart()`, the `io_context` object's `stopped()` function will return `false`.

This function must not be called while there are any unfinished calls to the `run()`, `run_one()`, `poll()` or `poll_one()` functions.