 an expiry time.
boost::asio::steady_timer timer(io_context);

// Set an expiry time relative to now.
timer.expires_after(std::chrono::seconds(5));

// Wait for the timer to expire.
timer.wait();
</pre>
<p>
        Performing an asynchronous wait (C++11):
      </p>
<pre class="programlisting">void handler(const boost::system::error_code&amp; error)
{
  if (!error)
  {
    // Timer expired.
  }
}

...

// Construct a timer with an absolute expiry time.
boost::asio::steady_timer timer(io_context,
    std::ch