template< typename ShutdownHandler> void-or-deduced async_shutdown( ShutdownHandler handler);
This function is used to asynchronously shut down SSL on the stream. This function call always returns immediately.
The handler to be called when the handshake operation completes. Copies will be made of the handler as required. The equivalent function signature of the handler must be:
void handler( const boost::system::error_code& error // Result of operation. );