#include <boost/asio.hpp>
#include <iostream>

void writeComplete(const boost::system::error_code & ec, size_t transferred)
{
	if (ec)
	{
		// cancel was called before the io_service was entered. I would 
		// expect an operation aborted error
		std::cout << "operation cancelled" << std::endl;
	}
	else
	{
		std::cout << transferred << " bytes transferred (not cancelled!)" << std::endl;
	}
}

int main(int argc, char * argv[])
{
	boost::asio::io_service my_io_service;
	char msg[] = {'h', 'e', 'l', 'l', '0', 0};

	{
		boost::asio::serial_port port(my_io_service, "/dev/ttyS1");

		// serial port is opened and we initiate an async write to probe for a device
		// attached
		boost::asio::async_write(port, boost::asio::const_buffers_1(msg, sizeof(msg)), writeComplete);

		// assume elsewhere in the code an error occurred, and we cancel all processing
		port.cancel();

		// the cleanup of the error also causes the serial port to be destroyed.
	}

	// meanwhile the error cleanup has completed and we're ready to continue without using
	// the serial port
	std::cout << "entering io_service" << std::endl;

	my_io_service.run();
}