ASIO ip::tcp::iostream and TCP_NODELAY

How do i set TCP_NODELAY option if i use ip::tcp::iostream? I need a soc开发者_如何学Pythonket for this, but i can't find how to extract it from iostream.

use iostream::rdbuf()

#include <boost/asio.hpp>

int
main()
{
    boost::asio::ip::tcp::iostream stream;
    const boost::asio::ip::tcp::no_delay option( true );
    stream.rdbuf()->set_option( option );
}