title: Is it safe to manipulated streambuf after doing boost::asio::async_read?
body: <p>I know it's not safe to manipulated streambuf while async_write working as stated by asio author on boost mailing list. What I want to know is, is it safe to manipulated streambuf after async_read?</p>
  
  <p>Example:</p>
  
  <pre><code>async_read(socket_, recv_streambuf_, ...);
  // manipulated while async_read is working
  // for example, after I call async_read,
  recv_streambuf_.consume(2); 
  // or something advance, like this...
  int var;
  std::istream recv_is(recv_streambuf_);
  recv_is &gt;&gt; var; 
  </code></pre>