title: Where is rdbuf()->str()?
body: <p>I am trying to understand the structure of IO stream.<br>
  From <a href="https://en.cppreference.com/w/cpp/io/basic_stringstream/str" rel="nofollow noreferrer">cppreference <em>std::basic_stringstream::str</em></a>  :</p>
  
  <blockquote>
    <p>Manages the contents of the underlying string object.</p>
    
    <p>1) Returns a copy of the underlying string as if by calling <code>rdbuf()-&gt;str()</code>.</p>
  </blockquote>
  
  <p><code>rdbuf()</code> returns a <code>std::basic_streambuf</code> object, but I can't find a <code>str()</code> member function in <a href="https://en.cppreference.com/w/cpp/io/basic_streambuf" rel="nofollow noreferrer">https://en.cppreference.com/w/cpp/io/basic_streambuf</a> .</p>