title: How to instantiate C++ member string reference
body: <p>I have a class with a <code>std::string&amp;</code> as a member of that class. I want to instantiate that reference, but I don't have anything to instantiate it to until a bit later. </p>
  
  <p>How can I instantiate the <code>std::string&amp;</code> member?</p>
  
  <pre class="lang-c prettyprint-override"><code>#include &lt;string&gt;
  class Temp {
      public : 
          Temp(): _line("") {}
      private:
          std::string&amp; _line;
  
  }
  </code></pre>