title: QString to const std::string
body: <p>I want to assign the value in QString to a const std::string</p>
  
  <pre><code>QString qfile("some value");
  </code></pre>
  
  <p>this is the const std::string variable</p>
  
  <pre><code>const std::string file
  </code></pre>
  
  <p>The code that I m using </p>
  
  <pre><code>file = qfile.toStdString();
  </code></pre>
  
  <p>above codes works fine for a normal std::string . But there is some problem because of the keyword 'const'. How do I solve it ?</p>