title: Correct usage(s) of const_cast<>
body: <p>As a common rule, it is very often considered a bad practice to use <code>const_cast&lt;&gt;()</code> in C++ code as it reveals (most of the time) a flaw in the design.</p>
  
  <p>While I totally agree with this, I however wonder what are the cases were using <code>const_cast&lt;&gt;()</code> is <em>ok</em> and the <em>only solution</em>.</p>
  
  <p>Could you guys please give me some examples you know/you encountered ?</p>
  
  <p>Thank you very much.</p>