title: Rule of three and inheritance
body: <p><code>class A</code> defines copy operator, destructor and operator=. (<a href="http://en.wikipedia.org/wiki/Rule_of_three_%28C%2B%2B_programming%29" rel="noreferrer">Rule of Three</a>)</p>
  
  <p>If <code>B</code> inherits from <code>A</code>:</p>
  
  <ul>
  <li>the destructor will be called automatically</li>
  <li>I need to chain the constructor</li>
  <li><code>operator=</code> ... should I define it explicitly for the class <code>B</code>?</li>
  </ul>