
      standard library...</li>

      <li><b>Expose relevant information about the cause of the error</b> in
      your exception class' public interface. A fixation on the
      <code>what()</code> message is likely to mean that you neglect to
      expose information someone might need in order to make a coherent
      message for users. For example, if your exception reports a numeric
      range error, it's important to have the actual numbers involved
      available <i>as numbers</i> in the exception