 in the examples:
        </p>
<p>
</p>
<pre class="programlisting"><span class="comment">// a simple complex number representation z = a + bi</span>
<span class="keyword">struct</span> <span class="identifier">complex</span>
<span class="special">{</span>
    <span class="identifier">complex</span> <span class="special">(</span><span class="keyword">double</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">double</span> <span class="identifier">b</span><span class=