Overloading output operator
<p>Why doesn't this work:</p>

<pre><code>ostream &amp; operator&lt;&lt;( ostream&amp; os, Polygon&amp; p)
{
    for (int i = 0; i &lt; p.antal; i++)
    {
        os &lt;&lt; p.veArr[i];
    }
    return os;
}
</code></pre>

<p>It says no operator matches these operands.</p>
