What does && mean at the end of a function signature (after the closing parenthesis)?
<p>In <a href="http://stackoverflow.com/questions/14562984/workarounds-for-no-rvalue-references-to-this-feature">Workarounds for no &#39;rvalue references to *this&#39; feature</a>, I see the following member function (a conversion operator):</p>

<pre><code>template&lt; class T &gt;
struct A
{
    operator T&amp;&amp;() &amp;&amp; // &lt;-- What does the second '&amp;&amp;' mean?
    {
        // ...
    }
};
</code></pre>

<p>What does the second pair of <code>&amp;&amp;</code> mean?  I am not familiar with that syntax.</p>
