Pair data type in C++ and FF SS operators
<p>I am new to C++ and wanted to know what'd this declaration mean:</p>

<pre><code>typedef pair&lt;double,double&gt; pairD;
pair&lt;pairD, long&gt; unknown;
</code></pre>

<p>what'd unknown be?</p>

<p>And more specifically, what'd these operators do:</p>

<pre><code>unknown.FF.FF;
unknown.FF.SS;
</code></pre>

<p>Can you provide an example on what data one could initialize or fill in in such unknown data structure?</p>

<p>Thanks!</p>
