ippet shows how to use <tt>function_requires()</tt> to make sure
that the iterator is a
<a
href="http://www.sgi.com/tech/stl/RandomAccessIterator.html">
RandomAccessIterator</a>.

<pre>
  template &lt;class Iter&gt;
  void stable_sort(Iter first, Iter last)
  {
    function_requires&lt; RandomAccessIteratorConcept&lt;Iter&gt; &gt;();
    ...
  }
</pre>

The definition of the <tt>function_requires()</tt> is as follows. The
<tt>Concept</tt> is the concept checking class that has been
instantiated with the mod