Reverse iterate over a std::vector with forward iterators
<p>If I have a function which takes a <code>std::vector&lt;T&gt;::const_iterator</code> called begin and a <code>std::vector&lt;T&gt;::const_iterator</code> called end, is it possible for me to iterate over it in a backwards direction?</p>

<p><strong>UPDATE</strong></p>

<p>I can't change the function signature, which is like this:</p>

<pre><code>void func(Foo::const_iterator begin, Foo::const_iterator end) 
{
   ...
}
</code></pre>

<p>and called with:</p>

<pre><code>func(foo.begin(), foo.end());
</code></pre>

<p>which I also can't change</p>
