Overload postfix increment operator
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/4421706/operator-overloading">Operator overloading</a>  </p>
</blockquote>



<p>Suppose I have a class <code>Foo</code> and I want to to overload the postfix increment operator. I do something like:</p>

<pre><code>class Foo{
.....
public:
   friend Foo&amp; operator++(Foo&amp;, int);
</code></pre>

<p>and then I define the new operator somewhere. What I really cannot figure out is where does this <code>int</code> come from. </p>

<p>If I have:  <code>f = Foo();</code> I can do:</p>

<pre><code>f++;
</code></pre>

<p>and this seems to me to be unary.</p>

<p>How is the syntactic rule?</p>

<p>In the tests I ran the int value passed was <code>0</code>. Is ti always zero?</p>
