title: g++ does not show a 'unused' warning
body: <p>I have a little piece of code in C++:</p>
  
  <pre><code>#include &lt;iostream&gt;
  #include &lt;iterator&gt;
  #include &lt;string&gt;
  
  using namespace std;
  
  int main() {
  
      int i=0;
      istream_iterator&lt;string&gt; EOS;
      double x;
  
      return 0;
  }
  </code></pre>
  
  <p>Now i compile it with my g++ (GCC) 4.4.4</p>
  
  <pre><code>g++ -W -Wall -pedantic test.cc -o test
  </code></pre>
  
  <p>And get:</p>
  
  <pre><code>test.cc: In function 'int main()':
  test.cc:9: warning: unused variable 'i'
  test.cc:11: warning: unused variable 'x'
  </code></pre>
  
  <p>Why there is no warning for unused EOS?</p>