title: constexpr for sizeof in template does not compile
body: <p>In Visual C++ 2012 (C++ 11) I am getting error for code</p>
  
  <pre><code>template &lt;typename T, T... I&gt;
  struct structFoo
  {
    static const T sz = sizeof...(I);        (1)
    static constexpr T size = sizeof...(I);  (2)
  };
  </code></pre>
  
  <p>the compiler takes the line (1) but complains that the line (2) is an error:
  'error C4430: missing type specifier - int assumed. Note: C++ does not support default-int.</p>
  
  <p>Why?</p>