title: How to know if a type is a specialization of std::vector?
body: <p>I've been on this problem all morning with no result whatsoever.
  Basically, I need a simple metaprogramming thing that allows me to branch to different specializations if the parameter passed is a kind of <code>std::vector</code> or not.</p>
  <p>Some kind of <code>is_base_of</code> for templates.</p>
  <p>Does such a thing exist ?</p>