title: Why does chrono have its own namespace?
body: <p>Everything else I have seen so far in the C++ standard library is in the <code>std</code> namespace. If I use things from <code>std::chrono</code> I usually exceed my 80 character per line limit - that is not a problem, just inconvienent.</p>
  
  <p>So here my simple question: Why does the chrono header has its own namespace?</p>