s="identifier">char_traits</span></code> is a classic
      example of a collection of type specific properties wrapped up in a single
      class - what Nathan Myers termed a <span class="emphasis"><em>baggage class</em></span><a class="link" href="background.html#background.references">[1]</a>. In the Boost type-traits library,
      we<a class="link" href="background.html#background.references">[2]</a> have written a set of very
      specific traits classes, each of which encapsulate a single trait from