title: How do I combine hash values in C++0x?
body: <p>C++0x adds <code>hash&lt;...&gt;(...)</code>.</p>
  
  <p>I could not find a <code>hash_combine</code> function though, as presented in <a href="http://www.boost.org/doc/libs/1_37_0/doc/html/hash/reference.html#boost.hash_combine" rel="noreferrer">boost</a>.  What is the cleanest way to implement something like this?  Perhaps, using C++0x <code>xor_combine</code>?</p>