title: Does std::unordered_multimap's bucket only contain elements with equivalent keys
body: <p>On www.CPlusPlus.com, it states the following for unordered_multimap,</p>
  
  <blockquote>
    <p>Elements with equivalent keys are grouped together in the same bucket and in such a way that an iterator (see equal_range) can iterate through all of them.</p>
  </blockquote>
  
  <p>I know we cannot infer this from that statement, but I'd like to know if a given bucket <strong>only</strong> contains elements with the equivalent keys?</p>