title: C++: multiple keyed map
body: <p>I am searching for a (multi)map where there values are associated by different key types. Basically <a href="https://stackoverflow.com/questions/822322/how-to-implement-a-map-with-multiple-keys">what was asked here for Java</a> but for C++. Is there something like this already or do I have to implement it myself?</p>
  
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  <p>Another, more simple case (the above case would solve this already but there may be a more simple solution esp for this case):</p>
  
  <p>I want a multimap where my values are all unique and ordered (the keys are also ordered of course) and I want to be able to do a search in the map for a specific value in O(log n) time. So I can get the associated key to a value in O(log n) time. And I can get the associated value to a key also in O(log n) time.</p>