title: How to get the closest item to my key from a SortedDictionary?
body: <p>Currently I'm using a binary search over a <code>SortedList&lt;T,U&gt;</code> for a specific number, and if it doesn't exist I get the closest lower-bound key-item instead. </p>
  
  <p>I saw that it was rather slow in <a href="https://stackoverflow.com/questions/1376965/when-to-use-a-sortedlisttkey-tvalue-over-a-sorteddictionarytkey-tvalue">inserting unsorted data</a> which I'm doing a lot of.</p>
  
  <p>Is there a way to do something similar with the <code>SortedDictionary</code>, or should I just stick to my <code>SortedList</code>?</p>