title: How could I use unordered_set with triplets being its elements?
body: <p>I want to use triplets to be elements of <code>unordered_set</code> . I want to check whether a combination of three values has been present or not:</p>
  <pre><code>unordered_set&lt;long, long, long&gt; myset;
  myset.insert(0, 1, 0);
  </code></pre>
  <p>Obviously that's not correct. How could I do this correctly?
  Thank you for your help.</p>
  <p>-------Updated-------</p>
  <p>If I don't use <code>unordered_set</code>, is there any other easier way to check whether a combination has been present or not?
  Thank you for your help.</p>