title: Why does std::set not have a "contains" member function?
body: <p>I'm heavily using <code>std::set&lt;int&gt;</code> and often I simply need to check if such a set contains a number or not.</p>
  
  <p>I'd find it natural to write:</p>
  
  <pre><code>if (myset.contains(number))
     ...
  </code></pre>
  
  <p>But because of the lack of a <code>contains</code> member, I need to write the cumbersome:</p>
  
  <pre><code>if (myset.find(number) != myset.end())
    ..
  </code></pre>
  
  <p>or the not as obvious:</p>
  
  <pre><code>if (myset.count(element) &gt; 0) 
    ..
  </code></pre>
  
  <p>Is there a reason for this design decision ?</p>