title: Why is there no ForEach extension method on IEnumerable?
body: <p>Inspired by another question asking about the missing <code>Zip</code> function:</p>
  <p>Why is there no <code>ForEach</code> extension method on the <code>IEnumerable</code> interface? Or anywhere? The only class that gets a <code>ForEach</code> method is <code>List&lt;&gt;</code>. Is there a reason why it's missing, maybe performance?</p>