title: Return zero for Count() on null IEnumerables
body: <p>I'm getting tired of using code like this:</p>
  
  <pre><code>var count = 0;
  if (myEnumerable != null)
  {
      count = myEnumerable.Count();
  }
  </code></pre>
  
  <p>And this is a bit pedantic:</p>
  
  <pre><code>var count = (myEnumerable ?? new string[0]).Count();
  </code></pre>
  
  <p>Is there any tidier way of doing this?  I once had a (badly named) PhantomCount extension method on IEnumerable&lt;> that used my first code example, but it had something of a smell about it (besides the name).</p>