title: How to check for the type of a template parameter?
body: <p>Suppose I have a template function and two classes</p>
  
  <pre><code>class animal {
  }
  class person {
  }
  
  template&lt;class T&gt;
  void foo() {
    if (T is animal) {
      kill();
    }
  }
  </code></pre>
  
  <p>How do I do the check for T is animal? I don't want to have
  something that checks during the run time. Thanks</p>