title: restricting c++ template usage to POD types
body: <p>I have a c++ template class, which only operates correctly if the templatized type is plain old data. Anything with a constructor that does anything will not work correctly.</p>
  
  <p>I'd like to somehow get a compiletime or runtime warning when someone tries to do so anyway.</p>
  
  <pre><code>//this should generate error
  myclass&lt;std::string&gt; a;
  
  //this should be fine
  myclass&lt;int&gt; b;
  </code></pre>
  
  <p>is there a trick to do this?</p>