title: unique_ptr destructor advantage
body: <p>What is the advantage of using the using a unique_ptr destructor over just closing the file directly in C++11?</p>
  
  <p>i.e. this code   </p>
  
  <pre><code>FILE* p = fopen("filename","r");
  unique_ptr&lt;FILE, int(*)(FILE*)&gt; h(p, fclose);
  if (fclose(h.release()) == 0)
      p = nullptr;
  </code></pre>
  
  <p>vs.</p>
  
  <pre><code>FILE* p = fopen("filename","r");
  fclose(p)
  </code></pre>