title: Testing about deletion of a node in list
body: <p>I have implemented a doubly linked cyclic list and I do want to write tests.</p>
  
  <p>So in this list, there is a deletion operator and I want to check if it is working properly. I hold an iterator to a node and then I deleted this node, now I want to verify that this iterator points to something that doesn't exist anymore. 
  How can I write a test to verify this? 
  While I was searching the net I found something about boost libraries and test libraries.
  Below there is a minimal example of what I am saying.</p>
  
  <pre><code>#include&lt;iostream&gt;
  struct Node{
      Node* back;
      Node* front;
      int data;
  }Node;
  
  int main(int argc, char* argv[])
  {
      Node* a = new Node;
      Node* b = a;
      delete a;
  
      //HOW TO CHECK IF THE NODE THAT I ALLOCATED, HAVE BEEN DELETED?
  }
  </code></pre>