title: Singleton without copy constructor
body: <p>I am viewing a source code and it has got a singleton class like :</p>
  
  <pre><code>class A {
      private:
       A() {}
       ~A() {}
  };
  </code></pre>
  
  <p>And i see no copy constructor and assignment operator. When i talked about it, i got the response that it would not fail. </p>
  
  <p>But i had read that making copy constructor and assignment operator private or inaccessible is important. But i am unable to generate some breaking test cases.</p>
  
  <p>What test case can create two objects of this class ?</p>