title: Struct varies in memory size?
body: <p>Why is not 12 in the first case?
  Tested on: latest versions of gcc and clang, 64bit Linux</p>
  
  <pre><code>struct desc
  {
      int** parts;
      int nr;
  };
  </code></pre>
  
  <p><code>sizeof(desc); Output: 16</code></p>
  
  <pre><code>struct desc
  {
      int** parts;
  };
  </code></pre>
  
  <p><code>sizeof(desc); Output: 8</code></p>
  
  <pre><code>struct desc
  {
      int nr;
  };
  </code></pre>
  
  <p><code>sizeof(desc); Output: 4</code></p>