title: What are the semantics of unions with both volatile and nonvolatile members?
body: <p>More specifically, I have (simplified) the following:</p>
  
  <pre><code>union foo
      {
      volatile int bits;
      char data[sizeof(int)*CHAR_BIT];
      }
  </code></pre>
  
  <p>If I never access the first <code>sizeof(int)</code> items of <code>data</code>, can i rely on <code>bits</code> working as expected?</p>