title: Convert data from const void *data to double
body: <p>I received data from some other function to <code>myfunction(const void *data)</code> where pointer <code>data</code> stores the values like <code>{0,0,0,0,0,0,0,40,20,0,0,0,0,0,0}</code>.</p>
  
  <p>I want to access just values from <code>{40,20,0,0,0,0,0,0}</code> and convert into a <code>double</code> type value that should give <code>8.0</code> . For accessing and conversion to double type I have tried pointer to double:</p>
  
  <pre><code>double* dptr;
  dptr=&amp;(*data+8);
  dptr;
  </code></pre>
  
  <p>that was giving error like</p>
  
  <blockquote>
    <p>"error: ‘const void*’ is not a pointer-to-object type"</p>
  </blockquote>