title: Why does qjsonvalue todouble conversion cause data loss?
body: <p>QJsonValue toDouble() conversion generates wrong values causing data loss. </p>
  
  <pre><code>QJsonObject obj;
  obj.insert("dbl",double(73183493944884961));
  
  
  double d = obj.value("dbl").toDouble();
  qulonglong ul = d;
  qulonglong ul2 = 73183493944884961;
  
  qDebug ()  &lt;&lt; ul &lt;&lt; ul2;
  </code></pre>
  
  <p>Output:</p>
  
  <pre>
  73183493944884960 73183493944884961
  </pre>