var number = 3500;
alert(new Intl.NumberFormat().format(number));
// → "3,500" if in US English locale
Ответ:
Глупая ошибка, я компилировал в Debug, поэтому загружались QtGui4d.dll и QtCore4d.dll, а не QtCore4.dll и QtGui.dll
Compare the addresses of `QWidgetPrivate::mapper in the DLL and in your code. Esp. if one is linked statically, there might be two instance of it, each with it's own, disjoint, set of widgets.