1. Open the Qt Quick Controls 2 Gallery example in Qt Creator.
   It's in Examples\Qt-<version>\quickcontrols2\gallery\gallery.pro
2. Open ComboBoxPage.qml
   QTCREATORBUG-20004 might get in your way.
3. Place a breakpoint in the onAccepted-handler:

               onAccepted: {
                   if (find(editText) === -1)
                       model.append({text: editText})
               }
   

4. Let the project run into the breakpoint.
5. See Creator's "Locals and Expressions" view.
   There are two lines which seem quite useless:
   

Instead, "this" should be expandable and then display all the values. When using Qt 5.10.1, this works correctly.