Actually if you open up these two headers: “AllowWindowsPlatformTypes.h” and “HideWindowsPlatformTypes.h”, you will find that the first one defines some names and the latter one undefine these names, and you can wrap your Windows code in between them, like this:
#include "AllowWindowsPlatformTypes.h"
#include "commdlg.h"
#include "HideWindowsPlatformTypes.h"
I think it’s just a trick to use Windows specific types without interfering with the rest of the codes.