P3: Somewhat important Description
The following snippet is from qdatastream.h:
...
#ifdef Status
#error qdatastream.h must be included before any header file that defines Status
#endif
...
The following snippet is from qsettings.h:
...
#ifdef Status // ### we seem to pick up a macro Status --> int somewhere
#undef Status
#endif
...
They should probably be handled in the same way.
Answer from Trolltech:
Since X11 headers are not namespace safe, they have to be included after Qt headers. Generally, headers should always be included in the order from the most specialized to the most general one to prevent namespace pollution:
#include "myownheader.h"
#include <someQtHeader.h>
#include <X11/someXheader>
#include <string.h> // system header