MOC's preprocessing is not conformant

#include <QObject>

namespace problem
{

#define FOR_EACH_ITEM( CALL ) \
  CALL( EXAMPLE ) \
  CALL( 123_EXAMPLE ) \
  CALL( OTHER_EXAMPLE )

enum FooItems
{

#define ENUM_ITEM(NAME, ...) FOO ## NAME,
  FOR_EACH_ITEM( ENUM_ITEM )
};

}

class Foo : public QObject
{
  Q_OBJECT
};