[Interest] Signed return type of QIODevice::pos() - why?

[lloyd konneker]

Possibly some underlying file systems allow negative values, and Qt did 
not want to adapt to prevent negative values.
In other words, it depends on the underlying implementation.

See discussions about the off_t type in unix. 
http://pubs.opengroup.org/onlinepubs/009695399/functions/lseek.html
" A negative file offset may be valid for some devices in some 
implementations."