[m-rev.] Sleep(3) library call for the posix library

[Volker Wysk]

Hi

What integer type should I use for the "sleep" predicate for the posix
library? 

   :- pred sleep(uint::in, uint::out, io::di, io::uo) is det.

or 

   :- pred sleep(int::in, int::out, io::di, io::uo) is det.

?

The C type is

   unsigned sleep(unsigned);

Bye,
Volker