Re: scm_bits_t / scm_ubits_t

[Jacques A. Vidrine]

On Sun, Jun 10, 2001 at 07:36:00PM +0300, Michael Livshin wrote:
> "Jacques A. Vidrine" <address@hidden> writes:
> 
> > On Sun, Jun 10, 2001 at 03:04:09PM +0300, Michael Livshin wrote:
> > > size_t is fine for
> > > vector lengths, but might not be enough for list and (bit) array
> > > lengths.  
> > 
> > This may be true [1], but...
> > 
> > > we should use uintptr_t (or unsigned long) for those.
> >                 ^^^^^^^^^
> > 
> > This is  wrong. uintptr_t should really  only be used to  hold pointer
> > values.  If one  is looking for the largest unsigned  integer, then it
> > would be  pretty safe to  have configure  check for the  following, in
> > order:
> 
> this is not wrong because we don't look for the largest unsigned
> integer type (well, in the case of list length, bit-array lengths are
> trickier).  we are looking precisely for an integer type that has the
> same width as a pointer (to be even more precise, same width as a
> pointer to cell, but at this point the C standard stops cooperating
> ;))

I hope I haven't got confused, but reading above I see two things:
 
   1. ``size_t is fine for vector _lengths_, but might not be enough
      for list and (bit) array _lengths_.'' (emphasis mine).

   2. ``we are looking precisely for an integer type that has the same
      width as a pointer''

These  are  different requirements.   I'm  suggesting  (1) should  use
uintmax_t, and that (2) should use uintptr_t.  What am I missing?

Cheers,
-- 
Jacques Vidrine / address@hidden / address@hidden / address@hidden