Re: inttypes.h incompatibility with iostream [#5060]

[Paul Eggert]

> Date: Fri, 7 Dec 2001 15:34:56 -0500 (EST)
> From: Keith Bostic <address@hidden>

> > Here's an idea for fixing things.  Very early in 'configure' you check
> > for the problem, and if so, you inform autoconf that there is no
> > inttypes.h.
> 
> How would I do that?  Explicitly set ac_cv_header_inttypes_h to "no"?

Pretty much, yes.


> > Perhaps we should fix this within Autoconf, by modifying Autoconf by
> > adding wchar.h to the standard headers, and check for it before
> > checking for inttypes.h (as wchar.h is the more senior include file).
> > That would be an easy change to make.  But I'd like to know the
> > answers to the above questions before advocating such a change.
> 
> Agreed -- Michael should be able to let you know soon.

OK.  Looking forward to the info.


> So, perhaps we should just include <stdint.h> and forget about
> <inttypes.h>?

No, because:

> Are there platforms that have <inttypes.h> but not <stdint.h>?

Yes.  Solaris 8, for example.

In my experience, <inttypes.h> is a bit more reliable than <stdint.h>
because it has been around longer.  <stdint.h> is a creation of the
C99 committee, whereas <inttypes.h> exists on many pre-C99 platforms.

C99 says that freestanding C99 platforms must have <stdint.h> but may
lack <inttypes.h>, which is the only reason I'd worry about <stdint.h>
at all.  I've never used such a platform, but I wouldn't be surprised
to come across one someday.


> my guess is that turning off autoconf's use of <inttypes.h> and
> <stdint.h> durign configuration, and then dropping them from our
> created include file, would be a good solution -- if we can easily
> convince autoconf that's what we want to do.

OK, but I would suppress <inttypes.h> and/or <stdint.h> only if you
detect the header incompatibility.  I think this will give you better
results on future platforms.  On some platforms, for example, I
wouldn't be surprised if intmax_t is wider than long long.