kdb@chinet.chi.il.us (Karl Botts) (11/04/90)
I am sending this to Microsoft; I thought it might be relevent here, too:
/*
Dear Microsoft Online,
MSC 6.0 correctly compiles this:
*/
enum {
A = (int)0x8001,
};
/*
but rejects this:
*/
enum {
B = (int)0x8000,
};
/*
with:
enum.c
enum.c(16) : error C2141: value out of range for enum constant
This doesn't make any sense, since both are valid values for a
16-bit integer.
This may be related to something I noticed in <limits.h>:
#define SHRT_MIN (-32767) /* minimum (signed) short value */
#define SHRT_MAX 32767 /* maximum (signed) short value */
This is clearly wrong. I don't have a copy of the ANSI standard,
but I suppose it is possible that it requires that the the _MIN and _MAX
constants for a signed integral type have the same absolute value.
If so we'll have to live with it, but otherwise you have a bad header
file.
If you have compiled the compiler using your <limits.h> this is
probably the source of the enum problem, above. But I claim that
regardless of the ANSI standard, the enum problem is a bug.
*/
/*
You may wonder how I ran into this. Well, I have a set of EMS
access routines which generate error codes by clearing the al register
if an EMS function fails; the native EMS error codes are in ah, and one
of them is 0x80. I wanted to make a a set of enum constants for these
codes.
*/kaiser@ananke.stgt.sub.org (Andreas Kaiser) (11/05/90)
In your msg to All, dated <05 Nov 90 08:31>, it said:
KB> enum { A = (int)0x8001, };
KB> but rejects this:
KB> enum { B = (int)0x8000, };
KB> enum.c(16) : error C2141: value out of range for enum constant
KB> This doesn't make any sense, since both are valid values for a
KB> 16-bit integer.
0x8000 is NOT a valid integer. -0x8000 IS a valid integer.
KB> This may be related to something I noticed in <limits.h>:
KB> #define SHRT_MIN (-32767)
KB> #define SHRT_MAX 32767
KB> This is clearly wrong. I don't have a copy of the ANSI
KB> standard, but I suppose it is possible that it requires that the the
KB> _MIN and _MAX constants for a signed integral type have the same
KB> absolute value.
BTW: Did you mean (-32768) ? The numbers in your include-file extract above HAVE the same absolute value.
I have not seen the mentioned restriction to symetrical limits in the MWC ANSI C book. It would enforce a one-s complement representation for integers. A funny idea today.
Andreas
A funny idea today.
Andreas
--
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:: Andreas Kaiser :: fido: 2:509/5.2512 & 2:507/18.7206
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