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Re: unsigned int

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On 02/08/16 19:16, supercat@casperkitty.com wrote:
> On Tuesday, August 2, 2016 at 11:50:36 AM UTC-5, Les Cargill wrote:
>> I simply have to disagree. The default 'C' int declaration is
>> signed unless it's explicitly made unsigned.
> 
> All ASCII characters are in the range 0..127, so all members of the C
> Character Set are guaranteed have character codes in the range
> 0..SCHAR_MAX regardless of CHAR_BITS.

True - for a C implementation that uses ASCII.  But the standards don't
require ASCII, and C can be implemented with many different character
sets as long as they cover the standard 26 letter Latin alphabet, 10
digits, and a range of punctuation and symbols.  Historically, EBCDIC
has probably been popular on some systems.  And in modern tools, UTF-8
and Latin-1 (Windows CP1252, IIRC) are also common for the execution
character set (if not necessarily for the source character set).  Those
use characters or encodings in the range 128-255 as well.

> 
> Implementations which use non-ASCII character sets may have
> characters whose codes are greater than SCHAR_MAX.  That would imply
> that unqualified `char` must be unsigned on such platforms, since all
> members of the C character set are required to have non-negative
> character codes.

No, a "char" only needs to be able to store any element of the "basic
execution character set".  This can be a subset of the full execution
character set.  In real implementations using UTF-8, Latin-1, or another
encoding (possibly multi-byte) for the execution character set would
have ASCII as the "basic execution character set".

> 
> On the flip side, a lot of code relies upon having all values of type
> `char` be representable as type `int`; implementations where
> `unsigned char` has a larger range than `signed int` would violate
> that expectation of unqualified `char` were unsigned.
> 

It is perfectly possible for a plain char to be an unsigned 16-bit value
while an int is a signed 16-bit value - thus there are valid "char"
values that cannot be represented as "int".  On systems with 16-bit CHAR
(such as some DSP's), it would not surprise me if this were the case.

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Re: unsigned int "Osmium" <r124c4u102@comcast.net> - 2016-07-31 12:40 -0500
  Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-01 11:01 +0200
    Re: unsigned int James Kuyper <jameskuyper@verizon.net> - 2016-08-01 10:15 -0400
    Re: unsigned int Les Cargill <lcargill99@comcast.com> - 2016-08-01 09:59 -0500
      Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-01 17:21 +0200
        Re: unsigned int Keith Thompson <kst-u@mib.org> - 2016-08-01 09:55 -0700
          Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-01 22:42 +0200
            Re: unsigned int supercat@casperkitty.com - 2016-08-01 14:18 -0700
        Re: unsigned int Les Cargill <lcargill99@comcast.com> - 2016-08-01 13:11 -0500
          Re: unsigned int Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-01 19:46 +0100
            Re: unsigned int Les Cargill <lcargill99@comcast.com> - 2016-08-01 18:20 -0500
              Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-02 10:18 +0200
                Re: unsigned int Les Cargill <lcargill99@comcast.com> - 2016-08-02 09:35 -0500
                Re: unsigned int Keith Thompson <kst-u@mib.org> - 2016-08-02 08:00 -0700
                Re: unsigned int Les Cargill <lcargill99@comcast.com> - 2016-08-02 11:12 -0500
                Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-02 17:11 +0200
                Re: unsigned int Les Cargill <lcargill99@comcast.com> - 2016-08-02 11:55 -0500
                Re: unsigned int supercat@casperkitty.com - 2016-08-02 10:16 -0700
                Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-03 14:02 +0200
                Re: unsigned int Keith Thompson <kst-u@mib.org> - 2016-08-03 08:58 -0700
                Re: unsigned int James Kuyper <jameskuyper@verizon.net> - 2016-08-02 13:57 -0400
                Re: unsigned int Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-02 19:30 +0100
                Re: unsigned int Keith Thompson <kst-u@mib.org> - 2016-08-02 11:38 -0700
                Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-03 14:12 +0200
                Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-03 13:45 +0200
          Re: unsigned int Keith Thompson <kst-u@mib.org> - 2016-08-01 12:02 -0700
            Re: unsigned int David Brown <david.brown@hesbynett.no> - 2016-08-01 23:01 +0200

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