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Re: wchar_t is useless

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On 2011-11-21, Lauri Alanko <la@iki.fi> wrote:
> I have recently written a number of posts regarding C's wide character
> support. It now turns out that my investigation has been in vain:
> wchar_t is useless in portable C programming, although I'm not quite

That is false; it is useful.

> So I looked at wchar_t. If __STDC_ISO_10646__ is defined and wchar_t
> represents a unicode code point, this would be just perfect. But that's
> not the case on all platforms. But that's okay, I thought, as long as I
> can (with some platform-dependent magic) convert between unicode code
> points and wchar_t.

wchar_t is an integral type which represents an integral value.  It does not
represent a code point any more than "char" represents an ASCII value.

> On Windows, it turns out, wchar_t represents a UTF-16 code unit, so a
> code point can require two wchar_t's. That's ugly (and makes <wctype.h>

This is a limitation of Windows. The Windows API uses 16 bit wide characters,
so you can't get away from this no matter what language you write in on
Windows.

Redmond has decided that characters outside of the Unicode BMP (basic
multilingual plane) are unimportant for its user base. So, if your programs has
customers who are Windows users, you can safely assume that they have already
swallowed this pill.

You get a lot of internationalization mileage out of the BMP. Actually all the
mileage. Above U+FFFF there is only academic crap. Anyone who cares about those
characters is likely also going to be some kind of "freetard" who won't pay a
dime for software.

> But then I found out about the killer: on FreeBSD (and Solaris?) the
> encoding used by wchar_t is locale-dependent!

I would expect this "locale dependent" to mean that if, say, Japanese user is
working with Shift-JIS files, then he or she can set that up in the locale such
that when these files are processed by your program, the characters being read
and written map to sane values of wchar_t (where sane == based on Unicode!). 

wchar_t does not have an encoding; it's an integral type. The encoding
of wchar_t is binary enumeration: 000...0101 encodes 5, etc.

Do you have some quotes from FreeBSD or Solaris documentation on this matter
that are giving you concern? Post them.

> So screw it all, I'll just use UTF-32 like I should have from the
> beginning.

But that just means you have to write your own library instead of just using
C95 functions like wscspn, wcscpy, etc.  What if you want to do printf-like
formatting to a wide string?  Can't use swprintf.

Here is a better idea: just use wchar_t, forget about U+1XXXX on Windows
because Microsoft has decided that one for your users already, and if
locale-dependent streams give you an allergic reaction, handle your own
decoding/encoding for doing I/O.

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wchar_t is useless Lauri Alanko <la@iki.fi> - 2011-11-21 14:14 +0000
  Re: wchar_t is useless Kaz Kylheku <kaz@kylheku.com> - 2011-11-21 16:17 +0000
    Re: wchar_t is useless James Kuyper <jameskuyper@verizon.net> - 2011-11-21 12:27 -0500
      Re: wchar_t is useless jgk@panix.com (Joe keane) - 2011-11-24 20:07 +0000
        Re: wchar_t is useless Kaz Kylheku <kaz@kylheku.com> - 2011-11-24 21:16 +0000
          Re: wchar_t is useless James Kuyper <jameskuyper@verizon.net> - 2011-11-24 17:15 -0500
        Re: wchar_t is useless Keith Thompson <kst-u@mib.org> - 2011-11-24 13:49 -0800
          Re: wchar_t is useless Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-11-27 10:33 +0000
        Re: wchar_t is useless Rui Maciel <rui.maciel@gmail.com> - 2011-11-25 14:17 +0000
          Re: wchar_t is useless Vincenzo Mercuri <vincenzo.mercuri@yahoo.it> - 2011-11-25 15:27 +0100
            Re: wchar_t is useless Vincenzo Mercuri <vincenzo.mercuri@yahoo.it> - 2011-11-25 15:29 +0100
    Re: wchar_t is useless Dann Corbit <dcorbit@connx.com> - 2011-11-22 09:50 -0800
  Re: wchar_t is useless blp@cs.stanford.edu (Ben Pfaff) - 2011-11-21 10:42 -0800
    Re: wchar_t is useless jmclnx@SPAMisBADgmail.com (Jack McCue) - 2011-11-21 19:18 +0000
    Re: wchar_t is useless Kaz Kylheku <kaz@kylheku.com> - 2011-11-21 21:02 +0000
      Re: wchar_t is useless Lauri Alanko <la@iki.fi> - 2011-11-21 22:07 +0000
        Re: wchar_t is useless Kaz Kylheku <kaz@kylheku.com> - 2011-11-21 23:54 +0000
          Re: wchar_t is useless Lauri Alanko <la@iki.fi> - 2011-11-22 01:15 +0000
            Re: wchar_t is useless Kaz Kylheku <kaz@kylheku.com> - 2011-11-22 01:57 +0000
              Re: wchar_t is useless Lauri Alanko <la@iki.fi> - 2011-11-22 09:28 +0000
  Re: wchar_t is useless Acid Washed China Blue Jeans <chine.bleu@yahoo.com> - 2011-11-21 11:11 -0800
  Re: wchar_t is useless "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2011-11-24 08:43 -0800
  Re: wchar_t is useless 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-24 16:42 -0800

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