wchar_t -> UTF-8?

[Jon Willeke]

This feels like a FAQ, but I've been unable to find a satisfactory
answer. Given a Unicode encoding (such as UCS-4) in wchar_t, I want to
convert to UTF-8 (or another locale-specific encoding) in a manner not
entirely unlike the following:

wstring w = L"H\xe9llo";

locale loc( "en_US.UTF-8" );
wcout.imbue( loc );
wcout << w << endl;

I've tried Visual C++ 6.0 and Borland C++ 5.6.4 on Windows, as well as
GCC 3.3.1 on Linux. They don't seem to do anything approximately like
this. I tried plugging in a hand-written codecvt subclass, but it
doesn't seem to be used.

[John Ericson]

Re: wchar_t -&gt; UTF-8?

"Jon Willeke" <j.dot.willeke@ verizon.dot.net > wrote in
message news:PLxVb.8466 $M8.7247@nwrdny 02.gnilink.net. ..[color=blue]
> This feels like a FAQ, but I've been unable to find a[/color]
satisfactory[color=blue]
> answer. Given a Unicode encoding (such as UCS-4) in[/color]
wchar_t, I want to[color=blue]
> convert to UTF-8 (or another locale-specific encoding) in[/color]
a manner not[color=blue]
> entirely unlike the following:
>
> wstring w = L"H\xe9llo";
>
> locale loc( "en_US.UTF-8" );
> wcout.imbue( loc );
> wcout << w << endl;
>
> I've tried Visual C++ 6.0 and Borland C++ 5.6.4 on[/color]
Windows, as well as[color=blue]
> GCC 3.3.1 on Linux. They don't seem to do anything[/color]
approximately like[color=blue]
> this. I tried plugging in a hand-written codecvt[/color]
subclass, but it[color=blue]
> doesn't seem to be used.[/color]

IIRC, Dinkumware has a library for various code conversions.
You might want to Google a bit in comp.lang.c++ and
comp.lang.c++.m oderated, since there are some good threads
in there on the various issues. Be prepared for some quirks,
depending on your system. Best regards, JE

[Tilman Kuepper]

Re: wchar_t -&gt; UTF-8?

Hello Jon,
[color=blue]
> [...] I tried plugging in a hand-written codecvt
> subclass, but it doesn't seem to be used.[/color]

You can find some codecvt-facets as part of the
arabica xml parser toolkit:

http://www.jezuk.co.uk/cgi-bin/view/arabica

Boost has similar facets ready for download:

http://groups.yahoo.com/group/boost/files/utf/

Plauger wrote a pair of columns in the April and
May 1999 editions of the C/C++ Users Journal. You
can find the source code on the cuj server:

http://www.cuj.com/code/

Tilman