(Was: Re: [Boost-users] Filesystem, serialization, character encoding and portable software)

On 14 August 2008 00:44, Robert Ramey <ramey@rrsd.com> wrote:

Daniel Krügler wrote:
> Robert Ramey wrote:
>> the wide character xml archives use UTF8.
>>
>> the narrow character xml archives use the currently set locale.
>>
>> Robert Ramey
>
> Sorry for asking offhand:
>
> What is the reasoning behind this different behaviour?

I assumed that most programs built with narrow characters used
the locale concept to deal with this.

Wide character systems lend themselves to UTF coding so I
used that for wide char archives. In order to do this, I used
Ron Garcia's UTF code conversion facet for streams.

It would be quite easy to generate UTF coding for narrow
character archives. Just do the following:

a) Build the UTF code conversion facet for narrow character
input (its templated on character type).

b) When the stream is opened, attach this facet to the stream.

Note the the output char format is not really a property of the
serialization
library, but rather an artifact of the way it has been used. That is, the
serialization library depends on the standard stream library for this
property.

I understand that to get a UTF-8 XML file, I need to use a wide-character stream, but I can't seem to understand how I can compress a serialized UTF-8 xml archive... it seems I can either do:

namespace bio = boost::iostreams;
namespace fs = boost::filesystem;

fs::wofstream ofs(path,ios::binary);
bio::filtering_stream<bio::output,wchar_t> out;
out.push(bio::gzip_compressor()); // PROBLEM: gzip_compressor only accepts char
out.push(ofs);
boost::archive::xml_woarchive oa(out);

--- OR ---

fs::ofstream ofs(path,ios::binary);
bio::filtering_stream<bio::output> out;

out.push(bio::gzip_compressor());
out.push(ofs);
boost::archive::xml_woarchive oa(out); // PROBLEM: only accepts wostream