"David Abrahams" <dave@boost-consulting.com> wrote in message news:uisebatkh.fsf@boost-consulting.com...
slavek.f.kuzniar@jpmorgan.com writes:
The previous version available at http://www.xmission.com/~turkanis/iostreams/.
I've since made some major simplifications and improvements, and am scrambing to update the docs. It now contains support for memory-mapped files (from Craig Henderson) and for compression and decompression in the zlib, gzip and bzip2 formats.
The thing I wanted recently was an "offset streambuf", an adapter for another streambuf that presents an "offset view" (i.e. with respect to seeking) of the underlying streambuf.
This sounds like it might be a job for a 'SeekableFilter' -- something I included support for even though I didn't have any use for it. The interface for a seekable filter is basically this: struct seekable_filter { // some typedefs streamsize read(char* s, streamsize n, streambuf& next); void write(const char* s, streamsize n, streambuf& next); streamoff seek(streamoff off, ios_base::seekdir way, streambuf& next); }; Here 'next' is the streambuf being filtered. Any number of filters can be chained. You take a filtering_streambuf<seekable>, add your filter, then add the underlying streambuf: filtering_streambuf<seekable> filtered; filtered.push(seekable_filter()); filtered.push(sbuf); What exactly did you want the offset streambuf to do? I'd be interested to see if I can implement it using the above framework. It would be a nice example of a concept which so far I haven't used. Jonathan