id summary reporter owner description type status milestone component version severity resolution keywords cc 1033 iostreams::restrict doesn't work on an iostreams::file_source phil@… Jonathan Turkanis "I ran into a problem when using restrict on a file_source. The problem was that it decided that the stream wasn't seekable and called the version of skip that reads a character at a time until it gets to the requested offset, instead of just calling seek. The code was similar to this: {{{ namespace io = boost::iostreams; std::string filename; io::filtering_istream rstr(io::restrict(io::file_source(filename), 10, 100)); }}} I've attached a patch that solved my problem. It was checking to see if the device was seekable (which means both input_seekable and output_seekable), but since it was an input device, it was just input_seekable. " Bugs closed To Be Determined iostreams Boost 1.34.0 Problem fixed iostreams