[Boost-users] Seekg on a gzip'd file...Is this possible?

Subject: [Boost-users] Seekg on a gzip'd file...Is this possible?
From: Gerrick Bivins (gbivins_at_[hidden])
Date: 2009-03-13 10:29:52

Hello all, 
I¹m switching one of my projects over from java to c++. Basically it¹s a
gzip file reader, where I¹d like to parse a bunch of numbers (floats, ints,
doubles)
 and in some instances I¹d like to skip some of the data. I¹m a  ³noob² to
boost and after getting the file reader working using the boost like this:
{
....
std::ifstream ormodelFile(filenameForTimeStep.c_str(),
                                  std::ios_base::in|std::ios_base::binary);

boost::iostreams::filtering_istreambuf compressedFileFilter;
compressedFileFilter.push(boost::iostreams::gzip_decompressor());
compressedFileFilter.push(ormodelFile);

this->inputFile.rdbuf(&compressedFileFilter); //where inputFile is a an
istream.
...
//do the file reading
}

I tried to add the skipping parts to the code by simply calling:
{
...
 double value;
 this->inputFile->seekg(sizeof(double),ios::cur);
...
}
 the fail bit is set on the inputFile istream. Is it possible to do this
using boost? I¹m pretty ³green² with boost so I¹m sure it¹s just my
misunderstanding of how to use the lib but I couldn¹t find my way around the
docs to well.

The best I could find was that I need to somehow make my stream ³seekable²
but it wasn¹t too clear to me how to do this.
Any help would be greatly appreciated.
Gerrick