1 Possible upgrades to gzfilebuf:
   2 
   3 - The ability to do putback (e.g. putbackfail)
   4 
   5 - The ability to seek (zlib supports this, but could be slow/tricky)
   6 
   7 - Simultaneous read/write access (does it make sense?)
   8 
   9 - Support for ios_base::ate open mode
  10 
  11 - Locale support?
  12 
  13 - Check public interface to see which calls give problems
  14   (due to dependence on library internals)
  15 
  16 - Override operator<<(ostream&, gzfilebuf*) to allow direct copying
  17   of stream buffer to stream ( i.e. os << is.rdbuf(); )