range.size() should be long, right?

[Mehrdad]

Shouldn't the length of a range should be a long?

Otherwise there's no way we could possibly replace streams with 
ranges.
32-bit systems have LOTS of common streams that are over 2^32 
bytes (e.g. DVD images, partition images, large movies, etc.).

And not just that -- if we use size_t instead of long, bit arrays 
will only have a maximum length of 512 MiB -- waay lower than 
what 32-bit systems can handle.