Alternative data types for output? about bitpacking

[fulmicoton]

This is not useful for tantivy so I won't implement it, but I accept pull request.

The binary size is indeed a problem, but we can put it behind a compilation flag.

[jean343]

I would like to see support for u64 for large databases.

[fulmicoton]

@jean343 same answer as above unfortunately...

[jean343]

Thank you for the answer. While I think about it, we are only storing deltas, and most u64 deltas can be stored in u32. So this isn't as big of a limitation as I thought.
Thanks again for your awesome library.

[jorgecarleitao]

I will try to take a stab a this for the Bitpack1.

The parquet format uses this format and accepts both u32 and u64.

[jorgecarleitao]

Not very easy in stable rust: the support for const generics is limited and we need it to call simd instructions irrespectively of the type, which requires a constant generic. Alternative is via macros. Will keep digging.