The bound on ValueStatistics is T: ParquetValueType, which isn't public. So it is impossible to call the methods on ValueStatistics from a generic function in another crate, forcing the use of macros to generate a call for each concrete type. The impl of ValueStatistics will compile is the bound is AsBytes, so I will send a PR for that.

I want a more ergonomic way to interact with Statistics - right now you either have to use Statistics::min_bytes_opt and do your own conversion, or use StatisticsConverter, which is an inconvenient API shape for my use case.

The alternative would be to make ParquetValueType be public, which seems like a much bigger commitement and is not necessary in this case.