commit 2a84869c38b0d69bddf86021029e5c003c7e74f0
author Sean Griffin <sean@seantheprogrammer.com> Thu Jul 06 15:09:53 2017 -0400
committer Sean Griffin <sean@seantheprogrammer.com> Thu Jul 06 15:09:53 2017 -0400
tree 47c1e58d8eae595fb6e209521b0b1da5241a9178
parent 51fb281c3fe85616ad6e83f134002172f6e4d8c6

Have `PgTypeMetadata` be an enum

The big benefit of this change is that the signature of
`TypeMetadata::metadata` doesn't need to change. We get to remove a lot
of the random `_: &()`, which is nice. The only code that isn't PG
specific that needs to change with this version is the signature of
`ToSql`.

However, I don't like this version, and I don't think I'm going to go
forward with it. This implementation has a lot more coupling to the
metadata lookup. Prior to this commit, the only time you have to know or
care about the lookup is when you are doing a dynamic lookup (and that
code has to care about the lookup either way).

However, with this form, anyone who needs an OID *also* has to care
aboute how exactly we go about getting it. I also don't like the idea
that you can get metadata that is sometimes useless unless you also have
another parameter. If we need the lookup to get the OID, we should
enforce that we always have it when we need an OID.