V2: dataclasses

[samuelcolvin]

dataclass validation should get MASSIVELY easier and more performant since we have the arguments validator in pydantic-core which means we can do validation before constructing the dataclass. Lots of examples in the docs here.

I think we should remove all the __post_init_post_parse__ shit, and just use validation functions and the standard stuff offered by dataclasses.

@PrettyWood as the master of dataclasses, would be willing to work on this? If not, I quite understand, please remove yourself as assignee and hopefully someone else can take over.

Either way, I'd love your insights on what we should do.

[dmontagu]

I'm going to close this as I think it is fully addressed. If there are things besides recursive/generics (which are being tracked in another issue) that we want to change or improve, please comment / reopen the issue.

[dmontagu]

(Also, #5271 tracks a few remaining things.)