Default serialization method for structs

[Octogonapus]

I am new to this library so please let me know if I am missing something, but why isn't the default serialization method for a struct StructTypes.Struct()? This means that if I need to serialize some struct, I need to implement

StructTypes.StructType(::Type{Foo}) = StructTypes.Struct()

for every struct I need to serialize, including types I don't own and/or don't interface with directly. I think that StructTypes.Struct() would be a sensible default.

[quinnj]

This was discussed and was the default for a short period of time, but it led to some hard-to-figure-out bugs where things accidentally serialized, but not in the way you wanted. Because everything was a Struct, it made for some weirdness. We could maybe consider changing it since the StructTypes API has matured quite a bit, but I'm still hesitant given those initial bug reports we saw.

Can you comment more on the cases you're running into w/ types you don't own? If they're in Base or stdlibs, we can define them in JSON3.jl or StructTypes.jl. Otherwise, it might be worth contacting the type package owners and seeing if we can work something out.

[Octogonapus]

One type was VersionNumber in Base. Otherwise, in my case, the other types were all from internal packages. Needing to implement a StructType method for all my serializable types doesn't prevent me from using JSON3.jl, it's just an unexpected requirement after using JSON.jl.

[quinnj]

Ah, yeah, that's a good one. It's really easy to add a default definition for that, as you can see in my PR here: JuliaData/StructTypes.jl#44. Let me know if you run into any other issues where we could ahve default definitions that would be helpful.