Idea: Source Generator for New types

[bash]

I want to write another source generator while following along this guide :) And since I have wanted to replace our reflection-based NewType converter with a source-generated one I thought a general new type generator would be fun.

What features should it have?

Off the top of my head:

• generate a JSON converter (and point to it via the [JsonConverter] attribute)
• replace the record's ToString() implementation with a more tuple-like representation
  so instead of DisplayName { Value = test } we should get DisplayName(test).
• delegate comparable operators <=, >=, > and <.
• delegate interface implementations? this one seems like a lot of hassle (especially for things like IComparable where other is an object that we need to "unpack" the value first before delegating).
  Maybe we start with a list of known interfaces (e.g. IComparable<T>, IComparable) first.

I think it's also OK to restrict the source generator to sealed class record / record structs with primary constructors for now.