> While protocols in Go are great (one of the very many breaths of fresh air that Go provided), operations on data structures without generics does not seem like a good time. Does everyone get around the lack of generics by making most generic-looking operations slightly-specialized structs and some interface composition?

When it comes to domain code - probably when you are starting to think about generics that's a bad sign. Probably you are trying to make it overcomplicated. Domain code should stay simple and interfaces should be enough to handle it.

But when it comes to libraries the situation is totally different. One of the example is https://watermill.io library (that we are authors of BTW). Generics could give some nice simplifications.

It's also a case for event-sourcing library that we are using in the company where we are working on now. But You can still do a lot with interface{} and reflection. But it's not perfect and generate a lot of boilerplate.

The third example is a decorator pattern. You can't create generic decorator without code generation. It is of course some sort of the solution, but it's not trivial to implement.