> For example, Rust's traits bounds are structurally typed, for exemple making a function that accepts a type that's Summary + Display. This "Summary + Display" type doesn't need to have a name, and in that case it's great.
That's still nominative. The bound is not named, but it's based on names, not on structure. Otherwise you couldn't have marker types in such a bound, or would always have all of them and be unable to opt out.
> I don't think there is "a" solution, only multiple solutions and tradeoffs.
I have a hard time seeing that: if you have a structure, you can always give it a name. But you can also give different names to the same structure. So a nominative type system is more flexible and powerful at the very limited cost of having to name things. And even then, nominative type systems can support anonymous types (where the name is simply implicit / automatically generated) e.g. lambdas in C++ or Rust.
