When to use nested-types?

[danmihai (Dan)]

Suppose the following model: You want to create a client-server program.
Where, the client would make no sense without the server.

Is that a good reason to make the client a nested-type of the server?:

struct Server {
   ....
  struct Client {
      ...
  }
}

Also, another advantage I see, you can have so private methods in the server, that the client can access , but no one else can.

However, is this a good reason? Are there any drawbacks to this approach? Someone mentioned testability, that the client is now not testable. Not sure if that's true.

[anon9791410]

@TeamPuzel

This makes sense because I can just use String.Color which makes it obvious what kind of Color it is and avoids colliding with other types. (You would have to name it StringColor anyway)

Any time you have the name of a type in front of another type, the latter should be nested. String.Color.Type unfortunately doesn't work; .Type is the exception.