Generic type in a protocol

[Danny]

Unfortunately, this will require even more reading.

Type declarations in protocols / protocols as namespaces?

I've skimmed a couple of related threads but didn't find the answer to this question, apologies if this has been answered before. Say I have some protocol Proto and some conforming types, and I want to group these types, and the name Proto happens to be the best name for both the protocol and the namespace. I might try the following, which will not compile: protocol Proto { // ... requirements ... } extension Proto { struct Foo: Proto { // ERROR: Types can't be nested in protocols //…